singletracksSC

...I am stuck on something maybe someone would have some hints for me....

swapped out an 9sp mtn cassette and Shimano LX rear der. for a med cage
road derailure (105) and a 12-25 cassette...all that works just fine in
the rear.

also swapped out the rings on the front to be 26 / 36 / 48...outer ring
is non ramped Salsa which may be part of my problem. (cranks are LX
taper 4bolt)

symptom is when rear is in the 12t cog (smallest) and in middle ring up
front the chainline rubs slightly against the outer front ring...

so I may be able to fix with a longer spindle bottom bracket but also
began wondering if the 9sp road cassette is wider the the 9sp mtn which
I really doubt since indexing is fine. other theory is the salsa ring is
just really thick or the bolt / mount tabs aren't think enough but not
sure I want to place washers between outer ring and the crank tabs it
mounts to (ie, not as solid of a mount)

any thoughts would be great...no thoughts are cool as well,

Mauriceloridans

chainring(s) could be on backwards.

Al1943

Not sure why this is happening but if you have a conventional bottom bracket you can move the crankset out a few mm with a bottom bracket spacer. This is a clean and easy installation often used to correct chainline problems. I'd try a 2mm spacer.

Al

singletracksSC

thanks, good idea and better than mine of getting a longer spindle. I'm still suspicious of the large chainring
https://jensonusa.com/store/product/C...Chainring.aspx
and I don't see the 48t listed on jenson and QBP also no longer has it which makes me even more suspicious. going to see what the old 44t does with the same cassette on. probably should have got the shimano 48t, well maybe...

singletracksSC

i did the opposite of what i said, ie, i put the old lx cassette on and same thing but now i'm wondering if when i adjusted my hub last maybe i off set the chainline but the brakes only needed a minor adjust and the axle threads are even...may try putting the old front ring on again now. any thoughts on the hub?

Cadfael

I don't want to hijack this thread, but just what are these? I understand they stop the cranks from riding to far up the axle as the crank screw is tightened, but how?

Retro Grouch 

Actually, I think they were originally produced as freewheel spacers but happened to be just the right diameter for bottom brackets. They look like aluminum cylinders but only 2mm long. I ordered mine through QBP, I have no idea how one might get them in the UK.

singletracksSC

first, it's the outer ring, too thick, salsa says good for single and x-9 speed use but maybe the reason qbp doesn't sell it anymore is it really doesn't work well with 9 speed.

and my logic had no basis in reality about the cones sliding over changing the cassette's juxtaposition to the rest of the bike, no idea how I came uop with that one.....at least it dawned on me before tearing into a freshly packed hub!

so, now I just need to get a new outer ring (a bb spacer would work w\ current setup but would rather just get the compatible ring).

Al1943

They actually are offered in several thicknesses, the 2 mm seems to be the most common. I used a 1.5 mm to correct a driveline problem on my wife's bike because my LBS was fresh out of the 2 mm size that he usually stocks.