XTR Shifting help

[nedshred]

I've got an Amp b-4 that I've really never gotten to shift well. Originally I was sporting a sram 8
speed 9.0 rear derailleur and shifters with a Truvativ Stylo Crankset and BB, and XTR cassette. It
was shifting OK, but should have been better. When I broke the derailleur, I put on an XTR rear
derailleur and a set of M910 XTR shifter/brake levers. I was using a sram PC68 chain with each
setup. The shifting actually got worse (braking was great), so I put on a Shimano IG90 chain,(per
Truvativ instruction) and then it was worse yet. I believe my chainline is correct, but I could be
wrong. I've spent hours trying to adjust it, and I will not give up until I get it right. I might
add that I've been building and repairing my own bikes for some time, and pride myself on the fact
that none of them have ever been in a bike shop for repairs. I'm too stubborn to take it in, and to
be honest, I am at odds with my LBS. If there's something I'm forgetting, or something I am not
aware of regarding compatibility, perhaps that could be addressed here. I can get it to shift up and
down the cassette rather well; it just skips a gear each way. It seems to me that the shifter and
derailleur aren't in sync. Just to make sure I put a Sram "plasma" shifter on temporarily, and it
really didn't shift any better. It looks to me as if I either have a chainline problem, or
compatibility issue. The derailleur is aligned pretty well, so that isn't the problem. Frankly, this
has me stumped. Any advice or suggestions would be greatly appreciated. TIA, Greg

 

[David Kunz]

[email protected] wrote:

> I've got an Amp b-4 that I've really never gotten to shift well. Originally I was sporting a sram
> 8 speed 9.0 rear derailleur and shifters with a Truvativ Stylo Crankset and BB, and XTR cassette.
> It was shifting OK, but should have been better. When I broke the derailleur, I put on an XTR rear
> derailleur and a set of M910 XTR shifter/brake levers. I was using a sram PC68 chain with each
> setup. The shifting actually got worse (braking was great), so I put on a Shimano IG90 chain,(per
> Truvativ instruction) and then it was worse yet. I believe my chainline is correct, but I could be
> wrong. I've spent hours trying to adjust it, and I will not give up until I get it right. I might
> add that I've been building and repairing my own bikes for some time, and pride myself on the fact
> that none of them have ever been in a bike shop for repairs. I'm too stubborn to take it in, and
> to be honest, I am at odds with my LBS. If there's something I'm forgetting, or something I am not
> aware of regarding compatibility, perhaps that could be addressed here. I can get it to shift up
> and down the cassette rather well; it just skips a gear each way. It seems to me that the shifter
> and derailleur aren't in sync. Just to make sure I put a Sram "plasma" shifter on temporarily, and
> it really didn't shift any better. It looks to me as if I either have a chainline problem, or
> compatibility issue. The derailleur is aligned pretty well, so that isn't the problem. Frankly,
> this has me stumped. Any advice or suggestions would be greatly appreciated. TIA, Greg

Several things come to mind...

1. You have the cable attached to the wrong side of the clamping bolt on the DR. It makes a
difference.

2. The DR is not parallel to the wheel; i.e., the DR hanger is bent. Your LBS will have a tool to
check and bend it back in needed. You can usually see it if it's bad enough for it to shift the
way that you're describing -- the DR tension arm should be parallel to the plane of the wheel --
just stand back from the bike and look at it.

3. The shifting cable is not moving freely. This is a common problem with 9 speeds and why I
personally have to use teflon coated cable. Plain steel just won't work reliably on my bike. Try
replacing the cable and housings.

David

 

[Nicholas & Domi]

<[email protected]> wrote in message news:[email protected]... I've got an Amp
b-4 that I've really never gotten to shift well. Originally I was sporting a sram 8 speed 9.0 rear
derailleur and shifters with a Truvativ Stylo Crankset and BB, and XTR cassette. It was shifting OK,
but should have been better. When I broke the derailleur, I put on an XTR rear derailleur and a set
of M910 XTR shifter/brake levers. I was using a sram PC68 chain with each setup. The shifting
actually got worse (braking was great), so I put on a Shimano IG90 chain,(per Truvativ instruction)
and then it was worse yet. I believe my chainline is correct, but I could be wrong. I've spent hours
trying to adjust it, and I will not give up until I get it right. I might add that I've been
building and repairing my own bikes for some time, and pride myself on the fact that none of them
have ever been in a bike shop for repairs. I'm too stubborn to take it in, and to be honest, I am at
odds with my LBS. If there's something I'm forgetting, or something I am not aware of regarding
compatibility, perhaps that could be addressed here. I can get it to shift up and down the cassette
rather well; it just skips a gear each way. It seems to me that the shifter and derailleur aren't in
sync. Just to make sure I put a Sram "plasma" shifter on temporarily, and it really didn't shift any
better. It looks to me as if I either have a chainline problem, or compatibility issue. The
derailleur is aligned pretty well, so that isn't the problem. Frankly, this has me stumped. Any
advice or suggestions would be greatly appreciated. TIA, Greg

check that the derailleur hanger and dropout is manufactured to the derailleur's spec laterally -
usually a spacing of 12.7mm +- 1mm for SRAM makes a big difference - I use a couple of filed washers

 

[nedshred]

Dave: Thanks so much for your advice. I did indeed have the cable on the wrong side of the
derailleur clamping bolt. I switched it around, and voila!, great shifting again. I feel a bit silly
for not noticing in the first place as the angle was bad. Anyway, thank you........ Greg