How do you measure the difference between a 27" & 700c?

[negaultra7]

Morning all

How do you measure the difference between a 27" & 700c wheels?

Ive got many 60s 70s Campagnolo hubed tub wheels im wanting to sell, but need to advertise them correctly

thanks
Neil

 

[avalonian]

Try this
http://velo-orange.blogspot.co.uk/2011/ ... reach.html
Chris

 

[negaultra7]

Re:

Thanks Chris

 

[Midlife]

All tubular (tubs) are 700c diameter unless they are a lot smaller for lo-pro / funny bikes and then the diffence is clear...

Shaun

 

[mrcpea]

700c wheels have a bead seat diameter (BSD) of 622mm
27" wheels have a BSD of 630mm
28" wheels are the same as 700c, making 27" bigger than 28!"

Work that one out

 

[Stewart H]

Re:

I tried an old tyre on the mystery rim, the 700c one fitted.

 

[Apple Tree]

As Midlife says, if the wheels are for sprints and tubs for a conventional bike the size is 700c. If you advertise them as S &T's you almost do not need to state the size.
Using mrcpea's figures you can see that the diameter difference from rim to rim is 8mm, 622 to 630. This translates to a difference at the brakes of 4mm as you are only working with the radius from the centre of the hub.