[Tim C Boston]

I have a brand new Durance with a brand new drivetrain - XT cranks (std rings), XT cassette (11-32), SRAM PC 99 chain, XT rear der, Dura Ace flat bar 10 spd braze-on front der.

My chain slips up front whenever both of the following are happening concurrently: 1) the drivetrain is under load and 2) the shock is cycling through it's travel. Basically, the drivetrain works fine when I pedal on the road on the way to my local trails (even going up steep hills). As soon as I try a rocky climb - crack! It feels like I'm about to break my chain. Sometimes, the chain falls all the way down to the bb, but mostly it just slips (in a manner similar to using a brand new chain on worn-out cogs/chainrings).

I've had 2 different reputable shops (including the Maverick dealer) try to fix the problem, to no avail, and my buddies and I have tinkered with it endlessly without luck.

Anybody have this problem with a Maverick before?

 

[crisillo]

umm.. sounds weird.. I would be interested to know about it too (subscribing to thread)

 

[banks]

Two things;

1. Correct Rear Shock pressure!! Weigh yourself with all of your riding gear on, take 95% of that number for your rear shock PSI. IE: 175 rider weight 166psi.

2. There needs to be more slack in the FD cable then "they" think, as it's a mountain shifter and a flat bar road FD and the pull ratio is not equal.


BTW, PC99 chain is Junk IMHO. Put a XTR 9 speed chain on.

 

[Count Zero]

SRAM chain + Shimano rings

One thing I've noticed during the past couple of years is that new Shimano XT middle rings behave poorly with new SRAM chains.

The rings are so wide when brand new that they are "grabbed" by SRAM chains, thus causing chain suck just as you might expect from a worn out, burred chainring.

As the ring is worn down, usually in a couple of weeks, the chainsuck goes away.

I ride a Maverick, but certainly this observation does not only apply to Mavericks. Friends on other brands have had exactly the same issues. Probably, the Maverick's slightly wide chainline magnifies the problem.

Best,

Tom

 

[Tim C Boston]

Thanks

Thanks for your replies. I have had some trouble inflating the shock accurately...I pump it up to 165ish (I weigh 175), and I think air is escaping when I unscrew the pump. I'll overcompensate.

I will also throw a Shimano XTR chain on, and adjust the FD cable tension as suggested.

I'll let you know how it goes...

 

[crisillo]

Thanks for your replies. I have had some trouble inflating the shock accurately...I pump it up to 165ish (I weigh 175), and I think air is escaping when I unscrew the pump. I'll overcompensate.

usually the air that you hear coming out is coming from the pump and not the shock, so don't "overcompensate" too much...

the lower reading you get when you reattach the pump, is just because the hose fills up with air from the shock, therefore lowering the read pressure...

 

[skleins]

Have you checked to make sure you've got no bent teeth on the chainrings /cassette and that the cassette is tight?
No stiff links in the chain?

Skleins

 

[rcharrette]

Chain is a good idea

You maybe on the right track trying a new chain.I had a road bike come in and I replaced the cassette and installed a new Durace chain.Once this was done the chain kept ridding up on the front chain wheel when in the 25 or 27. After banging my head for day's I finally said screw it and put on another new chan.........it fixed it. That'smy first ever "defective" chain.

 

[ssorgs]

I had a similar (same?) problem with my 4-5 month old XT middle ring, where it would 'skip' and often get thrown to the granny. I think the XT is aluminum and though it didn't look all that worn (especially b/c I spend more time in granny) I replaced it with a cheap steel one from Salsa -- fixed it.

 

[pktrekguy]

Shimano had a bad batch of rings on XT rings, they made some alterations that didn't go over so well. Have your shop call Shimano to get you free replacement middle ring. We have had to do this for several bikes just recently.

 

[Tim C Boston]

Put on Shimano XTR chain - fixed it

I put on a Shimano XTR chain and now it no longer slips. Never had compatibility issues before with SRAM chains / XT rings, but alas it now works. Appreciate the advice.

With respect to the bad batch of XT rings: I tried two different new XT rings - one of them was purchased over a year ago, and the other was purchased in the winter (the one on there now).

 

[rcharrette]

Not a compatability issue

I think you just had a bad chain. I put SRAM chains on Shimano all the time. Glad you got it worked out though:thumbsup:

 

[Almost_Dunn]

Tim C: I recently got the Matic with the DUC. When the chain slips, did you whack the left knee into the handle bars ?? I did so twice in the past two days and have an egg there now. Just wondering if I got the same issue.

Thanks