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Author Topic: Tire Pressure contradiction?  (Read 663 times)

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Offline NY Andrew

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Tire Pressure contradiction?
« on: August 20, 2020, 07:59:10 pm »
What is the correct tire pressure???

Thought I had a XVS95CJL (according to my purchase paperwork), but the Yamaha website only populates a manual for XVS95CJC & XVS95CJ and in that manual it says the tire pressure is: Front 33psi; Rear 36psi.

On the frame of the bike it says: Front 36psi; Rear 41psi.

The manual is dated 2017, so guessing they changed tires for the 2018 model?


2018 Yamaha Bolt-R

Offline DrM

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Re: Tire Pressure contradiction?
« Reply #1 on: August 20, 2020, 10:43:38 pm »
What's placarded on my 2019 R-spec lower belt guard is the same as what is posted in my owner's manual:  Front 33 psi, Rear 36 psi.

The part number for the tire label is 1TP-21668-00-00, which is the same part number for 2018 and 2019 R spec.  You might not be looking at the right label
« Last Edit: August 20, 2020, 10:56:32 pm by DrM »

Offline VIKEN

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Re: Tire Pressure contradiction?
« Reply #2 on: August 21, 2020, 01:35:30 am »
I'd say go with what's on your bike swingarm. Doubtful, but I'm guessing the manual varies by region? Personally, I usually go with the average of what it says on the bike and the tire manufacturers

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Offline lunkhead

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Re: Tire Pressure contradiction?
« Reply #3 on: August 21, 2020, 01:36:19 am »
In the US, Bolts don't come equipped for carrying a passenger so only pressures for "rider, cargo and accessories" is listed. They also come with a label on the tank that says "NEVER CARRY A PASSENGER". (OEM passenger seat kits come with a new label.) Bolts sold in other countries that come stock with a passenger seat and pegs do list both pressures. The higher pressures are listed for "rider, passenger, cargo and accessories". The label on the frame gives the pressure for the maximum weight the bike can support.
« Last Edit: August 21, 2020, 01:40:06 am by lunkhead »
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Offline DrM

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Re: Tire Pressure contradiction?
« Reply #4 on: August 21, 2020, 07:26:15 am »
In the US, Bolts don't come equipped for carrying a passenger so only pressures for "rider, cargo and accessories" is listed. They also come with a label on the tank that says "NEVER CARRY A PASSENGER". (OEM passenger seat kits come with a new label.) Bolts sold in other countries that come stock with a passenger seat and pegs do list both pressures. The higher pressures are listed for "rider, passenger, cargo and accessories". The label on the frame gives the pressure for the maximum weight the bike can support.

Any idea what Yamaha assumes are the individual average weights for rider, passenger, cargo, and accessories?  If I knew that I could construct a tire pressure chart for those rare times I actually have a passenger.

Offline Sdaniels

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Re: Tire Pressure contradiction?
« Reply #5 on: August 21, 2020, 09:56:08 am »
There are a thousand reasons to adjust tire pressure up or down from recommended settings.  Too low & gas mileage suffers, tire wears out quicker & runs hotter...too low & the tire can overheat.  I've read 10% difference between cold & hot pressures gives the best all around grip/longevity but also read 10% for front & 20% rear from another article.  I actually did the math using the 10/20% & found stock front tire pressure worked but the rear had to drop to 35psi.  I'm betting different brands will require adjusting those differences.  I typically have adjusted to higher pressures on just about every bike I've owned.  I tried running 38F/40R but the Bolt rode horribly, very rough.  Dropping to 35/37 helped but I'm betting shocks & fork work will help more than tire pressure.
2015 C-spec

Offline lunkhead

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Re: Tire Pressure contradiction?
« Reply #6 on: August 21, 2020, 12:22:40 pm »
Rider only is 0 - 198 lbs. (33/36 psi). With passenger, cargo, etc., it's 198 - 454 lbs. (36/41). ABS adds about 9 lbs. so maximum is that much less at 445 lbs. Manuals don't get into the science behind it like Sdaniels did. They keep it simple and imprecise.

I never know when I'll be carrying a passenger and adjusting for tire temperatures on the street is impractical so I fill to slightly less than maximum and by the time I check them again, they'll leak to around minimum pressure. Keeping an average between the two is good enough for the street and gives good service life. Conditions just aren't controlled enough to have a perfect pressure that works all the time.
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Offline Crilly Wizard

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Re: Tire Pressure contradiction?
« Reply #7 on: August 21, 2020, 12:53:11 pm »
Different tyre brands will have different recommendations for pressures for our bike as well, though not many make them available. Avon recommends ~35/40 single rider to ~40/45 with passenger for the Cobra Chrome for our bike, and these work well for me.

Offline lunkhead

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Re: Tire Pressure contradiction?
« Reply #8 on: August 21, 2020, 05:33:00 pm »
Michelin site shows 2 bikes in their Commander III ad, a Harley and a Bolt. Says the III has a rounder profile and if mixed with older generations, it should be used on the front.

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