Wheel sizes

Ok so how can i tell what size a wheel is and what size wheel a particular frame needs?
Thanks!

Care to give us some more clues to work with?

For example- do you have a frame that you are trying to work out the correct wheel diameter for?

Or a set of wheels that you do not know the dimensions of?

Or both?

Do the wheels have tyres on them currently?

i have a frame and a set of wheels for it without tires, i dont know any dimensions, but im selling the rims and need the size for the buyer and for me to buy some new ones.

Do you own a tape measure?

A 700C wheel should be 622mm in diameter, if it's not that then come back to us with the diameter.

It's probably a 27" if it's not a more modern 700C, but that said a friend of mine did end up with some 700B's, so odd things can happen.

ok yep diameter is 622mm
Thanks

i've had a quick search, if someone can use it better than me then cool but:

what is the difference between 27" and 700c wheels except for size? i.e. 700c seems more modern, so do people run this size on old frames (which i'm lead to believe are designed for 27" wheels?)

In short yes- I've run 700c in a frame designed for 27", the only tricky bit is finding a brake with enough drop (distance from the bolt that attaches brake to fork down to the rim).

i see thanks.

so the general advantage of 700c rims is that they are used a lot more (now) than 27" rims (being pretty much obsolete)?

i hope it's ok to hijack this thread but whats a normal wheel size inc. tire for a 23-622 rim?
i know they may vary between 660 and 680mm but whats a common size or informal standard?

i hope it's ok to hijack this thread but whats a normal wheel size inc. tire for a 23-622 rim?

Depends on:

rim profile, particularly the inside width and height above the bead, but other factors influence the final size too;

true casing width of the tyre, as 23c can be anything from 20 to 25mm wide when mounted on the rim;

tread thickness, which ranges from approx. bugger all on a Veloflex Record to nearly 5mm on a touring tyre.

Typically, if you measure the true width of the mounted and inflated tyre and add twice that and twice the tread thickness to 626mm you won't be far out.

My turn to hijack now. I'm looking for a wheelset for a frame I own. Dims are 700c with spacings 100mm front and 126mm back. My questions are these:

Do I have to get wheels with hubs that match the spacings on my frame? That is to say, can I fit a wheel onto the frame with a smaller hub spacing than I require? If so, how would I go about doing that (eg would I use washers)?

Is there a particular rim width I have to use with a given frame, or is it anything I am comfortable with?

If I buy a rear wheel with a cassette, what do I need to do to turn it into a single speed, ie how do I remove the cassette and install a freewheel?

Thidly, I took a look at my own wheelset on my current bike and I thought I would take the cogs off to see how they are fitted to the hub. However, my hub is a flipflop and there is a nut on either side of the hub, one securing each cog. How do I remove these nuts? (I figured that if I apply an inverse torque to each, there is no way of telling which will unscrew first. Also, if I remove the nut on one side, how to I remove the remaining one, since there is no position I can hold the axle from that isnt threaded)

Finally, is there anything else I should be weary of, in taking a frame that was probably originally intended for touring and trying to make it a sweet commuting singlespeed?

Bit of a long read, but I do appreciate any help, so thanks in advance.

A lot of basic questions that can be easily answered with a bit of searching, but i'll help you with a few points:

Best to match hub width (over-lock-nut) to frame spacings, but steel frames can tolerate a few mm of difference, or can be cold-set to a new spacing.

Hubs can be re-spaced by removing the lock-nuts and adding or removing spacers (fat washers, often aluminium) between the nuts and cones. You might need to replace the axle too.

The 'nuts' holding the sprockets onto your flipflop hub are lockrings, they have a left-handed thread and are removed with a lockring tool. You then need a chainwhip to remove the right-hand threaded sprockets, but if your hub isn't part of a wheel it will be very hard to get them off. Rotating them against each other might destroy the hub before they shift.

If your frame has vertical dropouts, you'll need a chain tensioner to run singlespeed, and can't easily run fixed.