View Full Version : Winter tyre pressures
Blue_SV650S
25-10-07, 06:31 PM
Anyone SET their tyre pressures at/to a different pressure in/for the winter?
toonyank
25-10-07, 07:04 PM
Not here
Edit:
Well strictly speaking, tyre pressure should be checked cold so if when cold you need to increase to the recommended pressure then your doing nothing wrong and should be done.
chazzyb
25-10-07, 07:10 PM
Anyone change their tyre pressures in/for the winter?
Er, why?
As it happens, I change the pressure in my tyres at least once a week. Sometimes I add air, other times I let some out. But all with the aim of maintainin 33/36. ;0)
Blue_SV650S
25-10-07, 07:13 PM
...
...
I can see where it was a little ambiguous now ... I'll reword the original post :)
toonyank
25-10-07, 07:15 PM
Well maybe ambiguous but I think the main thing is that people would probably not tend to change because it's winter because when you check regularly, you're making adjustments throughout the year.
Blue_SV650S
25-10-07, 07:18 PM
Well maybe ambiguous but I think the main thing is that people would probably not tend to change because it's winter because when you check regularly, you're making adjustments throughout the year.
Ok, less ambiguous still ... :D
If you normally set to say 36psi, would you tend to set to a different pressure (when checking pressures) for the winter?
i.e. you might choose to set pressures higher/lower than you would in the summer ... say 34psi, or 38psi (or whatever).
chazzyb
25-10-07, 07:21 PM
Anyone SET their tyre pressures at/to a different pressure in/for the winter?
OK, why might you want to? If the tyres perform optimally when set at say 33/36 cold in the summer, why would using different pressures in winter change things?
toonyank
25-10-07, 07:34 PM
Ok, less ambiguous still ... :D
If you normally set to say 36psi, would you tend to set to a different pressure (when checking pressures) for the winter?
i.e. you might choose to set pressures higher/lower than you would in the summer ... say 34psi, or 38psi (or whatever).
No just set at the same pressure you normally would (36psi) cold. 36psi when cold in the winter is the same as 36psi cold in the summer.
PS. Reason being is that temperature variations will affect the tyre pressure. 36psi in say 25 degrees will decrease in say 5 degrees so when you start off at 36psi when taken cold you're starting off the same. Only danger would be that in the morning when you set off it's 5 degrees and in the afternoon it's 25 degrees now you know that's not likely here.
Blue_SV650S
25-10-07, 07:35 PM
OK, why might you want to? If the tyres perform optimally when set at say 33/36 cold in the summer, why would using different pressures in winter change things?
Ah, right, yeah ...
Tyres don't work optimally at say 36PSI, they work optimally at say 40psi.
Air expands with temperature, the 36PSI COLD pressure is actually a base 'constant'* to achieve that hot pressure of 40psi ...
The rationale is that you would need to change the 'start' pressure in the winter as not so much heat will be generated as in the summer and you won't hit your optimum 40psi.
*you can always know when a tyre is cold/not used for a while, its hard to tell how hot it is after different length runs, so you set them cold - its more constant, a bit like valve clearances, you set them cold, but it is the hot clearance's that is important - you expect expansion of components with heat and take that into account when dreaming up the cold setting.
Not sure I have explained that particularly well? ... trying to multi-task!! :D
toonyank
25-10-07, 07:42 PM
Air expands with temperature, the 36PSI COLD pressure is actually a base 'constant'* to achieve that hot pressure of 40psi ...
The rationally is that you would need to change the 'start' pressure in the winter as not so much heat will be generated as in the summer and you won't hit your optimum 40psi.
Well this is so very true but it's not as critical in the winter cuz at low temps you're probably (hopefully) not pushing the tyres as much as you would in the summer.
I doubt it would be a great difference but surely the pressure cold in summer is not the same as cold in winter? winter being a hell of a lot colder... the air would surely be moving slower inside tryre?
Blue_SV650S
25-10-07, 08:43 PM
Ok, not many responses so I'll elaborate ... there are two clear diametrically opposed schools of thought WRT setting tyre pressure for different ambient temperatures ... its cooler ... reduce the pressure -> the extra movement in the tyre through wall/tread deflection generates more heat and you get to your optimum temp/pressure. The second school -> as you are not generating as much heat in the winter (its colder and you can't ride as fast), the air is not going to expand as much, so you pump the tyre up - therefore it doesn't have far to go to get to optimum pressure ...
So the question is kinda double barrelled ... firstly do you set the pressure to a different setting in the winter and if you do, do you set it higher or lower?? ...
I suspect most people just set it the same year round ...but probably through ignorance than any rationale ;) ... just wondering how many people actively change pressures ...
Not trying to sound clever as I don't even bother setting my pressure to anything specific* at any time of the year - so I just don't care/am just lazy!!! :D - like I said my question is just curiosity ...
*don't even know exactly what the SV pressures are supposed to be!! :D
chazzyb
25-10-07, 08:56 PM
I must say I have never heard of this practise. I'm not sure I'll be trying either approach - sounds like snake oil to me.
thebluelion
25-10-07, 11:39 PM
ok just having a few beers and trying to read this tread and i must say im lost its going right over my head,i took it for granted u keep ur tyres at the manufactures rec at all times :confused:
I only change my pressures if I'm taking a pillion or a heavy load, plus I don't feel the need to compensate in the winter simply because its the winter and I'm less likely to push the tires as I do in the summer. Most of the time with my Conti's I'm running 36/38 anyway, I imagine if I was running a softer compound I might try 34/36 as they will heat up quicker.
Blue_SV650S
26-10-07, 12:36 PM
ok just having a few beers and trying to read this tread and i must say im lost its going right over my head,i took it for granted u keep ur tyres at the manufactures rec at all times :confused:
Nothing WRONG with doing that, but that is not to say you can't fiddle ... a bit like the standard shock setting, hit has a default, but you configure it to your needs/tastes ...
Blue_SV650S
26-10-07, 12:40 PM
I only change my pressures if I'm taking a pillion or a heavy load, plus I don't feel the need to compensate in the winter simply because its the winter and I'm less likely to push the tires as I do in the summer. Most of the time with my Conti's I'm running 36/38 anyway, I imagine if I was running a softer compound I might try 34/36 as they will heat up quicker.
Do you tend to check your pressures? I tend just to pump them up initially when I put them on the rim to somewhere over 30 (but <40) and just leave them ... if they feel a bit squidgy, I pump them up ...
It surprises me how 4nal some people seem to be about tyre pressures to the last PSI ...
It is a fair question imo. The temperature differences from cold during summer riding can be 30C+ whereas in the winter it is probably only of the order of 15C. If the cold starting pressure is the same in both instances is stands reason that the summer operating pressure will be higher than that in the winter. Although I seem to remember reading somewhere (sorry no reference available) that in the wet reducing the pressure helps the tyre generate more heat. I am just guessing here but I would imagine manufacturers have to accommodate such a wide spectrum of riding condition with one set of pressures that it is only a comprise that is published so there will be some flexibility to suit the individual rider in various conditions.
just my opinion of course :)
i check my tyre pressures when i get new tyres and after that just make shure there hard with my thumbs and leave the rest up to the feel of the handling
Ok, not many responses so I'll elaborate ... there are two clear diametrically opposed schools of thought WRT setting tyre pressure for different ambient temperatures ... its cooler ... reduce the pressure -> the extra movement in the tyre through wall/tread deflection generates more heat and you get to your optimum temp/pressure. The second school -> as you are not generating as much heat in the winter (its colder and you can't ride as fast), the air is not going to expand as much, so you pump the tyre up - therefore it doesn't have far to go to get to optimum pressure ...
Maybe the answer, like often the truth is, is somewhere in the midde. When riding on a track--what is the common practice? Set lower tire pressures so the tire comes-up to its desired pressure quickly. On the other hand, we only expect to be on the track for about 20 minutes at a time and if were on the track longer, the pressure could exceed the desired point. Therefore, if you are making a 20-minute commute to work in the winter, would it be better to drop your pressures say 5 lbs below "normal" to facilitate the tire warming up quickly? :)
At a guess, I'd say it did answer. Then all he was listening to was a recording of a phone ringing. The longer they listen to the phone ringing, the more they have to pay :?:
eh :?: I've answered a different thread on this one. Dunno how that happened. Please ignore my previous reply. As you will have cunningly deducted, it makes no sense. :lol:
Do you tend to check your pressures? I tend just to pump them up initially when I put them on the rim to somewhere over 30 (but <40) and just leave them ... if they feel a bit squidgy, I pump them up ...
It surprises me how 4nal some people seem to be about tyre pressures to the last PSI ...
Given you've started a thread about changing the pressures for seasons, it's most likley that any useful responses will be from people "anal" enough to actualy keep an eye on these things. Personally I run the same pressures all year round, and the bike starts feeling a bit rubbish if I'm down more than about 2psi on the front tyre so setting it to 30-and-a-bit doesn't really do it for me;)
Do you tend to check your pressures? I tend just to pump them up initially when I put them on the rim to somewhere over 30 (but <40) and just leave them ... if they feel a bit squidgy, I pump them up ...
It surprises me how 4nal some people seem to be about tyre pressures to the last PSI ...
I tend to check my tyres about once a month to make sure the PSI is right, just to keep the wear even and all that stuff.
Blue_SV650S
26-10-07, 03:11 PM
When riding on a track--what is the common practice? Set lower tire pressures so the tire comes-up to its desired pressure quickly.
Thats just it ... I first heard about it when racing, and there were the two schools of thought ... I never knew which to follow as both had their own logic that made equal sense ... but complete opposite settings … so what do you do? ;)
Given you've started a thread about changing the pressures for seasons, it's most likley that any useful responses will be from people "anal" enough to actualy keep an eye on these things. Personally I run the same pressures all year round, and the bike starts feeling a bit rubbish if I'm down more than about 2psi on the front tyre so setting it to 30-and-a-bit doesn't really do it for me;)
Yep expected it to be by people who are vigilant over their tyre pressures!
On the road you can notice the difference with a 2psi resolution (<5% if trying to run at 36psi) … that is impressive!! :notworthy:
there were the two schools of thought ... I never knew which to follow as both had their own logic that made equal sense ... but complete opposite settings … so what do you do? ;)
Try both, let us know your thoughts?
On the road you can notice the difference with a 2psi resolution (<5% if trying to run at 36psi) … that is impressive!! :notworthy:
I run 36/42 on the ZX6, I wouldn't say 2 or 3 psi down at the front feels horrific, but it's a little different, enough to make the 3 minute adjustment worth while, plus I like my tyres to last as long as possible:smt045
Me too. I can always tell if the tyres are down by anything more than a couple of psi. Not saying that I would be able to tell on every bike I am likely to own. But on my SV I can. Never could on any other bike I have owned before the SV. But then I never knew anything proper about how to ride a bike and the forces and characteristics involved in doing so before either.
SVeeedy Gonzales
26-10-07, 07:11 PM
2 psi down, on the basis that they won't warm up as much + that pressure is based on the morning pressure - if you have them bang on the right pressure first thing in the morning in this weather and you'll find them several psi too high when you ride home in the evening (whilst being convinced they're still spot on)
DoubleD
26-10-07, 07:15 PM
Here is a way you can find out if your type pressure is different from summer to winter.
set your PSI to want you want before summer rideout, check what it is as soon as you get back. That way you will get an idea of what the PSI increase is.
Do the same in winter and then you will have the difference between summer and winter PSI increases in your tyres and weather or not you should increase your tyre pressure for winter use.
Or you could just set it as you do the same for both winter and summer as I don't think there will that much of a difference maybe half a PSI or so.
Blue_SV650S
26-10-07, 07:57 PM
Try both, let us know your thoughts?
Like I said, on road I don't really set my pressures to anything specific, but on the track I chose to with the 'let down when hot' brigade ...
2 psi down, on the basis that they won't warm up as much + that pressure is based on the morning pressure - if you have them bang on the right pressure first thing in the morning in this weather and you'll find them several psi too high when you ride home in the evening (whilst being convinced they're still spot on)
So you are a let them down for the cold to get the movement man right?
...
I think you have just nominated yourself as the man for the job!! .. make it so!! :D
DoubleD
26-10-07, 08:01 PM
I'll be putting 34 in the front and 38 in the back all year round as the bike "feels" nice at those pressures.
Alpinestarhero
26-10-07, 08:33 PM
I know I need to put my tyre pressures up. I can feel the handling is heavier than normal on turn in, due to colder temp lowering the pressure in the tyres
Problem is
Dust caps won't come undone :oops:
Matt
Michelin recommend 34/36 for the PR2's, and I can't see any reason for us to change from that for the winter. I do think, however, that the across-the-board setting of 36/42 that has been bandied about for all tyres might be too high for colder weather, especially as it is a lot higher than the recommended setting anyway.
I just check mine if i haven't done so for a while, about a month. Set to 33/36 myself, but if it's at 32/36 I don't go digging out the bloody pump! I probably lost that 1psi using the gauge!!! :mad:
For the sake of answering your query I'd be inclined to try out DoubleD's suggestion, seems the most scientific way. The only problem I see is the 6 month wait for results!
Do a given route in winter, and stick to it. Note the ambient temp, and if dry/wet road. Tyres set at 33/36 first time, then check reading after 5 mins riding and at end of route.
Repeat with a lower and higher pressure of your choice for the next 2 days, again hopefully with ambients close to the same. I'd suggest the incriments should be equal either side of the base 33/36 setting. ie. 30/33 and 36/39 say.
Repeat in summer. Of course to keep things equal you're not allowed to wear that set of tyres down any in the meantime. :smt120:D
Let us know how you get on.
tomjones2
27-10-07, 04:29 PM
Michelin recommend 34/36 for the PR2's, and I can't see any reason for us to change from that for the winter. I do think, however, that the across-the-board setting of 36/42 that has been bandied about for all tyres might be too high for colder weather, especially as it is a lot higher than the recommended setting anyway.
Depends on what bike really, my z750 certainly feels a lot better at 36/42 but the sv dosent, on bt020 mind. The z is significantly heavier (30kg iirc)
I have to say i normally go with what the manufactuers says, but i do adjust the pressure for winter summer to account for the change in ambient temp.
Matt Prince
27-10-07, 08:23 PM
Hi,
Long time without posting a thread but this one is important as it can make a difference.
Just to say that I contacted company direct re BT020 tyres They advised me to set 36 / 36. I've kept to this and it seems to work pretty well. Have just changed to BT021 at the rear which seems to stick to the road even better - I'm still running at these same pressures.
Anyone doing anything different with these tyres? Incidentally got nearly 6 thousand miles from the rear.
I tried this today and going up in pressure was definitely better than going down.
There were times when it was raining today and so the tyres never got warmer than stone cold. In this case, having the incresed pressure made a big difference because the tyres weren't warm enough to generate any increase. I was riding on very bumpy roads and the tyres still didn't warm up due to being wet.
So that's me sorted, I'll be running 3-4 psi more back and front for the remainder of the winter, especially if it's wet. I usually ride hard and generate a lot of heat so I suppose I'm roughly ball part with hot tyres now.
Good thread this! :)
Carl
Blue_SV650S
28-10-07, 04:47 PM
I tried this today and going up in pressure was definitely better than going down.
There were times when it was raining today and so the tyres never got warmer than stone cold. In this case, having the incresed pressure made a big difference because the tyres weren't warm enough to generate any increase. I was riding on very bumpy roads and the tyres still didn't warm up due to being wet.
So that's me sorted, I'll be running 3-4 psi more back and front for the remainder of the winter, especially if it's wet. I usually ride hard and generate a lot of heat so I suppose I'm roughly ball part with hot tyres now.
Good thread this! :)
Carl
Good work :notworthy:
Anyhoo, seems like there is one convert ... see every day is a school-day with Blue_, my mubmblings have educated and potentially made your ride more satisfying, even safer!!!! {pats self on back} :takeabow:
:D
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