[Motionboy2]

Ok so I have been setting up my new bike and I just can't get it to stop skipping gears. Here are the details:

horizontal Dropouts

XTR Rear Der, Xt Chain, XT Cassette, Spot chainring and XT front Der. The cassette is on a King Bolt on hub.

If I put a large amount of torque on the cranks the chain will skip. It does not move to another gear but it just POPS!!

This only happens when I put a lot of force on the cranks. IE: Sprinting from a standstill.

This is what I have done to try to fix it.
I have adjusted the der: First I adjusted it perfect. That didn't work, so I tried adjusting it so that it climbed a bit quick and dropped a bit slow. That didn't work. Then I tried the Vice Versa. That didn't work either. So now it is back to perfect.

I checked the der hanger, It is perfectly straight.

I checked every link of the chain, there are no stiff links, there are no problems and it has lube.

I initally had the wheel forward, I thought maybe this was making the chainstay too short to reach all gears but I moved it to the longest position and still have the same problem.

All the parts are new and no they are all installed properly.

The only thing that I can think of is the Freehub body. Is it possible for a King freehub body to skip?

I can not see what happens when this skips because...well...I am riding the bike! I can just feel it and it pops one to two times.

Does anyone have any Ideas?

 

[binary visions]

I had the exact same problem on my Imperial when I first built it up. It drove me nuts. I did everything short of buying a new drivetrain. In the end though, the problem is that the chain and the cassette aren't worn together so the chain doesn't "fit" the cassette quite right. If you put up with it, try not to make it skip too much, and ride it a bit, it'll go away by itself. The chain and cassette will wear into each other and work fine.

I'm not sure why this happens with new parts, as the parts should be to spec and not cause this kind of issue. But hey, guess it's not a perfect world right?

I have an XT rear der., xt chain, LX cassette.

Take the bike for some good long rides around town - go to the grocery store or whatever. Something where you don't need to put lots of torque on it because that "popping" will ruin your drivetrain eventually. But give it 10-20 miles to bed in, maybe more. I don't know exactly how long it took me, just several rides of tolerating it and then it just quietly went away.

 

[Motionboy2]

Maybe I will take my cassette off the DH bike and see if that works better...

Thanks for the input!

 

[speedbump]

Does it "skip" in any gear or only in specific gears? If so which ones does it skip in?

 

[Motionboy2]

It skips in the smallest (highest) 4 gears. I think that is because those are the only ones that I can get enough torque on to make is skip.

Just to reiterate, it does not skip to other gears. it just skips and then is still on the same gear.

 

[binary visions]

Incidentally, if you take the cassette off another bike, use the chain off the other bike too. That way you know the entire combo works smoothly.

 

[Motionboy2]

Originally posted by binary visions
Incidentally, if you take the cassette off another bike, use the chain off the other bike too. That way you know the entire combo works smoothly.

You make a good point, but I don't want to cut my stainless steal wipperman chain that is on my DH bike. Too much $$$ for an experiment.

I am sure that there will be something that I can bastardize here at the shop :devil:

 

[speedbump]

Because it only slips on some of the gears. I think you can rule out the freehub body. BV is probably on the right track with it being a chain/cassette issue. I'm sure you checked this, but you don't have an 8 spd chain with a 9 spd cassette or vice versa?

 

[Matt D]

Sounds like classic worn chain and/or cassette. Go to your LBS and use the chain checker to measure the stretch of the chain and replace as necessary. The shop might also have the tool to measure cassette wear, use that as well.

Generally if the chain is worn over 1 on the Park checker, you'll need a new chain as well as a cassette.

It's easier for the chain to slip around the smaller cogs because there are less teeth to hold onto.

 

[Motionboy2]

I don't have to go to the LBS. I work at a shop. The reason that I ask all this is because the chain, cassette and der...HELL everything on the bike is less than 2 days old. It all has literally less than 2 miles of riding on it.

As for the reason that i considered the hub. (which I don't know if it is or not)
It is in the smallest 4 cogs which are the hardest gears. I can only do it at a sprinting start. I would say that I can only get enough torque on these particular cogs to get it to skip. I don't think it is limited to these cogs, i think that it is limited to the amount of power I can get into the cogs.

I will have one of the Tech's look it over and give me some ideas tomorrow. I havent been a tech for anyone else in 4 years now so I am willing to hand it over for others to discuss.

 

[Motionboy2]

So the trouble shooting goes much faster when there are multiple people in the shop.

So here is the word. It is skipping on the front chainring! Who would have thought that?

We actually made it happen in the shop with one of the guys. with a lot of weight on it you can see it start ramping up the teeth. With a little bounce it just pops!

It is a brand new Spot chainring. I don't get it. I have to find something else now.

 

[binary visions]

It's very possible that it's not the chainring. I'd bet a dollar you have a bent spider.

Same deal - pull a chainring off another bike and try it, but if it's skipping in the front usually it's a bent spider.

edit: you didn't mention what kind of crank it was or if the cranks were new. I heard that FSA had some problems with their V-Drive Xtreme cranks having bent spiders right out of the box.

 

[ghostrider]

Originally posted by Motionboy2
So here is the word. It is skipping on the front chainring! Who would have thought that?

If I woulda seen this thread sooner, I would have guessed that. I went through the same thing. What crankset are you running?

 

[Motionboy2]

Originally posted by ghostrider
If I woulda seen this thread sooner, I would have guessed that. I went through the same thing. What crankset are you running?

Truvativ Hussefelt....Why?

I just got a Blackspire chainring we will see if that helps...

 

[Motionboy2]

Oh BTW I want my dollar! I put a bb in the vice and made a makeshift alignment thingy and the spider is straight..

It SEEMS to work fine now. I will give it a full test tonight though. If you guys don't see me on RM tomorrow send help!

 

[ghostrider]

Originally posted by Motionboy2
Truvativ Hussefelt....Why?

Because if it was four-arm XTR, you may as well toss 'em in the trash - you can buy a whole crankset for the price of one XTR chainring.