Drivetrain advice

[stumpysteve]

I need to replace the entire drivetrain on my friends 18 year old bike as the old chain has since snapped and the new chain I put on is jumping like crazy.

It has a shimano 6 speed rear cassette 11-24, a 38/32/24 Tracer crankset with non replaceable chainrings and a Suntour 68 x 118 bottom bracket.

The front mech is a Shimano Altus C90, bottom-pull/clamp-on 28.6 mm.
The rear shifter is 6 speed SIS.

Here are my questions:

1 - I have looked for a replacement 6 speed cassette but can only find one in the US, which would be expensive with postage. Would a 11-28t 7 speed be OK (there is a spacer behind the existing cassette)? Obviously I wouldn't be able to use the 28t ring with the shifters.

2 - I want to keep costs down and get a cheap set of replacement cranks, most seem to have a 42/32/22 teeth, would this be OK with a 11-28 cassette?

3 - Shall I stick to the same bottom bracket length even though I am going to change the cranks.

Any advice would be gratefully received

 

[MikeD]

Is it definitely a cassette? From the age and the rest of the spec there's a fair chance that it's a screw-on freewheel. Either way, a seven-speed won't go on as a straight swap, because it's wider to the tune of one sprocket and a spacer.

 

[South Bound]

Hmmm, unless this is a retro classic (you don't say if it is!), you could end up spending a fortune on this. Get him to cough £150 and buy a complete Kona from here, save all the hassle of out of date parts.

 

[mattpayne]

deffo a screwon...

but, as southbound says... unless there is some sentimental, is it really worth going there?!

 

[Augustus]

Where you been Matt? Good to hear you're about.

 

[mattpayne]

ive been on and off... but mainly just lurking! off to cannonk on the 21st to show a few modern 4" types what a real bike can do!!