tyre pressures vespa px125

[george1966]

Hi guys the book says 18front 26rear single rider is that what everyone uses?
thanks
george

[rab]

Rear depends on your weight but as a rule of thumb that's right

[henri]

as rab says , i'm a over-inflater an run around 22 front n 30 rear ,have to with potholes/speed bumps round my way , makes the scoot more twitchy but also more tippable/swervy in traffic .H

[george1966]

Thanks guys
george

[pxguru]

I just got a new front tyre. Put the Schwalbe that was on the front on the rear and the new Dunlop on the front. All fine.
Inflated them as usual. As I have always done, exactly the same pressures as H uses. 22 front and 30 rear.
Out on the road it was really twitchy and I wasn't happy. Was nervous on roundabouts and fell into bends too easily. Started letting the front tyre down, as it made me feel it was too hard.

By the time I was finished it was 18 front and still 30 rear. I never run a front tyre that low but handles great and all is right with the world again

Edit; btw, I am a bit over 17 stone which makes this low pressure more relevant. Maybe some of the new tyres have some stiffer walls. Don't know.

[RWS74]

Wocha folks, I was recommended to try 25psi front & 31psi rear by a well trusted Vespa Mechanic. His reasoning is the tyre pressures in the manual are meant for Italian weather where tyres warm up quicker.... Also heard the same for Ducati bike owners whose UK mechanics recommend higher tyre pressures too. I've ridden on this set up for 3 months without issue and I'm 16 1/2 stone.

[bryno]

Personally I think that's too high.

In my experience anything over 18 on the front and it gets skitty and bouncy.

For me 26 rear 18 front as per the manual and see no need to change that except when 2 up, but each to their own.

Schwalbe were suggesting crazy high pressures like 30 - 40psi when they had that spate of exploding tread a few years ago.. I'm surprised anyone still buys their tyres.

[george1966]

Hi guys i asked the vespa mechanic he said the low front is nothing to do with climate or temperature its weight distribution
the front is inevitably light with the engine at the back,so to get the optimum matching rubber on the road (back and front) 18 26 are the best grip option,he said using a higher pressure at the front is actually dangerous as it will reduce the contact patch .....me being the the eternal pessimist decided to test this theory lol

did a tape measure test with a mate on the scoot at various angles and on the road identical px125s (but mine,s white so better looking lol) even a slightly higher pressure definitely affects braking and stability
one proviso is this is based on the average weight say 13st so if your heavier or lighter so perhaps get a 13st friend to sit on the scoot 18 26 measure the contact patch,then you get on and inflate to match ,not very scientific but might be an adea
george

[pxguru]

All I was saying was some of the latest modern tyres have very stiff side walls, hence so many more threads about guys struggling to get them on or off, more than in the past. With the latest sportier stiffer side wall (usually not the whitewall type), it seems less tyre pressure is needed for the same ride as an old design of tyre. So, don't get too hung up on the number of psi, just put in what it needs to ride well for you. Always bear in mind the higher the tyre pressure, then the less tyre touching the road on the contact patch = more chance of falling off!