noobinsf 

I am communicating with a seller and seriously considering my first foray into tandem cycling with a '76 Paramount frame. However, I am a little stumped as to brake options. It originally had Mafac cantilevers, which of course would cost a pretty penny to find. Also, it originally had 27" wheels, and I'd like to use a spare 36-hole 700c wheelset I have lying around, just to get the thing off the ground and rolling. Can anyone offer advice on these questions?

1. Can I use a modern canti, like something from Tektro?
2. Would it be possible to swap in V-brakes? I like V-brake performance, so I would not be opposed to this if something would work.
3. Which brake choice will have the vertical adjustment that allows me to use 700c wheels?

Thanks in advance for your thoughts and advice!

headasunder

700c wheelset will be fine as long as the axle spacing is compatible, regarding the brakes it will depend on the post spacing as to whether more modern canti or v brakes will fit with enough clearance to fit the pads my old tandem didn't have room for a modern canti or v brake as the posts were to close together.

noobinsf 

Do you recall the distance between the posts on your old bike? I'm just curious how narrow is too narrow, based on your actual experience.

headasunder

Approximately 65mm, standard spacing is 80mm

jccaclimber

This link may help answer that as well.
https://velo-orange.blogspot.com/201...izing-psa.html
The TLDR is that current cantilever post spacing is in the 77 to 85 mm range, but some older bikes have it in the 55 to 65 mm range. I just checked my tandem and it's about 83 mm post to post. Estimated as I didn't pull the wheel or v-brake arms. My rim is around 23 mm and it has plenty of clearance even with new pads. Now, make that 20 mm smaller, things would probably clear. Go 30 mm and not all v-brakes are going to retract strongly enough without tweaking the return springs a bit, possibly putting the pads at a funny angle, etc.

Backing that up, our first tandem has 69 mm c-c spacing on the brake posts and I also ran a 23 mm rim on it. I didn't have issues running v-brakes, but it was a 650B to 700C conversion (why I took off the brakes from Mafac cantilevers to begin with) so the pads were a bit higher than normal on the v-brake arms. I'm not sure this would have worked very well with really wide rims either.

jccaclimber

One additional thought, I have a Mixte 1976 LeJeune that doesn't need to go home, but it can't stay here. You're not far from me, so I'll send you a PM.

jim_pridx

I did the very same conversion with our 1980 Richardson tandem several years ago. It also came with 27" wheels and Mafac cantilevers. While some brakes will likely work with your 700c wheelset, you might find that you'll need to go through a little trial and error to find a set that actually works well. While at the moment I can't give you any definite numbers regarding spacing and height placement, I did find some cantilever and V-brakes that were indeed suitable for the job. The key is to find a set that'll have a little more inward/outward flexibility as well as having a reasonable amount of vertical downward travel, for you'll need to drop the pads by a few millimeters to work properly with the rims. In our case, I had a vintage set of Dia Compes that worked pretty well, and I found a Tektro set that worked on the rear but not on the front. I also used a set of Shimano V-brakes for a while that were okay, but the pads should've been sitting a bit lower than they were, so they certainly weren't ideal. And finally, I tried some brakes that didn't work at all, so it can potentially be a pretty messy matter. Of course, there could be a number of brakes out there that could work very well without me knowing about them, but I have had pretty good luck with the vintage Dia Compes.

noobinsf 

I really appreciate everyone's advice! It's helping me think about whether this is something I *really* want to try or just an impulse buy.

Leisesturm

I personally think you would be dodging a bullet if you keep your powder dry and buy something at least 20 years closer to the present date. I had two bikes from 1984 and they were both ready to ride. A frame up build from 1976 ... OMG ... Ebay would be sending you love letters. Good thing because your spouse would have stopped. Don't do it. The brakes would be the least of it.

noobinsf 

The ad disappeared before I had a chance to buy it, and thanks in part to this thread, I felt relief rather than regret. For someone else, I'm sure this will be a labor of love, but I'm confident that it would have become a quagmire for me. I've worked with a good number of vintage bikes by now, and a bike that presents a host of unique issues has its place, but I'm trying to be more careful about that these days.