Ideas?

[lukesdad]

My Cannondale M2000 circa 1991 is very tired, and needs some attention.

At the moment its 7 speed triple with a ritchey logic chainset and shimano xt drive train and thumbshifters that can be used as either indexed or friction.

As decent 7 speed stuff is hard to get hold of ,here are my thoughts.

Drop in a 9 speed rear wheel and cassette, Ive got an old XTR rear mech if the current XT wont work. As I want to use it on the road as my winter bike thinking of putting a road chainset on the front double or triple the bottom bracket is a square taper. Will this work do you think?

Particular concerns would be;
Would the shifters throw the cages far enough?
Would i need to change the bottom bracket. I d like to stay with square
taper if I can would a road triple fit the existing bottom bracket.
Any other issues I might encounter?

Any thoughts would be appreciated.

 

[jpembroke]

You'll need to upgrade the shifters and chances are BB will be too wide - but that just means you'll have be showing a lot of spindle, if you know what I mean. It's a case of give it a go and see what happens.

 

[Landslide]

Old thumbies have a "hidden" extra postion, so you could use an 8spd cassette (on a Shimano 8/9/10 freehub). Alternatively, you'll probably get away with using them on the friction setting on pretty much any cassette.

As for the chainset/BB scenario, it's probably a case of "suck it and see".

 

[Steve Austin]

You can use friction shifters with any groupset. ie my daily ride uses 20 year old friction shifters on a 10 speed cassette.

The current BB will probably be too short and the road chainset will sit too close to the chainstays. Youcould try a longer BB but then you still might have problems with the larger chainrings a road chainset sawing through the the wide chainstays of the MTB frame.

 

[Landslide]

The current BB will probably be too short...

My gut feeling is that it'll be quite a long BB axle. 1991 components will (probably) be pre low-profile cranks, probably c.122.5mm for a triple.

 

[Steve Austin]

oh yeh!. You are probably right! low profile came in about '94?ish

 

[lukesdad]

Thanks guys ill have to measure the bottom bracket length. Are all square taper BBs the same size taper or do they differ ?

 

[Landslide]

There are 2 types of taper, JIS (Shimano and others) and ISO (Campag and others). See Sheldon for more info.

 

[lukesdad]

Thanks for that Landslide.

 

[lukesdad]

right sorted that used some compact chainrings on old triple mtb chainset 50/34 a bit low can I get larger compact rings or is that it.

 

[Landslide]

You want 110mm BCD chainrings.
Spa Cyles (other LBSs are available!) have a huge range of sizes available, from 33-61T, though they do get a little pricey in the more esoteric sizes!
http://www.spacycles.co.uk/products.php?plid=m2b0s113p0

 

[lukesdad]

Thanks again Landslide.

 

[lukesdad]

Well its all worked. Shakedown went well, all i ve got todo now is sort out a headset.