93 Marin Technical Question

[OnaMishun]

Hi Everyone

I have a 1993 Eldridge Grade that I’ve converted for touring. Part of that was adding a compact triple chainset (sugino impel). Since doing that I occasionally strike the frame with my right heel. I measured the crank to stay distances and the right crank is half a cm nearer to the stay than the left...

Is it simply a case of adding a bb spacer on drive side? I’ve noticed my old Kuwahara (same bb arrangement) has a spacer at bb drive side so am assuming it can be done. Will this work? I only need a few mm’s of clearance.

Cheers!

 

[hamster]

Assuming it's a cartridge BB, then simply buy and fit a longer one. You cannot just fit a spacer as the left side then is unsupported fully. At best it will creak, at worse possibly damage itself and the shell.

However if it's a loose BB, it sounds like the shaft has been inserted the wrong way round, it's quite common for asymmetric BBs to be longer on the RHS.

 

[pommieMJ]

Re:

Hi,

If it were me with this issue here's what I would do.

1. Make absolutely sure that I've got the BB in correctly and seated properly.

2. Check the clearance of the old chainset against the new to make sure that it it definitely the new chainset.

3. If it's the new chainset, then I would definitely look into getting another compact chainset but this time I'd make sure I get the right clearances

Maybe you could post a couple of pics and give us some more details on the bike. Which year? BB shell size? Spindle size? BB model and anything else would be very handy.

Cheers.

 

[nporternz]

Did you change the BB as well as the chainset?

What chainset was fitted before?

 

[Once A Hero]

Re:

Has the OEM BB been changed?
Pics or details of the chainset and BB will help us, however, the tables found here: https://www.sheldonbrown.com/bbsize.html tell us that the original BB with the OEM spec '93 chainset (Deore LX M560) would have needed to be a square taper of 113-118mm in length.

Unfortunately the only Sugino Impel chainset listed isn't compact, and would require a square taper BB of 110-113mm in length.

The overall length of the BB axle isn't the only factor on where the crank arms end up, as there is variation in the length of the tapered section onto which the crank attaches. So it's important to match the BB with the chainset. Quite what BB a compact drive Sugino Impel needs I don't know.