thedriveside

All of your 650b conversions are giving me sleepless nights, help me scratch my itch!

I'm in search if a 650b conversion candidate, something that I can squeeze 42-48s in. Requirements are: steel, lugged, 1" steerer, Vertical drop outs and nice lugs are a bonus. I'm willing to add the necessary braze-ons and do a full paint refinish, so it doesn't need to be in great shape.

Treks, Raleighs, etc. Let me know what you've got! TIA

ThermionicScott 

Although it would be sweet, 48s and vertical dropouts might be a tall order. I generally think of earlier frames as having more clearance, and associate later frames with vertical dropouts as having less. If you're not planning on fenders, that gives more wiggle room. I'd be prepared to do some chainstay dimpling no matter what.

Cynikal 

I agree with above statement. Most bikes that fit a 48 were built to fit that. A 42-43mm tires would be more doable on a conversion frame.

I have a 55cm Raleigh record ace that I'm about to list. Modern lugged frameset with a threadless 1 1/8th front end. PM me if interested and I'll send details and measure for tire clearance.

Dylansbob 

Even 42s are somewhat tough to fit in most bikes with the right BB drop. I strongly suspect the only frames you'll find that will hold 48s will have the bb too low or unusable canti-bosses.

rccardr 

Check out late 80's Schwinn Voyageurs. They come with 27" wheels, so conversion to 650B gives you room for 44's, easy. Semi-vertical rear dropouts.
Gugie did this conversion for me about five years ago, required moving the canti mounts around a bit to accommodate the MAFACs, but it worked fine.

rccardr 

Looking back, would do this a little differently today: high quality cantilevers (like Paul or similar) or Tektro 559 sidepulls. Hated those MAFACs, despite info & advice from experts they never really worked all that well at speed. Different levers, too- 6400’s or 1050’s, still non aero but SLR for more leverage. Would have it wet painted by Jack Trumbull, the only painter/powdercoater who’s ever done a good job with making sure those Schwinn lugs don’t get surface rust on the edges. Start with a 48/36/24 triple instead of ending up there. Dump the Concors saddle, which looked good but felt bad after 100 miles in a day.

Other than that, would do it abain in a heartbeat. Gugie’s a prince to deal with and the end result:sublime.

thedriveside

Noted, great tips. Ready to dimple some stays, thanks for the insight!

thanks! Will pass on the frame

Thanks for the note, more research needed on my end re: BB drop. I'm ready to chop bosses and get new ones put on though - part of the fun!

Wow! That thing is a piece of art!! Thanks for sharing!

jamesdak 

My conversion was done with a 1981 Fuji S-12s. Lot's of space for wide tires but it did need some long reach brakes. I put 650b x 42 tires on it with fenders and had room still.

https://www.bikeforums.net/classic-v...e-i-think.html

ThermionicScott 

Somehow I missed that thread the first time around. Very nice!

USAZorro

The 1973 RRA? If so, do you have 42's to try to fit into the front? I have one and it looks like it would be tight. I could attempt it if would be a decision point, but it would mean removing brakes (which I'd rather not do). Now 38's would fit. 48's definitely not.

Cynikal 

Mine is the modern reproduction, came out in 2011 I believe.