noobinsf 

I have a kinda-sorta cross post on the tandem forum, because I am ultimately asking about a tandem frame. However, I have a narrower question for this other collective font of knowledge, specifically about Mafac cantilevers. In general, is there a substitute that works for bikes that use these brakes originally, like a vintage canti (like Dia Compe), modern canti, or v-brake? Also, something that allows the vertical adjustment to swap from 27" to 700c?

I just don't want to be locked into using 27" wheels and Mafac cantis if I can use something else with the frame.

Thanks for your advice!

79pmooney

I picked up a Miyata 610 that was probably built ~1983 many years ago with Shimano cantis. Never learned the model #. First ride it was obvious they had all the stopping power of my Mooney's Mafac cantis, same feel and were just plain better, easy to work on brakes. Very soon I swapped the brakes. Those Shimanos have been on the Mooney for 31 years and 40,000? miles.

Now, I had the Mooney built with the canti bosses set midway between 27" and 700c. The 2mm vertical offset is easy. (A very worn and neglected pad can slip down off a 700c rim in a hard stop so be aware. It would be 4mm for you, going to 700c. I'd use rims that had fairly deep and square brake tracks for wet day security.

cyccommute 

Paul Neo Retro. Paul Touring if you want something with lower profile.

JohnDThompson 

The only real problem with 27" wheels is the dearth of high quality tires for that size.

ollo_ollo

Quite limited tire choice compared to 700c plus a change to 700c can make an almost too big frame into a slightly more tolerable one. Otherwise nothing wrong with 27" per se. Don

noobinsf 

Absolutely nothing wrong with 27", it's just that I have a 700c wheelset on hand that I'd want to use on this canti project, so if I could manage the conversion, I would. I also have spare 700c tires for the hypothetical project, come to think of it -- just would want to use what I already have in my stash rather than add to the stash for a specific new project. It's a non-issue with most calipers, but cantis make for more trial and error, and I'm just trying to avoid having a project sit unfinished because of this barrier. My time to dedicate to bikes is pretty limited these days, so I'm just trying to separate impulse buys from things I actually want to work on and ride.

I wonder how long until we see a gravel penny farthing.

79pmooney

Also allow more room for fenders and bigger tires. My city/rain/winter bikes have been converted to 700c for the past 45 years. (7 of 8 frames; I had to cut the fender for the one 700c frame and go no larger than 25c tires,.)