Mixture of tyre size

canoas

awoke nice and early this morning misty @6am through Surrey Hills, I tried for the first time a 25" tyre on the rear and 23" on front. I felt very smooth on the back, not the normal bumpy ride I'm use to in Surrey. I felt very confident with the grip down decents and cornering (well they are new tyres). I really like this mixture, going to stick with it.

My question,,,,,,is it ok to run a mixture of tyre like I have. I wouldn't have a clue? I'm sure it isn't, for example if I rode this combination down a decent on the Alps, would this be unstable? I gather not.....

What PSI would I run? 25" seemed to like less PSI than the front, usually its the opposite.

majormantra

Pressure depends on weight, but yes, the 25 should be run lower than you would a 23. And front is always lower than back.

Btw " denotes inches. The sizes you are quoting are in mm. A 25 inch tyre would fit a lorry, not a bicycle.

sungod

it's fine to mix, you can even buy sets like it, conti force/attack for instance

wider on the rear gives you better traction and a slightly comfier ride as you can drop the pressure a bit, with 23/25 front/rear you may find it best to run both at the same pressure

Monty Dog

Fit a 25mm on the front too, you can run lower pressures, reduce the buzz through the bars and get more progressive grip when cornering too.

paul1000

I run the same on my superking, would put a 25 on the front as well if it would fit.

markhewitt1978

The front and rear have very different characteristics and weighting anyway so no there is no reason they need to run the same tyre.

It's quite common with all sorts of vehicles eg motorbikes, Formula 1 cars, tractors! To have different size tyres on the front and back.

northpole

Conti's attack/ force are 22 front/ 24 rear. Must confess my basis for running with different pressure is not driven by anything other than the notion that the front will have less weight/ load on it and with slightly lower psi, will be slightly less buzzy.

Peter