Brompton slipping only in second hardest gear

[carrotmash]

Hi all,

I would be really grateful for any input on the below issue.
As a premise, I ride a 1992 5 speed brommie with the original sturmey archer hub. It’s a solid bike that meets my needs. And yes it’s super old but I can’t afford a new one now and this one works 90% of the time.
Also, I’m not a bike expert, but my local bike shop has given up even taking a look at the issue as they think the bike is not worth their time cos I won’t buy one of their new ones.

For the past two weeks or so it started slipping only in the second hardest gear, only under load so can’t reproduce by moving pedals only. Sadly I can’t ride it in the very hardest for very long or it starts making horrible squeaky sounds, I was advised it’s a worn component but the parts are hard to come by now, so I just don’t bother.
It doesn’t slip with any of the easier gears, but it makes for a very slow ride to cross London on those!

Things I have tried:
Cleaned and regreased the chain
Cleaned the sprocket, chain tensioner and derailleur.
Tightened the gear cable at the indicator.

Bear in mind I’m no bike expert and I might not have done any of the above perfectly.. but was at least going to try.
Sadly has not made any difference.

Keep thinking it can’t be the hub if it only slips in that one gear! At least I really hope it isn’t.
I’m at a loss, any suggestions?

 

[rogerzilla]

Hi all,

I would be really grateful for any input on the below issue.
As a premise, I ride a 1992 5 speed brommie with the original sturmey archer hub. It’s a solid bike that meets my needs. And yes it’s super old but I can’t afford a new one now and this one works 90% of the time.
Also, I’m not a bike expert, but my local bike shop has given up even taking a look at the issue as they think the bike is not worth their time cos I won’t buy one of their new ones.

For the past two weeks or so it started slipping only in the second hardest gear, only under load so can’t reproduce by moving pedals only. Sadly I can’t ride it in the very hardest for very long or it starts making horrible squeaky sounds, I was advised it’s a worn component but the parts are hard to come by now, so I just don’t bother.
It doesn’t slip with any of the easier gears, but it makes for a very slow ride to cross London on those!

Things I have tried:
Cleaned and regreased the chain
Cleaned the sprocket, chain tensioner and derailleur.
Tightened the gear cable at the indicator.

Bear in mind I’m no bike expert and I might not have done any of the above perfectly.. but was at least going to try.
Sadly has not made any difference.

Keep thinking it can’t be the hub if it only slips in that one gear! At least I really hope it isn’t.
I’m at a loss, any suggestions?

Is it the Sprinter 5 speed, with a single trigger for shifting? It may just need the internal clearances resetting (RH cone screwed right under finger pressure, then backed off between 3/8 and 5/8 of a turn, ideally 1/2 turn, so the lock washer will fit back over it).

The full list of possible faults is:

Jumping in fourth gear

Kinked or stiff gear cable - Replace or lubricate cable.
Twisted indicator chain/catching gear selector pulley - Replace indicators/Re-align gear selector pulley.
indicators not screwed in fully - Screw in fully.
Worn gear ring splines - Replace gear ring.
Worn gear ring pawls - Replace pawls and springs.
Weak or sticking gear ring pawl springs - Clean the hub, lubricate and/or replace pawl springs.
Worn secondary sun pinion - Replace secondary sun pinion.
Worn or ineffective gear selector key - Replace gear selector key.
Worn driver pawls - Replace pawls.
Worn right hand ball ring ratchet teeth - Replace ball ring.
Tight or weak clutch spring - Clean the hub and fit new spring.
Incorrect right hand cone adjustment - Re-adjust the hub
Worn clutch washer - Replace.
Worn clutch - Replace.

There is a SA repairer who advertises on eBay
and probably has parts. A 3 speed AW mechanism will also screw into the shell, I think. They are two a penny, and so are 3 speed triggers.

 

[carrotmash]

thanks so much, this is very comprehensive and helpful!
The hub is a Sturmey Archer 5 Star Gear System with two triggers.

I noticed today that the gear wasn’t slipping as much as usual (thought that’s likely to be fluke), and also it makes a clunking sound when it slips, almost as if it was coming from the bracket/pedals.
Would that point towards a more specific source for the problem?

Thanks again!

Is it the Sprinter 5 speed, with a single trigger for shifting? It may just need the internal clearances resetting (RH cone screwed right under finger pressure, then backed off between 3/8 and 5/8 of a turn, ideally 1/2 turn, so the lock washer will fit back over it).

The full list of possible faults is:

Jumping in fourth gear

Kinked or stiff gear cable - Replace or lubricate cable.
Twisted indicator chain/catching gear selector pulley - Replace indicators/Re-align gear selector pulley.
indicators not screwed in fully - Screw in fully.
Worn gear ring splines - Replace gear ring.
Worn gear ring pawls - Replace pawls and springs.
Weak or sticking gear ring pawl springs - Clean the hub, lubricate and/or replace pawl springs.
Worn secondary sun pinion - Replace secondary sun pinion.
Worn or ineffective gear selector key - Replace gear selector key.
Worn driver pawls - Replace pawls.
Worn right hand ball ring ratchet teeth - Replace ball ring.
Tight or weak clutch spring - Clean the hub and fit new spring.
Incorrect right hand cone adjustment - Re-adjust the hub
Worn clutch washer - Replace.
Worn clutch - Replace.

There is a SA repairer who advertises on eBay
and probably has parts. A 3 speed AW mechanism will also screw into the shell, I think. They are two a penny, and so are 3 speed triggers.

 

[rogerzilla]

Ah, one of those crazy devices! Try the troubleshooter here: https://hadland.files.wordpress.com/2012/07/5star.pdf

 

[Schwinnsta]

First off, I have no experience with the hub you have. Nor I know how well it has been maintained. Over time, oil can get gummy. Try squirting in a little WD40 just to loosen it up.