27 inch tire to 700c retrofit?

Question

Can a bike (Schwinn Voyager) with 27 inch tires and cantelever breaks be retrofited to accept 23 or 25 x 700c tires/wheels?

Answer 1

Are you SURE that the Voyager has cantilever brakes?! I am pretty certain that it has caliper brakes... centerpull calipers and cantilevers are vaguely similar but cantilevers have separate posts on either side of the frame or fork to which a single arm is attached http://www.flickr.com/photos/cookiem/209...  while centerpulls have both arms attached to a central body which is attached to the frame or fork through a center hole http://www.flickr.com/photos/lanceorama/...

I'm going to assume you have centerpulls.

The answer is no, you can't easily trade 27" wheels for 700C but it IS possible. There are a couple of ways:

1) Purchase a drop bolt for each brake caliper. This replaces the existing mounting bolt and brings the caliper down... 700C is smaller than 27". Drop bolts are very hard to find. They were common during the early transition between 27" and 700C but are quite rare now;

2) Try to find some longer reach calipers. This is probably going to be tough since the Voyager already has long reach calipers, or;

3) VERY carefully file the slot that holds the brake shoes to make them longer with a round file. You'll have to remove about 1/8" of material. This is a very last resort and will weaken the arms. The goal here is to allow the brake shoes to fully engage the rim without the shoe hitting the tire.

You'll also need to consider that the Voyager is likely a 5 speed rear which means it has 120mm spacing between the rear stays. Modern wheels- at the very least- have 126mm spacing with most road wheels having 130mm spacing. It is not a good idea to "spring" the stays out to make room for the wider wheel, so it might be necessary to visit a shop and have the frame reset for the wider hub.

Good luck!

EDIT: I found another solution. I remembered seeing this a long time ago and it finally surfaced in my brain. I don't like to provide links but a picture is worth a thousand words...

http://sheldonbrown.com/home-drop.html for a home made drop bolt configuration.

Answer 2

Those two gave good answers already, so I'll just add a bit since I've been through this a few times.   First off, if you have cantis you're probably out of luck.  If you have center or sidepulls, then you might be able to do this.  It depends on the frame size and how it was made.....and everything has to do with getting your brakes to reach the new, smaller rims.  

If you have a large frame size, chances are that you won't be able to do it....but measure the drop that you have now (from the center of the brake to the center of the lowest position the pads will go).  Then look around at the long-reach and extra-long-reach calipers on the market and see if one will work.  For two of my old bikes, the ONLY brake that would work was a newer dual-pivot model from Tektro.   It's the R556 and you can see it here:  http://www.tektro.com/02products/10rb-1....   Even many of the "long-reach" calipers still weren't long enough to make 700c's work for me.

Mirage is right about the frame spacing on the rear wheel.  I had a good shop spread my stays to 130mm (from 126mm) with no problems, but you have to have someone experienced do this....with the right tools....and on some frames it's just not a good idea at all.  

Another rather stupid option if you have a local framebuilder or handy bike people to employ, is to have them undo the fork, cut the legs short, rebraze them to the crown.....and have them drop and rebraze the brake bridge on the seatstays.  This means repainting the frame, too, of course....see where it's getting stupid?   LOL.  People have done it, though.  It would make more sense to buy a more modern frame (even one from the early 90's) for a couple hundred bucks.   It quickly becomes a money pit when you try to retrofit an outdated frame like that.  

If you're having problems finding good 27" tires, check out Nashbar.  They even have some rockin' Panaracer Paselas with kevlar belt on sale for $9.95 right now, and it's a pretty good tire.   Decent 27" rims are hard to find and the only ones I've seen have been heavy and squarish.   It's the dinosaur size now and probably won't be around for too much longer.  

Hope this helps some...hope you can keep that old beast running!    :o)

Answer 3

I worked part time in a Schwinn bike shop during my college years. Some Voyagers had cantilever brakes. They were Schwinn's "touring bikes" of those years. You should have very little problem using 700c wheels in place of the old 27s. 700c wheels are...... just a hair..... smaller than the old 27s. So, you may have to readjust the brake pads, but that's about it.