Shifting Mystery

[pshloss]

OK, here's one for the expert mechanic to solve (and no, I don't know the right answer yet): I have a new chain, cassette, and crankset. The chain and cassette are 8-speed (as are the shifters- the rear der is XTR rapid rise) and the cranskset is a 9-speed compatible LX. If I adjust the rear derailleur so it is properly adjusted for the middle chainring, it shifts fine in the middle ring and in the big ring. However, in the small ring, the indexing is off by one full click. It goes into first gear on the second index step, second gear on the third click and so forth. I checked the low limit and the cable tension (in middle chainring) and they all seem OK. Of course the cable is slack on the first click when using the small ring, but if I take the slack out to make it OK on the small ring, then the middle ring is off. The only thing I can think of is possibly the chain is a little too short. I sized it according to the big ring, big cog method with about 1-1/2 links extra. Ideas?

[Neccros]

I'm totally guessing here, but check and make sure your derailer hanger isnt bent....

[jruiz]

Bottom bracket spindle length issue?

[Neccros]

I doubt its the spindle length since thats consistant and never a variable so either your shifting works or its just whacked through the entire range...

Also check your cable ends and the ferruls, I had a set of Flak Jackets and the shifting was so slow or not at all due to the ferruls clamping down on the ends of the cables and causing serious drag. The way the shifting acted, you would have no idea it was the cables. Then the Path suggested a cable swap since they dont like flak jackets and sure enough, it was back to shifting like butta after I was done!!!

[EndoMaster]

I'm thinking chainline as well. Did you buy one of the newer cranksets with the integrated bottom bracket? You are describing a problem that I had when I installed a Raceface X-type crankset onto a bike that I have. I installed it per the instructions but found that it behaved as you're describing. I adjusted the chainline by moving the drive-side crank inwards towards the bottom bracket by removing one of the spacers that the install instructions called for. Once I did that and readjusted the limit screws on the front derailleur I was able to get the shifting in order.

Agustin

[Neccros]

Might be... I am still running old school cranks and seperate BB so I havent dealt with any of the issues with the new stuff

[pshloss]

Thanks for the ideas. I think you guys are on the right track with the chainline. I am going to see what happens after going to the 9-speed cassette and shifters. I did have to change the bottom bracket when I put in the new crankset (it is the older type Hollowtech I octalink, the one i was replacing was the even older square taper type. So maybe the BB is the wrong spindle length. How would I determine the right one? I put in a 68 x 121 because there were only three choices on Pricepoint and the other two were 78 and my old one was 68. Performance Jenson only sell 121 length, too. So I assume that's right. Hopefully, it's just from mixing the 8 and 9 speed stuff. It's rideable, just a little annoying and I should be able to get the 9-speed stuff in this weekend or early next week.

[jruiz]

Are you talking about the es51 bottom bracket? They say that the LX m752 is only compatible with this bottom bracket. I told that to my budddy when he bought this crankset. He said he bought a es71(specific for the xt) and it fit. I don't believe him, but you might want to check this out. These are available with 113 and 118 spindle lengths.

[pshloss]

Originally Posted by jruiz

Are you talking about the es51 bottom bracket? They say that the LX m752 is only compatible with this bottom bracket. I told that to my budddy when he bought this crankset. He said he bought a es71(specific for the xt) and it fit. I don't believe him, but you might want to check this out. These are available with 113 and 118 spindle lengths.

Yes, the ES51. I might have to check out your suggestion if I'm still having the problem after switching the cassette and shifters.

[EndoMaster]

If you are using the LX m572, check out this thread. I remember it because I was looking for something else a while back but I ended up reading it anyway.

http://forums.mtbr.com/showthread.ph...+deore+lx+m572

Read responses 5 through 7, they seem to have the info you might need.

Agustin

[dirttorpeedo]

your spindle maybe too long,there is a meaurement from centerline of the seat tube to the midddle ring. i belive it's 47 1/2 - 50 mm.this is for best shifting. you shood have about a 113-118 length spindle.when you get that part correct put the der. in the small ring and titen the cable.make shur you've got some room to adjust the slack in the cable with the barrel adjuster. MR. shloss, my bill is in the mail. ....hope that helps!