Tyre pressures

Interestingly I'm currently running 32psi on the front Anakee 3 of my Rallye Sport in an endeavour to reduce shocks when the bike runs over such things as pot holes. 32 psi is the same as 2.2 bar used on pre LC GSs at the front and I always ride solo. So far steering and handling seems the same and comfort is better. Time will tell.
 
Thats the whole point, do you know how reliable your pressure gauge is? Or more to the point how accurate. 2 different things.
Very basically then BMW TPMS reading on your dash wont change during a ride, it should give you a theoretical 'cold' pressure. If the tyres are warm and you measure the pressure you will get a different reading.
As you ride they tyre temp will increase and therefore the pressure should also go up. Thats why pressures usually are set cold.
If the tyre pressure increases a lot, then the cold tyre was at too low a pressure - too much flex and movement in the tyre causes lots of heat and therefore the big pressure increase.
If the tyre pressure hardly increases during riding then the cold pressure was set too high.
Front should increase in pressure more than the rear. Hope that makes sense.
I understand totally how pressure varies with temperature and how working the tyre will increase pressure, hence why we measure the pressures when cold.
However, as there is no temperature sensor in the tyre how the begeezers can the TPMS compensate for temperature? And if my TPMS shows 2.3/2.7 when setting off and stays there how does that tally with the "too low to start with hence bigger increase due more flexing argument? I
I would rather trust my guage, which I have compared with 2 or 3 others, and simply use the TPMS as a reference or puncture warning system.

Note - Just discovered the TPMS does measure temperature inside the tyre, but can't compensate for increases in altitude.
 
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When I picked up my new bike in April from Jefferies it felt a bit odd. Checked the on board pressure and it was reporting 42 front and 48 rear. Double checked with a guage when I got home and they'd cooled down, and sure enough the TPMS was accurate and they'd over inflated. I let the dealer know and let air out to correct the pressures.

When the wife collected her new bike in May they only went and did the same thing. This time, 43 front and 49 rear!

Both were RSs, which run 36/42 pressures.
 
Losing the will to live here
Check TPMS if it needs air pump it up or let some out
No TPMS check with gauge if worried
If my bikes a few pound out soon feel it on the handling and check asap
Ffs quit whingeing
 
Don't give up so easily. This can be a 5 pager!

I'm going to 8.

As you say, the OP should take resposibility for his own bike and just let the dealer know he wasn't happy instead of whinging like a 14 year old on here!.

I thought we used to have fun in the hexhead section........:rolleyes:
 
To be fair I think the tyre pressure thing is a red herring here.

A small thing like that make you think.......well what else have they gashed or got wrong ??

Were the valves done or did they just sound OK with ear to engine etc etc etc

It is most definitely not unreasonable to be a bit pissed at that.
 
My brand new Honda VFR1200 was in for a service and while it was there I asked them to stick a new rear tyre on it.

Got home, filing paperwork and noticed a typo.

Thought nooo... cant be.

Yep, they'd fitted the wrong tyre, and they were the Authorised Honda Dealer.

I give all my bikes a thorough inspection now before leaving the monkey shop.
 
Thats the whole point, do you know how reliable your pressure gauge is? Or more to the point how accurate. 2 different things.
Very basically then BMW TPMS reading on your dash wont change during a ride, it should give you a theoretical 'cold' pressure. If the tyres are warm and you measure the pressure you will get a different reading.
As you ride they tyre temp will increase and therefore the pressure should also go up. Thats why pressures usually are set cold.
If the tyre pressure increases a lot, then the cold tyre was at too low a pressure - too much flex and movement in the tyre causes lots of heat and therefore the big pressure increase.
If the tyre pressure hardly increases during riding then the cold pressure was set too high.
Front should increase in pressure more than the rear. Hope that makes sense.

That's not quite right. Yes the pressures should go up but the rear will show a slightly greater increase. This is my experience from the TPS on my Triumph and my experience of racing.

In most road environments the pressures increase about the same amount, usually about 5 to 6 psi in my experience.


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What is the correct tyre pressure?

And what is the best tyre to have on? ;)

The correct tyre pressure is the one the manufacturer states, as this will cover a range of temperatures and riding conditions/style. However some tyre manufacturers will state alternative pressures for their products for a specific model.

Now if you're racing, that's a different story.


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Ah, tyre pressures!

Now then...... the manual states the front at 2.5 bar cold and the rear at 2.9 bar cold and some riders are adamant that you must stick to these pressures. Apparently pre LC GSs had lower pressures for solo riding but not the LC for some obscure reason.

I'm currently running a lower front pressure of 2.2 bar to reduce jarring over pot holes and the like which is frowned on by some even though it seems not to affect the way the bike handles ( bear in mind I have been on 2 wheels for 58 years so I might be expected to have noticed any down side).

The manual says '...the RDC control unit differentiates between 3 tyre pressure ranges, all of which are parametarised for the motorcycle : - tyre pressure within permitted tolerance/ - tyre pressure close to limit of permitted tolerance/ - tyre pressure outside permitted tolerance'. SO, since the RDC control isn't telling me that 2.2 bar is either 'close to the limit' or ' outside permitted tolerance' then I can run different pressures to suit my requirements e.g. solo/sensible speeds/road only/comfort, provided that the RDC doesn't complain!

Surely the tyre pressures recommended by BMW are set to cover the worse case weight/speed scenario e.g 2 up, luggage, long distance at high speeds etc. which doesn't apply to all riders.

Anyone see a flaw in my logic?

(P.S. Anyhow a lower front tyre pressure will reduce shocks on the suspect suspension stanchion tubes, Tee Hee, just joking!)
 
Ah, tyre pressures!

Now then...... the manual states the front at 2.5 bar cold and the rear at 2.9 bar cold and some riders are adamant that you must stick to these pressures. Apparently pre LC GSs had lower pressures for solo riding but not the LC for some obscure reason.

I'm currently running a lower front pressure of 2.2 bar to reduce jarring over pot holes and the like which is frowned on by some even though it seems not to affect the way the bike handles ( bear in mind I have been on 2 wheels for 58 years so I might be expected to have noticed any down side).

The manual says '...the RDC control unit differentiates between 3 tyre pressure ranges, all of which are parametarised for the motorcycle : - tyre pressure within permitted tolerance/ - tyre pressure close to limit of permitted tolerance/ - tyre pressure outside permitted tolerance'. SO, since the RDC control isn't telling me that 2.2 bar is either 'close to the limit' or ' outside permitted tolerance' then I can run different pressures to suit my requirements e.g. solo/sensible speeds/road only/comfort, provided that the RDC doesn't complain!

Surely the tyre pressures recommended by BMW are set to cover the worse case weight/speed scenario e.g 2 up, luggage, long distance at high speeds etc. which doesn't apply to all riders.

Anyone see a flaw in my logic?

(P.S. Anyhow a lower front tyre pressure will reduce shocks on the suspect suspension stanchion tubes, Tee Hee, just joking!)

Personally I can feel a difference when the tires are down .2 or .3 bar

It's not horrendous or anything but it does lose its edge a little, feels a tad heavier, steers a tad slower

So I run it at the values in the manual

Having said that, I've ridden bikes for the last 30 years without RDC so your tires had to be well under pressure for you to feel it, kinda makes me wonder how much of it is in your head with the figures in front of your eyes :nenau
 
If they can't get the tyre pressures right what chance of you of getting a proper service done?

Tyre pressure is a safety item as well


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Agreed,

(pretty important stuff on a car... absolutely life threatening on a motorbike)

( Aberdeen Angus may not understand it , but he's stupid beyond beleif /clearly never seen a motorcycle crash because it lost grip)
 
Ah, tyre pressures!

Now then...... the manual states the front at 2.5 bar cold and the rear at 2.9 bar cold and some riders are adamant that you must stick to these pressures. Apparently pre LC GSs had lower pressures for solo riding but not the LC for some obscure reason.

I'm currently running a lower front pressure of 2.2 bar to reduce jarring over pot holes and the like which is frowned on by some even though it seems not to affect the way the bike handles ( bear in mind I have been on 2 wheels for 58 years so I might be expected to have noticed any down side).

The manual says '...the RDC control unit differentiates between 3 tyre pressure ranges, all of which are parametarised for the motorcycle : - tyre pressure within permitted tolerance/ - tyre pressure close to limit of permitted tolerance/ - tyre pressure outside permitted tolerance'. SO, since the RDC control isn't telling me that 2.2 bar is either 'close to the limit' or ' outside permitted tolerance' then I can run different pressures to suit my requirements e.g. solo/sensible speeds/road only/comfort, provided that the RDC doesn't complain!

Surely the tyre pressures recommended by BMW are set to cover the worse case weight/speed scenario e.g 2 up, luggage, long distance at high speeds etc. which doesn't apply to all riders.

Anyone see a flaw in my logic?

(P.S. Anyhow a lower front tyre pressure will reduce shocks on the suspect suspension stanchion tubes, Tee Hee, just joking!)

No flaw in your logic.

The issue is what is the correct tyre pressure for the conditions the machine is being used in. Off road will require lower pressures as will racing, but each for different reasons.

I would say that if you are running a lower pressure to avoid jarring, then the issue isn't tyre pressure but suspension settings!

The issue is is that even on a normal ride the bike will travel under many different conditions. Therefore the tyre pressures will need to be at a point that covers most probable range of conditions.

For most people I would ask what is a good enough reason to deviate from the manufacturer recommended pressures?

Also consider this, if you have an accident and the police inspect your machine, depending on how far away from the manufacturer tyre pressures your tyres are can have an influence on causation i.e. if they deem your tyres under or over inflated then this may be a factor in the cause of any accident and can impact on your insurance or worse any legal action against you.


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