Changing Rim Size - Road Bike

Question

Okay so I have an older bike (I've posted about the bike itself before) and it has 27in tires...

Now, that's not really practical for getting new tires put on... So I want to change out the rims to a 700c(622)... I figure I can, because that's smaller and the clearance should be there...

Is it okay to do this and would any modifications be necessary (besides the possible rim brake modification)

Answer 1

Contrary to the other answers, it is pretty doubtful that you can go from 27" to 700C.

Although it is true that 700C is smaller it is probable that you won't be able to adjust the brake pads low enough to fully engage the rim without nabbing the tire as well.

See if you can get a friend to lend you one of their 700C wheels and try it on for size. Try to adjust the pads... if it works you are good, if not you'll likely spend more upgrading than the value of the bike.

Another possible glitch is the number of rear gears. It's tough to find 5 or 6 speed rears anymore and you can't simply go to 7, 8, 9, or even 10 gears without frame resetting and possibly drivetrain modifications.

Answer 2

I've done this before and yes, the tyre clearance is fine but getting the brake calipers to reach the rims can be a real pain, I think at the time I had some longer reach weinmann calipers I swapped on.

It would be easier to shop on ebay for some new 27 inch tyres for now, I've just checked and there are 5 pairs in UK, and 1 pair in USA going, which indicates that they are on the decline - I'm guessing you live in the USA, by your spelling of tires!

My advice would be to get some new tyres for now, if you can, and use that extra time to shop around for a good replacement bike. It would be a lot cheaper to get a second hand road bike (you can get them for peanuts in UK) than to invest in replacement 700c wheels, and then try to find calipers that will fit.

Answer 3

Yup. 27" and 700C are pretty much the same size. I did it without any mods to the brakes.