With all the adjustability and versatility, on paper it looks to me to be a better bike than my Scott Spark. I would love to get this! I currently ride a Stumpy Evo mostly but the short travel trail bike has a special place in my heart and this bike has got it beating fast!
That would be ace! We've been requesting Transition test bikes from the local distributor, but so far they haven't been interested in sending us anything to review. We'll keep trying! [Wil]
Linkage driven single pivot 😉 I'm happy to see an Alu model. IF they built a model on the light side I could see it as a XCM bike over the supercalibre
Funny you should make that comment Shaun, Trek has just dropped the price on the Top Fuel 8 ($4,499 AUD) and the Top Fuel 9.8 GX AXS ($7,499 AUD). Improves the value proposition by quite a bit! [Wil]
Thanks mate! It appears that Trek Oz still has stock of the previous Top Fuel 5, so I'd expect that once those sell through they'll start bringing in the new Gen 4 version. I'd love to see Trek bring back the high-spec alloy bikes; a Top Fuel 9 would be pretty sweet I reckon! I'd also love to see a dedicated 120/120mm XC build with the Top Fuel - I've been riding our test bike with that configuration and it absolutely rips. We'll have a long-term review coming to the Flow MTB website soon! [Wil]
So Trek catfished us with the 240g weight reduction of the new frame since it's for an unpainted frame, and the actual reduction is 100g with paint (the previous gen was 2.7kg). I was originally a little bummed since this was announced 2 months after i bought a gen 3, but not anymore. I actually like the look of the gen 3 better than this new one minus the smaller trek logo, and I don't care about only 100g of weight savings and the extra adjustability. Same geo too
I think a lot of media reported on the 240g weight reduction for the new Top Fuel, but it was clear to us that it didn't quite check out so we held back from publishing that figure. I encountered a similar degree of confusion when the Gen 2 Supercaliber came out last year, so we always try to confirm frame weights where possible. Ultimately the only way to verify those claimed figures is to weigh a frame ourselves. I'll be holding onto this Top Fuel as a long-term test bike, so I'll see if I can strip it down to get a real-world weight with the shock. It'd be great to get a hold of the Gen 3 frame to see how it compares. That being said, I think frame weight is only a small contributor to the overall ride quality of the new Top Fuel. It's really the improved compliance that makes the biggest difference on the trail. Of course there's the added versatility from the 4-position Mino Link for those riders who want to explore different suspension and geometry configurations. [Wil]
Beautiful. Beautiful. Considering the AL version of this over the new AL Specialized Chisel. Looking to have a bike to do 30-50 miles rides through my local mountains that sometimes require a little suspension. Currently using a fully rigid specialized Diverge gravel bike to do this, and shit gets scary. My gen 5 Fuel EX has been amazing and hits above its weight class but is too burly to take on 30+ mile rides for this reason
That new Specialized Chisel FS looks fantastic! It is a more dedicated XC bike with 110mm of rear travel and a 120mm travel fork, though Specialized does say it's rated for a 130mm fork too. And according to the claimed weights, it's around a full kilo lighter than the Top Fuel AL frame (2,720g vs 3,700g). I own a Chisel HT frame myself, and I'd love to get a ride on the new FS bike. Will see if we can organise one to review! [Wil]
No issues with the BB so far! Our test bike has largely been faultless over the past 4 months of riding with no creaks or damage to speak of. I’ll have a proper long-term review coming soon after I strip it down to the bare frame and get a closer look at everything before rebuilding it as a lightweight XC bike - stay tuned to the Flow website for that one! [Wil]
The new Pike with buttercups is a lot stiffer and handles hits way better. The 130 doesn't negativity change the ride dynamics of the 120 version. The weight difference is not noticeable. Its a win win
My 10.2kg XL Top Fuel 9.9 from 2018 doesn't even recognize this bike, but this new Top Fuel is probably perfect when you need something less capable downhill than a Slash but slower climbing than the Supercaliber
I think the slower climbing comment really depends on what trails you're riding. I've spent a lot of time on both the Gen 1 and Gen 2 Supercalibers, and I found them to be incredibly responsive and lightweight. On smooth trails and on the road, they're scorchingly fast. However, the firm suspension and high anti-squat means there is considerably more feedback on technical terrain, which can cause the rear wheel to hangup and lose traction. In comparison, the Top Fuel generates a lot more grip that can be really beneficial if you're riding loose and chunky trails. I recently tried out a set of XC race wheels and tyres on the Top Fuel, and in my experience I'd say it's a better technical climber than the Supercaliber. [Wil]
01:17 I'll have to correct you there. The Top Fuel DOES NOT feature a four-bar suspension system. It's actually a single pivot system. The axle path is only dictated by just a single member/bar - the rear axle rotates concentrically around the main pivot. As such, it's a two-bar single-pivot system.
I tried to order a Top Fuel late 2020ish. After a few months I gave up and bought a Spark aluminum. I think like 10 or 11 months later a Trek dealer ended up calling me saying they had one in stock. Scott Spark has had tons of little problems - Twinlock lever broke (fixed under warranty), Twinlock cable broke inside frame (I said screw it and left it), headset cover plastic creaks and eventually stress cracked, had to retape the wheels to actually get them to seal, no grease from factory in dropper, fork blew up within 3 months + derailleur is typical SRAM junk (not Scott's fault but still...), Shimano brake levers anodizing came off which I've literally never seen before. Since then its been through probably a dozen XC races (even a gravel race), a few bike park runs even, thousands of miles, lots of fun regardless of the nonsense. But hey my spark got two water bottles in the frame so I forgive it for everything. Seriously though - 130F/120R is the perfect travel for XC racing but everyday useability, glad they kept he trek the same.
i got the spark that has the shock in the open in late 2021 so it was a 2020 model. i got it as the spark team 900 rc model. none of the issues you described happened to me but when they acquired BOLD cycles i think they started taking shortcuts and internal routing unfortunately
You mention adding travel using the existing fork and shock. I have heard this elsewhere but have not seen anybody do it. I have also read about some downsides of doing this on other shocks, since it isn't necessarily tuned for that travel. Can anybody expand on that?
Changing travel for the RockShox Pike is relatively straightforward with an air spring swap. You can get 120 and 140mm air shafts for that fork, and the process is no more complicated than a basic lower leg and air spring service. As for the shock, it's possible to change the stroke from 50 to 55mm by removing the internal travel reducer. This is easy with a Fox Float/Float X shock, and no special tools are required to take it out. It's a more involved process with the Deluxe shock, which requires the damper to be pulled apart in order to remove that travel reducer. SRAM Australia quoted us $220 AUD for a full service and rebuild, during which they can remove the travel reducer to extend the stroke to 55mm. You could also have the damper shaft (main stanchion) replaced for an extra hundred bucks if you wanted the sag gradients to match up with the 55mm stroke. When you change the stroke to 55mm, you will need to modify the air pressure to maintain the same sag. I haven't changed from the stock tune however, and so far it's working just fine. I'll have a more detailed explanation of the travel change and its effect on the Top Fuel in an upcoming long-term review - stay tuned to the Flow MTB website for that one! [Wil]
Hi there! Someone else mentioned this, so I've pasted in the response; Initially I thought the same thing as you, but after riding the Top Fuel I've found it to be pretty different. There are the obvious spec differences - the previous generation Fuel EX came with big 2.6in tyres, the proprietary RE:aktiv shock and a Fox 36 on the higher-end models. It also had the Knock Block steering limiter (the Top Fuel has ditched this), the head angle was steeper at 66-66.5 degrees and the seat angle was slacker at 75-75.5 degrees. I spent a lot of time on the previous Fuel EX as we had one as a long-termer. The frame was quite stiff, which translated to more feedback on choppier trails. In comparison, the Top Fuel is much springier and livelier overall. It isn't the lightest bike in its category, but it's eager to ride a lot faster than its weight suggests. It's quite a bit more adaptable in terms of its suspension, so you can set it up as a 120/120mm travel XC bike, which isn't possible with the Fuel EX. I also like that Trek has moved away from proprietary suspension. The Deluxe is really well tuned for this bike, and it's been easy to dial in. Subtle differences on paper, but the Top Fuel has a distinct personality for sure. Hope that helps explain! [Wil]
Initially I thought the same thing as you, but after riding the Top Fuel I've found it to be pretty different. There are the obvious spec differences - the previous generation Fuel EX came with big 2.6in tyres, the proprietary RE:aktiv shock and a Fox 36 on the higher-end models. It also had the Knock Block steering limiter (the Top Fuel has ditched this), the head angle was steeper at 66-66.5 degrees and the seat angle was slacker at 75-75.5 degrees. I spent a lot of time on the previous Fuel EX as we had one as a long-termer. The frame was quite stiff, which translated to more feedback on choppier trails. In comparison, the Top Fuel is much springier and livelier overall. It isn't the lightest bike in its category, but it's eager to ride a lot faster than its weight suggests. It's quite a bit more adaptable in terms of its suspension, so you can set it up as a 120/120mm travel XC bike, which isn't possible with the Fuel EX. I also like that Trek has moved away from proprietary suspension. The Deluxe is really well tuned for this bike, and it's been easy to dial in. Subtle differences on paper, but the Top Fuel has a distinct personality for sure. Hope that helps explain! [Wil]
@@FlowMountainBikeUA-cam Nice overview. So it seems you are saying this new Top Fuel is more comfortable while also being livelier and more capable than the old EX? That would be an awesome combination. I tried a Gen 6 EX and it was more bike than I wanted.
That's been my experience for sure. The newer Gen 6 Fuel Ex has gone even further in that direction - these days it's quite a burly trail bike! I think that does suit riders who are placing higher and heavier loads on the bike, where the extra chassis stiffness and travel have benefits. It also has a cruisier and more upright riding position. In comparison, the Top Fuel positions you lower and further forward in the cockpit. Along with the efficient pedalling performance, it feels well suited to covering ground quickly. The way Trek has slimmed down the Top Fuel to bring back some compliance has had a really positive impact on its ride quality. It's a difficult attribute to get across in the marketing lingo however, so I can appreciate that a lot of folks just assume the new Top Fuel looks much the same as the old version, or indeed an older generation Fuel EX. [Wil]
Another great review, Wil! The new Top Fuel appears to be pretty versatile - from down country to trail. I’m surprised you folks have not reviewed a Transition. The Spur and Smuggler seem to cover similar ground. Guessing they have no distribution in Australia. Cheers.
Thanks Nick, appreciate the feedback! The Transition Spur and Smuggler look ace, would love to swing a leg over one for sure. We've requested Transition test bikes through the Aussie distributor, but they're yet to send one out. Here's hoping 🤞 [Wil]
@@FlowMountainBikeUA-cam the Smuggler was a real eye opener for me. It’s the best bike I’ve owned. Nearly as pedal-friendly as the Spur but heaps more capable. I hope you get to ride one soon. Heck, maybe I’ll message the guys over at Transition HQ and shame them into sending you one to review. 😉
Great question! Both are fantastic short travel trail bikes, though the Trance 29 is a bit older having last been updated in late 2021. There haven't been any changes to the frame since, and new spec options are a bit limited. As such, it's a little tricky to compare directly in terms of spec and pricing. Looking at the Giant Australia website, there is a newer Trance Advanced Pro 29 0, which is more expensive at $9,999 AUD. However, it does come with Fox Factory Series suspension and a SRAM X0 Transmission. Geometry is very similar between the Trance 29 and Top Fuel when it comes to the angles, reach, chainstay and wheelbase length. However, the riding position is different due to two important aspects. The Trance 29 has a taller stack (619 vs 603mm) and it has a more generous BB drop (45 vs 32mm, both bikes in the Low geometry setting), which clocks you into a fairly upright position. To put it simply, it feels more relaxed like a trail bike. In my experience of riding the Trance 29, I found it to feel a little plusher and bit burlier overall than the Top Fuel. A lot of this is because Giant specs a piggyback shock on the top-end model along with chunky 2.5in tyres. I like how the latest Maestro platform has been tuned for grip, but it does bob quite a bit and requires more low-speed compression damping to stabilise. For that reason, I really liked the Live Valve system on the Trance 29, but it appears that Giant is moving away from that across all of its mountain bikes and e-MTBs. While both are great riding trail bikes, a lot of the differences come down to the finishing details. The downtube storage is much better on the Top Fuel, and the 4-position Mino Link gives it a greater range of adjustment. The fact that you can up-stroke the suspension and set it up as a mullet makes it a more adaptable package compared to the Trance 29. I also think the Top Fuel does a better job of morphing into an XC bike with a 120mm travel fork, where it feels zippy and enthusiastic. Hope that helps to answer your question, but just yell out if you've got any specific details you'd like to know! [Wil]
@@FlowMountainBikeUA-cam Thanks so much! I got the Trance Advanced 29 Pro 2 with the Live Valve and didnt like it. I thought it made everything too firm and stiff, bumpiest bike I ever had. So I got Fox Factory suspension, 34 GripX 130mm fork and Float shock. The new shock helps the bobbing sensation a lot, last one really relied on the Live Valve I guess. Good to know it feels more plush than the Top Fuel. But I still think the front end is a little harsh at times, still playing around with different tunes.
I have the 2022 version with a 120mm SID. I still feel the Pike is a lot of fork for this bike but I also do not live in country with rocky trails but then I would most likely had gone up a bike. Trying to say I am not sure about the direction they are taking with the specs and why not have both SID and Pike versions. I do like the updates to the frame.
I agree about having both SID and Pike versions. I'd love it if there was a dedicated 120/120mm bike, as currently there's a fair gap between the Top Fuel and Supercaliber. So far I've been really enjoying the 140/130mm travel configuration too. I'm guessing Trek decided not to offer that as a stock option as it pushes it pretty close to the Fuel EX in terms of travel, even if the two bikes ride quite differently. Cool that the one bike has so many options though! [Wil]
Interesting. So you can run 120/120 or 140/130 without any hardware changes. That should cover most riders needs. Unless you're racing or only doing downhill trails it sounds like the top fuel is the better choice compared to the super calibre or fuel ex.
You certainly can! I've set up our Top Fuel in both configurations - there are some images and more detail in the review if you fancy checking it out; flowmountainbike.com/tests/trek-top-fuel-review-2025/ [Wil]
@@FlowMountainBikeUA-cam You write in the review: "It’s worth noting that you can set up the Top Fuel in its 140/130mm travel configuration using the stock fork and shock". I can't find any information about this i.e. how you make the change? Btw I will get a gen 4 frame next week as my rear seat stay broken in a crash. Will keep light weight build with Sid and Control SL wheels. Thank you again for some really good reviews and comments.
Hi there! Changing travel for the RockShox Pike is relatively straightforward with an air shaft swap. You can get 120 and 140mm air shafts for that fork, and the process is no more complicated than a basic lower leg and air spring service. As for the shock, it's possible to change the stroke from 50 to 55mm by removing the internal travel reducer. This is easy with a Fox Float/Float X shock, and no special tools are required to take it out. It's a more involved process with the Deluxe shock, which requires the damper to be pulled apart in order to remove that travel reducer. SRAM Australia quoted us $220 AUD for a full service and rebuild, during which they can remove the travel reducer to extend the stroke to 55mm. You could also have the damper shaft (main stanchion) replaced for an extra hundred bucks if you wanted the sag gradients to match up with the 55mm stroke. When you change the stroke to 55mm, you will need to modify the air pressure to maintain the same sag. I haven't changed from the stock tune however, and so far it's working just fine. I'll have a more detailed explanation of the travel change and its effect on the Top Fuel in an upcoming long-term review - stay tuned to the Flow MTB website for that one! [Wil]
I've got the white Top Fuel 9.8 GX T-type gen 3. Best bike I have ever ridden. The new gen4 9.8 looks very similar but it's a downgrade because they swapped the carbon wheels for alloy ones for almost the same price. Sneaky. Also prefer the look of the Gen3.
Hey Sebastien! FYI, we've just gotten word from Trek about some updated pricing - the Top Fuel 9.8 GX AXS has dropped down to $7,499 AUD. You raise a good point about the change from carbon wheels on the Gen 3 9.8 GX AXS to alloy wheels on the new bike. Interestingly, despite the difference in rim material the two wheelsets almost come out at an identical weight. These are confirmed weights for both wheelsets including TLR rim strips and valves; - Line Elite Carbon (2,071g) - Line Comp Alloy (2,094g) From a strength standpoint we have found Bontrager's carbon rims to be impressively sturdy. And they come with a 2-year crash replacement guarantee which is really nice for peace of mind. That being said, they are very much on the stiffer side. They are super responsive, but I actually prefer the ride quality of the Line Comp Alloy wheels, which are significantly more compliant on rough terrain. So far they've held up really well too, I've had no issues with spoke tension or rim damage (I do always run CushCore inserts in the rear wheel of every test bike though), and the bearings and freehub are still running smooth. Given it's a stock own-brand wheelset, I've been pleasantly surprised! [Wil]
It may be related to stock levels - it appears that Trek Australia still has the Gen 3 Top Fuel 5 in stock, so perhaps when those sell through we'll see the Gen 4 version arrive Down Under. [Wil]
@@CR-di1lg I hear you. I am referrancing the Top Fuel 9.9 XX AXS Gen 4 spec for an example. $10,000+bike that weighs almost 30 lbs and is not an Enduro bike? I would not classify the Ultimate PIKE and Carbon wheel set as "heavy". I love TREK, don't get me wrong, I think they just miss the mark on this one. Plenty of sub 26lb. bikes in this category that cost way less and have better spec. I know it probably most definitely rides awesome and planted, but thats a 30lb plus bike in the real world you are dragging up and down all day. 2 more pounds and its FUEL EX ( which is an awesome bike) . Good discussion, cheers!
That's a good point! I suspect there's probably just enough clearance to physically fit a 36T chainring but not quite enough for Trek to officially recommend it to consumers. [Wil]
Trek must have been listening - the prices on the Top Fuel 8 and Top Fuel 9.8 GX AXS have just dropped in Australia by quite a bit! The Top Fuel 9.8 GX AXS has dropped down to $7,499 AUD, which makes it quite good value compared to the Specialized Epic 8 EVO Comp ($8,200 AUD), the Scott Spark 920 TR ($8,499 AUD) and the Santa Cruz Tallboy S ($8,499 AUD). [Wil]
Hey Trent! We've just got word from Trek about updated pricing - the Top Fuel 9.8 GX AXS has dropped down to $7,499 AUD. That makes it pretty good value compared to the Specialized Epic 8 EVO Comp ($8,200 AUD), the Scott Spark 920 TR ($8,499 AUD) and the Santa Cruz Tallboy S ($8,499 AUD). [Wil]
That is what I was trying to say. Do most people really need more travel in this category. I think 120mm is a sweet spot for this category. If you need more its trail bike time and I would much rather have a Fuel EX then. That said as a 2022 Top Fuel owner I will say the improvements they have I do think makes sense and its an even better frame now just not the spec of the bike.
Yeah bikes are getting kinda ridiculous, they got hard tail "trail bikes" and eduros with 140mm forks up front, that has to feel ridiculous blowing thru all that travel up front on a hard trail, feel like it would make you dive over the bars
To be honest, I’ve been really impressed with the Select+ version of the Pike. Aside from some machining on the crown, it has an identical chassis to the Ultimate version and it also has exactly the same new DebonAir+ spring and Charger 3.1 damper. The only real difference is the lack of Buttercups, but I’m not sure how much performance those add. I’ve got an Ultimate Pike on test at the moment, and it feels very similar to the Select+ version. [Wil]
Not necessarily - the Pike is available with 120, 130 and 140mm air shafts, so it's a pretty easy change to make if you want to switch up the travel. That said, I'd love to see Trek offer a dedicated 120/120mm travel Top Fuel with a lighter spec. There's currently a big gap to the Supercaliber, and I think there are riders who would be into a lightweight 120mm bike. Maybe that's too many spec options for Trek though, as I understand the brand is attempting to streamline its lineup by reducing the number of models and variants it offers. [Wil]
With all the adjustability and versatility, on paper it looks to me to be a better bike than my Scott Spark. I would love to get this! I currently ride a Stumpy Evo mostly but the short travel trail bike has a special place in my heart and this bike has got it beating fast!
Interesting to see the variety of shorter travel trail bikes increasing! Would love to see a review of the new Ibis Ripley.
That new Ibis Ripley looks fantastic - we've been chatting with the local distributor here, hopefully we can get one in to review soon!
[Wil]
Hello Wil, what is your opinion Top Fuel Vs Transition Spur?
Would definitely enjoy a Spur / Top Fuel comparison !
That would be ace! We've been requesting Transition test bikes from the local distributor, but so far they haven't been interested in sending us anything to review. We'll keep trying!
[Wil]
Linkage driven single pivot 😉 I'm happy to see an Alu model. IF they built a model on the light side I could see it as a XCM bike over the supercalibre
I built my gen 4 Top fuel 8 quite light and it’s about 28lbs
Interesting to see the return of lock-outs. I've found it very useful on my TTFv9.7 2021.
A great bike, looking to grab one once the prices come back down from the stratosphere! will keep riding my '17 Fuel EX till then!
Funny you should make that comment Shaun, Trek has just dropped the price on the Top Fuel 8 ($4,499 AUD) and the Top Fuel 9.8 GX AXS ($7,499 AUD). Improves the value proposition by quite a bit! [Wil]
Great review
Great review. Hopefully some lower priced aluminium versions will become available
Thanks mate! It appears that Trek Oz still has stock of the previous Top Fuel 5, so I'd expect that once those sell through they'll start bringing in the new Gen 4 version.
I'd love to see Trek bring back the high-spec alloy bikes; a Top Fuel 9 would be pretty sweet I reckon! I'd also love to see a dedicated 120/120mm XC build with the Top Fuel - I've been riding our test bike with that configuration and it absolutely rips. We'll have a long-term review coming to the Flow MTB website soon!
[Wil]
So Trek catfished us with the 240g weight reduction of the new frame since it's for an unpainted frame, and the actual reduction is 100g with paint (the previous gen was 2.7kg). I was originally a little bummed since this was announced 2 months after i bought a gen 3, but not anymore. I actually like the look of the gen 3 better than this new one minus the smaller trek logo, and I don't care about only 100g of weight savings and the extra adjustability. Same geo too
I think a lot of media reported on the 240g weight reduction for the new Top Fuel, but it was clear to us that it didn't quite check out so we held back from publishing that figure. I encountered a similar degree of confusion when the Gen 2 Supercaliber came out last year, so we always try to confirm frame weights where possible.
Ultimately the only way to verify those claimed figures is to weigh a frame ourselves. I'll be holding onto this Top Fuel as a long-term test bike, so I'll see if I can strip it down to get a real-world weight with the shock. It'd be great to get a hold of the Gen 3 frame to see how it compares.
That being said, I think frame weight is only a small contributor to the overall ride quality of the new Top Fuel. It's really the improved compliance that makes the biggest difference on the trail. Of course there's the added versatility from the 4-position Mino Link for those riders who want to explore different suspension and geometry configurations.
[Wil]
Beautiful. Beautiful. Considering the AL version of this over the new AL Specialized Chisel. Looking to have a bike to do 30-50 miles rides through my local mountains that sometimes require a little suspension. Currently using a fully rigid specialized Diverge gravel bike to do this, and shit gets scary. My gen 5 Fuel EX has been amazing and hits above its weight class but is too burly to take on 30+ mile rides for this reason
That new Specialized Chisel FS looks fantastic!
It is a more dedicated XC bike with 110mm of rear travel and a 120mm travel fork, though Specialized does say it's rated for a 130mm fork too. And according to the claimed weights, it's around a full kilo lighter than the Top Fuel AL frame (2,720g vs 3,700g).
I own a Chisel HT frame myself, and I'd love to get a ride on the new FS bike. Will see if we can organise one to review!
[Wil]
Looks great! Now, are the holes round and clean? How is the BB? Does it come faced and machined properly?
No issues with the BB so far! Our test bike has largely been faultless over the past 4 months of riding with no creaks or damage to speak of. I’ll have a proper long-term review coming soon after I strip it down to the bare frame and get a closer look at everything before rebuilding it as a lightweight XC bike - stay tuned to the Flow website for that one! [Wil]
@@FlowMountainBikeUA-cam thanks!
Lighter bikes and simple are rad. I want a titanium.
Good luck getting one of these if it is not already in stock. If you order one, you better have something else to ride while you wait for its arrival.
The new Pike with buttercups is a lot stiffer and handles hits way better. The 130 doesn't negativity change the ride dynamics of the 120 version. The weight difference is not noticeable. Its a win win
My 10.2kg XL Top Fuel 9.9 from 2018 doesn't even recognize this bike, but this new Top Fuel is probably perfect when you need something less capable downhill than a Slash but slower climbing than the Supercaliber
I think the slower climbing comment really depends on what trails you're riding. I've spent a lot of time on both the Gen 1 and Gen 2 Supercalibers, and I found them to be incredibly responsive and lightweight. On smooth trails and on the road, they're scorchingly fast. However, the firm suspension and high anti-squat means there is considerably more feedback on technical terrain, which can cause the rear wheel to hangup and lose traction.
In comparison, the Top Fuel generates a lot more grip that can be really beneficial if you're riding loose and chunky trails. I recently tried out a set of XC race wheels and tyres on the Top Fuel, and in my experience I'd say it's a better technical climber than the Supercaliber.
[Wil]
01:17 I'll have to correct you there. The Top Fuel DOES NOT feature a four-bar suspension system. It's actually a single pivot system. The axle path is only dictated by just a single member/bar - the rear axle rotates concentrically around the main pivot. As such, it's a two-bar single-pivot system.
Denim shorts and no knee pads for the win ✌🏻 ✌🏻
@FlowMountainBikeUA-cam When will the 140/130 review be released? I’m looking forward to the comparison between the 140/130 and stock setup.
We're working on it right now! Should be live on the website next week - keep an eye out for it, got lots to talk about ;-) [Wil]
I tried to order a Top Fuel late 2020ish. After a few months I gave up and bought a Spark aluminum. I think like 10 or 11 months later a Trek dealer ended up calling me saying they had one in stock. Scott Spark has had tons of little problems - Twinlock lever broke (fixed under warranty), Twinlock cable broke inside frame (I said screw it and left it), headset cover plastic creaks and eventually stress cracked, had to retape the wheels to actually get them to seal, no grease from factory in dropper, fork blew up within 3 months + derailleur is typical SRAM junk (not Scott's fault but still...), Shimano brake levers anodizing came off which I've literally never seen before. Since then its been through probably a dozen XC races (even a gravel race), a few bike park runs even, thousands of miles, lots of fun regardless of the nonsense.
But hey my spark got two water bottles in the frame so I forgive it for everything. Seriously though - 130F/120R is the perfect travel for XC racing but everyday useability, glad they kept he trek the same.
i got the spark that has the shock in the open in late 2021 so it was a 2020 model. i got it as the spark team 900 rc model. none of the issues you described happened to me but when they acquired BOLD cycles i think they started taking shortcuts and internal routing unfortunately
Those prices are insane!
Yeah….should be half of that…….
agreed!!!
9K for a bike and you still get the entry level wheelset smh
Agreed!
There is a Trek supplier in my city that still has 2022 Top fuels both alloy and carbon with 30% off he can't sell.
You mention adding travel using the existing fork and shock. I have heard this elsewhere but have not seen anybody do it. I have also read about some downsides of doing this on other shocks, since it isn't necessarily tuned for that travel. Can anybody expand on that?
Changing travel for the RockShox Pike is relatively straightforward with an air spring swap. You can get 120 and 140mm air shafts for that fork, and the process is no more complicated than a basic lower leg and air spring service.
As for the shock, it's possible to change the stroke from 50 to 55mm by removing the internal travel reducer. This is easy with a Fox Float/Float X shock, and no special tools are required to take it out. It's a more involved process with the Deluxe shock, which requires the damper to be pulled apart in order to remove that travel reducer.
SRAM Australia quoted us $220 AUD for a full service and rebuild, during which they can remove the travel reducer to extend the stroke to 55mm. You could also have the damper shaft (main stanchion) replaced for an extra hundred bucks if you wanted the sag gradients to match up with the 55mm stroke.
When you change the stroke to 55mm, you will need to modify the air pressure to maintain the same sag. I haven't changed from the stock tune however, and so far it's working just fine. I'll have a more detailed explanation of the travel change and its effect on the Top Fuel in an upcoming long-term review - stay tuned to the Flow MTB website for that one!
[Wil]
@@FlowMountainBikeUA-cam Excellent info, thank you!
This has many features of a 2018 Fuel EX. Trek going almost full circle.
Hi there!
Someone else mentioned this, so I've pasted in the response;
Initially I thought the same thing as you, but after riding the Top Fuel I've found it to be pretty different.
There are the obvious spec differences - the previous generation Fuel EX came with big 2.6in tyres, the proprietary RE:aktiv shock and a Fox 36 on the higher-end models. It also had the Knock Block steering limiter (the Top Fuel has ditched this), the head angle was steeper at 66-66.5 degrees and the seat angle was slacker at 75-75.5 degrees.
I spent a lot of time on the previous Fuel EX as we had one as a long-termer. The frame was quite stiff, which translated to more feedback on choppier trails. In comparison, the Top Fuel is much springier and livelier overall. It isn't the lightest bike in its category, but it's eager to ride a lot faster than its weight suggests. It's quite a bit more adaptable in terms of its suspension, so you can set it up as a 120/120mm travel XC bike, which isn't possible with the Fuel EX. I also like that Trek has moved away from proprietary suspension. The Deluxe is really well tuned for this bike, and it's been easy to dial in.
Subtle differences on paper, but the Top Fuel has a distinct personality for sure.
Hope that helps explain!
[Wil]
So it's the previous fuel ex with a name change!!
Initially I thought the same thing as you, but after riding the Top Fuel I've found it to be pretty different.
There are the obvious spec differences - the previous generation Fuel EX came with big 2.6in tyres, the proprietary RE:aktiv shock and a Fox 36 on the higher-end models. It also had the Knock Block steering limiter (the Top Fuel has ditched this), the head angle was steeper at 66-66.5 degrees and the seat angle was slacker at 75-75.5 degrees.
I spent a lot of time on the previous Fuel EX as we had one as a long-termer. The frame was quite stiff, which translated to more feedback on choppier trails. In comparison, the Top Fuel is much springier and livelier overall. It isn't the lightest bike in its category, but it's eager to ride a lot faster than its weight suggests. It's quite a bit more adaptable in terms of its suspension, so you can set it up as a 120/120mm travel XC bike, which isn't possible with the Fuel EX. I also like that Trek has moved away from proprietary suspension. The Deluxe is really well tuned for this bike, and it's been easy to dial in.
Subtle differences on paper, but the Top Fuel has a distinct personality for sure.
Hope that helps explain!
[Wil]
@@FlowMountainBikeUA-cam Nice overview. So it seems you are saying this new Top Fuel is more comfortable while also being livelier and more capable than the old EX? That would be an awesome combination. I tried a Gen 6 EX and it was more bike than I wanted.
That's been my experience for sure. The newer Gen 6 Fuel Ex has gone even further in that direction - these days it's quite a burly trail bike!
I think that does suit riders who are placing higher and heavier loads on the bike, where the extra chassis stiffness and travel have benefits. It also has a cruisier and more upright riding position.
In comparison, the Top Fuel positions you lower and further forward in the cockpit. Along with the efficient pedalling performance, it feels well suited to covering ground quickly.
The way Trek has slimmed down the Top Fuel to bring back some compliance has had a really positive impact on its ride quality. It's a difficult attribute to get across in the marketing lingo however, so I can appreciate that a lot of folks just assume the new Top Fuel looks much the same as the old version, or indeed an older generation Fuel EX.
[Wil]
Another great review, Wil! The new Top Fuel appears to be pretty versatile - from down country to trail. I’m surprised you folks have not reviewed a Transition. The Spur and Smuggler seem to cover similar ground. Guessing they have no distribution in Australia. Cheers.
Thanks Nick, appreciate the feedback!
The Transition Spur and Smuggler look ace, would love to swing a leg over one for sure. We've requested Transition test bikes through the Aussie distributor, but they're yet to send one out. Here's hoping 🤞
[Wil]
@@FlowMountainBikeUA-cam the Smuggler was a real eye opener for me. It’s the best bike I’ve owned. Nearly as pedal-friendly as the Spur but heaps more capable. I hope you get to ride one soon. Heck, maybe I’ll message the guys over at Transition HQ and shame them into sending you one to review. 😉
By all means put in the good word for us Nick!
How does this compare to the Giant Trance Advanced Pro 29 120/130?
Great question! Both are fantastic short travel trail bikes, though the Trance 29 is a bit older having last been updated in late 2021.
There haven't been any changes to the frame since, and new spec options are a bit limited. As such, it's a little tricky to compare directly in terms of spec and pricing.
Looking at the Giant Australia website, there is a newer Trance Advanced Pro 29 0, which is more expensive at $9,999 AUD. However, it does come with Fox Factory Series suspension and a SRAM X0 Transmission.
Geometry is very similar between the Trance 29 and Top Fuel when it comes to the angles, reach, chainstay and wheelbase length. However, the riding position is different due to two important aspects. The Trance 29 has a taller stack (619 vs 603mm) and it has a more generous BB drop (45 vs 32mm, both bikes in the Low geometry setting), which clocks you into a fairly upright position. To put it simply, it feels more relaxed like a trail bike.
In my experience of riding the Trance 29, I found it to feel a little plusher and bit burlier overall than the Top Fuel. A lot of this is because Giant specs a piggyback shock on the top-end model along with chunky 2.5in tyres. I like how the latest Maestro platform has been tuned for grip, but it does bob quite a bit and requires more low-speed compression damping to stabilise. For that reason, I really liked the Live Valve system on the Trance 29, but it appears that Giant is moving away from that across all of its mountain bikes and e-MTBs.
While both are great riding trail bikes, a lot of the differences come down to the finishing details. The downtube storage is much better on the Top Fuel, and the 4-position Mino Link gives it a greater range of adjustment. The fact that you can up-stroke the suspension and set it up as a mullet makes it a more adaptable package compared to the Trance 29. I also think the Top Fuel does a better job of morphing into an XC bike with a 120mm travel fork, where it feels zippy and enthusiastic.
Hope that helps to answer your question, but just yell out if you've got any specific details you'd like to know!
[Wil]
@@FlowMountainBikeUA-cam Thanks so much! I got the Trance Advanced 29 Pro 2 with the Live Valve and didnt like it. I thought it made everything too firm and stiff, bumpiest bike I ever had. So I got Fox Factory suspension, 34 GripX 130mm fork and Float shock. The new shock helps the bobbing sensation a lot, last one really relied on the Live Valve I guess. Good to know it feels more plush than the Top Fuel. But I still think the front end is a little harsh at times, still playing around with different tunes.
I have the 2022 version with a 120mm SID. I still feel the Pike is a lot of fork for this bike but I also do not live in country with rocky trails but then I would most likely had gone up a bike. Trying to say I am not sure about the direction they are taking with the specs and why not have both SID and Pike versions. I do like the updates to the frame.
I agree about having both SID and Pike versions. I'd love it if there was a dedicated 120/120mm bike, as currently there's a fair gap between the Top Fuel and Supercaliber.
So far I've been really enjoying the 140/130mm travel configuration too. I'm guessing Trek decided not to offer that as a stock option as it pushes it pretty close to the Fuel EX in terms of travel, even if the two bikes ride quite differently.
Cool that the one bike has so many options though!
[Wil]
Interesting. So you can run 120/120 or 140/130 without any hardware changes. That should cover most riders needs. Unless you're racing or only doing downhill trails it sounds like the top fuel is the better choice compared to the super calibre or fuel ex.
You certainly can! I've set up our Top Fuel in both configurations - there are some images and more detail in the review if you fancy checking it out; flowmountainbike.com/tests/trek-top-fuel-review-2025/
[Wil]
@@FlowMountainBikeUA-cam You write in the review: "It’s worth noting that you can set up the Top Fuel in its 140/130mm travel configuration using the stock fork and shock". I can't find any information about this i.e. how you make the change? Btw I will get a gen 4 frame next week as my rear seat stay broken in a crash. Will keep light weight build with Sid and Control SL wheels. Thank you again for some really good reviews and comments.
Hi there!
Changing travel for the RockShox Pike is relatively straightforward with an air shaft swap. You can get 120 and 140mm air shafts for that fork, and the process is no more complicated than a basic lower leg and air spring service.
As for the shock, it's possible to change the stroke from 50 to 55mm by removing the internal travel reducer. This is easy with a Fox Float/Float X shock, and no special tools are required to take it out. It's a more involved process with the Deluxe shock, which requires the damper to be pulled apart in order to remove that travel reducer.
SRAM Australia quoted us $220 AUD for a full service and rebuild, during which they can remove the travel reducer to extend the stroke to 55mm. You could also have the damper shaft (main stanchion) replaced for an extra hundred bucks if you wanted the sag gradients to match up with the 55mm stroke.
When you change the stroke to 55mm, you will need to modify the air pressure to maintain the same sag. I haven't changed from the stock tune however, and so far it's working just fine. I'll have a more detailed explanation of the travel change and its effect on the Top Fuel in an upcoming long-term review - stay tuned to the Flow MTB website for that one!
[Wil]
I've got the white Top Fuel 9.8 GX T-type gen 3. Best bike I have ever ridden. The new gen4 9.8 looks very similar but it's a downgrade because they swapped the carbon wheels for alloy ones for almost the same price. Sneaky. Also prefer the look of the Gen3.
Hey Sebastien! FYI, we've just gotten word from Trek about some updated pricing - the Top Fuel 9.8 GX AXS has dropped down to $7,499 AUD.
You raise a good point about the change from carbon wheels on the Gen 3 9.8 GX AXS to alloy wheels on the new bike. Interestingly, despite the difference in rim material the two wheelsets almost come out at an identical weight. These are confirmed weights for both wheelsets including TLR rim strips and valves;
- Line Elite Carbon (2,071g)
- Line Comp Alloy (2,094g)
From a strength standpoint we have found Bontrager's carbon rims to be impressively sturdy. And they come with a 2-year crash replacement guarantee which is really nice for peace of mind.
That being said, they are very much on the stiffer side. They are super responsive, but I actually prefer the ride quality of the Line Comp Alloy wheels, which are significantly more compliant on rough terrain. So far they've held up really well too, I've had no issues with spoke tension or rim damage (I do always run CushCore inserts in the rear wheel of every test bike though), and the bearings and freehub are still running smooth. Given it's a stock own-brand wheelset, I've been pleasantly surprised!
[Wil]
You only have 1 aluminium version down there? Here in Sweden it starts at Top Fuel 5
It may be related to stock levels - it appears that Trek Australia still has the Gen 3 Top Fuel 5 in stock, so perhaps when those sell through we'll see the Gen 4 version arrive Down Under. [Wil]
This is almost a 30lbs bike in the top spec, let that sink in.
Heavy fork and wheels is the main problem. You get a burly bike with a burly weight.
@@CR-di1lg I hear you. I am referrancing the Top Fuel 9.9 XX AXS Gen 4 spec for an example. $10,000+bike that weighs almost 30 lbs and is not an Enduro bike? I would not classify the Ultimate PIKE and Carbon wheel set as "heavy". I love TREK, don't get me wrong, I think they just miss the mark on this one. Plenty of sub 26lb. bikes in this category that cost way less and have better spec. I know it probably most definitely rides awesome and planted, but thats a 30lb plus bike in the real world you are dragging up and down all day. 2 more pounds and its FUEL EX ( which is an awesome bike) . Good discussion, cheers!
Enduro bikes weigh 35 lbs... @@michaelcuddihee6754
We are furious that they've dropped the 9.7 and are now charging the same price ($4,799) for an aluminum frame.
Max chainring - 38t or 36t?
Trek states a maximum chainring size of 34T for the new Top Fuel. [Wil]
@@FlowMountainBikeUA-cam Trek top fuel (Riley Amos) - 36t?
That's a good point! I suspect there's probably just enough clearance to physically fit a 36T chainring but not quite enough for Trek to officially recommend it to consumers. [Wil]
I wouldn't call a Trek a four bar. I thought it was a single pivot with a concentric axle. Rides much different than a four bar bike.
Man, those Trek prices.....
Trek must have been listening - the prices on the Top Fuel 8 and Top Fuel 9.8 GX AXS have just dropped in Australia by quite a bit!
The Top Fuel 9.8 GX AXS has dropped down to $7,499 AUD, which makes it quite good value compared to the Specialized Epic 8 EVO Comp ($8,200 AUD), the Scott Spark 920 TR ($8,499 AUD) and the Santa Cruz Tallboy S ($8,499 AUD).
[Wil]
$9k for a 30lb 120mm bike that looks quite homely. Especially that rocker link, it looks like some generic open mold frame I'd find on aliexpress.
Hey Trent! We've just got word from Trek about updated pricing - the Top Fuel 9.8 GX AXS has dropped down to $7,499 AUD. That makes it pretty good value compared to the Specialized Epic 8 EVO Comp ($8,200 AUD), the Scott Spark 920 TR ($8,499 AUD) and the Santa Cruz Tallboy S ($8,499 AUD).
[Wil]
"Short travel bike" - running a Pike.
That is what I was trying to say. Do most people really need more travel in this category. I think 120mm is a sweet spot for this category. If you need more its trail bike time and I would much rather have a Fuel EX then. That said as a 2022 Top Fuel owner I will say the improvements they have I do think makes sense and its an even better frame now just not the spec of the bike.
Yeah bikes are getting kinda ridiculous, they got hard tail "trail bikes" and eduros with 140mm forks up front, that has to feel ridiculous blowing thru all that travel up front on a hard trail, feel like it would make you dive over the bars
9 grand and not running a top spec fork? Insanity
To be honest, I’ve been really impressed with the Select+ version of the Pike. Aside from some machining on the crown, it has an identical chassis to the Ultimate version and it also has exactly the same new DebonAir+ spring and Charger 3.1 damper. The only real difference is the lack of Buttercups, but I’m not sure how much performance those add. I’ve got an Ultimate Pike on test at the moment, and it feels very similar to the Select+ version. [Wil]
120mm at 13kg for 9k 😂
And you need to buy a 120mm fork 😂
Not necessarily - the Pike is available with 120, 130 and 140mm air shafts, so it's a pretty easy change to make if you want to switch up the travel.
That said, I'd love to see Trek offer a dedicated 120/120mm travel Top Fuel with a lighter spec. There's currently a big gap to the Supercaliber, and I think there are riders who would be into a lightweight 120mm bike.
Maybe that's too many spec options for Trek though, as I understand the brand is attempting to streamline its lineup by reducing the number of models and variants it offers.
[Wil]
Looks like a YT izzo I bought in 2020…