650B musings
 

Picked up a '77 Raleigh Competition GS yesterday, original except for the saddle (as usual) and the pedals. It is not as nice as the black 1979 I had before, but still quite decent. After converting two other bikes (1986 Trek 310 and an '86 Bianchi Sport SX), trying it, not being completely satisfied with the outcome, I think this may be my next victem. I think brakes may be a problem due to decent clearence though. I used MAFAC 2000's on the last builds and they barely made it. Any advice that does not include Dia Compe 750's, or Zaphoods genius-yet-expensive drum brake solution would be appriciated.

This chart might help. http://ruedatropical.com/2009/01/maf...l-brake-specs/
Or you could follow J.P. Weigles lead and have Cantilever bosses installed.

Cheers,
Chris

Which is what I did. However, it requires the frame to be repainted afterward. If the frame's original paint is in good shape, it makes less economical sense to go the cantilever route. In my case, I knew I was going to have the frame PC'd anyway, so for an additional $75 it was worth it to me to add properly placed cantis studs.

Neal Lerner did a Raleigh Comp GS 650B conversion: http://web.mit.edu/nlerner/www/Competition650B.html

I think Mafac 2000s and Racers are about the same reach. I used Racers on this Comp GS conversion and it worked fine, but it pretty much maxed out the available reach. You can always add a few millimeters with a file.

http://i229.photobucket.com/albums/e...s/P1010019.jpg

http://i229.photobucket.com/albums/e...s/P1010016.jpg

I love the tall stem. Is it a Technomic?

Yep.

its not that expensive.

you can do a Sturmey 70mm drum brake for 60 bux shipped., and a shimano FHR-700 for 30 bux maybe plus shipping. spokes be 35 bux, and you can spend between 70 and 200 on a pair of rims. or find a donor wheelset and snag the rims.

then build!

or try the super long reach Tektro dual pivots. They make em nutted for old frames.