Chain Slap.

[Caerus]

Hi All,

 

For some reason my chain seems to be slapping a lot more now then it normally ever has, I'm not sure if it's the trails I'm riding or it might be something else.

 

Not sure what to try, as I'm in the right gear and it still seems to be doing it. My chain should be the right length as it was installed by the bike shop when I had my bike built up, so I can't think that I might have one link to many.

 

What solutions are there? I'm running a 3x9 setup and it is really starting to get on my goat.

 

Will a better derailleur work or should I get a chain tensioner or something else?

Edited November 23, 2013 by Caerus

[David Marshall]

Could be one of a few things. First check the obvious - chain length - In the granny and small at the back the chain should be roughly paralell to itself at the pulley wheels. When on the large/large gears the derailleur cage should not be pulled forward more than about 45 deg. Next check that the RD is mounted properly, making sure that the small extension on the mounting assembly that hooks on the step on the deraileur hangar is on the right side ie at the back of the hangar so that the spring will be activated when the cage is pulled forward. If you can't find the cause get someone to have a look at it. You shouldn't need any additional bits and pieces - these things are normally robust and reliable.

[Skylark]

Never assume that the work of an LBS comes straight out of the Park Blue books!

[Caerus]

My gears are changing fine, the chain as mentioned was fitted by my bike mechanic. Seems strange that this is happening all of a sudden

 

Nothing seems to look out the ordinary either.

[Mags vd walt]

What I did on my stumpy, made a chain device from a old reflector bracket and hosepipe, its working a charm for me.

[gummibear]

Do you have a clutch derailleur?Check that the clutch is on.

 

Check the chain length

[Bobbo_SA]

What I did on my stumpy, made a chain device from a old reflector bracket and hosepipe, its working a charm for me.

pics???

[shaper]

Chain slap is normally due to chain length not being correct.

 

Maybe also check the spring in the derailleur ?

[Caerus]

Chain slap is normally due to chain length not being correct.

 

Maybe also check the spring in the derailleur ?

I had two of the best mechanics in the country build my bike for me, I can't believe that they would have got the chain length wrong for some reason, the springs in the deraileur seem fine as well. This is hell of a confusing as its something that's only recently developed over the last three or so weeks. I've not wiped out or had a crash, but the chain seems to flap about more then it should.

 

Is there a way of knowing or finding out the correct chain length for a specific bike?

[Tigershel]

I had two of the best mechanics in the country build my bike for me, I can't believe that they would have got the chain length wrong for some reason, the springs in the deraileur seem fine as well. This is hell of a confusing as its something that's only recently developed over the last three or so weeks. I've not wiped out or had a crash, but the chain seems to flap about more then it should.

 

Is there a way of knowing or finding out the correct chain length for a specific bike?

 

Google is your friend: http://www.parktool.com/blog/repair-help/chain-length-sizing

 

It's possible the chain has worn ('stretched') or that the derailleur is on its design limits and any wear has pushed it over.

Have you made any gearing changes?

[Goblin]

clutch derailleur works like a charm. There where certain sections of Groenies that by the time I got to the bottom, my chain was 90% of the time, off. new type derailleur = problem gone.

[Mike Bike]

OP has a 3X9 setup, there are unfortunately no clutch derailluers available for this. If the chain has recently been replaced i would blame that as the culprit. put the bike in smallest cog front and rear making sure the chain is still under tension and not hanging loose.

[Mags vd walt]

pics???

[Mags vd walt]

Sorry stupid ipad thought it would be fun to atach the photo upside down.

[Skylark]

That thing you used looks a lot like a light holder?

[Mags vd walt]

Used to hold my sons rear reflector on his bike. Just took that off warmed up some hose pulled it over and zip tied it on..