Front tire pressure - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 10 (permalink) Old 07-03-2019, 06:53 PM Thread Starter
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Front tire pressure

I just replaced my front tire, Shinko 777. It's another Shinko brand, but a different model. The shop that mounted the tire recommended 42 PSI, based on the tire manufacturer. Vulcan manual says 28 PSI. Who is right?

On one hand, I always trusted the car manufacturer recommended pressure over the tire manufacturer recommended pressure. But this is a motorcycle. Adverse handling effects are a lot more scary on a motorcycle.

On the other hand, this is a reputable shop and I am new to motorcycles.

Any thoughts?


'89 Vulcan 750 Bought 4/12/18 @ 17805.9 miles $800
Purchased stock. Wrecked once
22490.0+ miles

Completed modifications:
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Pick-up coil re-gapped to .020"
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Repainted Metallic Blue w/ new tank bages
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post #2 of 10 (permalink) Old 07-03-2019, 07:29 PM
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The tire manufacturer number is probably the "maximum safe pressure", i.e. tires are warmed up and carrying a heavy load. The recommended pressure on the bike frame is the recommended cold pressure. Two different numbers that don't conflict with each other. The shop shouldn't be filling them to max, but to the recommended cold pressure.

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post #3 of 10 (permalink) Old 07-03-2019, 07:34 PM
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Hrm. Just did some googling around, and someone quoted Shinko (can't find original Shinko source) as saying that the rating for the tire should be used, not the stamped pressure. It's possible Shinko uses different materials/technology and requires a much higher pressure. So, basically, I have no idea. Ignore what I said earlier.

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post #4 of 10 (permalink) Old 07-04-2019, 08:46 AM
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This has been a issue for years, with many aftermarket tires. Some makers offer a suggested tire pressure and some don't, but print a MAX pressure on the tire.

Marathons for instance, "recommend" 40psi (the tire lists 45 max) many riders found 38psi seemed to work well.
I think I tried to find information on Shinko tires a few years back and never found a "recommended tire pressure" from them, only from owners or tire sellers.

42 psi sounds pretty high given the front tire size and bike weight, but I'd try riding on that for while and see how it feels. I'd say 28psi might be too low for that tire.

Sadly, if you search online, you'll find A LOT of different answers regarding the Shinko tires. General consensus is something in the mid 30's...

You can, however find the ideal pressure yourself. All you need is one of those laser temperature guns, and some time. At the same time each day (and hopefully at the same ambient temp) ride the bike for several miles (avoiding hard stops and starts) and take a temperature reading of the center tread.

Do this for several days, with starting out each day with a different tire pressure (30,34,36,38,40 and 42). Which ever pressure results in the lowest tire temperature is the one you should use.

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Last edited by Knifemaker; 07-04-2019 at 08:57 AM.
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post #5 of 10 (permalink) Old 07-04-2019, 09:25 AM
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42 psi does sound high, that's what much heavier bikes like the HD Ultra Classic use.

The 777 does have a higher weight rating, so would most likely show a higher max. psi on the sidewall. But, the max. psi on a sidewall is the max. psi at max. weight, which most vehicles will never see. It's the same on all tires, car, truck, bike, etc.

On your car, the sidewall always shows a higher max. psi versus the OEM psi recommendation on the door sticker. You should always go by the door sticker, not the sidewall.

Check the sidewalls, it should read something like - max. xx psi @ xxx lbs max. weight.

I run 30 psi in the Tourmaster 230 Shinko on mine, front and rear.

42psi sounds like a really harsh ride.

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Last edited by Spockster; 07-04-2019 at 09:28 AM.
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post #6 of 10 (permalink) Old 07-04-2019, 11:24 AM
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I've been running 32 front and 28 rear. Seems to ride well.

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post #7 of 10 (permalink) Old 07-04-2019, 06:59 PM Thread Starter
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The front is the Shinko 230. I have it at 28 PSI right now


'89 Vulcan 750 Bought 4/12/18 @ 17805.9 miles $800
Purchased stock. Wrecked once
22490.0+ miles

Completed modifications:
Removed mufflers, straight pipes out of GB
110/90 Front Tire
Pick-up coil re-gapped to .020"
Compufire 55402 r/r series regulator
USB Outlet + Voltmeter
Repainted Metallic Blue w/ new tank bages
Ear Shave (wo/ coasters) 40/140 NO shims 45MPG
MCCT conversion

Planned modifications:
Custom LED turn signals
Windshield
Highway Pegs
(Possible) ignition advance
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post #8 of 10 (permalink) Old 07-10-2019, 05:45 PM Thread Starter
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My previous front tire was a Shinko 777. Before that, it was a Dunlop, but i don't know the model. I always ran the tires at the bike manual recommended pressure of 28 PSI.

When I put on the Shinko 777, the front felt very nice and secure. It was quite stable in the turns and gave a very confident feel around the corners. It felt like it had grip for days, and stuck to the road. Gave the bike a real snappy sporty feel.

When I asked the shop for a new front, they put on a Shinko 230 instead of a Shinko 777. I'm not sure if they misunderstood, or if they told me and I misunderstood.

The Shinko 230s feel more like the old Dunlop that was originally on the front. It just doesn't feel as confident in the corners. I'm more hesitant to lean it over.

Anyone else tried both the 777 and the 230? Specifically, 777 rear and 230 front? What was your experience? I don't think I can return the 230 at this point.


'89 Vulcan 750 Bought 4/12/18 @ 17805.9 miles $800
Purchased stock. Wrecked once
22490.0+ miles

Completed modifications:
Removed mufflers, straight pipes out of GB
110/90 Front Tire
Pick-up coil re-gapped to .020"
Compufire 55402 r/r series regulator
USB Outlet + Voltmeter
Repainted Metallic Blue w/ new tank bages
Ear Shave (wo/ coasters) 40/140 NO shims 45MPG
MCCT conversion

Planned modifications:
Custom LED turn signals
Windshield
Highway Pegs
(Possible) ignition advance
Jason Pittenger is offline  
post #9 of 10 (permalink) Old 07-10-2019, 07:08 PM
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I have always used the "max pressure" number on the side of the tire. On both bikes and cars. I'm 240 pounds, and don't like the idea of riding on an underinflated tire. I don't ride sport bikes so I don't worry about handling to much. I never push a cruiser to anywhere near it's limits. My main concern on both motorcycle tires and care tires is tread life, and they seem to last longer when inflated to the pressure on the tire sidewall. I have never noticed any unusual tire wear from doing this. If a tire is over inflated it will wear faster in the center. Tire manufacturers leave a wide safety margin on their recommended pressures. But I don't trust tire manufacturers as much as I used to. They now make car tires with 1" sidewalls, which cannot possibly be safe. I won't use a car tire with less than a 6" sidewall.

I am a motorcyclist, NOT a biker.


1997 Vulcan 750, purchased about a week ago
2006 Sportster 1200 Low
2013 Royal Enfield Bullet 500, converted to carb
2001 Yamaha XT225, heavily modified
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post #10 of 10 (permalink) Old 07-13-2019, 10:37 AM
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Using MAX pressure listed on the tire will not hurt the tire and usually will not cause uneven wear. It will give you the best fuel savings. It will however not offer the best handling.
Generally lower pressures give better handling, but increase wear and reduce fuel economy. Higher pressures do the opposite of each. So finding a compromise between the two extremes is what most "suggested air pressures" do.
Given the fact that the Vulcan doesn't eat up tires as fast as a sport bike (my FJR needed a new rear after 5500 miles) I adjusted my pressures on the Vulcan to give the best performance in turns as tire wear or mpg's wasn't a concern to me.
Again, ideally, the temperature adjustment I posted above is the best way to find that best compromise.

I had done some experimenting with tire pressures years back you can read in the Verses here:
https://www.vn750.com/forum/43-wheel...-pressure.html

Keep in mind these were on my fairly new bike, with my lightweight butt on the bike and without any scientific controls other than my own seat of the pants observations. I was also ONLY looking for what pressures seemed to make the bike more sure-footed on the road, and NOT what gave the smoothest ride, best gas mileage, or least wear. YMMV

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Last edited by Knifemaker; 07-13-2019 at 11:33 AM.
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