Tyre pressures!!!

[stranger]

Peering knowledgeably at the Powabyke tyres this morning, (my husband usually deals with such things for me but he is away for a day or two) I was amazed to discover that the recommended pressure (on the tyre itself) was

65psi.

Surely not!

I am scared to try to blow them up to that in case they go 'BANG'.

I chickened out at 40.

 

[Straylight]

65 sounds about right, the pressure for my Wisper is the same

Some tyres can take up to 120psi These are usually found on road bikes with ultra skinny wheels.

You'll find that the bike will roll with alot less resistance, and that your battery will last longer, if you brave the recommended psi.

 

[Mussels]

High pressure can also make the wheel stronger as well as a little quicker and less prone to punctures, it will be less comfortable though.
I use 559-60 tyres at 70psi, if you do get a blowout it will be because something isn't working properly or you have ridden across a police stinger.

 

[JohnInStockie]

I keep mine at 80, and re-inflate them every 2 weeks -ish

John

 

[Fecn]

65psi on my agattu

 

[Footie]

55 psi on my Cougar Mountain Electric bike
65 psi on my none-electric Mountain bike
28 psi on my Kawasaki VN800 motorcycle
60 psi on my 3.3 ton Talbot Campervan
It's a mystery to me how they work them out

-----------------------------------------------
Cougar Mountain Electric Bike 36v 200w Hub motor (Jul07)
fitted with 10 Ah LiFePo4 battery (Apr08)
Maximum range (road/hills - Cornwall) 18 miles
Maximum range (on flat) 25 miles
.

 

[prState]

Generally, (and someone can correct me if I'm wrong) tyres under load are usually recommended for higher pressures. If you consider that most electrics are heavier anyway, and plus when we carry extra stuff, staying on the high side probably keeps you in better shape anyway.

But yeah, it can be a rougher ride.

And oh, man if you've ever let your front tire get too low, and then try to take a sudden turn -- surprise!

 

[JohnInStockie]

Thats the way I understand it too. If your tyres say 60 - 80 PSI, then a 75Kg person (expected human weight in bike designs) should be at 70 PSI for optimum tyre performance.

So if your over 75Kg, you should be in the upper pressure (say 80 PSI) to stop deformation of the tyre on road, and visa versa if your lighter than 75Kg.

John

 

[flecc]

But tyre size (air volume) is a very big factor in pressures.

Skinny race bicycle tyre circa 120 lbs

Road bike like John's say 80 lbs

Utility shopping bike maybe 60 lbs

Car tyre circa 29 lbs

Etc

Larger tyre pressures start rising again with load, e.g. truck and bus, but fall again with high load balloon tyres, JCB rear tyres etc.

There's a balance between the two factors, tyre size and load.
.

 

[stokepa31_mk2]

It should also be noted that running with too low a pressure may increase tyre wear. I keep mine at the max but that has more to do with my rather portley frame

 

[stranger]

And oh, man if you've ever let your front tire get too low, and then try to take a sudden turn -- surprise!

I think I might have made that mistake once. Tried a nifty turn at the mini-roundabout and the damn thing shied violently and we both ended up in a heap in the road.

Luckily there was no-one coming at speed.

So I need to get some more air in there do I?

The Powabyke tyres are quite podgy (as I daresay you all know). Not at all like the ultra-thin ones on the husbands 'real bike'. Now they really do 'pump up well'. And, come to think of it--THEY don't go bang.

I will be brave with the compressor tomorrow.

 

[Charlie]

Does anyone know if the pressure reading of the gauge is altered if the weight is taken of the wheels?
For a motorcycle that has a lot more weight, should you check the tyre pressure on the side stand, with the weight of bike on the tyres, or on the centre stand with all weight removed?

Just curious really.

Charlie.

 

[flecc]

It won't make any difference Charlie. Any compression of the tyre surface will be compensated by the expansion of the sidewalls outwards, the volume, and therefore the pressure inside remaining the same.
.

 

[stranger]

The tyres didn't go bang! (You knew that already didn't you.)

 

[flecc]

The tyres didn't go bang! (You knew that already didn't you.)

They could be waiting for later to take you by surprise.
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