# Chain slap on hard tail



## The Jayler (26 Aug 2009)

Can any one recommend any thing that may ease this. My chain seems to be hitting my chain stay a lot when going over particulary bumpy ground and would like to stop this in case it damages the frame.


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## Berger and Chips (26 Aug 2009)

Firstly there is things like this you can buy

http://www.chainreactioncycles.com/Models.aspx?ModelID=34461

Secondly the more tension you put on the chain the less slap.

If you are just downhilling using gravity, go for a gear combination something like the big outer ring at the front and a big ring on the back.
Although avoid cycling with the absolute biggest rings on both front and back at the same time, it stretches and twists the chain and is known as "extreme gears", something that bike shops tell you not to cycle in.
However for just cruising downhill you should be ok in say the big (outside) ring on front and the second biggest (inside) ring on the back.
You would get really bad slap if you were in the small (innermost) ring on (front) chainset and small (outermost) ring on the cassette at the same time, going downhill.
Now, that is not an extreme gear, but it will give the worst possible maximum case of chain slap, with a very loose sloppy chain having next-to-no tension banging all over your chainstays and leaving chunks of paint on the trail, not on your bike, where you want it to be...


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## Jonathan M (26 Aug 2009)

Is the chain too long? Shimano instructions are to run a new chain around the outer chainring and the largest cassette ring without going through the rear mech, then add a link. This should be the correct length. Too little and the bike can't run in big:big, and will damage the rear mech, too much and you will get a lot of chain slap, and probably chainsuck too.

The neoprene chainstay guards provide a little padding but only help with the symptom rather than the cause. Check everything in Bergers post, and if your chain has been replaced recently consider checking is it too long.


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## lukesdad (26 Aug 2009)

I would think your chain is too long


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## Cubist (26 Aug 2009)

You get chain slap no matter what length chain you use. You can pay £7 through the nose for a proper lizard skin protector, which wear out and look shite, or you can wrap a length of old inner tube round the chainstay and fix it in place with 2 or 3 cable ties. Still looks shite, but doesn't cost £7.........


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## Berger and Chips (27 Aug 2009)

Yes, that would work, often those protectors are given away free with magazines though and I am sure you can get them for less than £7.


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## marzjennings (27 Aug 2009)

Go with the an inner tube around the chain stay's. It's free and better than most chain stay protectors. It's almost impossible to avoid chain slap on a mountain bike so you need something to protect the chain stay.


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## maurice (28 Aug 2009)

It's not as bad with SRAM rear mechs for some reason, you'll still get it though, fact of mtb life.


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## The Jayler (28 Aug 2009)

Do chains stretch? It's the origonal chain fitted by Trek so may have stretched over the past year. 
On a ride yesterday all my mates chains were not slapping the chain stay on the ride where mine was. I'll check the chain length i think.


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## bonj2 (28 Aug 2009)

don't be tempted to think it's 'cos the chain's too long. That's not to say your chain isn't too long, but it will still happen when it's the right length. That's what lizard skins are made for.


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## marzjennings (28 Aug 2009)

The Jayler said:


> Do chains stretch? It's the origonal chain fitted by Trek so may have stretched over the past year.
> On a ride yesterday all my mates chains were not slapping the chain stay on the ride where mine was. I'll check the chain length i think.



Here's a quick check on chain length, shift the gears until the chain is on the smallest chain ring at the front and smallest at the back. If the rear derailleur is folded completely in on itself and there doesn't seem to be any tension in the chain then it's too long. Take out a link at a time until derailleur doesn't quite fold all the way back and there's some tension in the chain.


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## Cubist (28 Aug 2009)

The Jayler said:


> Do chains stretch? It's the origonal chain fitted by Trek so may have stretched over the past year.
> *On a ride yesterday all my mates chains were not slapping the chain stay* on the ride where mine was. I'll check the chain length i think.


Can't have been very adventurous

Seriously, check chain length AND add a stay protector.


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## 02GF74 (28 Aug 2009)

chains do not stretch. they can elongate due to wear but we are tallking 1 or 2 percent, i.e. sod all of **** all as far as your problem is concerned, oin other words, the duistance between chain link pins has nothing to do with it.

there is not enough tension in the chain due to either the chain being too long or the spring in the read shifter has gone weak.

it could just be that the ground is so rough that the chain is gonna slap the frame no matter what you do - some frame designs may be more susceptible.

to fix it either you need to put more tension into the rear shifter - there is a spring type jobbie, maybe already posted or if you cannot stop it, you can prevent damage to the frame by wrapping the stay.

or get off and walk.


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## The Jayler (29 Aug 2009)

Thanks guys, got a £7 guard which has done the trick. Cheers.


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## Bodhbh (1 Sep 2009)

I've noticed it happens a fair bit lately. The issue with chainslap is just cosmetic with the removal of paint, or there's possibility of real frame damage?


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