Interesting article on tire pressure

[the Ferret]

how to find the best tire pressure for your bike

How to Find the Right Tire Pressure | American Sport Touring

not saying it's right, not saying it's wrong, just saying it's interesting

 

[tommymck]

That is interesting. So, the way I read this, you'll end up needing to lower your tire pressure if you aren't an aggressive rider in order to hit the 10%/20% pressure increase goal... - less aggressive riding results in less ride-induced heating, which results in less heat induced pressure increase.... and according to the article, lower inflation pressures causes more heat induced build-up on a percentage basis. That seems counterintuitive. I'd have thought that more aggressive riders would want a higher tire pressure.

It'd have been nice if the article explained the rationale. I'm sure it makes sense though.

 

[Rocky_imp]

'interesting" is a word I would use too, but since I've been using the recommended pressures for over 30 years, and since they have served me well in many different road conditions...................

 

[GoldOxide_imp]

... those airless tires can't come fast enough.

 

[Tev62]

The piece seems counter intuitive until you read the qualifying statement "Slightly lower tire inflation allows additional flexing and generates more heat". So they are saying the end result will be a higher up to temperature pressure. I can't say I would get that focused myself and have stuck with standard recommended pressures and like Rocky that has served me well too. But for one exception.

Many bikes seem stick to the common 36/42 PSI but Triumph changed the tyre size and pressure on the Tiger 1200/Explorer and dropped the pressures right off to 32/39 from 36/42. I find the front super vague at that lower pressure and get significantly better handling at 36PSI on the front. I even asked Bridgestone Technical Services when I fitted their tyres should I use the Triumph 32/39 or their recommended 36/42 and they clearly stated stick with their higher pressures. So who is right?

Were Triumph expecting me to be more aggressive a rider and get the temperatures up on my tyres? If so I'm going to disappoint them!

 

[GoldOxide_imp]

Adventure motorcycle sites significantly lower their tire pressures when off roading. 18 psi is not unusual, however, they would be also travelling at much reduced velocities and commonly traversing through mud and river streams - all which serve to minimize tire heating. I am sure if they hit the open road that the tires would heat up quickly and handle dangerously.

Nothing here is profound.

 

[Whoops]

Adventure motorcycle sites significantly lower their tire pressures when off roading. 18 psi is not unusual, however, they would be also travelling at much reduced velocities and commonly traversing through mud and river streams - all which serve to minimize tire heating. I am sure if they hit the open road that the tires would heat up quickly and handle dangerously.

Nothing here is profound.

Same thing for vehicles when rock crawling. Most drop their pressure to about 15-20 psi on their tires. This allows the tires to deform more and grip the rocks while also giving them a bigger contact patch. If you are going any distance or speeds over 10 mph though you would typically air back up. Most folks carry a compressor or have an onboard unit installed.

 

[GoldOxide_imp]

Adventure motorcycle sites significantly lower their tire pressures when off roading. 18 psi is not unusual, however, they would be also travelling at much reduced velocities and commonly traversing through mud and river streams - all which serve to minimize tire heating. I am sure if they hit the open road that the tires would heat up quickly and handle dangerously.

Nothing here is profound.

Same thing for vehicles when rock crawling. Most drop their pressure to about 15-20 psi on their tires. This allows the tires to deform more and grip the rocks while also giving them a bigger contact patch. If you are going any distance or speeds over 10 mph though you would typically air back up. Most folks carry a compressor or have an onboard unit installed.

 

[tommymck]

The piece seems counter intuitive until you read the qualifying statement "Slightly lower tire inflation allows additional flexing and generates more heat". So they are saying the end result will be a higher up to temperature pressure. I can't say I would get that focused myself and have stuck with standard recommended pressures and like Rocky that has served me well too. But for one exception.

Many bikes seem stick to the common 36/42 PSI but Triumph changed the tyre size and pressure on the Tiger 1200/Explorer and dropped the pressures right off to 32/39 from 36/42. I find the front super vague at that lower pressure and get significantly better handling at 36PSI on the front. I even asked Bridgestone Technical Services when I fitted their tyres should I use the Triumph 32/39 or their recommended 36/42 and they clearly stated stick with their higher pressures. So who is right?

Were Triumph expecting me to be more aggressive a rider and get the temperatures up on my tyres? If so I'm going to disappoint them!

The simple way that I interpret the article is that the real tire pressure that matters is the pressure that you see when you are actually riding. The manufacturer has a number in mind for this, but they can't explicitly state it because they don't know what kind of rider you are. So, they give a recommended cold pressure number for the average rider that results in the riding pressure that they are looking for (assuming that the average rider will get a 10% increase in front tire pressure and a 20% increase in rear tire pressure.) If that was as far as it went, it would make sense to me. So, a recommended cold pressure of 36 psi for a front tire means that the manufacturer wants a riding pressure of 39.6 psi. OK, fine. Following the advice of the article, if I were a non-aggressive rider and I only saw a 5% increase (37.8 psi) i'd actually want to back off the starting pressure. Unless the increase in tire pressure due to heating is more than the decrease in starting cold tire pressure (and it can't be) I actually end up with a lower riding tire pressure than I otherwise would have if I used the recommendation.

As you say though, this seems all down in the noise in any case.

 

[j3gq_imp]

I wonder, is the recommended cold tire pressure which we find in our user manuals really coming from the m/c manufacturer, or are these values more likely coming from the tire manufacturers who of course know about, respectively set the maximum conditions (speed, load) for their tires AND the pressure values ?