Brompton gear upgrade

[srw]

My classic 3-speed Brompton is beginning to get a bit tired. The gear feels as if it needs a good clean, and the aluminium rack has snapped. Now that I'm working in London much less I'm tempted to convert it from a pure commuting folder into a commuting-touring hybrid folder - with half an eye on the Fridays' tour and my irregular trips to Munich. Unlike some people (mentioning no names) I don't particularly fancy touring on a 3-speed.

Mrs W didn't sound impressed when I suggested getting a second Brompton, so I'm looking at the various upgrade options from Tiller or Kinetics. Does anyone have experience of any of them? I know various people (@GrumpyGregry, @Trikeman) have bought ready-converted bikes, but both Tiller and Kinetics are in geographically inconvenient places. And I'm not ready to engineer my own solution just yet.

I was reading one of the pages provided by one or other of the suppliers, which claimed a 30-minute conversion time. That sounds somewhat optimistic..

 

[velovoice]

Tiller Cycles, hands down. Kinetics was a nightmare: you can read about my experiences and those of the blogger at Pedalitis (and read the comments). Pedalitis Bob and I both had lots of problems with Kinetics, needing all sorts of modifications to get it to work. One of his readers ditched Kinetics for Tiller and found it worked great. Bob soldiered on with further modifications to the Kinetics kit and ended up happy with the result. I ditched Kinetics altogether for the JTEK 3-speed conversion kit from SJS Cycles. It doesn't have the same range of course but it's much lighter than Brompton's 3-speed system and works very smoothly. In fact.....

We're going touring in Provence in June and the Brompton is the bike I'm taking.


ETA: The Kinetics 8-speed rear wheel and hub is unbelievably heavy.

 

[GrumpyGregry]

As I recall, Greg bought a single speed and a kit to do the job.

True dat! Kinetics. Plug'n'play. Worked fine from the off. Still works - or did last time I was in sthlm.

The Kinetics 8-speed rear wheel and hub is unbelievably heavy.

I was aware of the weight. It doesn't stop my carrying Rhubarb the sorts of distances I need to carry him. But I am what some people call 'a big unit'.

 

[GrumpyGregry]

I was reading one of the pages provided by one or other of the suppliers, which claimed a 30-minute conversion time. That sounds somewhat optimistic..

Kinetics takes about two hours ime, and you need replacement grips.

 

[srw]

Kinetics takes about two hours ime, and you need replacement grips.

I see that @velovoice and Pedalitis went for the SA 8-speed, which doesn't require a frame adjustment. Is yours the same SA model or the Shimano alfine version, which does? Kinetics supply a replacement rear triangle, while Tiller (which, having looked at a map is less geographically inconvenient than I thought) bends the frame.

 

[GrumpyGregry]

I see that @velovoice and Pedalitis went for the SA 8-speed, which doesn't require a frame adjustment. Is yours the same SA model or the Shimano alfine version, which does? Kinetics supply a replacement rear triangle, while Tiller (which, having looked at a map is less geographically inconvenient than I thought) bends the frame.

SA, no frame bending needed. Just drops straight in.

 

[Flying Dodo]

Re the conversion, I think about 2 hours was right for the length of time it took to upgrade @velovoice 's Brompton. Less than an hour for the actual work, and at least an hour to understand the instructions!

That Brompton is now 3 speed again, courtesy of the cheap & specifically light weight J-Tek wheels sold by SJS. The 8 speed Sturmey Archer hub is now on my converted flat bar Bickerton. Even with the extra weight from that wheel (1.5kg), the bike still weighs less than a Brompton! And slightly off topic, I think they must have spotted me cycling around on it, as they've decided to bring back the classic design, but updated like mine (although I wouldn't want a rear dérailleur).

 

[CopperBrompton]

Tiller offers a collect-and-return service at a good price – that's what I was going to do until he offered me a deal on an already-converted new bike made for a customer who went AWOL. I can't recommend the SA-8 highly enough: the combination of close-range gears and twist-grip shifting is a joy.

It is heavy, it's true, but the beauty of a Brompton is you never have to carry it more than up/downstairs. The rest of the time, use the Easy Wheels if it's a smooth surface or just unfold and wheel otherwise.

 

[PaulM]

I bought my upgrade kit from kinetics, and yes I had to wait a bit. It works well. Yes, you do need to check clearance of the swing arm and the chainset, and the modified rear derailleur and the rotary gear adjuster on the hub, but simple enough to fix I think if needed. I agree with what Trikeman says, much better gearing and shifting at the penalty of a bit more weight. I'm not a Brompton enthusiast but it's a good upgrade. Heaven knows why the factory doesn't supply it as an option.

 

[srw]

So the consensus is that the SA 8-speed conversion works well, but there's disagreement about whether Kinetics is a reliable supplier. At £395 it's decent value for a 325% gear range (according to Kinetics, for the X-RF8(W), which I think is the version that GG has got). The Shimano Alfine is either 309% or 406% depending on whether you get 8 or 11 speed, and you're paying about £100 to £300 more and have to bend or replace the frame. Which, in my book, are decent reasons not to go down that route.

Tiller cycles is recommended by you lot, but his website (http://www.tillercycles.co.uk/index.html) is discouraging of new customers and he only appears to offer the Alfine versions these days rather than the SA versions.

According to a random calculator online the standard Kinetics kit offers a lowest gear roughly equivalent to a 1:1 ratio derailleur on a 700c wheel. Which is pretty damn good - lower than my lovely titanium bike with a triple but not quite as good as the tandem's wall-climber. I'm less bothered by the top end!

@GrumpyGregry - I can't find your gallery referred to in this post:
N+1 Got my brompton this afternoon

Can you direct me to it, please - or post a couple of Scandinavian photos?

Thanks all - food for thought! I'm reasonably capable of getting things right if I take them slowly. If I didn't do this upgrade myself I'd be looking at laying out £200 or so to replace grips, rebuild rear wheel (second time inside a year) and a general service.

 

[PaulM]

The direct bottom gear of the X-RF8(W) is a real joy. I pedalled up a long hill in it tonight and it felt wonderfully efficient.

 

[GrumpyGregry]

Try these, apologies for the poor quality of some....

https://www.cyclechat.net/media/users/grumpygregry.5193/albums

 

[GrumpyGregry]

So... it is all a bit heath robinson, and I think a little undergeared for me tbh, but it works. I no longer use the Brompton folding pedal btw, I've gone over to the MKS swappable jobbies.

Edit. The chain does sometimes catch on the triangle when folding indicating the crank is about 1mm to far inboard and not flat as it doesn't do it every time. I live with it.

 

[GrumpyGregry]

@srw be warned the crank on the folding pedal side is not a thing of beauty. Basically he reprofiles it with an angle grinder.

 

[CharlieB]

The 8 speed Sturmey Archer hub is now on my converted flat bar Bickerton. Even with the extra weight from that wheel (1.5kg), the bike still weighs less than a Brompton! And slightly off topic, I think they must have spotted me cycling around on it, as they've decided to bring back the classic design, but updated like mine (although I wouldn't want a rear dérailleur).

I quite like this, though, @Flying Dodo …