Building - What Can I Do to Stop My Chain Coming Off?

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What Can I Do to Stop My Chain Coming Off?

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Forum Name: Building
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URL: https://forum.bhpc.org.uk/forum_posts.asp?TID=7579
Printed Date: 27 March 2026 at 4:34am
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Topic: What Can I Do to Stop My Chain Coming Off?

Posted By: RoyMacdonald
Subject: What Can I Do to Stop My Chain Coming Off?
Date Posted: 13 August 2023 at 5:06pm

What Can I Do to Stop My Chain Coming Off the front single ring on my After 7? There is no way to adjust the thing that I can see as there is nothing connected to it.

Anyone got any bright ideas?

Is it something I'm doing do you think?

All the best.

Roy

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Replies:

Posted By: AlanGoodman
Date Posted: 13 August 2023 at 5:35pm

On a single ring you can make/attach chain guards/guides both sides of the ring. Some of the pedal car folks do that…

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Posted By: RoyMacdonald
Date Posted: 13 August 2023 at 6:07pm

Thanks Alan.

Will it be OK to glue them on? There is not much metal for any fixings. It's one of Daniels specials.

I could mount something on the carbon fibre box beam that the bottom bracket it bolted too of course. It's the same as an Alpha's construction.

All the best.

Roy

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Posted By: AlanGoodman
Date Posted: 13 August 2023 at 6:17pm

They are usually circular, just a bit bigger diameter than the chairing and mounted using longer chainring bolts.

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Posted By: RoyMacdonald
Date Posted: 13 August 2023 at 9:32pm

This is the chainring.< id="BFI_" style="width: 1px; height: 1px; display: none;">

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Posted By: RoyMacdonald
Date Posted: 13 August 2023 at 9:43pm

I think Daniel removes the chainring installation completely to work on it. I'm not sure I have the physical ability or confidence to do that. I never saw him put the Chainring in. He has to obscure what he is doing when he is working on the front.

He adjusts the length of the chain in situ in a way that I never could.

I'm just about OK sticking bits on and pumping up the tyres (although I do get covered in sealant occasionally) but even removing the back wheel takes me to the limit.

All the best.

Roy

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Posted By: RoyMacdonald
Date Posted: 13 August 2023 at 9:50pm

Have to wonder how the chain wraps itself around the pedal axle. That's where it ended up and it was a devil of a job to get it off and untangled again. Bizzare.

It's not dropping onto the bottom bracket axle like you would expect.

All the best.

Roy

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Posted By: AlanGoodman
Date Posted: 13 August 2023 at 10:06pm

Very strange!! Are you planning to race it this year?

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Posted By: RoyMacdonald
Date Posted: 13 August 2023 at 10:18pm

Yes Alan. I'd like to do the ones closest to me. Betteshanger, Gravesend, and of course Hillingdon.

I have the car out of action at the moment so it depends on that I think. It never gets the attention the bikes do.

PS. Just noticed you can actually see the marks of the chain on the pedal axle.

All the best.

Roy

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Posted By: AlanGoodman
Date Posted: 13 August 2023 at 10:40pm

Hope to see you at Betteshanger next month!

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Posted By: atlas_shrugged
Date Posted: 14 August 2023 at 5:27pm

Roy

You can buy chain-rings with integrated guards from Aligit a NL company. I have one on my Bachetta which has a guard only on one side. My guess is that you could get a chain-ring with a guard on both sides. Take some good quality photos and email them to Aligit and see what they suggest.

Chains coming off the velomobiles you speak of are par for the course unfortunately. My chain fell off the chain-ring racing at Maasmechelen in my velo. This was very unfortunate because I was trying to keep pace with a rather good looking racer.

Posted By: atlas_shrugged
Date Posted: 14 August 2023 at 5:35pm

The other thing you can do to prevent chain-loss is glue foam pads underneath the chain. This stops the chain resonating at the fundamental frequency (think putting your finger gently on a guitar string to get a harmonic).

The foam does not need to touch the chain during normal operation but it should be close so operates only when you are banging over flipping UK pot-holes and not peddling (so the chain is slack).

Posted By: melle
Date Posted: 14 August 2023 at 6:41pm

I can highly recommend Alligt chainrings and idlers.

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Optima Stinger | 2x Baron

Posted By: RoyMacdonald
Date Posted: 14 August 2023 at 8:32pm

atlas_shrugged wrote:

The other thing you can do to prevent chain-loss is glue foam pads underneath the chain. This stops the chain resonating at the fundamental frequency (think putting your finger gently on a guitar string to get a harmonic).

The foam does not need to touch the chain during normal operation but it should be close so operates only when you are banging over flipping UK pot-holes and not peddling (so the chain is slack).

That sounds like a good idea to try first. Simple and possible without too much effort. Both chains? (Drive side and return) I'm a bit more positive about that than the chain ring with guards because it has to be happening before the chain gets to the chainring, otherwise how is it getting onto the pedal axle? If it was dropping onto the bottom bracket axle, yes chainring guards, but it's not.

Thanks Brian.

All the best.

Roy

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Posted By: RoyMacdonald
Date Posted: 17 August 2023 at 11:15am

While working on the foam blocks and looking at the construction I developed a theory that the swinging arm can crack the chain like a whip in top gear (while going over a bump) when everything is at it's loosest and the shock wave travels around the gear through the durralier and up the return tube shooting out of the return tube and getting caught by the pedal as it comes around and as the pedal continues it's rotation it pulls the chain off the chainring leaving you wondering how it got wrapped around the pedal and off the chainring. Anyone got any thoughts on this theory?

All the best.

Roy

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Posted By: zoxed
Date Posted: 18 August 2023 at 11:54am

Using a normal chain ring the chain was often coming off, but TA 1x ring fixed it https://specialites-ta.com/mono/27-83-mono-mono-plateau-specialites-ta-one-110-shimano-sram-specialites-ta-pl58110339.html#/25,denture,44-dts

Posted By: atlas_shrugged
Date Posted: 18 August 2023 at 12:00pm

Translation of the TA chainring website details suggests the fine/wide tooth is what stops the chain from coming off:

"ONE" concept, fine tooth, wide tooth allowing perfect chain retention without anti-derailment, even in extreme conditions

My guess is that the wide tooth keeps the chain centrally located and in the event of possible derailment the next fine tooth is still able to keep the chain located on the chainring.

Posted By: RoyMacdonald
Date Posted: 18 August 2023 at 12:07pm

That explains Daniel Fenn's latest chainring design except his is designed to work with 12 speed unlike the French one.

All the best.

Roy

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Posted By: RoyMacdonald
Date Posted: 26 August 2023 at 5:38pm

Here is Daniel Fenn's latest chainring.

All the best.

Roy

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Posted By: RoyMacdonald
Date Posted: 26 August 2023 at 6:21pm

Here is a photo of the foam blocks I put in. There is also a small foam block on the swinging arm close to the chain on the return side but I did not bother to photograph it as I was mounting a Loud Mini bike horn at the same time.

All the best

Roy

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Posted By: RoyMacdonald
Date Posted: 05 September 2023 at 2:34pm

It did not work! Chain came off again. Wrapped itself around the pedal shaft again! Wondering if I am spinning too slow? Keep it in a lower gear and spin the pedals faster?

All the best.

Roy

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