700c wheels on frame meant for 27" wheels

A shy person asked:

Quoted message said:

I have an old Oyama road bike with 27" wheels that are beyond repair.

Can one replace the damaged 27" 5-speed rear wheelset with a modern 700c 9-speed rear wheelset?.

There are two issues: Width and diameter.

5-speed wheels/frames usually are 120 mm wide where the axle fits into the frame. 8- and 9-speed
road wheels/frames are 130 mm wide.

It is not difficult to re-space an older steel frame to work with modern hubs. See: sheldonbrown.comframeOpen ↗
spacing.html

The other issue is the diameter. 700c wheels are 8 mm smaller in diameter, so you'll need to lower
the brake shoes by 4 mm. Many bikes/brakes will have sufficient adjustment range available for this.
You can generally tell just by looking at where the brake shoe is mounted in the caliper arm.

If it won't go down far enough, you may have a problem. Older brakes tended to be longer than newer
ones, and if your old ones are not long enough, it may be difficult to find anything that will fit.

Quoted message said:

If the 700c can't fit, can one remove the 9-speed to use the old 5-speed? Will the narrow 9-speed
chain fit the double chain-rings?

It will fit, but may be slow to catch on the smaller chainring when downshifting, especially if you
downshift the front while in one of the outermost rear sprockets.

Quoted message said:

Replacing the front 27" with a 700c should be pretty straightforward, except of course, the brakes
will need to be replaced too.

The brakes are the main issue, but, as mentioned above, _usually_ they don't need to be replaced,
just re-adjusted.

Then again, 27 inch stuff is not actually extinct. See: sheldonbrown.comwheels.htmlOpen ↗

Sheldon "630/622" Brown +---------------------------------------------+
| Life is made up of sobs, sniffles, and | smiles, with sniffles predominating. | --O. Henry |
+---------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone 617-244-
9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

kak61 said:

I have an old Oyama road bike with 27" wheels that are beyond repair.

Can one replace the damaged 27" 5-speed rear wheelset with a modern 700c 9-speed rear wheelset?.
If the 700c can't fit, can one remove the 9-speed to use the old 5-speed? Will the narrow 9-speed
chain fit the double chain-rings?

Replacing the front 27" with a 700c should be pretty straightforward, except of course, the brakes
will need to be replaced too.

A similar 27" wheel not only costs far less but you may then reuse your rubber, skewer, chain and
gear system, avoiding several purchases. As you note, possibly even the brakes might need to be
changed if you change wheel formats.

If you actually want to chnge to 9speed that's a different (and expensive) discussion apart from
fixing your immediate problem.

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

As always where men on 2 wheels are concerned you will get different opinions, but fwiw...

I changed the 27" wheels on an old ('75 or so) Viscount to 700c, and also changed the brakes.

Changing the brakes on the front was easy (because I also changed the fork) but changing them on the
rear was difficult -- it took awhile until I found rear brakes with a long enough reach.

Sheldon and others (who know much more than I do about bikes) may give articulate reasons for
sticking with 27" is a good idea, or why old brakes are as good as new ones, my subjective
experience is:

1. The combo of new wheels and new brake was fantastic -- zowie! The bike seems to ride way better.
Perhaps modern 27" wheels would have the same result.

2. The brakes were wayyy improved. And I mean the brakes (the cables and housings were already new,
so they are not a factor here). IMO, modest Shimano 105 is dramatically better than old GB's.
And very likely modern wheel rims stop a lot better than old ones.

- Charles

[email hidden]

"kak61" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I have an old Oyama road bike with 27" wheels that are beyond repair.

Can one replace the damaged 27" 5-speed rear wheelset with a modern 700c 9-speed rear wheelset?.
If the 700c can't fit, can one remove the 9-speed

to

Quoted message said:

use the old 5-speed? Will the narrow 9-speed chain fit the double chain-rings? Replacing the front
27" with a 700c should be pretty straightforward,

except of course, the brakes will need to be replaced too.

This might be what you need for the front brake sheldonbrown.comdpdropbolt.htmlOpen ↗