phenry24 

I'm building up a BS T700 and am stuck with 27" wheels since I have yet to find proof of someone discovering cantis that will allow for a 700c conversion. The rear dropout is 126mm and I'm not entirely opposed to spreading it to 130mm. Since the only 27" wheels I have laying around are steel, my options for this bike are:
1) build new wheels with the Sansin hubs I have (36h front, 40h rear) with Velocity Synergy rims since those are the only ones I've found with both 36 and 40h drillings in 27". This would leave me with a freewheel but I wouldn't be spreading the rear triangle.
2) find some alloy 27" rims/wheels on eBay and hope for the best (Craigslist offerings around me are scant at best)
3) Lace a 36h Sun CR-18s to new Tiagra hubs. This would allow for the added durability of a freehub over freewheel.

Any suggestions? I'm leaning towards option 1 since that would put those hubs to good use.

bikemig 

I'm running 700c wheels on a bike designed for 27 inch wheels (a 1983 trek 720). I'd post a question on bike mechanics first to see what suggestions there are for cantis that can to this job. I'd be leery of building a 27 inch touring wheel if a 700c will work on your frame.
You're talking about 4 mm difference. Shimano cantilevers appear to have good up and down adjustability and might work.

https://www.chainreactioncycles.com/u...A&gclsrc=aw.ds

phenry24 

I've done a lot of digging on the internet and have only found a few examples of failed attempts, but maybe performing a 700c conversion on a T700 is a Bridgestone owner rite of passage that must never be spoken about once completed.

But in all seriousness, thanks for the suggestion, I'll post over there and see what they have to say.

icepick_trotsky 

If you want to maintain your current spacing, these are a good value:

WEINMANN LP18 SILVER 27 126mm ROAD 5/6/7 speed wheelset [72774716654] - $99.00 Velomine.com : Worldwide Bicycle Shop, fixed gear track bike wheelsets campagnolo super record vintage bike

bikemig 

I'm running some old modolo cantilevers that work just fine with 700c wheels on my 1983 Trek 720. They'd be tough to source (and their set up is kind of weird) or I would have recommended them. I had no idea you weren't supposed to run 700c wheels on a bike with cantilevers designed for 27 inch wheels when I built the bike. So I just went ahead and did it when I bought the frame since I preferred 700c wheels. I had a pair of modolo cantilevers lying around and they worked great. I rode across the country on this bike in '97 and never had an issue. Lately I've been running the bike as a single speed commuter but I should rehab it and get back into touring trim.

icepick_trotsky 

In this blog post, Velo Orange recommends Tektro 720s for 27" to 700c conversions, because they have a lot of adjustment.

The Velo ORANGE Blog: 27" Wheels and Measuring Brake Reach

I haven't tried them in a conversion, but I do have these brakes on a bike and like them a lot. Good looking (enough), inexpensive, and very easy to set up.

desconhecido 

I think you can get wheels with CR18 rims from the same place for not much more money. The LP18 rims are sort of narrow, the CR18s a bit wider than the LP18.

bikemig 

There is a second problem which is that the canti posts on older bikes are narrower than has become the norm. That may make it impossible to properly adjust the cantilever brakes. I tried some tektro 720s on a 1993 bridgestone xo-2. They worked fine on the rear but gave me headaches on the front. I ended up going with a suntour xc pro cantilevers and they worked fine. The posts on this bike are considerably wider than on my '83 Trek 720 and the tektros still didn't work.

dailycommute

B/c of low demand one can sometimes find great deals on alloy 27 in vintage wheelsets. I picked up a set of araya mid 80s alloy 27s that were NOS on ebay for around 40 shipped. Put some paselas on them and they were rock solid for touring or commuting duty.

mparker326

If you have a bike coop, stop by because they have tons of 27 inch wheels laying around. Also, some LBS will have used sets laying around for cheap as well. Another thought is to post a WTB add on Craigslist.

inkandsilver

If you don't fear the Helicomatic I have a nice low-mileage set that I would let go for cheap.

SkyDog75

You beat me to it.

I have a set of LP18's on a Peugeot UO-8. Their internal diameter is under 14 mm, which means a 28-ish maximum tire width according to the charts published by the ETRTO, Sheldon Brown, and others. Those charts are conservative and there's some room to fudge upward, but LP18's aren't ideal for wider tires. CR18's are a better choice for a touring bike.

desconhecido 

Thanks for the confirmation. I tend to get a little blind about wheels and rims because almost all the wheels I build are for 650A wheels and the CR18 is about the only decent rim available. Particularly in that it comes in 32 hole and 40 hole so you can use them on old Raleighs and other British bikes. Then I ended up building several sets of 700C wheels with CR18 rims and a couple 27" wheels too. So I kind of have CR18s on the brain and sometimes don't know if I'm maintaining objectivity.

The Golden Boy 

I've heard the two vintage cantis that work well are the BR-MC70 and M732 Deore XT cantis.

Out of those two, the M732 have more adjustment.

Forum member Robatsu built up a 1985 Trek 620 and detailed his choices in his blog: Fuji Otaku: The Phoenix Project - Shimano M732 Cantilever Brakes




The brakes I would be most willing to try are the XC Pro brakes- as they can be tensioned from any point in the arc.

I totally lucked into finding a set of 27" Phil Wood/Super Champion 40 spoke wheels. The finest wheels I've ever had, and probably have spoiled me for any other set of wheels.

phenry24 

Do you know of any major differences between the M732 and M730? I have an M730 set that I could borrow off a Miyata I just put together for my mom to see if they fit, just by looking at pictures online they look very similar.

And I've seriously considered buying some XC Pros to see if they'll work, all I've been able to find on eBay is some pricey NOS stuff so far though.

I've looked for 27" 40h CR18s and have yet to have any luck. Do you know where they're hiding?

Thanks for the offer, but I do believe I'm afraid of the Helicomatic

clasher

I had an early 80s Bianchi Randonneur a few years back and I think it was designed for 27" wheels. The comments above about canti post spacing on earlier bikes was totally true in my case. I used some dia-compe cantis, I think they were 981 or maybe 983. They came with the bike and I purchased a 700c wheelset that was built around generic hubs and the cantis worked fine. I didn't have the original wheels so I dunno if they were 27" or not. Modern cantis didn't work since they all seem to be designed aroun 80mm spacing between the posts. I guess I should fish all the dia-compe cantis out of the bins at the co-op they seem to be in demand.

Standalone 

Long reach dual pivot front brake is also an option. I have a Trek 620 that has serious brake judder on the front. I'm running 27"s but am ready to just switch it out and get reliable strong modern braking on the thing....

desconhecido 

I was referring to the 650A 590 mm rims. Those are readily available in 40 hole probably because of the plethora of English three speeds with 40 hole SA hubs. I don't know of any CR18s in 27" with 40 holes. Sorry for the confusion.

A quick search did turn up an ad for Velocity Aero rims in 27" with 40 hole. Someplace called smartbikeparts.com.
Velocity Synergy is advertised on the Velocity site in 40 hole. $85 each (ouch). The Dyad comes in 700C with 40 hole -- doubt 27" though.

There are some black with black sidewall CR18s still out there in 700C with 40 hole. I bought one from bikewagon.com for about $20 including shipping.

Is going to 700C an option?

mrv 

i'm really glad no one told me i COULDN'T run 700mm wheels on a bike built for 27in wheels
- i used to switch back and forth frequently on THIS CANNONDALE, depending if I needed the 700mm wheels on another bike.

and i've done it on THIS BIKE with dual pivot caliper brakes (57mm long reach)

phenry24 

If my eyes aren't fooling me I'd say those might be 960s, but they very well could be 981s given the two look so similar.

I haven't completely ruled out finagling some calipers on there, but I'm saving that as a last resort if I absolutely need to go 700c for some reason.

Ah, understood. Going to 700c is the ultimate goal, this thread has actually rejuvenated my interest in trying to find a solution for the brake issue.

desconhecido 

I just checked bikewagon and they still list those 40 hole black on black 700c CR18 rims, now for just under $20. The one they sent me is a fine rim, now built up with a 40 hole SA AW hub. I don't think there is a big demand for those rims.

clubman 

Best /toughest vintage 27's I've had were Weinmann concaves with any decent hubset. Lots were made too.

The Golden Boy 

I *think* the only difference is the spring tension adjustment for load balancing.

Just a guess, though.

I've always thought the XC Pro brakes are THE prettiest canti brakes ever made.

mparker326

they stopped making them. I found one about 4 years ago, but it was hard to do.

I have 2 used Weinmann concaves in good condition that have 40 holes and are 27s. You are welcome to one of those if you are willing to pay shipping.

The Golden Boy 

After doing a bit of remembering- I do believe those particular Maillard/Matrix rims are quite nice... 700 level hubset, if I'm not mistaken...

(from the Trek 720?)