Brompton gear systems

[Yellow Fang]

I have been having problems with Brompton ever since I decided to replace the sprocket earlier this year. The hub came apart and it took me hours and hours of work trying to get it to function properly again. Even now it's not right. I get it working for a while, then it starts misbehaving again. I am thinking that next year I might get a whole new rear wheel but with two speed derailleur gears rather than hub gears. I think I can get away with two gears provided they're the right ones. I am also considering asking SJS cycles to build me a wheel based on the Sturmey Archer kick shift hub, but I wonder whether this hub is compatible with a Brompton. Would the back wheel lock up as you tried to fold up the bike?

 

[GrumpyGregry]

Couple of guys in the states are using the S2 I think, and I'm sure I read one report of an S2C (with the coaster brake). As it happens I run an S2C on a 700c wheeled bike. They commented you just need to be 'careful' when folding. But is the S2/S2C available in a width that will fit the Brompton rear triangle and if so, will the chainline be the same? Also the size of the sprocket may require a modified tensioner depending on how big you go.

 

[Night Train]

What' wrong with the hub gear? Maybe it can be fixed to make the ride better in the meantime.

 

[Yellow Fang]

It doesn't seem to let me select all three gears, no matter how much I push the little rod in or out. The chain was going a bit slack while coasting - definite sign something is wrong in the hub.

 

[Twanger]

If you've adjusted the indicator rod as per the instructions (1 mm sticking out when you look through the view hole in middle gear - there's a very clear picture in the user manual), and it doesn't work, then there is, as you said, something wrong with the hub. Changing the sprocket shouldn't affect the hub (I have done so on mine, an SRAM, and have had no probs). If the hub "came apart", I'd take it in for servicing. I wouldn't know how to begin servicing an epicyclic gear myself.

Is the lock nut locked, or is the gear cable slipping somewhere or need tightening?

Oh, and are you sure you have the right indicator rod? SA and SRAM use different rods.

 

[SavageHoutkop]

I have much more grief with my derailleur than with my hub, but again it's probably just that I don't care for it enough.
My derailleur doesn't like wet weather much, and I've also just noticed my cable has broken by the hinge (which is probably why it's not changing at the moment).In winter I pretty much ride 3 speed rather than 6. I also am not sure how the derailleur, even if it is working perfectly, would handle riding in snow (as I tend only to have 3 working gears in winter, I've not tried this!).

My hub is now working like a dream. I've never opened it up personally but I have had the bike shop open it up for me when there was noticable chain slack while freewheeling, it's been behaving ever since. Mr SHK's also had the chain slackening off problem but his also rides OK now (I think his hub is busted, personally - it feels rough, but it rides OK and selects all 3 gears). His has always been a harder ride than mine, which is odd as they were bought from the same shop less than a month apart. Neither of us have had gear selection problems though (aside from riding without the gear indicator rod correctly adjusted, of course) - TBH I haven't adjusted my rod in months and months.

 

[Yellow Fang]

If you've adjusted the indicator rod as per the instructions (1 mm sticking out when you look through the view hole in middle gear - there's a very clear picture in the user manual), and it doesn't work, then there is, as you said, something wrong with the hub. Changing the sprocket shouldn't affect the hub (I have done so on mine, an SRAM, and have had no probs). If the hub "came apart", I'd take it in for servicing. I wouldn't know how to begin servicing an epicyclic gear myself.

Is the lock nut locked, or is the gear cable slipping somewhere or need tightening?

Oh, and are you sure you have the right indicator rod? SA and SRAM use different rods.

I've never noticed a view hole - where's that? The lock nut was finger tight, as far as I remember. I've discovered it's not a good idea to overtighten it though. The indicator rod is the same as it's always been.

 

[Yellow Fang]

I have much more grief with my derailleur than with my hub, but again it's probably just that I don't care for it enough.
My derailleur doesn't like wet weather much, and I've also just noticed my cable has broken by the hinge (which is probably why it's not changing at the moment).In winter I pretty much ride 3 speed rather than 6. I also am not sure how the derailleur, even if it is working perfectly, would handle riding in snow (as I tend only to have 3 working gears in winter, I've not tried this!).

My hub is now working like a dream. I've never opened it up personally but I have had the bike shop open it up for me when there was noticable chain slack while freewheeling, it's been behaving ever since. Mr SHK's also had the chain slackening off problem but his also rides OK now (I think his hub is busted, personally - it feels rough, but it rides OK and selects all 3 gears). His has always been a harder ride than mine, which is odd as they were bought from the same shop less than a month apart. Neither of us have had gear selection problems though (aside from riding without the gear indicator rod correctly adjusted, of course) - TBH I haven't adjusted my rod in months and months.

Sounds like I should stick with the hub gears then.

 

[SavageHoutkop]

I've never noticed a view hole - where's that?

Er.. hang on. OK, read your post properly now. Which hub gear do you have - the BWR (i.e. 6 speed) or the Sturmey Archer close range 3 speed?

And while changing the sproket the hub just came apart?!?

 

[Yellow Fang]

Er.. hang on. OK, read your post properly now. Which hub gear do you have - the BWR (i.e. 6 speed) or the Sturmey Archer close range 3 speed?

And while changing the sproket the hub just came apart?!?

It was the Sachs 3 speed, which is part of SRAM now (I think). I think the bike was made between Sturmey Archer going bust and it being bought by SunTour.

The hub didn't fall apart. I undid various nuts and bolts trying to work out how to get the sprocket off.

 

[GrumpyGregry]

My understanding is that the hub dimensions are fine but the 36 spoke drilling is not because it makes getting a pump on the valve very tight.

90 degree adaptor perhaps....

 

[SavageHoutkop]

It was the Sachs 3 speed, which is part of SRAM now (I think). I think the bike was made between Sturmey Archer going bust and it being bought by SunTour.

The hub didn't fall apart. I undid various nuts and bolts trying to work out how to get the sprocket off.

Ah.
Might be worth seeing if a LBS could fix it for you, else perhaps time to get a new hub? Might be worth upgrading to a 6 speed at the same time, if you're inclined. I've had 'brilliant' service from brilliantbikes; and they seem to have the rear (hubbed) wheels in stock; in both BWR and Sturmey flavours. What you can also do is upgrade to the 6 speed, and IIRC you can swap out the rear wheel for one without a hub, leaving you with a 2 speed.

 

[Yellow Fang]

I see Moulton do a kick-shift version of their bikes, i.e. the TSR2. They have small wheels. How many spokes do they have?

 

[Yellow Fang]

Ah.
Might be worth seeing if a LBS could fix it for you, else perhaps time to get a new hub? Might be worth upgrading to a 6 speed at the same time, if you're inclined. I've had 'brilliant' service from brilliantbikes; and they seem to have the rear (hubbed) wheels in stock; in both BWR and Sturmey flavours. What you can also do is upgrade to the 6 speed, and IIRC you can swap out the rear wheel for one without a hub, leaving you with a 2 speed.

I'm not sure I need six gears. Most days I only use two: 1st gear for hills and 2nd gear for everything else. 3rd gear is too high geared even after having a larger sprocket put on the back.

Part the problem is I'm not sure I trust my local Brompton dealer to do a good job. I never rated their know-how before they started selling Bromptons. The local Evans appears to have stopped selling them. The shop I bought it from, who I did rate, closed down years ago. The nearest LBS I trust to do a good job is in Oxford.

 

[GrumpyGregry]

Couldn't you whip the wheel off and send it....