I dunno why I was randomly watching this video when I have no Brompton, aside from appreciating the amazing production quality as usual, but thanks to you I realized that people can manually change the front chainring by hand! That idea would've never occured to me otherwise, and my mind is blown! I'm 80% sure I wouldn't be able to fit a front derailleur on my old 6-speed foldie because of the design, but now I have one less worry even if it doesn't.
Fitted the Schlumpf drive in 2017 and it is worth every dollar spent . It is Easy to use with no visible changes or cables or the need to perform any gymnastics to get the chain to jump from one chain ring to another 👍🏽
Excellent as always. Thank you. My favourite Brompton is my Alfine 11 conversion. It gives a wide gear ratio and is lower at the bottom end and higher at the top. I like having a single shifter as well. I appreciate that the rear triangle needs widening or replacing if one is fitted. It is also about 1 kg heavier than my S6R which whilst noticeable lifting up stairs, onto trains etc, isn’t an issue cycling along. Thanks.
@@ukrytykrytyk8477 Tiller Cycles widened the rear triangle but they don't exist any more. Most people get a replacement triangle, such as the one from Kinetics in Glasgow.....See my other comment. thanks.
I finally installed my 40t chainring today and also fitted the conti tires. I think I have a much better touring brompton now. I just pedalled up a hill and it‘s still a hill, but it‘ll help to stay on the bike longer. Also the contis ironed out cobbles much nicer i feel then the standard marathons. I am ready for my next adventure, thanks to your excellent videos
Thanks for this, I'm excited to be picking up a (second hand) 3 speed this afternoon. It's reassuring to know that there's plenty of options to upgrade if the gearing doesn't work out. I particularly like the 2x option, hubby would likely use the big chain ring as he is fitter and likely to carry smaller loads. I on the other hand am not as fit and more likely to transport our 3 year old whether that's in a seat or a trailer.
Excellent video! Thank you! I live in a hilly area, so I have the 44T 6 speed. The range of 29-88 gear inches is absolutely fine, but I miss the additional gears for fine tuning my cadence. The three chainring conversion looks very tempting.
You my dear, are magic! These videos are invaluable so I wish I underside how to identify what I am experiencing in relation to what would work better for me but that is looking like it's going to take me experience. Tank you so much!
This is a great video. I thought I am the only nerd around who actually did all the gear inches calculations on my excel based on different chain ring and sprocket sizes. And yes, I have a collection of different chain ring and sprockets to change. To add on, perhaps you can also mention about other compatible internal gear hubs such as SRF5W which I am currently using. But this video is really good to illustrate to casual cyclists who do not do their gear calculation. Great job!
We didn’t mention the SRF5W as it would not significantly improve the gear range provided by a 6speed BWR (would simplify it however). We see the SRF5W as a great upgrade path for somebody with a 1-2 or 3speed who wants a better range (having a 2nd rear wheel would make the “swapping” even more seamless). Maybe we will discuss this in a follow-up video
Slightly smiling at seeing this come up in my recommendations (now subscribed 😇), especially after my comment about my recently updated 5spd (was 3spd; upgrade via BrommiePlus custom wheel upgrade). Awesome video, and definitely worth the exploration for some riders.
Thanks for your video ! As I lived in a hilly area, my current setup is a 39T Shimano chainring and 19-15-12 rear sprockets. My minimum meters development is 1,74 or 21,8 inches.
Hi Pam and Gilbert!, I love watvhing your videos and learning from it, I would like request a video in coverting 6 speed c line to 7 speed external hub gears, 4 speed p line to 7 speed without changing the hub, and in the process can you also explain how brands like h&h was able to fit 7 speed external hub to a 4 speed pline standard hub?, if possible can you explain the hubs of different bromptons and the third party brands and their approaches to conversion, I'm in the process of converting my pline 4 speed to 7 speed but I dont want to pay the premium h&h is asking for, brands I'm considering is the following: 1. Suncord which as i observed is going for the same deraileur design as the 6 speed c lin 2. H&H which by the look of it is based on the Pline design deraileur and too expensive. 3. Union Jack design also based on Pline , again this is just base on watching it from youtube. 4. Litepro also cheap but I think they use ordinary deore hub or 105 hub but the price is a bit steep for me as well, looking into the brompton third party OEM Sunray. Hope you can shed light on this matter because your channel is the best when it comes to technically explaining all about the Brompton. God bless you guys!.
Bond, James Bond? Thanks for the good words and suggestions for future technical videos. We will see what we can do, meanwhile keep us posted if there is any progress with your P-Line 7speed upgrade.
As an owner of a LightweightH6LXBrompton I have bought an 11 teeth, titanium chainring for higher speed and also larger versions in front. I have seen the double chainrings and also a shifter for the frame in front (One more changer for the handlebar)! But I mostly need low gears, as I sometimes have to walk going up steep hills.
@@2Bikes4Adventure It is the standard setting for a 2019 flame painted model, after some modifications (titanium/carbon/alu) SuperlightM6LXBrompton. Now somewhat lighter and down to 9,35 kilo, of which I expect to reach 9 kilo soon, and still with my mudguards, as a "Rainy Dane"! The brackets holding the original Titanium stays for the mudguards are really "heavy metal" from the factory, as also those holding them on the frame. I have found some from carbon, with bolts and two aluminum holders for the mudguards, as also titanium parts for my original brakes (A.E. China). When fixed and with a carbon handlebar I'm sure to be below 9 kilo - and then why waste money on a less gears T-Line, which with mudguards is well past 8 kilo, I have seen on UA-cam (Making one lighter) Finn. Denmark 😄
My bike is presently down to 8,75 kilo, with mudguards and modifications and I expect it to end with 8,5 kilo with mudguards and 6, heavy functioning S.A. gears on my bike. I have seen an option for a 7 speed chain gear and shifter, for a Brompton. Finn. Denmark
Hi. Thank you for a brilliant video summary first of all. Have you considered writing a book based on your brilliant findings? Or a blog at least? I see someone mentioned already converting rear wheel to take Alfine 8. I can mentioned one other front derailleur, similar to Schlumpf but cheaper and better imho. It's called Efneo. It's in essence 3 speed IGH but enclosed inside the front chain ring. It's also compatible with Brompton. I'd like to see it being added to your comparison.
Hello, and thanks a lot for this video! You gave me the idea to swap my 44T chainring to a 39T. I am currently on a tour around Switzerland (approx. 1100 km). Especially on the mountain passes, the even smaller gear range is a welcome benefit. The loss of the fast gears is absolutely bearable for me.
Totally agree. In this kind of environment (Switzerland) we would gladly sacrifice the 6th gear to get a lower first gear (you will be going plenty fast on the downhill anyway). Besides, you can aways keep the 44T in reserve for a later trip. Enjoy!
Great and easy upgrades! Love your graphics. But I still dream of a 14 hub gear for our darling Bromptons. The 44T makes a lots of difference for biketouring 👍🏻😊 Keep Safe! Keep Riding!
Hi Chris. We didn’t mention upgrades requiring a new back wheel and/or a wider rear triangle (maybe in a follow-up video :-) Having a 14speed Rohloff would certainly be nice, but a similar range could probably be achieved with a dual-chainring (would be cheaper, lighter and have better power transfer efficiency). Still, wouldn’t mind trying a Brompton/Rohloff.
@ChrisByBike there is a Rohloff option by Kinetics… needs new rear triangle and makes possible the addition of disc brakes and even larger (18-20in) wheels.
so many good videos and illustrations. I see people putting up to 7 speed cassettes with dodgy wheels from Ali express. have you guys seen much success or failure with these around ?
We would not be worrying with any upgrades mentioned in the video. However, integrating a 7 speed cassette with an Aliexpress rear wheel would indeed raise our stress level a notch while touring.
Upgrading to a dual-chainring is likely the most cost efficient way to increase the factory gear range. Alternatively, you could fine-tune the 3-speed by selecting a different chainring and/or sprocket.
A very useful overview of the options. I hadn't heard of the duo chain ring before. Would that need the ss or 2s tensioner - or either? Currently 6s with third party electric assist because I'm pushing 70 and live uphill in a hilly area - but I'm fitter than I was and I would like to be more self contained
@@2Bikes4AdventureThanks for that. I guess the calculator will be coming out to see if I can put together a more functional "gear box" than I have now. The factory shifting sequence has never felt truly natural 🙂
Do you have a video explaining and showing how Schlumpf drives work, and what the “speed” and “mountain” options are good for in practise? I have been a “utility” rider, I guess you could say, and have strong but slow legs. I always rode at a slow cadence except when having to shift for traffic flow. For years and years I just used cheap old bikes with six or seven speed twist gears - I got used to not looking, or even knowing what gear I’m in, just what felt right. Hills were just something you had to slog up. (My city is partly built on a series of hills). Now as I age I’m thinking of getting a good folding bike to combine with train & underground - and trying to understand which Schlumpf gear, if either, would be useful to me.
Schlumpf drives come indeed in a few flavours: - Speed Drive - High Speed Drive - Mountain Drive They basically act as having a virtual 2nd chainring, thus expanding your total gear range either above or below the existing range. In the case of the Speed Drive, that virtual 2nd chainring would be 1.65 bigger, (or 2.5 for the High Speed), while for the Mountain drive it would be 2.5 smaller. ATS from Taiwan offers similar drives as well, at a somewhat lower cost. Which configuration to choose for your Brompton? It will depend which chainring is installed. You want your most efficient setup (1:1 front and 2-/+ rear hub) to be your most commonly used gears. Availability and cost could also be a factor. Note this will affect the total weight of your bike, so less practical if you plan to do intermodal transport. We would suggest going for a 6speed 44T chainring first. If not sufficient, replace the 44T by a 39T. If still not sufficient, consider a speed or mountain drive.
@@2Bikes4Adventure Wow, thank you for such a detailed answer! I am at an early stage, and I am not sure if it will be a Brompton. I was also looking at vello bikes. The whole folding bike things is a new thought to me. In fact, I’m trying to decide whether an electric one would be best, and that’s a new kettle of fish too. I’m not even sure why electric motors should come on bikes with mechanical gears at all. You can see I’m pretty equally in the dark about all of it!
So far I’ve only replaced the chainring to 39t, but that only gives you 25 gear inches.. I need to get to 20 gear inches for touring and climbing… I’m considering the 17t sprocket and the 33t chainring now that I’ve seen that video
Thank you so much for this video! I have been considering a 4-speed P-line, but I'm afraid that since it already has a 18 teeth sprocket and a 50t chainring option, it's out of simple ways to extend the lower gear range for easier climbing :/ Perhaps changing the chainring to a 40t one?
It could be interesting to see if there is enough clearance for a 19T in the new titanium rear frame. The derailleur range could also come into play. Choosing a smaller chainring (39T to 44T) involves fewer unknowns, but is more expensive and would reduce your top speed.
What about the option of replacing both the internal gears and the rear gears (I have a 6-speed model) with a 4-ring rear cassette, reducing both weight and complexity? I've seen this done on UA-cam, but without sufficient technical details to repeat the task. And yes, I'm willing to replace the rear wheel at this opportunity, as well as the shifters.
Retrofitting 4 speed on an existing 6 speed would indeed require a rear wheel replacement in addition to a new shifter/derailleur setup. Not cheap. If the main goal is to save weight, we would recommend buying a 2 speed rear wheel. It would be interchangeable with the 6 speed wheel, no need to change the shifters. Changing between wheels would only take minutes (ex.: using the 2 speed for commuting during the week and the 6 speed for longer trips).
Have you considered the Efneo GTRO 3-speed gear box, a Polish Schlumpf-alternative? Looks interesting online, an effective 50/40/28 up front. If merged to a BWR 6-speed with 13/15 cogs, your lowest gear would be below 20 gear inches, and your highest at 100 gear inches. But more importantly, it neatly spaces the gears between the 50 and 40 chain rings in sequence, almost like an old "half-step" set up. Highest gear would be 50-3+, shift down to 50-3-, then 40-3+, then 40-3-, then 50-2+, then 50-2-, then 40-2+, then 40-2-,...all with small gear steps of 8 or 15.
hello good morning I love your way of making videos so technical and so easy to understand for new brompton users, thanks for your time I would like to take the opportunity to ask a question, I just bought my brompton and I opted for the P line over the C line 6 speeds, I have been there for 3 months and I think that only because of the speeds I was wrong in my choice, it occurred to me that by buying a new 6 speed wheel it is possible to mount it in the P Line? What do you think? , Cheers
Installing a 6speed wheel on a P-Line could open up a serious can of worms and may not be worth the cost and effort. Cheaper (and less risky) alternatives to increase the gear range include replacing the 1st gear sprocket for something bigger than 18T ($10 US?) and/or installing a BCD130 dual chainring (ex. 54T/33T, approx $150 US). Note that you may have to install a longer chain depending on the option(s) selected. Both upgrades would require no permanent mechanical modification, they are light weight and the bike could easily be reconfigured to its original specs if you change your mind (or want to sell it).
If money is no object ($700), this 7 speed upgrade could do the trick www.fantastic4toys.com/collections/brompton-upgrade-parts/products/thx4ride-7-speed-kit-set-for-brompton-bicycle-p-line
Indeed, we didn’t cover all possible upgrades, limiting ourselves to the easiest/less expensive ones (except for the SpeedDrive). Maybe something for a follow-up video if subscribers are interested
The 17T could interfere with the rear triangle on older Brompton models. If your C Line is a recent model, you should be fine. While increasing your total range from 302% to 348% (good), a 12T/17T configuration will also significantly increase the +/- gear step (from 23% to 42%: not so good)
Adding a 2nd sprocket (and associated 2speed derailleur, cable and shifter) won’t be sufficient to complete the conversion. You would need to replace the internal gear hub for a BWR model which has a wider range than the regular hub used on the A-Line.
I got a 39 T chainring from Stronglight from my local bike shop. It was around 20-25€. Basically any 9 speed 130 mm BCD five arm chainring will fit ("five arm" is the "difficult to find" part because only vintage road bikes seem to use five arms, almost everybody else (think MTB) has chosen four arms). (You need to shorten your chain slightly for the chain to stay on during folding/unfolding) (Hint: I might actually have a ten speed chainring, but since it's thinner than my 9 speed chain it will still work)
Going from a 3 speed to a 6 speed is not as straightforward as it might seem. You would need to change the gear hub, add a 2nd sprocket, add a new derailleur, change the gear tensioner and a 2nd shifter. It could end up being quite costly. If you have a post-2013 Brompton, a cheaper solution could be to add a dual chainring (33T/50T or 33T/54T). It would cost you about $150US. You may also need to buy a new/longer chain (+$10US) depending on the size of chainring you presently have. The drawback of this solution is the absence of a shifter to control the chain position. For some, this is a showstopper. We plan to release a video later this year showing how to install a dual chainring on a Brompton, it may be of interest if you are not in a rush. Another option would be to replace your 3 speed hub with a 5 speed hub. Brompton used to sell a 5 speed version (20 years ago) but the supplier making the hub went bankrupt, forcing Brompton to design an in-house 6 speed replacement. Now that 5 speed hubs are available on the update market, it would be a relatively easy upgrade.
@2Bikes4Adventure oh wow that's good to know. Im in the UK so will have to look around. Yh I'm happy to wait a bit that's fine but when I travel I would love to have a bike to zip around on. 5 speed might be fine for me. Will look at post 2013 ones some more, I've looked at 2006 - 2012 second hand ones so will keep an eye out. The brand new ones are too expensive I can't afford that 😭
We used the C-Line Explore 6-speed as baseline (which has a BWR 3-speed Internal Hub and 2 sprockets). A mid-price internal hub upgrade would be to install a Sturmey Archer S-RF5(W) thus creating a 5x2 (10 speed) drivetrain. Installing an Alfine or Rohloff internal hub would require a new rear triangle, an expensive proposition that was outside the scope of this video.
The new 12T/17T sprockets will indeed extend your gear range significantly, from 302% to 348%. The drawback of this new setup is the uneven increment between each gear. While the standard 13T/16T setup varies from 23% to 27% between gears, the 12T/17T setup fluctuates from 10% to 40%. Expect a very significant jump (40%) when you use the +/- gear selector.
Thanks, I plotted it in excel and see the issue you mention. Do you have any preference for how low the highest gear should be if one brings camping stuff. I pairing the 17T with a 39T chain ring to get a low gear but wonder if 13 or 14 would be best
If you are planning on touring/camping, we would recommend a 44T chainring if you don’t have one already (or even 39T as you suggested). If you feel your first gear is not low enough, changing from 16T to 17T while keeping the 13T won’t affect the gap between gears too much.
Hello. I develop a bicycle gearbox. Let me ask you something. I can make 350-400% center drive at 7 speed. Do you think this specification is enough for mini bello or city bikes? I'm curious about the specifications that consumers want.
The idea of a gearbox for folding bike is interesting. The range you propose is satisfactory (350 to 400%). The main competition would be internal hub (not derailleur) with a similar range. Three factors, in addition to range, would come into play: 1- Price (the main reason many don’t go for a Rohloff) 2- Weight: An heavy folding bike compromises its portability 3- Power Efficiency: What would be the power efficiency for each gear. Would the most efficient one (direct drive?) correspond to the most used gear?
@@2Bikes4Adventure Thank you for your feedback. I am currently developing a 15-speed speed. I can make a 7-speed speed, but I haven't developed it. I was curious about the marketability of the 7-speed gearbox. I'm planning a gearbox to compete with the draylor. 1.The price is expected to be 150-200 dollars. 2. Weight is 2kg or less. 3.Most gearboxes have similar efficiency. This gearbox won't make a difference either. The singular of the highest efficiency is unknown. The structure is the same as the effigear with two axes. My goal is to release a 15-speed gearbox, but I also plan to release a 7-speed gearbox if there is marketability. Have a nice day.
@@all-to If the 7-speed gearbox is significantly lighter (and possibly cheaper) than the 15-speed, it would be a good selling argument for a folding bike users. Brompton owners are willing to pay $1000 extra to save 1 Kg on their bike.
@@2Bikes4Adventure All right. Your opinion is... 1.There is a possibility if the price is low. 2. If it is very light, there will be a buyer even if it is expensive. It's not like there's no way to lower the weight. But I'm not in the condition to proceed right now. 7 speed (360-400%) is the best choice for me, weighing 2kg. We are investigating whether it is possible to use it for household bicycles, student bicycles, back hub electric bicycles, and mini-bellos. Thank you for your opinion.
@@2Bikes4Adventure Is it not enough if we make it 300% (33% increase) at 5 speed? I can also make a gear of aluminum at 5 speeds. This is not durable, but I think it's possible. The weight is definitely within 1.4kg. The price goes up because aluminum gears have to be processed. I'm expecting 500 dollars.
![Explaining Brompton Gearing - [Including P & T Line]](http://i.ytimg.com/vi/7uVwMx9OZ94/mqdefault.jpg)
![Explaining Brompton Gearing - [Including P & T Line]](/img/tr.png)
Very rarely do I feel so out of place and unworthy of receiving such detailed high-quality information for free as when I watch your videos.
Your feedback makes it all worthwhile
Got my new Brompton recently, and have now ordered a 40t for easier riding at 70 years old. Thanks to you both.
I have a 36. Still hard on the hills lol
I dunno why I was randomly watching this video when I have no Brompton, aside from appreciating the amazing production quality as usual, but thanks to you I realized that people can manually change the front chainring by hand! That idea would've never occured to me otherwise, and my mind is blown!
I'm 80% sure I wouldn't be able to fit a front derailleur on my old 6-speed foldie because of the design, but now I have one less worry even if it doesn't.
Fitted the Schlumpf drive in 2017 and it is worth every dollar spent . It is Easy to use with no visible changes or cables or the need to perform any gymnastics to get the chain to jump from one chain ring to another 👍🏽
Excellent as always. Thank you. My favourite Brompton is my Alfine 11 conversion. It gives a wide gear ratio and is lower at the bottom end and higher at the top. I like having a single shifter as well. I appreciate that the rear triangle needs widening or replacing if one is fitted. It is also about 1 kg heavier than my S6R which whilst noticeable lifting up stairs, onto trains etc, isn’t an issue cycling along. Thanks.
Sounds like a great conversion. How much would you estimate the upgrade cost? What chainring are you using?
Hi. Thanks for sharing that tip. Have you replaced the rear triangle or just widened the standard one?
@@ukrytykrytyk8477 Tiller Cycles widened the rear triangle but they don't exist any more. Most people get a replacement triangle, such as the one from Kinetics in Glasgow.....See my other comment. thanks.
I finally installed my 40t chainring today and also fitted the conti tires. I think I have a much better touring brompton now. I just pedalled up a hill and it‘s still a hill, but it‘ll help to stay on the bike longer. Also the contis ironed out cobbles much nicer i feel then the standard marathons.
I am ready for my next adventure, thanks to your excellent videos
Enjoy your new upgrades and hope our paths will cross in the future
I switched my 54t for a 44t on my H6L so much better up the hills, Thanks for all your info x
This indeed must have made a noticeable difference
Thanks a lot for your ideas to improve the Brompton drivetrain. I can see 1 or 2 options that I can definitely use. Thanks!!
Kinetic’s in the UK offer a range of conversions inc Rohloff hubs amongst it range of custom Brompton options
Indeed. Maybe the subject for a future video!
Thanks for this, I'm excited to be picking up a (second hand) 3 speed this afternoon. It's reassuring to know that there's plenty of options to upgrade if the gearing doesn't work out. I particularly like the 2x option, hubby would likely use the big chain ring as he is fitter and likely to carry smaller loads. I on the other hand am not as fit and more likely to transport our 3 year old whether that's in a seat or a trailer.
Our first 2 Brompton were 2nd hand 3-speed as well. These are indestructible.
Enjoy!
Excellent video! Thank you! I live in a hilly area, so I have the 44T 6 speed. The range of 29-88 gear inches is absolutely fine, but I miss the additional gears for fine tuning my cadence. The three chainring conversion looks very tempting.
We have the same configuration (6speed 44T). The dual chainring is probably our next step.
You my dear, are magic! These videos are invaluable so I wish I underside how to identify what I am experiencing in relation to what would work better for me but that is looking like it's going to take me experience. Tank you so much!
This is a great video. I thought I am the only nerd around who actually did all the gear inches calculations on my excel based on different chain ring and sprocket sizes. And yes, I have a collection of different chain ring and sprockets to change. To add on, perhaps you can also mention about other compatible internal gear hubs such as SRF5W which I am currently using. But this video is really good to illustrate to casual cyclists who do not do their gear calculation. Great job!
We didn’t mention the SRF5W as it would not significantly improve the gear range provided by a 6speed BWR (would simplify it however). We see the SRF5W as a great upgrade path for somebody with a 1-2 or 3speed who wants a better range (having a 2nd rear wheel would make the “swapping” even more seamless). Maybe we will discuss this in a follow-up video
Slightly smiling at seeing this come up in my recommendations (now subscribed 😇), especially after my comment about my recently updated 5spd (was 3spd; upgrade via BrommiePlus custom wheel upgrade). Awesome video, and definitely worth the exploration for some riders.
Your BrommiePlus 5speed upgrade deserves a video of its own :-)
This is an excellent and super-useful video, thank you. The level of detail and the very clear explanations are amazing!
Bonjour, Pam et Gilbert, merci pour le vidéo ! Very handy.
Thanks for your video ! As I lived in a hilly area, my current setup is a 39T Shimano chainring and 19-15-12 rear sprockets. My minimum meters development is 1,74 or 21,8 inches.
No problem with the 19T touching the rear frame?
Did you have to modify the rear triangle to fit the 19T?
That is really interesting ! thank you for sharing the information.
Hi Pam and Gilbert!, I love watvhing your videos and learning from it, I would like request a video in coverting 6 speed c line to 7 speed external hub gears, 4 speed p line to 7 speed without changing the hub, and in the process can you also explain how brands like h&h was able to fit 7 speed external hub to a 4 speed pline standard hub?, if possible can you explain the hubs of different bromptons and the third party brands and their approaches to conversion, I'm in the process of converting my pline 4 speed to 7 speed but I dont want to pay the premium h&h is asking for, brands I'm considering is the following:
1. Suncord which as i observed is going for the same deraileur design as the 6 speed c lin
2. H&H which by the look of it is based on the Pline design deraileur and too expensive.
3. Union Jack design also based on Pline , again this is just base on watching it from youtube.
4. Litepro also cheap but I think they use ordinary deore hub or 105 hub but the price is a bit steep for me as well, looking into the brompton third party OEM Sunray.
Hope you can shed light on this matter because your channel is the best when it comes to technically explaining all about the Brompton.
God bless you guys!.
Bond, James Bond?
Thanks for the good words and suggestions for future technical videos. We will see what we can do, meanwhile keep us posted if there is any progress with your P-Line 7speed upgrade.
As an owner of a LightweightH6LXBrompton I have bought an 11 teeth, titanium chainring for higher speed and also larger versions in front. I have seen the double chainrings and also a shifter for the frame in front (One more changer for the handlebar)! But I mostly need low gears, as I sometimes have to walk going up steep hills.
How big is your chainring now?
@@2Bikes4Adventure It is the standard setting for a 2019 flame painted model, after some modifications (titanium/carbon/alu) SuperlightM6LXBrompton. Now somewhat lighter and down to 9,35 kilo, of which I expect to reach 9 kilo soon, and still with my mudguards, as a "Rainy Dane"!
The brackets holding the original Titanium stays for the mudguards are really "heavy metal" from the factory, as also those holding them on the frame. I have found some from carbon, with bolts and two aluminum holders for the mudguards, as also titanium parts for my original brakes (A.E. China). When fixed and with a carbon handlebar I'm sure to be below 9 kilo - and then why waste money on a less gears T-Line, which with mudguards is well past 8 kilo, I have seen on UA-cam (Making one lighter) Finn. Denmark 😄
My bike is presently down to 8,75 kilo, with mudguards and modifications and I expect it to end with 8,5 kilo with mudguards and 6, heavy functioning S.A. gears on my bike.
I have seen an option for a 7 speed chain gear and shifter, for a Brompton. Finn. Denmark
I'm 75 by the way, and a former craftsman with reasonable skills to change most on my bike for a better function.
Excellent video! Thank you for sharing and summarising all the upgrade options!
Some other upgrades were not covered (ex.: 5-speed hub, Rohloff hub….). Maybe in a follow-up video…. Stay tuned
Hi. Thank you for a brilliant video summary first of all. Have you considered writing a book based on your brilliant findings? Or a blog at least?
I see someone mentioned already converting rear wheel to take Alfine 8.
I can mentioned one other front derailleur, similar to Schlumpf but cheaper and better imho. It's called Efneo. It's in essence 3 speed IGH but enclosed inside the front chain ring. It's also compatible with Brompton. I'd like to see it being added to your comparison.
Thanks for the info concerning the Efneo, maybe something to add in a follow-up video.
Hello, and thanks a lot for this video! You gave me the idea to swap my 44T chainring to a 39T. I am currently on a tour around Switzerland (approx. 1100 km). Especially on the mountain passes, the even smaller gear range is a welcome benefit. The loss of the fast gears is absolutely bearable for me.
Totally agree. In this kind of environment (Switzerland) we would gladly sacrifice the 6th gear to get a lower first gear (you will be going plenty fast on the downhill anyway).
Besides, you can aways keep the 44T in reserve for a later trip.
Enjoy!
Great and easy upgrades!
Love your graphics.
But I still dream of a 14 hub gear for our darling Bromptons.
The 44T makes a lots of difference for biketouring 👍🏻😊
Keep Safe! Keep Riding!
Hi Chris. We didn’t mention upgrades requiring a new back wheel and/or a wider rear triangle (maybe in a follow-up video :-)
Having a 14speed Rohloff would certainly be nice, but a similar range could probably be achieved with a dual-chainring (would be cheaper, lighter and have better power transfer efficiency). Still, wouldn’t mind trying a Brompton/Rohloff.
@ChrisByBike there is a Rohloff option by Kinetics… needs new rear triangle and makes possible the addition of disc brakes and even larger (18-20in) wheels.
@@ARJWright that's cool!
@@2Bikes4Adventure a couple of gear would help a lot on the mountains 👍🏻😊
Same dream with T line 😢
so many good videos and illustrations. I see people putting up to 7 speed cassettes with dodgy wheels from Ali express. have you guys seen much success or failure with these around ?
We would not be worrying with any upgrades mentioned in the video.
However, integrating a 7 speed cassette with an Aliexpress rear wheel would indeed raise our stress level a notch while touring.
Great video, as always. Am curious what kinds of updates one could do if starting from a 3-speed... :)
Upgrading to a dual-chainring is likely the most cost efficient way to increase the factory gear range. Alternatively, you could fine-tune the 3-speed by selecting a different chainring and/or sprocket.
I have the 3-speed Brompton. I installed the dual-chainring from “BikeGang”. Very practical. Highly recommended.
A very useful overview of the options. I hadn't heard of the duo chain ring before. Would that need the ss or 2s tensioner - or either?
Currently 6s with third party electric assist because I'm pushing 70 and live uphill in a hilly area - but I'm fitter than I was and I would like to be more self contained
The dual chainring works with both types of tensioner although most users install it on 6s models.
@@2Bikes4AdventureThanks for that. I guess the calculator will be coming out to see if I can put together a more functional "gear box" than I have now. The factory shifting sequence has never felt truly natural 🙂
Do you have a video explaining and showing how Schlumpf drives work, and what the “speed” and “mountain” options are good for in practise? I have been a “utility” rider, I guess you could say, and have strong but slow legs. I always rode at a slow cadence except when having to shift for traffic flow. For years and years I just used cheap old bikes with six or seven speed twist gears - I got used to not looking, or even knowing what gear I’m in, just what felt right. Hills were just something you had to slog up. (My city is partly built on a series of hills). Now as I age I’m thinking of getting a good folding bike to combine with train & underground - and trying to understand which Schlumpf gear, if either, would be useful to me.
Schlumpf drives come indeed in a few flavours:
- Speed Drive
- High Speed Drive
- Mountain Drive
They basically act as having a virtual 2nd chainring, thus expanding your total gear range either above or below the existing range.
In the case of the Speed Drive, that virtual 2nd chainring would be 1.65 bigger, (or 2.5 for the High Speed), while for the Mountain drive it would be 2.5 smaller.
ATS from Taiwan offers similar drives as well, at a somewhat lower cost. Which configuration to choose for your Brompton? It will depend which chainring is installed. You want your most efficient setup (1:1 front and 2-/+ rear hub) to be your most commonly used gears. Availability and cost could also be a factor.
Note this will affect the total weight of your bike, so less practical if you plan to do intermodal transport. We would suggest going for a 6speed 44T chainring first. If not sufficient, replace the 44T by a 39T. If still not sufficient, consider a speed or mountain drive.
@@2Bikes4Adventure Wow, thank you for such a detailed answer! I am at an early stage, and I am not sure if it will be a Brompton. I was also looking at vello bikes. The whole folding bike things is a new thought to me. In fact, I’m trying to decide whether an electric one would be best, and that’s a new kettle of fish too. I’m not even sure why electric motors should come on bikes with mechanical gears at all. You can see I’m pretty equally in the dark about all of it!
So far I’ve only replaced the chainring to 39t, but that only gives you 25 gear inches.. I need to get to 20 gear inches for touring and climbing… I’m considering the 17t sprocket and the 33t chainring now that I’ve seen that video
A dual chainring with a 17T sprocket would indeed provide 20.6 gear-inches in first gear. No hill would be too step!
Thank you so much for this video!
I have been considering a 4-speed P-line, but I'm afraid that since it already has a 18 teeth sprocket and a 50t chainring option, it's out of simple ways to extend the lower gear range for easier climbing :/
Perhaps changing the chainring to a 40t one?
It could be interesting to see if there is enough clearance for a 19T in the new titanium rear frame. The derailleur range could also come into play.
Choosing a smaller chainring (39T to 44T) involves fewer unknowns, but is more expensive and would reduce your top speed.
🧑🏼🦲Nice Video! Thanks!!
Thanks for the assistance concerning the dual chainring.
What about the option of replacing both the internal gears and the rear gears (I have a 6-speed model) with a 4-ring rear cassette, reducing both weight and complexity? I've seen this done on UA-cam, but without sufficient technical details to repeat the task. And yes, I'm willing to replace the rear wheel at this opportunity, as well as the shifters.
Retrofitting 4 speed on an existing 6 speed would indeed require a rear wheel replacement in addition to a new shifter/derailleur setup. Not cheap. If the main goal is to save weight, we would recommend buying a 2 speed rear wheel. It would be interchangeable with the 6 speed wheel, no need to change the shifters. Changing between wheels would only take minutes (ex.: using the 2 speed for commuting during the week and the 6 speed for longer trips).
Have you considered the Efneo GTRO 3-speed gear box, a Polish Schlumpf-alternative? Looks interesting online, an effective 50/40/28 up front. If merged to a BWR 6-speed with 13/15 cogs, your lowest gear would be below 20 gear inches, and your highest at 100 gear inches. But more importantly, it neatly spaces the gears between the 50 and 40 chain rings in sequence, almost like an old "half-step" set up. Highest gear would be 50-3+, shift down to 50-3-, then 40-3+, then 40-3-, then 50-2+, then 50-2-, then 40-2+, then 40-2-,...all with small gear steps of 8 or 15.
Thanks for bringing up this interesting alternative, we will look into it.
hello good morning
I love your way of making videos so technical and so easy to understand for new brompton users, thanks for your time
I would like to take the opportunity to ask a question, I just bought my brompton and I opted for the P line over the C line 6 speeds, I have been there for 3 months and I think that only because of the speeds I was wrong in my choice, it occurred to me that by buying a new 6 speed wheel it is possible to mount it in the P Line? What do you think? , Cheers
Installing a 6speed wheel on a P-Line could open up a serious can of worms and may not be worth the cost and effort.
Cheaper (and less risky) alternatives to increase the gear range include replacing the 1st gear sprocket for something bigger than 18T ($10 US?) and/or installing a BCD130 dual chainring (ex. 54T/33T, approx $150 US). Note that you may have to install a longer chain depending on the option(s) selected.
Both upgrades would require no permanent mechanical modification, they are light weight and the bike could easily be reconfigured to its original specs if you change your mind (or want to sell it).
If money is no object ($700), this 7 speed upgrade could do the trick www.fantastic4toys.com/collections/brompton-upgrade-parts/products/thx4ride-7-speed-kit-set-for-brompton-bicycle-p-line
What about the new bromptons with gears inside the hub
That's a good suggestion for a future video
Thanks you,
Why don't talk about the replacement of the rear center of the wheel? By a rolhoff or alfine 8?
The Alfine 8 would not change the gear range compared to the 6-speed Brompton, both have about 306-308%.
A rohloff is a dream, but changing the rear triangle is quite the project too
Indeed, we didn’t cover all possible upgrades, limiting ourselves to the easiest/less expensive ones (except for the SpeedDrive). Maybe something for a follow-up video if subscribers are interested
Would you please confirm whether it is possible to switch out 16T and 13 T sprockets on a C line explorer for 17T and 12T.
The 17T could interfere with the rear triangle on older Brompton models.
If your C Line is a recent model, you should be fine.
While increasing your total range from 302% to 348% (good), a 12T/17T configuration will also significantly increase the +/- gear step (from 23% to 42%: not so good)
@2Bikes4Adventure I appreciate your quick response and look forward to your future videos. They are very helpful for me as a new brompton owner.
c-Line 16/13 ->17/14?
i can't found any 14T can use at out ring
where i can buy?
i can only find 16/13->17/13
or
chang to 17/16/13 or 19/16/13 (3x3)
You can buy individual sprocket (about $5) at www.brommieplus.com
Is it possible to turn an A-line 3 speed into a 6 speed explore by asking a second rear great?
Adding a 2nd sprocket (and associated 2speed derailleur, cable and shifter) won’t be sufficient to complete the conversion. You would need to replace the internal gear hub for a BWR model which has a wider range than the regular hub used on the A-Line.
150 bucks for 1 chain ring? is it made of adamantium?
I got a 39 T chainring from Stronglight from my local bike shop. It was around 20-25€.
Basically any 9 speed 130 mm BCD five arm chainring will fit ("five arm" is the "difficult to find" part because only vintage road bikes seem to use five arms, almost everybody else (think MTB) has chosen four arms).
(You need to shorten your chain slightly for the chain to stay on during folding/unfolding)
(Hint: I might actually have a ten speed chainring, but since it's thinner than my 9 speed chain it will still work)
Where can I get a 17 teeth sprocket?
www.brommieplus.com has some for $5US
If you wanted to make a 3 gear into a 6 gear then which one is good for that and can I do it myself or should I go to a shop ?
Going from a 3 speed to a 6 speed is not as straightforward as it might seem. You would need to change the gear hub, add a 2nd sprocket, add a new derailleur, change the gear tensioner and a 2nd shifter. It could end up being quite costly.
If you have a post-2013 Brompton, a cheaper solution could be to add a dual chainring (33T/50T or 33T/54T). It would cost you about $150US. You may also need to buy a new/longer chain (+$10US) depending on the size of chainring you presently have. The drawback of this solution is the absence of a shifter to control the chain position. For some, this is a showstopper. We plan to release a video later this year showing how to install a dual chainring on a Brompton, it may be of interest if you are not in a rush.
Another option would be to replace your 3 speed hub with a 5 speed hub.
Brompton used to sell a 5 speed version (20 years ago) but the supplier making the hub went bankrupt, forcing Brompton to design an in-house 6 speed replacement. Now that 5 speed hubs are available on the update market, it would be a relatively easy upgrade.
@2Bikes4Adventure oh wow that's good to know. Im in the UK so will have to look around. Yh I'm happy to wait a bit that's fine but when I travel I would love to have a bike to zip around on. 5 speed might be fine for me. Will look at post 2013 ones some more, I've looked at 2006 - 2012 second hand ones so will keep an eye out. The brand new ones are too expensive I can't afford that 😭
What about an internal gear hub?
We used the C-Line Explore 6-speed as baseline (which has a BWR 3-speed Internal Hub and 2 sprockets). A mid-price internal hub upgrade would be to install a Sturmey Archer S-RF5(W) thus creating a 5x2 (10 speed) drivetrain. Installing an Alfine or Rohloff internal hub would require a new rear triangle, an expensive proposition that was outside the scope of this video.
Hi do think on a 6 speed, changing the sprocket from 13/16T to 12/17T would work to expand the gear range and it would shift well?
The new 12T/17T sprockets will indeed extend your gear range significantly, from 302% to 348%.
The drawback of this new setup is the uneven increment between each gear. While the standard 13T/16T setup varies from 23% to 27% between gears, the 12T/17T setup fluctuates from 10% to 40%. Expect a very significant jump (40%) when you use the +/- gear selector.
Thanks, I plotted it in excel and see the issue you mention. Do you have any preference for how low the highest gear should be if one brings camping stuff. I pairing the 17T with a 39T chain ring to get a low gear but wonder if 13 or 14 would be best
If you are planning on touring/camping, we would recommend a 44T chainring if you don’t have one already (or even 39T as you suggested).
If you feel your first gear is not low enough, changing from 16T to 17T while keeping the 13T won’t affect the gap between gears too much.
Hello. I develop a bicycle gearbox. Let me ask you something. I can make 350-400% center drive at 7 speed. Do you think this specification is enough for mini bello or city bikes? I'm curious about the specifications that consumers want.
The idea of a gearbox for folding bike is interesting.
The range you propose is satisfactory (350 to 400%). The main competition would be internal hub (not derailleur) with a similar range. Three factors, in addition to range, would come into play:
1- Price (the main reason many don’t go for a Rohloff)
2- Weight: An heavy folding bike compromises its portability
3- Power Efficiency: What would be the power efficiency for each gear.
Would the most efficient one (direct drive?) correspond to the most used gear?
@@2Bikes4Adventure Thank you for your feedback.
I am currently developing a 15-speed speed.
I can make a 7-speed speed, but I haven't developed it.
I was curious about the marketability of the 7-speed gearbox.
I'm planning a gearbox to compete with the draylor.
1.The price is expected to be 150-200 dollars.
2. Weight is 2kg or less.
3.Most gearboxes have similar efficiency.
This gearbox won't make a difference either.
The singular of the highest efficiency is unknown.
The structure is the same as the effigear with two axes.
My goal is to release a 15-speed gearbox, but I also plan to release a 7-speed gearbox if there is marketability.
Have a nice day.
@@all-to If the 7-speed gearbox is significantly lighter (and possibly cheaper) than the 15-speed, it would be a good selling argument for a folding bike users. Brompton owners are willing to pay $1000 extra to save 1 Kg on their bike.
@@2Bikes4Adventure All right. Your opinion is...
1.There is a possibility if the price is low.
2. If it is very light, there will be a buyer even if it is expensive.
It's not like there's no way to lower the weight. But I'm not in the condition to proceed right now.
7 speed (360-400%) is the best choice for me, weighing 2kg.
We are investigating whether it is possible to use it for household bicycles, student bicycles, back hub electric bicycles, and mini-bellos.
Thank you for your opinion.
@@2Bikes4Adventure Is it not enough if we make it 300% (33% increase) at 5 speed?
I can also make a gear of aluminum at 5 speeds.
This is not durable, but I think it's possible.
The weight is definitely within 1.4kg.
The price goes up because aluminum gears have to be processed.
I'm expecting 500 dollars.
Dizzying...in a good way,
The rear wheel is noise, slow and left-right deviated. Throw it away and changed to a cheap wheel from other cheap brand.