[CalPolyClimber]

I've noticed that my Hollowpoint is really loud out on the trail with all kinds of chain slap noises and my rear deraileur actually taps up against the frame as it pivots at the deraileur hanger. I use old tubes to protect the chainstay, and hopefully quiet it down a little, but it still seems louder than other bikes I've ridden. I know a lot of the noise is coming from the chain slapping back and forth inside the cage of the front der, is there any way to avoid this? Any other tips to quiet down my ride? Most of the trails I ride are quite rocky, so it just gets loud sometimes...

 

[KevinB]

Any other tips to quiet down my ride? Most of the trails I ride are quite rocky, so it just gets loud sometimes...

If you're in the small chain ring, there's less tension on the chain and it'll bang around a bit more. Shifting to the middle or even large chain ring on rocky downhills will put more tension on the chain and will quiet things down somewhat.

You should also check the chain length. Running a chain that's slightly too long can make chain slap worse.

 

[CalPolyClimber]

Yeah, I do try to stay in the middle cogs in rocky sections, and that does help. My chain is actually one link too short, at the time (it wont shift into big/big, not that I ever would anyway). I'm going to study it a little more tonight, and see if I can't figure out exactly where all my noises are coming from.

 

[KevinB]

I'm going to study it a little more tonight, and see if I can't figure out exactly where all my noises are coming from.

You might also consider increasing the rear derailleur spring tension.

Let us know what you find out...

 

[Appendage]

How do you do that?

You might also consider increasing the rear derailleur spring tension....

How do you do that? I didn't even know the tension was adjustable! Maybe that would help with my MkIII's problem of dropping the chain when I hit big bumps.

 

[KevinB]

How do you do that? I didn't even know the tension was adjustable! Maybe that would help with my MkIII's problem of dropping the chain when I hit big bumps.

Zinn documents the procedure in Zinn and the Art of Mountain Bike Maintenance in the section entitled Lower knuckle pivot spring ("p-spring") tension adjustment. It involves disassembling the lower pivot and moving the end pin of the p-spring to a different hole which will increase the tension. You may be able to view some instructions online by doing a Google book search for "derailleur p-spring"

 

[CalPolyClimber]

Is it possible to adjust the p-spring on an xt rear derailleur? i kindof thought you could only do that on the XTR?

 

[KevinB]

Is it possible to adjust the p-spring on an xt rear derailleur? i kindof thought you could only do that on the XTR?

According to Zinn's book, it is possible to make this adjustment on an XT derailleur as well. In fact, it's supposed to be somewhat easier on an XT derailleur due to the set screw which facilitates disassembly of the pivot.

 

[Appendage]

Zinn documents the procedure in Zinn and the Art of Mountain Bike Maintenance in the section entitled Lower knuckle pivot spring ("p-spring") tension adjustment. It involves disassembling the lower pivot and moving the end pin of the p-spring to a different hole which will increase the tension. You may be able to view some instructions online by doing a Google book search for "derailleur p-spring"

Thanks for the info, Kevin. I already have Zinn's book- stupid me, I should've looked there before I asked.

 

[lifer]

Do you ever drop your chain?

Do a search for the heim 3 guide. It quieted down my drivetrain so much even one of the XC weight weenies I ride wth commented on how quiet my Bullit is