Tyre pressures

[vwtriker1948]

I have 275/60/15 Dunlop GT Qualifiers on my trike, at present running at 25psi. I feel this is to high a pressure and maybe 20psi would be better.
I have contacted Dunlop UK but they will not give me a pressure for legal reasons. To my way of thinking the bigger the tyre size ie. 275 the lower the pressure can be, especially when you consider that a Trike weights less the the original VW is heavier that the Trike,

Does anyone else have this size of tyre and if so what pressure are you using,

[Loner]

When I've had tires that size on one of my VW trikes, I always targeted 18-20 pounds in each rear tire. Seemed to always give me the best ride. For the smaller rear tires I only move that to about 22-23 pounds.

[vwtriker1948]

Hey Loner, I was thinking that way myself. I will drop them to 20 psi first. Need to replace clutch cable first though.

[stinger608]

I run my back tires at 25psi and my front at 40psi. However I do have an 11 gallon fuel tank that pretty much sits right above the center of the tires. I also have the passenger seat just in front and usually have gear and wife on the trike. When I load it down heavy I will usually bump my pressure up to 30-32psi.

[vwtriker1948]

Cheers, it all helps. Mainly it just myself and the wife, she only weight about 8 stone. I will do some experimenting. Still need a clutch cable at the moment though.

[vwbug72501]

Brave man!! Posting wife's weight on the Internet. Generally doesn't matter how big or small they are they think that they're "too fat".

[vwtriker1948]

Nah, she won't see this lol.

I emailed Dunlop UK about this and they couldn't help, I then tried Dunlop US and they were very helpful. The tyres are only made in the US. He is sending me some sheets that may help, I need to get yhe weight of each wheel and cross reference it to the sheets he's send to get a pressure.
Maybe useful but in the meantime I will go the hit n miss route for now.

[ea81slush]

I run 295/50R15 rears. Trike weighs 660 kgms total. plus two heavy riders and a 3 kgms dog. We often tow our 300 kgms camper trailer.

We run 22psi on the rear maybe 24. In my view the softness of the sidewall (ie under 20psi) shouldn't be sought so to give you a better ride. That's what suspension is for. Tire pressure should be high enough that the sidewalls don't flex too much. You'll feel the trike move sideways a little if they are and the tire distorts. But not hard enough that you feel every pebble on the road.

Air pressure is an odd thing. for example I have airbags on my rear swing arms. Most of us Australian Panther owners have 45 psi in them. I thought when I installed my roof (an extra 50 kgms) that at least 53 psi would be needed to offset the weight. Not so. 48 is ideal. only 3psi more. I don't know the reason. But seems 3psi say 6% more pressure gives say 20% more hardness.

Think 25psi would be max. I never go over 24psi even when towing. Middle tire wear also becomes apparent if I did.

[vwtriker1948]

Thanks for the info, you right about tyre pressure being funny more a black are really.
I will look into getting my trike weighed, though it's basically a vwtriker rear end with engine.
I think it's reasonably light.