Car Tires and Tire Pressure

[Adventurer]

I was initially going to post this in another tire thread but decided it may be too much of a hijack.

Being a Spyder rider for less than a year I have no experience with anything other than the OEM Kendas, but I expect I will replace the tires with a car tire when the time comes. I expect to need a new rear tire in six months or less. Due to apparent supply shortages I’d like to get a tire ordered in the next few weeks, but I have some remaining concerns I’d like answers to before committing to switching over to a CT.

My first concern is the lower pressures recommended for car tires, I understand it’s less weight on a tire designed to support a heavier vehicle hence the lower pressures, but I fear rolling the bead off the rim when riding twisties and incurring high lateral loads on an under inflated tire. Is this a legitimate concern? Why or why not? Has anyone ever heard of this occurring to anyone riding a Spyder with car tires?

2nd concern is how do you determine what the proper lower tire pressure is in order to get the best ride performance but not so low rolling the bead off the rim is a high probability?

Is my concern unfounded? Has this phenomenon been tested?

Is there a chart or formula to calculate proper tire pressure for car tires on motorcycles and trikes?

Please educate me

[Navydad]

All I have is personal experience on my 2015 RT. I have Federals on front and an Altimax on the rear. I run 18psi in all three. Why, because that is what works for me, your results may vary. I have been cornering so hard that Nanny not only cut the power she also applied the brakes HARD. I have cornered hard enough to lift a wheel before Nanny caught on and kicked in. I have never popped a bead or rolled a tire off the rim. Hmm, maybe that does answer the "Has this Phenomenon Been Tested" question. I bet that if you push the stock Kendas that hard you would be in trouble.

[BLUEKNIGHT911]

I was initially going to post this in another tire thread but decided it may be too much of a hijack.

Being a Spyder rider for less than a year I have no experience with anything other than the OEM Kendas, but I expect I will replace the tires with a car tire when the time comes. I expect to need a new rear tire in six months or less. Due to apparent supply shortages I’d like to get a tire ordered in the next few weeks, but I have some remaining concerns I’d like answers to before committing to switching over to a CT.

My first concern is the lower pressures recommended for car tires, I understand it’s less weight on a tire designed to support a heavier vehicle hence the lower pressures, but I fear rolling the bead off the rim when riding twisties and incurring high lateral loads on an under inflated tire. Is this a legitimate concern? Why or why not? Has anyone ever heard of this occurring to anyone riding a Spyder with car tires?

2nd concern is how do you determine what the proper lower tire pressure is in order to get the best ride performance but not so low rolling the bead off the rim is a high probability?

Is my concern unfounded? Has this phenomenon been tested?

Is there a chart or formula to calculate proper tire pressure for car tires on motorcycles and trikes?

Please educate me

I'm considered to be one of the TIRE GURU's here ....Peter Aawen is the other one .... Fact : Our Spyders when using Auto tires MUST have a lower PSI to perform at their best - Period ...... Peter and I like 15 to 17 front ( 17 if you are aggressive ) and 18-19 Rear for avg. to heavy - weight. As far as bead separation is concerned - I DRAG raced mine a few times using 45 front ( less rolling resistance ) and 12 REAR , better traction..... even with massive burnouts there was no bead issues ( and it marked the wheel and the tire so I would know ) ...... good luck .... Mike .... PS for the rear look for a General Altimax RT43 in 215/60-15 or a Vredestein " Quatrac " in 205/60-15 or 205/65-15....TireRack has both

[Woodaddict]

I was initially going to post this in another tire thread but decided it may be too much of a hijack.

Being a Spyder rider for less than a year I have no experience with anything other than the OEM Kendas, but I expect I will replace the tires with a car tire when the time comes. I expect to need a new rear tire in six months or less. Due to apparent supply shortages I’d like to get a tire ordered in the next few weeks, but I have some remaining concerns I’d like answers to before committing to switching over to a CT.

My first concern is the lower pressures recommended for car tires, I understand it’s less weight on a tire designed to support a heavier vehicle hence the lower pressures, but I fear rolling the bead off the rim when riding twisties and incurring high lateral loads on an under inflated tire. Is this a legitimate concern? Why or why not? Has anyone ever heard of this occurring to anyone riding a Spyder with car tires?

2nd concern is how do you determine what the proper lower tire pressure is in order to get the best ride performance but not so low rolling the bead off the rim is a high probability?

Is my concern unfounded? Has this phenomenon been tested?

Is there a chart or formula to calculate proper tire pressure for car tires on motorcycles and trikes?

Please educate me

we need YOU to be a ginnea pig!!! everyday lower tire pressure 1 lb, go for a ride until you have bead separation, one day. you would have to be at 0 psi with alot of heat build up with a light machine to get bead separation. i have car tires with those pressures, and they preform fine. been no talk on forum of any bead separation in my 4 years here with a problem

[canamjhb]

Your concern IS unfounded. I'm quite large and ran 18 psi in all three tires for tens of thousands of miles. Bead separation has not been an issue from anyone that I have seen. More likely, you will tend to have too much pressure. Good luck..... Jim

[Adventurer]

All I have is personal experience on my 2015 RT. I have Federals on front and an Altimax on the rear. I run 18psi in all three. Why, because that is what works for me, your results may vary. I have been cornering so hard that Nanny not only cut the power she also applied the brakes HARD. I have cornered hard enough to lift a wheel before Nanny caught on and kicked in. I have never popped a bead or rolled a tire off the rim. Hmm, maybe that does answer the "Has this Phenomenon Been Tested" question. I bet that if you push the stock Kendas that hard you would be in trouble.

It is good to hear solid antidotal evidence too, thank you. I can’t say I’m an aggressive rider since I’ve never had the nanny kick in so far so worrying about bead separation may be unfounded...I dunno. I do plan on going to a parking lot one of these days to try to find out at what point that is as I just want to know where that edge is and how it feels ahead of it just happening someday on the road.

[Adventurer]

I'm considered to be one of the TIRE GURU's here ....Peter Aawen is the other one .... Fact : Our Spyders when using Auto tires MUST have a lower PSI to perform at their best - Period ...... Peter and I like 15 to 17 front ( 17 if you are aggressive ) and 18-19 Rear for avg. to heavy - weight. As far as bead separation is concerned - I DRAG raced mine a few times using 45 front ( less rolling resistance ) and 12 REAR , better traction..... even with massive burnouts there was no bead issues ( and it marked the wheel and the tire so I would know ) ...... good luck .... Mike .... PS for the rear look for a General Altimax RT43 in 215/60-15 or a Vredestein " Quatrac " in 205/60-15 or 205/65-15....TireRack has both

Thanks Mike, that’s information I can use.

[Adventurer]

we need YOU to be a ginnea pig!!! everyday lower tire pressure 1 lb, go for a ride until you have bead separation, one day.

I’m going to assume you meant that to be funny, sorry I don’t see that way.

been no talk on forum of any bead separation in my 4 years here with a problem

That’s good to hear.

[Adventurer]

Your concern IS unfounded. I'm quite large and ran 18 psi in all three tires for tens of thousands of miles. Bead separation has not been an issue from anyone that I have seen. More likely, you will tend to have too much pressure. Good luck..... Jim

Thanks for the info, I appreciate it.

[pidjones]

GL1800s have been known to run car tires at zero psi without bead separation, and they don't have "J" beads. Several of the GL1800 "dark siders" have reported full pressure loss (road hazard or valve stem failure) that was only discovered when they arrived home. Now, these are usually on run-flat tires, but still...

[Navydad]

It is good to hear solid antidotal evidence too, thank you. I can’t say I’m an aggressive rider since I’ve never had the nanny kick in so far so worrying about bead separation may be unfounded...I dunno. I do plan on going to a parking lot one of these days to try to find out at what point that is as I just want to know where that edge is and how it feels ahead of it just happening someday on the road.

I agree with the parking lot testing. Get the feel of Nanny cutting the power and even applying the brakes. Make sure you find a lot with some sand or grit so you can get the feel of the ABS and traction control as it operates. Good riders never stop learning.