Chainset replacement

leaflite

TheRevOlutionary wrote:

nicklouse wrote:

TheRevOlutionary wrote:

Thanks again guys, crankset ordered from the bike-discount website and a BB from Woolly Hat has hopefully sorted my issue! Also very happy to find a little tool kit that will be useful, and looks smart too!

http://www.bike-discount.de/shop/k1262/ ... ieces.html

that is actually well thought out. quality? let us know.

Will do...not sure how long it will take to some from Germany though?

Should be 1 week or less. Ive ordered stuff from other German sites before and the items have always come promptly.

TheRevOlutionary

Despatch has already been confirmed, so hopeful i'll see it before the weekend.

TheRevOlutionary

Received Wednesday fitted, and fantastic little tool kit - see Buying Advice for picture and review!

Issue though...

Front mech has been adjusted (height) and tried to tweek the shift so it moves nicely on the front rings, but cannot get the cage to reach to the top ring consistently! If you pull the cable you can just about get the chain on, but it rubs on the cage, and no amount of adjustment with the H or L screws sorts it. So far can use bottom and middle ring no problem, and shifting is good, but what can be wrong? New mech needed? It sometimes jams at the outer adjustment too, so does it need soaking to see if it frees it up? Crazily it was fine on the outer ring of the previous crank set, although the axle was technically 10mm shorter with that BB, so does that 5mm each side mean the adjustment is not possible?

nicklouse

Axel length means nothing. Chain line does.

Axel length only changes chain line on the same crankset.

Different cranksets use different axel lengths to give the same chain line.

What did you end up fitting?

TheRevOlutionary

Original crank set was Truvativ Isoflow, 44/32/22, and bought the Shimano M431 (http://www.bike-discount.de/shop/a34687 ... id=8008404).

Any help?

nicklouse

So that is only half the story.

What BBs? And axel lengths?

I know what was suggested but what was and is actually there?

TheRevOlutionary

Apologies;

Original BB 68 x 113 UN54

Now 68 x 122.5 also UN54

Shimano tech sheet suggests 123mm?

TheRevOlutionary

*bump

Anyone...?

nicklouse

is the mech catching on any thing?

TheRevOlutionary

Like?

The mech makes full movement when pulling the cable manually, but sometimes jams in the top ring position - ie when you release the cage to middle ring you need to tap it to make the movement. The chain has made it on to the outer ring, but when the cage is at full extension it still doesnt line up correctly.

Furthest reach of mech;


Middle ring position;

Chunkers1980

mech at the correct height?

nicklouse

TheRevOlutionary wrote:

you need to tap it to make the movement.

there be your problem.

what is it catching on?

TheRevOlutionary

Nothing obvious, just siezed? Tried plenty of WD and working it in out out, and it worked fine on the previous crankset, so I'm guessing that the extra reach is more than the mech is 'used to' so sticks? Doesn't help the reach issue though surely?

nicklouse

measured the chain line? what are you getting.

TheRevOlutionary

With my very technical ruler and naked eye it's between 48/49mm, about where it should be?

nicklouse

which is also where the old one was so there should be no issues.

i would look to the mech alignment and height.

TheRevOlutionary

Height is no more than 2mm above the outer chain height when extended, and alignment allows the inner and middle ring to go 1-9 on the cassette without rubbing except on inner and 9 which I'd never use anyway!

Forgive my ignorance, but how are those going to help the mech reach outer ring?

nicklouse

Hang on. You are saying it is not even able to reach the chain ring? And the Chainline is the same?

Have you fitted the cable correctly?

TheRevOlutionary

Not sure what the chainline was before, but must be about the same at 48mm.

LBS has checked the cable and adjustment, but neither of us are any the wiser. It's a BMX shop though, so not sure how much they'll know about MTBs!

nicklouse

Back to the beginning. Has the cable been removed?

Pics of cable attachment if it has been removed.

Even if it has been fitted by the lbs.

TheRevOlutionary

Cable was only loosened to adjust the mech up the tube, but here is a pic anyway;

nicklouse

Looks more like a 530 front mech and the routing looks odd but as the pics are so small i can not say.

TheRevOlutionary

Here's a direct link to the original;

http://i42.photobucket.com/albums/e303/ ... G_0399.jpg

It is indeed the FD-M530, but that should be suitable for 42-48teeth according to Shimano?

nicklouse

still the same size. and zoom in and blurry.

TheRevOlutionary

What do you need? I can take another picture and make sure it's not scaled down?

TheRevOlutionary

Anyone?

I'm getting frustrated with this now! Shall I just take a punt on a new front mech? If so, which one?!

leaflite

Im guessing that the cable tension isnt quite correct.
Re setup as per:
http://www.parktool.com/blog/repair-help/front-derailleur-adjustments

TheRevOlutionary

leaflite wrote:

Im guessing that the cable tension isnt quite correct.
Re setup as per:
http://www.parktool.com/blog/repair-help/front-derailleur-adjustments

Been there, tried that!

This really is bamboozling me. I've lost count of the number of similar forum posts I've read, with varying solutions, but none that have fixed my issue! Thanks though leaflite

nicklouse

TheRevOlutionary wrote:

What do you need? I can take another picture and make sure it's not scaled down?

Please just those two not scaled.

TheRevOlutionary