Front mech and chainset problems

[sikora]

I'm posting this up for a friend who's recently kitted out his GT Aggressor frame with new components.

The problem he's having is that the front mech wont reach the largest chainring.

I'm not sure on the make/model of the Chainset or Bottom Bracket, but i know the bottom bracket is an older style - both were supplied and fitted by his local bike shop.


i49.photobucket.com/albums/f271/hektik2006/DSCF1289.jpg

i49.photobucket.com/albums/f271/hektik2006/DSCF1286.jpg


The shop have assured him that everything is fitted correctly, but looking at the pics i dont think they are.
The bottom bracket looks like it could screw in further, and the axle looks like its sticking out too much. Anyone agree?

I'll get him to take i close up photo of the bottom bracket

[Oggy]

Carnt tell feck all from that crap photo mate ;D but have you tried adjusting the upper limit screw which will allow the front mech to reach further over?

[sikora]

Whats wrong with the photos? I'll get a close up one of the Bottom Bracket, but those above show the distance the chainrings stick out.

The mech is at its furthest reach and will only run on the middle chainring

[gw8izr]

measure the axle from the bearing surface to the spline - even though its a crap photo, it looks like the axle has been fitted the wrong way round.

[Oggy]

It does look like the axle is to long, what length is the axle?

[gw8izr]

If you measure from the centre of the seat tube, use the cage lugs as a reference on that frame - to the middle ring it should measure 48mm ( I think there is a tolerance maybe a mm either way.. dont quote me)

My old campag axles could be put in the wrong way round which would put the chainring out of line but you need to take the axle out to see if thats the case with yours.

I put the middle ring in line with the middle of the block but I think most of you hard core MTB men set the small ring in line.. YMMV

I guess in this order check :- Limit screw not adjusted - incorrect axle length, axle in wrong way round.

There may be other reasons but thats wot I'd check first.