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38 in back and 32 up front - is this correct for an 02 Bonnie with stock tires?
 

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I run 38 and 34 in mine. The rear seems to be more sensitive to lower pressure.

Darcy
 

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On 2006-12-14 15:21, bruin wrote:
The Haynes Manual states 38 in the rear and 33 up front.
I've played with the tire pressures a bit and found these to be just about perfect. The same numbers are on the placard on my '03 T100.
 

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Just in front of the tank...on the right hand side...tire pressures should be listed as well as some other valuable info.

The biggest problem with keeping air in the tubes seems to be the valve cores of the Schrader valves. Get a handful of new ones from a tire shop and change them until you find a couple that don't leak. After doing this, I find my tires hold pressure for months--the biggest problem now is how much air I let escape every time I check the pressure. :-D

Larry

[ This message was edited by: RedBird on 2006-12-15 19:56 ]
 

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Quote:
"The biggest problem with keeping air in the tubes seems to be the valve cores of the Schrader valves. Get a handful of new ones from a tire shop and change them until you find a couple that don't leak. After doing this, I find my tires hold pressure for months--the biggest problem now is how much air I let escape every time I check the pressure."

You are absolutely right, those valves are extremely inconsistent,however,and nobody ever believes me when I tell them this, but I have been in the tyre business almost 30 years.It is actually the valve stem cap that holds in the air. The schreader valve is provided primarily to keep the air in while adjusting pressure. Don't believe me? Email any major manufacturers tech line. This is why it's important to have high quality metal caps, with gaskets, in place. Allegedly, centrifugal force can actually unseat schreader valves,at high speed.

One thing you can do to keep your tyre pressure consistent is to fill them with nitrogen. The larger molecules don't seep out as readily as plain ol' atmosphere.
 

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In my Metzler LaserTecs I run 35 PSI in the front and 38 PSI in the rear. This results in good handling and about 43 mpg.
 

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commando,

It is not the valve part of the core (spring action part) that is the problem with the tubes. It is the sealing surface between the core and the tube stem. The tube stem is a little too large--why the tubless valve stems are smaller, I don't know. On my last set of tubes, I went through 30 valve cores and could not find any that would seal, so I used a very thin coating of silicone glass sealer on the sealing surface that mates with the tube stem and that did the trick.

I have never had any luck with a cap keeping the pressure in if the valve core doesn't seal--guess I haven't had good enough ones. My current caps are metal with gaskets; however, when the valve core leaks, the air disappears. :(

Larry
 

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"Plain ol' atmosphere" is 70% nitrogen.

The info about the valve cores is interesting. I can't let my tires go for more than two weeks without significant loss of pressure. The back especially loses about 2-3 psi per week, which seems to be a lot to lose through the rubber.

I almost wiped out at 60mph from a nail in my back tire--the bike had about 100 miles on it at that point and I hadn't ridden in nearly 20 years, so my sense of how it should feel was not good.

Now I'm neurotic about checking the tire pressures.
 

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I'm sorry, after re-reading my post, I realise I was not clear. I didn't mean that installing proper valve caps alone would solve the problem. I meant only to point out that it is the caps,not the cores, that are the primary pressure retention method.And of course, the caps keep out debris, which can unseat the valves, or keep them from sealing in the first place. It's my opinion that our tyres lose pressure via "osmosis" through the tube itself. It's common on my spoke wheeled machines to lose 2-3 psi per month, while my tubeless tyred Sportster might lose that in three-four months. Redbird,if you have found a valve/tube combo that retains pressure that well, then kudos to you. Maybe I will try some positive seal R12 valves in my tubes. Those better seal. After all it's illegal to vent that stuff into the atmosphere.

As to the nitrogen,I have not tried it myself. My shop does not yet have it, and I can't bring myself to plonk down $5.00 per tyre, at this point. I'll wait til we get it. However, alot of fleets in these parts, incuding local police departments, swear by it.
It supposedly runs cooler,at a more consistant temperature, retains pressure longer, which leads to reduced tyre wear, and better fuel mileage, and eliminates oxydation from the inside of the tyre. Michelin states in their handbook that a tyre filled with nitrogen will retain it's pressure up to 3 times longer.
:chug:
 
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