Measuring clearances for wider tyres

[WeymouthWailer]

hi, totally new here, I have an old Reynolds road frame that I want to convert to a hybrid style bike. At the moment the rims are 700c x 23 and I'd like to fit something more substantial. What's the best way to measure the clearance on the forks and rear stays for a wider tyre?
I'm also looking to have it resprayed, what's the best way to protect the threads from the powder coating? Buy a very cheap BB and headset to fit and then remove? Or maybe a suitable size wood dowel screwed in?

 

[Tim Hall]

Hi
Do you mean the rims are 700c x 23 or the tyres are marked 700c x 23? Big difference. I'd say an easy way to measure is to put the existing wheel and tyre in position then see what the gap is where it goes through the chainstays.

Regarding thread protection, your chosen paintshop/powder coater should sort that for you. If they don't you could use masking tape. Buying a headset and BB seems an expensive way round the problem.

 

[MichaelW2]

The depth of a tyre can vary a little depending on the width of the rim. The only way is to try various wheels and tyres. If your bike has low-drop racing calipers, you may be able to fit some 28mm tyres, but every 25mm should fit.

 

[Ajax Bay]

[QUOTE 4046484, member: 9609"]the closest they come to the frame is just behind the bottom bracket[/QUOTE]

On mine this distance overall is 45mm (roughly) and I successfully ran a 28 Schwalbe Marathon Plus between the chanistays (which is more than 28). The other limiting point, only relevant if mudguards are to be fitted, is the bottom of the mudguard support clamp (under the brake). Tyres with extra puncture protection, like the Schwalbe Marathon Plus, are likely to have a higher profile.

 

[WeymouthWailer]

I'm back with some further info. Rims are old Mavic 622x13 fitted with 700x25. I think this is at the limit for this narrow rim.
Guess I need to find some new rims, any suggestions that won't break the bank and would be suitable for a 32 tyre? I'd quite like to keep the Ultegra hubs.