Originally Posted by
rustystrings61
Originally Posted by
Ironfish653
700c wheels are easier to find (although not any less expensive) , and 700c tires come in a lot wider range of sizes / styles than 27" However, you will have to replace your brakes, since the wheel is smaller, and the vast majority of vintage brake calipers just don't have enough adjustment range. Also a modern cassette hub is going to need some tweaking to make it play nice with the rest of your 70's era 5~6-speed drivetrain, or vice versa.
I must respectfully disagree. I've owned lots of vintage bikes built for 27-in wheels, and usually if..................and I bet it will work just fine with the smaller wheels.
If you have any doubt, though - before buying 700C wheels, just look at the slots in the brake arms. If you have 4 mm or more space to go down, you're fine. For that matter, you can sometimes substitute a narrower brake pad and cheat things down a bit that way, too.
You're not wrong, although in my case it's been an 'as often as not' situation. Could just be the bikes i've worked on.
So, without measuring, I can't say for sure that the brakes on the OP's bike will accomodate both wheel sizes.
Originally Posted by
rustystrings61
The cassette hub will probably play nicely with 70s era parts, though you'll want a new chain. The only limits you may run into are how far out you can set the rear derailleur limit screws to handle a wider cog block and how much cable pull you get out of your levers. I used to shift a Campagnolo Olympus mtb derailleur over an 8-speed Campagnolo cassette hub with 70s SunTour barcons and it worked, but I had to have everything dialed in just so to get all 8 gears. The modern cog shapes and a modern chain on old derailleurs usually shift very nicely, though.
One of the nice things about C&V is the amount of mixing and matching you can do to get sometimes 'off-the-wall' combintations to work. And yes, modern 'SIS' cassettes (even freewheels) and 8-sp chains do make an old bike shift nicely.
In the case of the OP, I should have been a little more specific. He states he's getting ready for a multi-day trip, and not knowing what sort of support / mechanical skill he has, recommended the course of action that changes the least number of components. No sense in missing the start date because you were waiting on parts, or suffering through a trip with a bike that doesn't quite work right.
I should have been a little more specific about that.