SavageHoutkop
Veteran
- Location
- South Manchester-ish
Warlands? They were the ones that opened up my hub.
Brompton gear systems
- Thread starter Yellow Fang
- Start date
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Warlands? They were the ones that opened up my hub.
OP
OP
Yellow Fang
Legendary Member
- Location
- Reading
That's the one.
Night Train
Maker of Things
- Location
- Greater Manchester
I have opened and repaired my Sachs 3 speed with no major issues. Mine wasn't shifting properly and slipping catching the wrong gears.
I found the little bar that the indicator chain screws into was cracked and then broke in half and the pawls for the freewheels inside were sticky.
I gave the hub a good clean and reassembled with a new part to replace the one that broke.
It now works fine.
To adjust the indicator chain you should have a black block of plastic on the end of the cable. It has a little metal trigger that catches the thread on the indicator chain.
Disconnect the indicator chain from the plastic block by pressing in the metal trigger.
Select 3rd gear on the shifter.
Insert the indicator chain into the plastic block, it should ratchet against the metal trigger. Stop when the slack in the indicator chain is almost all gone.
In third the chain should be just snug but not pulling and this should then work fine. If there is still a shift problem adjust the indicator chain, by only 1 or 2 threads in the plastic block, in either direction.
I have uploaded the Brompton manual. Gear adjustment is on pg15.
I found the little bar that the indicator chain screws into was cracked and then broke in half and the pawls for the freewheels inside were sticky.
I gave the hub a good clean and reassembled with a new part to replace the one that broke.
It now works fine.
To adjust the indicator chain you should have a black block of plastic on the end of the cable. It has a little metal trigger that catches the thread on the indicator chain.
Disconnect the indicator chain from the plastic block by pressing in the metal trigger.
Select 3rd gear on the shifter.
Insert the indicator chain into the plastic block, it should ratchet against the metal trigger. Stop when the slack in the indicator chain is almost all gone.
In third the chain should be just snug but not pulling and this should then work fine. If there is still a shift problem adjust the indicator chain, by only 1 or 2 threads in the plastic block, in either direction.
I have uploaded the Brompton manual. Gear adjustment is on pg15.
OP
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Yellow Fang
Legendary Member
- Location
- Reading
I had another go at it last night, but it's no better. It's not changing gear at all now. I suspect the sliding rod may be broken. I find one of the problems is that you just don't know how tight to screw everything up.
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Yellow Fang
Legendary Member
- Location
- Reading
1625771 said:
There's a version of the S2 (without the coaster brake) which has 32 spoke drillings, but annoyingly it only comes in the larger size, There's a smaller size with an Over Locknut dimension of 110mm that looks like it might fit on a Brompton, but it seems like that version only comes with 36 spoke drillings.
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Yellow Fang
Legendary Member
- Location
- Reading
I see the Sturmey Archer S-RF5(W) comes with a 148mm axle and a 111mm over lock nut width. It comes with 28 spoke drillings too.
I emailed Sturmey Archer's European office about the S2 duomatic spoke drillings issue. It worked with Schmidt and their SON XS dynohub for the Brompton.
I emailed Sturmey Archer's European office about the S2 duomatic spoke drillings issue. It worked with Schmidt and their SON XS dynohub for the Brompton.
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Yellow Fang
Legendary Member
- Location
- Reading
It looks like the Sturmey Archer S-RF5 is a bit temperamental. So I'll drop that idea. Sturmey Archer say they have no plans to introduce a duomatic with 28 spoke holes, but just because the shell has 36 spoke holes doesn't mean you have to use them all, does it? Presumably you could still build a wheel with a 28 hole rim and a 36 hole hub.
Night Train
Maker of Things
- Location
- Greater Manchester
You could but spoke measurment would be a bit hit and miss. It might mean some spokes needing to be filed down a little and others showing threads.
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Yellow Fang
Legendary Member
- Location
- Reading
I'm going off the duomatic idea too. The gear ratios are 100% and 138%. I believe the gear ratios on my old hub were 75%, 100% and 133%. I rarely used 3rd gear (133%) because it was too high. I used 2nd gear most of time with 1st gear for hills. To fit a duomatic I'd either have to fit a much bigger sprocket or a smaller chainwheel, and both of these are quite new. This factor is putting me off the two-speed derailleur system too.
A couple of people from the Yahoo Brompton group have installed an S-RF5 hub in their rear wheel. I gather from other cycling forums that the S-RF5 is difficult to set up, tends to slip and requires lots of tweaking with the adjustment rod. I wonder if that's just the case for the narrower hub or for the wider hub too.
Edit: a potential way of getting around the gear adjustment problem is to install a barrel adjuster on the gear shifter.
A couple of people from the Yahoo Brompton group have installed an S-RF5 hub in their rear wheel. I gather from other cycling forums that the S-RF5 is difficult to set up, tends to slip and requires lots of tweaking with the adjustment rod. I wonder if that's just the case for the narrower hub or for the wider hub too.
Edit: a potential way of getting around the gear adjustment problem is to install a barrel adjuster on the gear shifter.
Crankarm
Guru
- Location
- Nr Cambridge
Forgive me for being blunt but it looks like you should take your wheel and hub to some one who knows what they are doing .................... Talking about getting alternative hubs, gear systems might be a waste of money and time when the solution might be a lot simpler and cost effective by getting some one to look at your existing one and repairing/servicing it for you. Reading to Oxford is not so far.
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Yellow Fang
Legendary Member
- Location
- Reading
Could do, Warlands would do a good job. OTOH I could get a whole new back wheel from SJS cycles. I am not sure what rim life Brompton wheels have, but I've had the bike for about eight years now.
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Yellow Fang
Legendary Member
- Location
- Reading
The new wheel arrived. The Sturmey Archer is physically much larger than the old Sachs hub. Annoyingly, it looks like I will have to send off for another part because the gear anchorage for a Sachs is different from a SA hub.
I notice the new wheel has a wear indicator groove in the rim. The tyre seems to go on much easier too. I recently switched over to Brompton Green tyres because they're easier to change than Schwalbe Marathons, but I bet even changing Marathons would not be so hard on these rims.
I notice the new wheel has a wear indicator groove in the rim. The tyre seems to go on much easier too. I recently switched over to Brompton Green tyres because they're easier to change than Schwalbe Marathons, but I bet even changing Marathons would not be so hard on these rims.
Roger Saunders
Regular
- Location
- Utley
I had terrible trouble with my SRAM hub. Eventually took it apart sufficient to soak away oll the gunge in an oil bath then reassembled it with clean car oil as a lubicant. It is better than new now!
The problem was muck salt and grit which had got in during the bad weather.
The problem was muck salt and grit which had got in during the bad weather.
Spares for the Sram are not normally available but a new internal assembly is, and this is very easy to fit if your LBC does not understand hub gears. the Sram is a very effective unit: Heinz Stucke who has ridden around the world several times used them because he reckoned to get 50000km per unit despite carrying up to 70 kg load!
Roger Saunders
Regular
- Location
- Utley
You can buy the wheel bearings too.
