Brompton 6 to 3 speed conversion
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- Опубліковано 5 січ 2025
- Bromptons come in different gear options:
1 speed (discontinued for 2021)
2 speed - 2 sprockets and a derailleur
3 speed - Sturmey Archer Hub gear - BSR
6 speed - a combination of the Sturmey Archer BWR hub and a 2 speed derailleur
Why downgrade?
It partially comes from a question we had about Brompton Electric - can they be made 3 speed
Cleaner look without the derailleur mechanism
Simpler with less gear levers / combinations
Wide range 3 speed compared to the standard 3 speed
Steps
Remove old chain tensioner
Tip - remove tension
Tools required: 15mm spanner
Remove wheel - including fixings and chain tensioner
Here’s a video we made earlier
• Brompton Roadside Rear...
Tip: remove air from tyre so it will fit between the brake blocks
Here's a bit about the inside of the Sturmey Archer hub: • My Brompton is ticking...
Remove old sprocket stackTools required: small flat head screwdriver
Tip: Whenever you change your sprockets - change your chain
Clean wheel - inside to get warm!
Install new sprocket stack - QRSPRSTACK-BWR3
Remove chain pusher etc
Shorten chain
Use chain link pliers - to remove the master link
and chain tool to cut two links outRejoin the chain
Link to chain choice and installation: • Brompton chain install...
Install wheel
Install new chain tensioner and set up gears
Hub gear setup: • Brompton hub gear setu...
Remove gear shifter
Get out and ride (when the snow stops)
As a person who makes videos, I have to say that the way you explain and exhibit quite tricky bits with crystal clarity is a testament to your considerable skills.
Thank you so much. We enjoy making them so think that helps!
The dry humor in this video is simply fantastic.
The man behind the camera, is by all accounts, a legend!
I have just brought my Brompton to the Danish and very hilly island of Bornholm, and I loved all my 6 gears, and had to walk once in a while! So I definitely don't intend to loose any of mine! 😁
Fabulous commentary. Makes me want to listen to you all day, plus I actually learn a few things.
Thank you! And thank you for watching!
Very informative and fun.Thank you. Would suggest a video on converting a 6 seed to a 9 speed. Also, how to change the gear and brake cables.
I love brilliant bikes . They ship the items really quick 😋
Glad everything arrived quickly. Thanks for watching.
I love the Brompton tree and I love your videos, keep them coming!
I did two talkie videos today, I hate talking on film but your bloopers inspired me! Thanks x
That's a compliment by the way!
My wife has asked me to convert her 6 speed to a 3 speed. I have delayed this action, informing her Brompton trees are currently out of stock. Seriously, an excellent, informative presentation.
Thank you so much for your comment and for watching! Good luck with the conversion, when the trees come into stock and grow enough 😊
Lovely sense of humor! I was bit confused though regarding the. Brake lever sNs gear shift. It looked exposed.
Update: I have successfully converted my M6L into wide-range M3L. Thank you so much 🙏🏼 Your videos are treasures!
So glad it helped! Thank you for watching!
Another great presentation 👍
I had a 6 speed with rack and lights and dynamo etc etc but for the past 13 years my 3speed has done everything and is just lighter and simpler .. leaner meaner 😀
Love your videos guys
Thank you
Thank you for your comment and for watching!
Thanks Ms Brompton when you have fun we all have fun, so keep on doing what you do 👏🏽
Thank you for making me smile!
Definitely food for thought. BTW I noticed that the bike has the Continental tyres. Very polite reminder, still waiting for a long term review.
Thanks for the reminder!
I changed my chain and sprockets this afternoon on my H6L, with replacements bought from you. (aka bromptonautie).
I read that as "Bromptonauntie" and thought, " Aunty Hannah with her Park Tools Spanner " has a certain ring to it.
@@devjon123 🤣🤣🤣
I do love the brompton tree!
Please make one on converting it back to a 6 speed, complete with a fresh cable 😊
Been binge watching brompton related bikes and hopefully when I get to save enough, I can go back home and buy one since I found out there's none in the UAE but we have in Philippines!
This raised some happy memories from my early experimental days mucking around with bikes....the cyclo Benelux unit! Who remembers this ? It was a single block of three sprockets that simply keyed onto the driver unit of your three speed s.a. hub , converting it to a nine speed system. Of course, derailleurs are a bit of a phaff , I'm not a fan, it's not too far fetched to say epicycling can save the world (!). I wonder would the excellent Shimano Alfine 8 or 11 speed hub be a dream upgrade? I suspect their increased width and diameter may preclude them .
I am trying to work out why taking the derailleur OFF is necessary..(?)... when you could not just not USE it. Moreover, with the equipment still fitted to the bike, you could change you mind about which set of three gears are NOT being used at any one time!
And once again, thanks for sharing the bloopers. Hilarious. Humor in pure form!
Thank you! Glad they make you smile
Thanks!
Wow thank you sooooo much we really appreciate this, thank you!
You're welcome! I had a 3 speed brompton but unfortunately I slipped on some water and later ended up getting brain surgery and got rid of my bike, but I'm buying another one!😂 And I was wearing a helmet. Thanks again for the instruction.@@brilliantbikes
Thanks for all your informative and humorous content! Bromptons , BMX race, track( not 1-1/8”)and other single speed bikes all use a 3/32” chain . Maybe there is a shortage of all 3/32” chains? I have used a BMX race chain ( KMC Z610HX) for a 54t chainring conversion and it works the treat .:)
Another great video guys, you always make clear well explained content which are a great help to non technically minded people who unlike myself may find maintaining their bikes a bit daunting. In regards to this video, if the rear sprocket size didn't change, Why would one need to buy a sprocket kit just to use the spacer or are they not available to buy individually?
keep up the good work. You're not far away from myself but we have had no snow in the last week, strange indeed.
...definitely a nice idea and good to know... Unfortunately I m pretty much used to the fine-tuning of the derailer... especially while riding uphill... also the advantage of changing, at least one gear without losing momentun!
TBH I’m a 6 speed girl, the cameraman is a 3 speed and dislikes the derailleur. Hence the upgrade for him and others like him.
Thanks for watching!
Lovely presentation as usual. Like jour sens of humour. Charminvg.
Your videos are informative. always make me laugh on the last part :D
Glad you like them!
And thanks for the kind comments
Thank you so much for this video!
Thank you so much for watching!
Excellent teacher!
Good job as usual
Love these videos!
Please do a review on Ergon "horn" grips. I tried one on a demo bike at my local Brompton Junction and it was a great experience.
Great idea! And one we will add to the list. Thanks for watching!
Which Ergon grips did you try?
@@brilliantbikes Not quite sure but it might have been the GP2 (the demo Brompton' Ergons had relatively short "horns").
Do u need a special bush to hang your bike or will any bush do ? Very informative 👍🏻
Sounds like an idea for a limited edition 😊
Well done. Great detail
Thanks
Thank you so much for your video💕
I have a desire to do exactly as you've done. But why can't I just leave the two sprockets on along with the stock OEM derailleur?
Will the chain just continue to ride along either the 13T or the 16T without flopping back and forth on their own? My preference would
be to use just the 16T so I'm able to still do hills. I really don't need the speed.
Very informative. I am a fan of internally geared hubs for durability and low maintenance. I personally am comfortable with the wide 3-speed gear ratios for road and utility riding and wouldn't miss the 2 speed derailleur for "normal" riding. Is there something unique about the chain's Brompton produces that precludes the use of another available brand of chain?
What about doing a inspection on a older Brompton. my one was purchased second hand in Sydney Australia and is a September 2006 model.
Excellent 👍🤣 Love the outtakes too.
I wish I had the opportunity to show my "Project 8" Brompton that I made after learning to build wheels.
Now that sounds cool!
Loved the intro
And, for less weight, it is possible to buy a set of titanium nuts also for the gear hub and front axle. As I weigh a 100 kilo, it really is just for fun!
Thanks so much for watching! It is fun upgrading the Brompton’s 😀
If I’m not wrong the standard three speed model has a diferent gear ratio than the one used at the six speed
Thanks for watching
Yes - the standard 3 speed is a closer ratio - for me (the person with the camera) I like to combine the simplicity of the 3 speed with the extra ratio of the wide ratio
There is a great gear ratio calculator here:
xldev.co.uk/bgc.html
Yep, I had a 3 speed b75, ratios are closer together and as a result the bottom gear whirrs a lot less. I upgraded it to 6 because I live on steep hills so got to compare both hubs on the same bike. Not sure I’d want to run that wide hub without the 2 sprockets though
I have a 6 speed but never really use the derailleur bit, as it seems more temperamental than its equivalent on my 2 speed for some reason. I just leave it in + and use the hub shifter. So I might as well shift to 3 speed instead. My 6 was bought from someone who lived in a hilly area, so has the smaller 44T at front. Would this have an effect if combined with a change to 3 speed? Provided parts were available (and that’s a big if at the moment), I’d bring it into you guys to do the work.
Dancing 'round the Brompton Tree.
😀. Thanks for watching
@@brilliantbikes Thanks for making great informative Brompton content! It has taught me a lot.
Enjoyed the humour 😊
Many thanks! We do have fun making them 😀
Presumably, the same procedure could be used to fit a [new] wide-ratio rear-wheel to an existing 3-speed Brompton? I'm not too bothered about removing the derailleur from my 6-speed electric Brompton [although I very rarely actually use it - only occasionally when wanting to change down a tad going uphill and not wanting to take pressure off the chain to change down the Sturmy Archer] but I would really like the wider ratio on my older 3-speed manual Brompton.
Thanks for watching
Yes - that's actually even easier
A new (wide ratio) 3 speed wheel - with a BWR-3 sprocket stack can be changed directly for the standard ratio wheel
I always run my Brompton like this - for the wider ratio!
@@brilliantbikes Ordered, received, fitted...and all good! (If we ignore the fact that I initially set my hub gears up *thinking* I was in 2nd gear but was actually in 1st - you'd think after 50+ years of setting Sturmey-Archer gears up I wouldn't make that mistake LOL)
Where can one buy that frog?
Everybody should have a Brompton-🌳
Some of us have two LOL.
so if i were to convert my 2011 single speed brompton to a 3 speed, all i would need is a new rear wheel with a bwr 3 speed hub, indicator chain, gear cable & housing, and a rh shifter?
but if i were to go further and convert from that to a 6 speed, would i then only need a 2/6 speed chain tensioner, lh shifter & gear cable, and the other derailleur parts??
Thanks for watching! Yes the three speed you just need to add the hubs gearing. The 6 speed both hub and derailleur gearing
Good work, wearing gloves no less.👍👍⚡️
Thank you!!! And thank you for watching!
Brillant !
Thank you!
Would u consider making a post-2017 brompton 3 to 6 sp upgrade please? Thank you!
Great idea! Thanks for the suggestion!
I have an M6R. Just wondering if the 3 speed Sturmey Archer hub can be replaced with a 6, 7, or 8 speed hub, eliminating the derailleur? I'm sure that a new shifter would be needed but this would be an interesting modification.
You can use the 5 speed relatively easily as the axle length is the same, so it’s a case of relaxing the wheel and a new shifter.
So... you wanted the same width in gear ratios but without the derailleur, yes? I guess bigger gear jumps, yes? Not arguing, just clarifying.
Thanks
Great. Apart from tidiness, is there any reason to replace the chain tensioner? Couldn't you just set the limit screws on the sprocket pusher, and then remove all the cable, spring, etc?
Many thanks for the question. Yes in theory to make sure the roller wheels don’t slide then yes you could adjust the limit screw.
i wonder how much lighter is the bike now? I want to upgrade to the new 5 speed SA IG. The most thing that bothers me is that it is 150-200 gram heavier than BWR 3 speed...
Two questions: firstly isn't there any other after market chain you could use? Secondly isn't there any internal gear hub to get the simplicity of a single speed but with the range of the six speed?
Thanks for watching
Great questions
Yes - there are other alternatives - we were planning on trying a KMC 8 speed "non-rust" which sounded ideal - but haven't got around to it yet
We also used to have a 5 speed SRF-5(W) - wide range 5 speed - which gave a great range - we are about to re-create one!
@@brilliantbikes when you do re-create the 5 speed please show us
There are some people putting 8 speed hubs on their Brompton, but you have to widen the rear triangle to make it fit. With some aftermarket rear triangle, you can use a 14 speed German hub.
Could the two rear gears be left in place and only the chain tensioner changed and still have the same effect?
So, this reduces the overall gear range by removing the larger sprocket, thus losing the lowest gear ie it is now harder to cycle uphill? As an alternative, can one fit a single 16 tooth sprocket - which would keep the lowest gear, and would also make shortening the chain unnecessary?
Yes.
Hi i am from malaysia, can i buy the wide ratio hub from your web?
well done!
Thank you - and thanks for watching :-)
It makes us feel like our time was worthwhile
Are all the Brompton 3 speed hubs the same? I now have a 2014 M3L. Is this the same ratios as the new 3 speed hubs?
Thanks for watching!! It depends what you are comparing to, the A line will still be the same as the BSR three speeds, but these are different to the BWR 3/6 speed. The following might help
Brompton 3 to 6 speed upgrade - is it possible?
ua-cam.com/video/RGPrueyTFAY/v-deo.html
@brilliantbikes Thank you and Merry Christmas 🎅
Hi may I know what is the thickness of the spacers?
I changed from 6 speed to 3 speed and there’s only one spacer, resulting in free play grinding.
what are the grips on this bike? would look great on my black edition frame lacquer m6!
Are nut caps an aftermarket addition? I’ve noticed my 2-speed electric didn’t come with any nut caps.
They are new-ish on new bikes and available as an after market addition as well
How much weight does this conversion save? I'm desperately trying to lighten my M6L
Many thanks for watching! It will be very little weight saving, as the wheel is the same, it’s just the chain tensioner and one sprocket.
Thanks@@brilliantbikes I suspected as much. May have to consider going from 6 to 2 speed and changing the rear wheel.
Always precise and clear. In fact, even with three gears the brontom travels very well.
When do you make a video with the sun? 🤔 😎🌞
Thank you for taking the time to watch and comment so kindly
Actually - today was warm (for us compared to the last two weeks) - +12C!
We love riding in warm weather - like this photo from close by Pisa - when travel was easy
instagram.com/p/CKTa_w3A7ER/
so you dont have to change the wheels with the 3 speed and still use the existing 6 speed wheel?
That’s correct. Many thanks for watching and the comment
Can you please do a video going from 3 speed to 6 speed?
Thanks for the suggestion, it’s a really common question, it’s on our list. We did do one about why it needs a new wheel, link as follows:
ua-cam.com/video/RGPrueyTFAY/v-deo.html
Thank you for watching and we will do it soon (ish!)
Hi , When I bought my 3 speed I changed the chainring to a 44 Tooth for better climbing. I think I’d like to go even smaller and saw a 40 tooth that you have to shorten the chain for. I have a 2012 . Have you had any experience with this switch ❓
No so sorry no experience with a 40tooth, but the chain still needs to be shortened when changing from 50 tooth to the 44.
So in practical terms you lost your lower end gears. It's the same as riding a 6 speed Brompton with the left shifter always on (+).
Can't you use only the larger cog on that mod instead, so you get the lower gears?
I don't think you lose the lower-end gears - I think you lose gears 1, 3 & 5 and keep 2, 4 & 6.
@@frankhooper7871 yes. Let me rephrase that. You loose the lowest gear and the steps between gears are higher (in theory, because in the real world no one ever does that mambo jambo to go through gears on e 6 speed Brompton).
But my question remains unanswered: can I use only the large cog on this same mod, so I get to keep the lower gear?
@@MrBaptista I concur with you 100% as I wonder the same. In fact, can one just leave the 2 rear sprockets on and utilize the same derailleur while looping the same length chain onto the 16T gear? Alleviates having to buy extra gear, spacers, and new fixed derailleur. Not to mention shortening the chain. In the meantime it still gets a makeover and cleanup by removing the cable, shifter and all the derailleur adjustment goodies. Now let's hope for some answers @MrBaptista
I don't understand why we need to shorten the chain. Old and new sprockets are the same 13 teeth. The chain tensioner is taking up the same slack. Surprised nobody noticed this!
Thanks for watching and the comment
The original was a 6 speed sprocket stack with a 13/16T combination
The new is 3 speed single 13T sprocket
So the chain is based on the largest sprocket in use - we went from 16T to 13T - so need a shorter chain
We hope that makes sense?
Could I also just use the old 16 teeth sprocket instead of the 13 ?
Or just leave the old double sprocket and the old chain tensioner?
Could you find a workshop with good lighting out of the cold
Lol the lighting just is not good enough!
@@brilliantbikes And not so fun for us to watch you shivering
Can you use the 16T with the 2 spacers instead of the new 13T sprocket?
This is really useful, this is something I've been wanting to do since getting the bike as I regularly just use the + Gears and quite like the simplicity of just the 3 gears. Am I right in thinking though that by changing to a single sprocket and removing some chain links that the resulting gear ratio is slightly lower? Would it be possible to post what the gear ratio would end up being for this build? Ideally I'd like to replace with the 3 gear chain tensioner but kind of leave the sprockets alone, will the 3 gear chain tensioner work with two sprockets (with the chain on the + sprocket)?
That`s what I had in mind also. Did you every proceed with this project? If so, what did you do?
Is the 3 speed, runs on (+) 1,2,3 of the 6 speed or the (-) 1,2,3?? Tkq n look fwd to ur reply. Appreciated.
Very informative and entertaining hehe
I want to do this, I have a 6 speed but found I rarely use the derailleur. Could you use the original tensioner?
I ordered the bits and did it! Thanks.
Great video, well made and very informative. But must ask WHO is the person behind the camera? all 10.9 subscribers need to know!!! keep Safe!
Thanks for watching! I think his camera shy!
@@brilliantbikes LOL!!!
I have had a 6 speed Electric Brompton since last October. I found it under geared so have upgraded to the larger crank chain ring and longer chain. I really find the swapping between the two gear mechanisms fussy and would far prefer to either downgrade to 3 speed or even better upgrade to a 5 speed hub - I found this summary of ratios that are possible. docs.google.com/document/d/1f6iOsBHb0bdkGBxkYGA0J4Sg-LCvrIFPdL8HDpOTYmk/edit Has anyone direct experience of going to 5 speed in the hub?
Very helpful summary, thanks for sharing it! I saw some reviews of 5-speed hub on SJS website, all of them positive. I wonder why Brompton doesn't offer that option as standard? Guessing hub cost is an issue.
Hello my friend, I want a brompthon, is really really really jajajaja a good bike..?????? Respect and love from Chile
You should be on telly😃
Many thanks - UA-cam the new telly 😊
Bromptons grow on trees!
Can we meet the Man behind the camera one day, not as good looking as you I’m sure but would be nice to put a face to the name.
Let’s see if he can make a guest appearance!
I like everything about the Brompton apart from its stupid anachronistic gearing. The last time I used a 3 speed hub was on my Raleigh Chopper when I was a kid. Bromptons should have 10 speed cassettes, a rear derailleur and quick release wheels.
Advantages of the Brompton 6 speed setup:
1. As the hub mechanism gears up, a high gear can be achieved without recourse to large chainrings and/or very small sprockets.
2. The range is very wide.
3. There are evenly spaced small steps if using all 6 gears sequentially.
4. Or you can get much larger steps by just using just the hub gear change. You can then finely trim the gear using the derailleur. In fact a lot of people use the gearing that way.
5. The hub gear can be changed when stationary. Very useful when you pull up to traffic lights or if you have to stop suddenly.
6. The derailleur mechanism for a wide range 10 speed cassette would be very close to the ground.
7. The Brompton fold requires a narrower hub than derailleur geared hubs (especially 10 speed!)
8. The wheel does not need to be dished
9. As the 3 speed hub uses only one epicyclic arrangement the inherent losses of epicyclic gears are minimised whilst still giving a large range with even steps.
10. Anachronistic? I prefer to think of it as esoteric. And very Brompton.
Quick release would be nice but it ain't going to happen.
Seems a tad ridiculous to take the time and effort to get rid of the derailer and the two cogs.
Not really. 6 speed can be a bit much for Urban use with limited hills!!