AK550 Tire Pressure ?

[Luckyword]

For AK 550 owners, what time pressure do you like to run?

I've had my bike for a week and am trying to find what's most comfortable.

I just set pressure to 40 fr and 42 rear (both cold) -- which is what's indicated on the sidewalls.

I looked in the manual and it indicates pressure as below (I've converted to psi as well, using a website). From the manual (with psi added):

front: 3.2 kgf (45.5 psi) and 1.6 kgf (22.75 psi)
rear:  3.75 kgf (53.33 psi) and 1.65 kgf (23.46 psi)

[rjs987]

That's not the USA owners manual is it?
Mine shows totally different.
First off, if your tires are over 42 psi cold pressure you will eventually end up with a tire failure while riding at speed. I don't recall seeing any motorcycle tire that has a higher max cold pressure than 42 psi, but I haven't seen all mc tires so...
I'm surprised your TPMS doesn't give you a tire pressure warning for over pressure. That's the symbol of the tire cross section with a "!" in the middle of it.
Second, I find the TPMS on my AK to be somewhat pessimistic for actual psi so be careful to consider that. It is consistent in how much it is off but still always reads lower than any pencil gauge I've used by just over 1 psi. Then again, who knows how accurate the pencil gauge may be, so maybe the TPMS is more accurate. 

My owners manual shows recommended cold pressure to be front tire: 2.4 kgf/cm2 and rear tire: 2.7 kgf/cm2 (page 66 of the USA owner manual). It also shows the same on the sticker on the back of the storage box that was printed specifically for USA models.
That translates to a recommended pressure of about 34.1 psi for the front and about 38.4 psi for the rear.
That is 1 up as well as 2 up.
Both my Metzeler Feel Free tires say max psi at max load is 42 psi right on the sidewall. Keep in mind, those are maximum psi at maximum load.
On all my bikes since my Gold Wing that I had back in 2003 I was told that bumping up the psi a little improved tread wear and in some cases handling for touring tires so that's what I've always done. So with most of my bikes, regardless if my GW or ST1100 or CTX1300 or Burgman 650, I usually set the pressure at 40 psi front and 42 psi rear (except when I was riding on a Shinko tire which had a max cold pressure of 41 psi rear). My tires would usually last at least 20-30% longer than others with the same bike and same tires but lower psi, and handling was great (except for that Shinko rear tire which was like riding on banana peels all the time).
BUT NEVER MORE THAN THE MAX COLD PSI SHOWN ON THE SIDEWALL. Just need to emphasize that point.
Oh, and always check psi when tires are cold. Hot tires vary wildly depending on how hot they are and there is no way to come close to what it's supposed to be doing that.

So on my AK I usually keep the front at about 38 psi and rear at 42 psi. Or close to that. But since I cannot guarantee the accuracy of either my pencil gauge or the TPMS reading on the dash I do stay conservative about that a little. So I used my pencil gauge to set the pressures at 38 psi front and 42 psi rear. That showed up on the TPMS as 37.4 psi front and 40.9 psi rear. So I now keep my AK tires set to show that on my TPMS. Sometimes I'll let the front get a little higher, like 37.9 psi, but not usually. I keep it at 37.1-37.7 psi front and 40.6-40.9 psi rear every time I check using the TPMS. I feel most confident at these pressures and handling is great even in torrential rain storms and high winds on newer asphalt pavement (experienced on my recent 1374 mile trip from central Iowa to N Tennessee). Tires seem to be lasting well but it remains to be seen how many miles I end up getting from them. So far the front is wearing more than the rear so I might consider increasing the psi on that one a little now that I have some time with the bike. I expect from the wear I am seeing I'll likely get between 6000-7000 miles on the front and 7000-8000 on the rear. That is a little more than I was getting on my Burgman regardless what tires I put on that one. I currently have over 4100 miles on my AK.

Your tire wear WILL differ from anyone else even with the same bike and same tires. That is because of differences in climate, pavement surfaces, riding style, and a few other factors including psi. Chip Seal road surfaces typically eat tires for breakfast. Concrete seems to be easier on tires IME. Asphalt is in between depending how much aggregate is in the mix. I've known riders with the same bike and tires as I have and keeping the same psi in those tires but only getting 4000 miles on a tire, or less, when I was getting 7000-8000 miles on that same tire. All due to them riding on mostly chip seal roads. My area has mostly concrete roads for me to ride.

[Stig / Major Tom]

This is kind of spooky - because I keep reading of people inflating their scooter tires to the figure found on the tire's sidewall!

The tire pressure embossed on the sidewalls of tires is never the recommended inflation.
It is, the maximum pressure after which destruction of the tire may occur - and should never be exceeded - but it is certainly never the recommended PSI.
The correct tire inflation figures are found on driver's door stickers of cars and trucks, and on labels affixed to scooters in prominent locations, or under the seat.

If all else fails, - the owner's manual will give the correct inflation figures. Never the tires.
Stig

[Neil955i]

Mmm maybe it's time I checked my pressures again....

[rjs987]

...The tire pressure embossed on the sidewalls of tires is never the recommended inflation.
It is, the maximum pressure after which destruction of the tire may occur - and should never be exceeded - but it is certainly never the recommended PSI.
The correct tire inflation figures are found on driver's door stickers of cars and trucks, and on labels affixed to scooters in prominent locations, or under the seat.

If all else fails, - the owner's manual will give the correct inflation figures. Never the tires.
Stig

Actually that is a false statement. The Honda CTX1300 user manual and service manual both show a factory recommended rear tire psi of 42. The pressure indicated on the sidewall of the OEM tires is also 42 psi. I always ran the rear tire on my CTX1300 to factory spec... 42 psi. I agree to never exceed the psi indicated on the sidewall of the tires which CAN result in a really bad day for the rider. But it is OK to go up to that with the understanding that the ride will be effected. Skilled riders know how to manage that without any issues. Higher inflation results in a slightly harder ride but better wear (based on experience over the last 19 years of paying very close attention to my tires). Lower inflation will result in a softer ride (which is what manufacturers want you to experience) but worse wear and possibly cupping (scalloping) of the tire (also based on experience over the last 19 years of paying very close attention to my tires). I rather like the slightly harder ride. But then I really never noticed much difference in that with low inflation vs higher inflation.

[monkeybongos]

Not to mention more responsive handling w higher psi.  Believe tire manufacturers recommend being within 10% of max psi?
Don't understand using the same pressure on a tire w max psi of 32 as one w 41.  Recommended pressures listed on bikes/in manuals may be appropriate for the oem tires, but imo not for upgraded rubber w higher max psi.

[Luckyword]

Thanks for the useful, helpful discussion, and information.

I had measured it cold and (...cough, cough -- should have looked at the Owner's Manual, for sure).

I've adjusted the pressure, and for now am going to run 34 front and 38 rear psi when cold.

With the 40 front and 42 rear that I had set it to, I did experience having that tire warning on the dash a few times, but it went away each time, after a few minutes, and in each case only appeared when starting the bike.

[Iahawk]

as with most things, be careful of blanket statements that may not be accurate in all circumstances...my small, light motorcycle calls for 28 front, 32 rear....big, heavy touring bikes may call for much higher psi.

Race bikes using race rubber call for much lower tire pressures than regular street pressures.

I agree that you never use the sidewall max pressures as a set point. Most should defer to the manufacturer's recommendation unless you are an expert/advanced rider and are able to go out on the  track and make 1 or 2 psi adjustments at a time until you get the handling / feel you're looking for.

[rjs987]

...
With the 40 front and 42 rear that I had set it to, I did experience having that tire warning on the dash a few times, but it went away each time, after a few minutes, and in each case only appeared when starting the bike.

That tire pressure warning symbol that flashes over the bike icon often comes on a flashes a few times when I first start the bike, as do all the other indicators. So that is normal. I did see it come on while riding once while I was on my recent long trip and when I checked the psi while I was riding I saw the front pressure was higher than it normally gets while riding when the tires are hot. I attribute that to the air temp being a bit cool when checked the TPMS in the morning and later in the day when the warning showed the temps had warmed up a LOT. So I let a few psi out at the next stop and all was good. On the AK I find the front tire needs to be below 38 psi to avoid the warning when the tire gets hot. That may have also been the case for my other bikes but I didn't have TPMS on those. I always set my front tire psi lower than the rear anyway by about 3-4 psi at least so: 40.9 psi rear and 37.9 psi front. But just be aware that if you check in the morning when temps are, say, around 60 F and are riding later on when temps have gone up to, say, 80 F then the psi will need to be adjusted again for the warmer ambient air temps. Best to check just before a ride to account for that temp differential. Or if you cannot check the cold psi, such as my example when traveling all day long without stopping, getting to know how much of a change at the hot psi is appropriate is part of getting to know your bike. Experience will teach you what psi should get to if you look at it once in a while when the tires are hot. I can say the hot psi won't be consistent since it matters just how fast you are riding and what the air temp and road temp gets to. Black asphalt gets hotter than tan concrete pavement in the same air temps and roads with lots of traffic will be hotter than roads with very little traffic so take all that into consideration. That's why checking the tires when cold for a starting point will give the most consistent results (as long as the day doesn't warm up too much    )


btw- I also notice the heated grips LED on the left grip flashes white and red a few times when I first start the bike. This also is normal.

[Stig / Major Tom]

as with most things, be careful of blanket statements that may not be accurate in all circumstances...my small, light motorcycle calls for 28 front, 32 rear....big, heavy touring bikes may call for much higher psi.

Race bikes using race rubber call for much lower tire pressures than regular street pressures.

I agree that you never use the sidewall max pressures as a set point. Most should defer to the manufacturer's recommendation unless you are an expert/advanced rider and are able to go out on the  track and make 1 or 2 psi adjustments at a time until you get the handling / feel you're looking for.

Point taken - Hawk....blanket statements are never a good idea (unless talking political parties
So, to revise my Statement : "Your source for determining your tires correct PSI is found somewhere on the vehicle itself, or in the owner's manual. "
Also, I read that this PSI figure is not tire dependent - in that it is the vehicle, not the tire,  which sets the optimum PSI figure  - brand regardless.
 
My Liberty needs the same PSI to maintain grip, braking and mileage - whether I running Michelins or Pirellis. (obviously - if you want to put a sand-paddle tire on your Burgman 650 - you'll likely....or dirt nobbies on your LIKE200i.....use a different PSI)

Certainly - it seems I can play with the PSI to lessen my tire contact patch, change where my tire wears, and for 'sporty handling' and firmer riding - but I've found on my lighter scooters that increasing the PSI even 2 or 3 lbs beyond the recommended results in an unpleasantly harsh ride on an already ride-compromised plastic scooter!

Stig

[Iahawk]

something more to consider...from Dave Moss Tuning...a video on proper tire pressure setup ..he says the pressure listed on the sticker is all wrong!

[wymple]

As I understand it, the pressure ratings on the tires is maximum pressure that should be used on a fully loaded bike. I commonly run 35 lbs rear & 30 front, never have issues. I do know from talking to touring riders that running high pressures will puff up the center of the tire to the point where the outer edges aren't doing much, so the tires wear faster. I know a Wing rider who rides all over the country on 30 in the rear.

[rjs987]

something more to consider...from Dave Moss Tuning...a video on proper tire pressure setup ..he says the pressure listed on the sticker is all wrong!

BINGO!
What he said.
Make adjustment for what works best for you and your riding.

[Ruffus]

Reminds me a little bit of this famous motor oil thread.😄

[Stig / Major Tom]

Reminds me a little bit of this famous motor oil thread.😄

Yep.
Definition of intransigent 🙃

Stig