Author Topic: Brompton chain catching when reversed / tips on cleaning derailleur  (Read 1042 times)

jiberjaber

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So I have made the leap in to the clown bike scene and am now a proud second owner of a 2017 S6L Black Brompton.

I noticed when I folded it yesterday I had managed to get the crank in the wrong position, so naturally rotated the crank to get the alignment for the fold, at which point it unshipped the chain from the chainring.  I managed to do this twice but overcome it by making sure the crank was in the right place before the fold.

Today I noticed when it is on the inner rear cog and I roll the bike back that the chain stutters and starts to fold up, which I suspect was the issue with the fold issue also.

I suspect this might be that the derailleur may need cleaning  so what's the tips on how best to do this, is it just a case of water, degreaser and a toothbrush or is there a better way?


Regards,

Joergen

Re: Brompton chain catching when reversed / tips on cleaning derailleur
« Reply #1 on: November 08, 2018, 12:03:20 am »
I've had my P6R (second hand) for something over six months. I just find that you have to be careful. If I can, I rotate pedals forward into roughly the right position, before folding. It's quite unpredictable.

I don't see any reason to clean in any other way than for a "normal" bike. I've used a chain bath and so on.

jiberjaber

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Re: Brompton chain catching when reversed / tips on cleaning derailleur
« Reply #2 on: November 09, 2018, 10:36:48 am »
I've had my P6R (second hand) for something over six months. I just find that you have to be careful. If I can, I rotate pedals forward into roughly the right position, before folding. It's quite unpredictable.

I don't see any reason to clean in any other way than for a "normal" bike. I've used a chain bath and so on.

Thanks  :thumbsup:  - I took a closer look this morning, the chain tensioner was very wobbly, the retaining nut was only just on, so I think that was the main culprit.  Whilst I was there I gave it all a good clean, there was lots of gunk in the drain holes of the tensioner pulley as well, took out the indicator chain and cleaned and lubed that and cleaned the chain etc.  I could have saved the last job if I had bothered to measure the chain *before* I cleaned it, it's very worn!

I think the original owner did about 1100 miles on it before I got it, so suspect it also needs a new chain.

Anyway - now it's re-assembled, reversing the direction is no longer causing grief! :)

I think I'll pop out for a coffee and call in to our local Evans for a new chain this morning  :thumbsup:

Regards,

Joergen

Re: Brompton chain catching when reversed / tips on cleaning derailleur
« Reply #3 on: November 13, 2018, 04:03:03 pm »
So I have made the leap in to the clown bike scene and am now a proud second owner of a 2017 S6L Black Brompton.

I noticed when I folded it yesterday I had managed to get the crank in the wrong position, so naturally rotated the crank to get the alignment for the fold, at which point it unshipped the chain from the chainring.  I managed to do this twice but overcome it by making sure the crank was in the right place before the fold.

Today I noticed when it is on the inner rear cog and I roll the bike back that the chain stutters and starts to fold up, which I suspect was the issue with the fold issue also.

I suspect this might be that the derailleur may need cleaning  so what's the tips on how best to do this, is it just a case of water, degreaser and a toothbrush or is there a better way?



I reckon the previous owner probably didn't keep it very clean. He has a reputation!

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Re: Brompton chain catching when reversed / tips on cleaning derailleur
« Reply #4 on: November 13, 2018, 04:06:55 pm »
I was only joking about the previous owner, who actually has OCD levels of cleanliness. I was pleasantly surprised at the low cost of a chain and  rear cogs, which you should change at the same time.

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jiberjaber

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Re: Brompton chain catching when reversed / tips on cleaning derailleur
« Reply #5 on: November 13, 2018, 07:28:47 pm »
I was only joking about the previous owner, who actually has OCD levels of cleanliness. I was pleasantly surprised at the low cost of a chain and  rear cogs, which you should change at the same time.

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Haha no probs Tim, the first thing he said as he got it out of his bunker was it needed a clean (it was fairly spotless tbf!)

I replaced the chain and had some slipping issues which as you correctly point out were as a result of me not changing the rear sprockets at the same time.  I've since done this and it's all sweet again! :)  First commute in London today, I survived as did the brommy, so all good!  :thumbsup:

Good service from Brilliant Bikes for my rear sprockets, next day delivery and letterbox friendly packaging so I was able to fit them tonight after getting in from That London.
Regards,

Joergen

Re: Brompton chain catching when reversed / tips on cleaning derailleur
« Reply #6 on: November 13, 2018, 08:15:14 pm »
I think the original owner did about 1100 miles on it before I got it, so suspect it also needs a new chain.
I've done at least that since buying mine "lightly used" second hand. I'd not really thought of replacing anything for several thousand more, but then I date from the days of 5-speed, which went on forever.

Re: Brompton chain catching when reversed / tips on cleaning derailleur
« Reply #7 on: November 13, 2018, 08:16:15 pm »
Brompton sprockets only last one chain? I knew they went through chains relatively quickly what with all the road crud it catches, but are the sprockets made of cheese?

jiberjaber

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Re: Brompton chain catching when reversed / tips on cleaning derailleur
« Reply #8 on: November 13, 2018, 08:33:11 pm »
Well the chain was off the scale on my chain checker which I only applied as the chain lifted off the chainring by quite a lot.... so decided to replace it, the new one slipped as soon as I tried to accelerate in every gear. New sprockets solved the problem.

They look worn, but not as much as I was expecting. 

Top right is new 13t


Regards,

Joergen