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Discussion Starter #1
Reading the thread about a twitchy highway ride I saw some comments about tire pressure. While I've never really had an issue with a twitchy ride, I've always been confused about the way Kawasaki feels these pressures should be set.

The manual recommends we ride with only 28 PSI in the front tire, regardless of weight carried. The rear from 36 to 40 PSI, depending on weight carried. I assumed the front was set so low because the Vulcan rides with most of the weight positioned towards the bike's rear and that higher pressures in the front weren't needed. To be honest, it just didn't seem right.

I've never pushed the front up very high, keeping my Classic (with Michelin tires) at about 30 PSI and the Voyager (stock shoes) at 32 PSI (cold). The rears on both bikes are kept at the 40 PSI mark.

What pressure do others ride in their front tires?

If you run with higher pressures, what might change in the bike's ride?
 

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BOTM Winner, August 2015
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1+ on 38 to 40 front, 40 - 42 rear. That is what Avon recommends as the air pressure on their Cobra tires depending on the bike's load. Metzler recommends similar pressures. Doesn't feel twitchy at all. My opinion is Kawasaki's recommended tire pressures are to give the bike a cushy ride, not the best pressures for handling or for tire wear.
 

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Discussion Starter #4
1+ on 38 to 40 front, 40 - 42 rear. That is what Avon recommends as the air pressure on their Cobra tires depending on the bike's load. Metzler recommends similar pressures. Doesn't feel twitchy at all. My opinion is Kawasaki's recommended tire pressures are to give the bike a cushy ride, not the best pressures for handling or for tire wear.
ol' school, on that note... I work in the auto repair industry and one of the common statements made by auto makers to their dealers is that the dealers should NOT follow the tire maker's published PSI. The concern is that tire companies only publish overall max air pressure numbers because the tire makers are not able to account for every vehicle's specific weight, balance, etc... Two different vehicles with the same tire size and make will perform different based on their design, so it is the vehicle maker that should establish a proper PSI, based on the tire maker's published max requirements.

I admit that tire wear will be improved with higher pressures, but what handling changes do you notice when moving to the higher pressures.
 

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BOTM Winner, August 2015
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IMHO it improved the handling by making the bike more nimble in the twisties and also increased the mileage I get out of the tires. And I surely am not the only person on this forum that is running higher pressures than the owners manual states. There are many threads that have discussed this topic before. I think the motorcycle handled more wishy washy at the manufacturers recommended pressures. I also ran Avon's recommended pressures when I had my 900 Classic LT with the same improvement in handling as have those I ride with on their motorcycles with whatever tire brands they were running (Metzler, Dunlop, Bridgestone, etc...).
 

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IMHO it improved the handling by making the bike more nimble in the twisties and also increased the mileage I get out of the tires. And I surely am not the only person on this forum that is running higher pressures than the owners manual states. There are many threads that have discussed this topic before. I think the motorcycle handled more wishy washy at the manyfacturers recommended pressures. I also ran Avon's recommended pressures when I had my 900 Classic LT with the same improvement in handling as have those I ride with on their motorcycles with whatever tire brands they were running (Metzler, Dunlop, Bridgestone, etc...).
This.

:) :) :)
 

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I'm not an overly aggressive rider - but the term "spirited" does fit me.

Here we are on the Wing, taking in some curvy roads. Some of you might recognize this road. We run 42/front -n- 44/rear on this bike and get (roughly) 18,000 from a front and 14,000 from a rear. Pressures less than that... and we will have cupped tires.

Pretty close to the same on most everything we've owned.

(Sometimes) your riding style and terrain dictates the tire pressure. i.e. if we only rode flat, straight roads then we could probably get good tire wear with less air pressure.
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THIS one works best at 40/40
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My opinion is that Kawasaki set the pressure low on the front to better absorb small imperfections on the road. They did this to compensate for the budget front suspension. I did Gold Valve Cartridge Emulators and new springs as well as all new bushings. Then I changed my air pressure to 36 PSI.
 

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My dealer recommends 42 rear (either for Bridgestone Exedra Max or for the Dunlop American Elite that I am using now) and 36 for the front (Bridgestone Exedra Max) The higher pressures seem to help with the tire wear and do not adversely affect the handling.
 

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Just throwing some facts into the argument. I have a somewhat different opinion on tire pressures noted at the bottom, but this is what the manufacturers say. I have contacted a number of tire mfg and they all indicated the following:

The 40 PSI or whatever on the side of tires is the tire mfg MAXIMUM recommended COLD tire pressure. If they don't publish specific recommendations for specific tires and bikes, all tire mfg contacted recommended that you use the bike mfg recommended tire pressures.


The following is what I do and, so far, it has worked very well. (Disclaimer - I have only used this system on one bike and not the Voyager yet. I'm waiting on a new TPMS unit. The last one got damaged and does not work):
I use a TPMS (tire pressure management system) to monitor the temperature and pressure. After doing a lot of research, I use a system that uses pressures that result in a 3 - 4 PSI increase in the front tire and 5 - 6 PSI increase in the rear tire once the tires have warmed up. From what I have gathered, it does not matter what bike or what tire, this seems to work. My personal system is a little more complicated than that because I also take into account the low and high temps for the day (set for 70° F cold, allowing for 1 PSI change for every 10°F), but this system got me nearly 30% more miles out of the same tire type than using the bike mfg recommendations. I also felt I have better control than using either higher or lower pressures. So far, I have never gone above 36 PSI as the cold pressure for the rear tire.

For very cold weather, I adjust the ambient target down, usually to around 35° F which is about as cold as my garage ever gets even when it is down to single digits outside. At very cold temps the tires never warm up to much so the pressure will be far too low otherwise and you get cupping.

Using this system takes into account the rider (and passenger) weights, luggage carried, etc. because increased weight at the same pressure will cause the tires to heat up due to excess flexing and results in a higher PSI, indicating that the pressure is too low for the increased weight. If the pressure does not rise enough, the pressure is too high and the tire is not flexing as it should.
 
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