MTB gearing to road bike

[buzzkirk007]

I have recently bought a Viscount Grand Prix. I also have a Claude Butler MTB with a 21 gear Shimano setup. Would it be possible to transfer all the rear and front gearing along with the controls to the Viscount? I have already added straight bars.

 

[RecordAceFromNew]

Chance is not many, I suspect, but it all depends on what the bikes have at present.

If it is original I suspect the donee is 5/10 speed with 120mm rear dropout distance? If so the donor's 7 speed cassette won't transfer, which means the 7 speed indexed shifter won't either without a new rear wheel and some faff. It is also possible that the donor has different seat tube diameter, chainline and bottom bracket shell width, if so the chance that the front mech, chainset and bottom bracket being transferable is also not good. Components that are more likely to be transferable are the chain (if the Viscount drivetrain doesn't require a longer chain than what the CB has) and the rear mech (if both frames have or don't have hangers).

You might be better off refurbishing what is on the Grand Prix and/or selectively purchase compatible components, if necessary funded by selling the donor or donor components.

If the Grand Prix has alloy forks, you should read this.

and good luck!!

 

[buzzkirk007]

Many thanks for the reply, saved me a lot of work.

It does not have the death forks I think it is slightly later.

 

[tyred]

The thing to watch for is the taper on the bb axle. Several were used I believe and some are non standard. The bb design is non standard in the first place but this is a minor inconvenience and very easy to overhaul. The bearings are a standard part, available for 99p each from ebay. I can dig up the part number for you if you need it. Straight, square tapered bb spindles in the correct 17mm diameter are out there if you need a different one. I bought one from someone on Spanish ebay in the width I needed, it was very cheap but postage wasn't.

These are a very under-rated bike imo. I love my Aerospace, and it's lighter than my 531 framed Carlton.

 

[tyred]

Oh, and if you are re-using the original bb spindle, check carefully for any evidence of cracks around the circlip grooves. They have been known to break at this point. Replacements never had the circlip grooves and it makes no difference whatsoever.