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Discussion Starter · #1 ·
I have a plain old tire pressure question. I have raced (autocrossed) cars for many years and understand the importance of tire pressures for safety, performance, fuel economy, and tire longevity. Understanding that a rider's needs and decisions should be the result of the prioritization of the above-mentioned four factors, I am a relatively new moto rider.
On a moto, the tire pressures are obviously much more important. On my '09 street triple, the factory recommends 34 psi front & 42 psi rear COLD!
I have a dial tire pressure gauge that I think (?) is accurate but I will get a new one just for the hell of it to compare.

My question is this: What is the advantage, if any, in going a few psi UP or DOWN? If you are a racer, please chime in.

I do not track my bike, however, for the record I ride in a "spirited" fashion on the street (i.e. city, twists, highway)

Thanks in advance for your comments...:whistle:
 

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I usually run 34 front 38 rear on the road...with BT003 RS.

Works for me.

S.
 

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36 Front-38 back works best for me, Im 90kgs just play with your pressure and find one that works best for you. I use to use 34 front 36 back but found the extra 2psi feels alot more fine and nimble cornering.
 

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to answer the original question...

Tire pressure controls tire flex. More air = less flex. Flexing tires heat up faster. That might be a good thing for a track day or a bad thing for a 5,000 mile trip. Hotter tires make the rubber stickier. If you want mileage, go for higher presure. if you want grip, go lower,

The pressures I run depend on 1) passenger (higher rear pressure) 2) track condition (usually 30f 29r on BT16's) 3)weather (I run lower pressure in colder temps to heat up the tires) and 4) what tire I am running.

I use the old addage that hot pressures should be 10% higher than cold pressure.

IHTH - your pressures will vary.
 

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42 psi in the rear will have you highsiding into a hedge in no time!

Generally you're shooting for around 38-40 when hot.

I run 33F 35-36R and it seems to be pretty sweet, thats for the road.
 

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I have been playing around with pressures the last few days on my STR and found 33F / 36R cold is quite good as most guys are saying.
I had 42 in the rear and was really unsettled by how it was moving around at decent lean angles and in the wet, forget about it. But now at 36 on the rear it is hanging on much better. Tyre wear is definately more noticable at the lower pressures.
 

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I have been playing around with pressures the last few days on my STR and found 33F / 36R cold is quite good as most guys are saying.
I had 42 in the rear and was really unsettled by how it was moving around at decent lean angles and in the wet, forget about it. But now at 36 on the rear it is hanging on much better. Tyre wear is definately more noticable at the lower pressures.
For better or for worse for you?
I was chewing through it when i got mine new (42 cold) then once it was run in and i was riding harder i checked it then dropped to 35, seemed to ease up on the wear then...
 

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The tech at the dealer I bought my bike from said to keep both front and rear at 40psi. 12k miles later I am still running the original front Qualifier, rear of course has changed. Bike rides and handles proper as far as I am concerned.
 

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Lower pressures give more grip in the dry at the expense of slower steering and increased wear. Higher pressures can cause excess wear to the centre of the rear tyre, squaring the profile, and give sharper steering at the expense of grip.

Higher pressure in the rear should be used with luggage or a pillion to maintain the shape of the tyre under the extra load.

Significantly lower pressures in the wet can cause the tread pattern to close up as the tyre flexes, reducing the clearance of water and in particular, increasing the risk of locking the front wheel under braking.

Then you add personal taste to the mix.

Personally I think that 42 is a bit much for a rear tyre ridden solo.

Rob
 

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I am liking 34F/36R for sportriding on Q2's. If I was commuting/easy touring I would bump up 2psi for good wear . Conversely I will drop 2 psi for my two days at CSS .
 

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The tech at the dealer I bought my bike from said to keep both front and rear at 40psi. 12k miles later I am still running the original front Qualifier, rear of course has changed. Bike rides and handles proper as far as I am concerned.
No offense meant here but you musnt ride very hard at all, because 1 you'd have binned it with 40psi in the front by now and 2 you'd have never gotten 12k from a tire either.
 

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No offense meant here but you musnt ride very hard at all, because 1 you'd have binned it with 40psi in the front by now and 2 you'd have never gotten 12k from a tire either.
I used to get great results back in my ZX/6R days with PR2's and 38psi front, 40 psi rear. No problems except for spinning up the rear now and then out of very tight turns.

But 12,000 miles? I was struggling to see more than 5,500 kilometres before the edges disappeared. I have never seen anything even close to 12,000 miles from bike tyres in my whole life. Running sticky tyres such as Racetec K2's, I usually see about 3,000 kilometres.

Expensive habit.

O.B
 

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I used to get great results back in my ZX/6R days with PR2's and 38psi front, 40 psi rear. No problems except for spinning up the rear now and then out of very tight turns.

But 12,000 miles? I was struggling to see more than 5,500 kilometres before the edges disappeared. I have never seen anything even close to 12,000 miles from bike tyres in my whole life. Running sticky tyres such as Racetec K2's, I usually see about 3,000 kilometres.

Expensive habit.

O.B
Yeah its not cheap!

My Street Triple was recently totalled due to some stupid bitch in a cage, it had just ticked over 4000ks from new on that ride, both front and rears werre just on the wear indicators!
 

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Discussion Starter · #16 ·
Thanks for the advice.

It think the most common responses were the 33/36 combination.

That seems to make sense since the factory 34/42 that I have been riding

feels a little firm in the rear. Firm in the rear is great on yer lady friend

but not on yer mistress if you know what I mean. I will drop the rear a few

psi and see if that grips a bit better. My striple is a weekend toy, so I want

grip and I'm not afraid to pay for it!

Cheers :yeehaw:
 

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A lot of it is tyre dependant.

With my original Qualifiers, I had to run them high, 36F 38R to get reasonable grip.
Switched to Michy PR2s, they felt better at 34F 36R.
Now on Pirelli Angels and run 34F 34R. They heat well, wear well and grip f'n well! For a sport tourer tyre they are brilliant! I am a pretty spirited rider aswell so the fact I have done over 4500kms and have plenty left I am very happy with, especially seeing as a fair bit of that has been 2 up (35F 38R).

For track tyres on my other bike I run Supercorsa SPs and 32F 31R, depending on ambient and track temps of course. I just manage 2 trackdays out of them.

Oh and for the record, I am about 84kgs, other half is 58 (but don't tell her I told you or I'll die! :p)
 
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