I had a problem after changing the tires on my Can Am Spyder RT 215/65R15.

[kongdoly]

Today I replaced it with Hankook Tire Kinergy 215/65R15.

The terrain in Korea is very bad, so sometimes the tires hit the bottom under the saddle. (Horrible sound of hitting plastic...)

In this case, would it be a good idea to replace the tires? Or should I increase the suspension air pressure further? T_T

Current tire pressure is 27 PSI.

[pegasus1300]

Try lowering your tire pressure to 20Lbs. Your Spyder isn't as heavy as a car and the tire you have has stiffer sidewalls then the stock tire so it doesn't need as much air to do its job.

[kongdoly]

Try lowering your tire pressure to 20Lbs. Your Spyder isn't as heavy as a car and the tire you have has stiffer sidewalls then the stock tire so it doesn't need as much air to do its job.

thank you!!! I think I added too much...

[BajaRon]

Is your rear shock spring preload adjustable? You might try increasing that setting.

[kongdoly]

Is your rear shock spring preload adjustable? You might try increasing that setting.

After adjusting the spring preload, the driving feel was very poor, and I had a hard time finding and ordering Altimax RT43 radial tires - the 215/60R15 tires recommended by BajaRon. Thank you.

Also, when I installed the sway bar, the performance was very good. I'm so happy that I can drive safely even at high speeds.

[BLUEKNIGHT911]

After adjusting the spring preload, the driving feel was very poor, and I had a hard time finding and ordering Altimax RT43 radial tires - the 215/60R15 tires recommended by BajaRon. Thank you.

Also, when I installed the sway bar, the performance was very good. I'm so happy that I can drive safely even at high speeds.

No one else has reported that a 215/65 - 15 on an .... RT ... has a fitment problem. You have a HANKOOK which is possibly larger ( in height ) than the General RT tire, I'll do some research and get back to you .... Mike

[RayBJ]

Your description reads more like the rear shock is bottoming out. If your RT has an air bag rear shock it needs about 50 PSI (minimum?) to stiffen the back end.

[BLUEKNIGHT911]

Your description reads more like the rear shock is bottoming out. If your RT has an air bag rear shock it needs about 50 PSI (minimum?) to stiffen the back end.

[kongdoly]

Your description reads more like the rear shock is bottoming out. If your RT has an air bag rear shock it needs about 50 PSI (minimum?) to stiffen the back end.

As RayBJ said, a problem arose because he kept hitting the bottom. When I increased the pressure on the rear airbag, the ride quality became strange. In the end, I will find 215/60R15 tires and ride quietly until the tires arrive. It seems that 65 tires are not suitable for the Korean terrain. It's sad.

[BLUEKNIGHT911]

As RayBJ said, a problem arose because he kept hitting the bottom. When I increased the pressure on the rear airbag, the ride quality became strange. In the end, I will find 215/60R15 tires and ride quietly until the tires arrive. It seems that 65 tires are not suitable for the Korean terrain. It's sad.

This is interesting ..... the difference in height between a 215/65 profile tire and a 215/60 profile tire is about 10mm .... less than 1/2 in. ..... I doubt a 60% aspect is going to fix whatever issues you are having ....JMHO .... good luck ....Mike .... PS ...I tried to get info on your Hankook tire .... well Hankook makes SIX versions of the Kinergy tire ..... need more specific info

[Mikey]

As RayBJ said, a problem arose because he kept hitting the bottom. When I increased the pressure on the rear airbag, the ride quality became strange. In the end, I will find 215/60R15 tires and ride quietly until the tires arrive. It seems that 65 tires are not suitable for the Korean terrain. It's sad.

You say the ride quality is strange, what do you mean by strange? Is it bouncing, bottoming out, is it still hitting your fender when you hit a hole? It will take a little testing to see what pressure you need for your type of riding. What do you mean by strange?

[BajaRon]

As RayBJ said, a problem arose because he kept hitting the bottom. When I increased the pressure on the rear airbag, the ride quality became strange. In the end, I will find 215/60R15 tires and ride quietly until the tires arrive. It seems that 65 tires are not suitable for the Korean terrain. It's sad.

I suspect that the terrain has created this problem and it's not the tire at all. The quandary here is that none of the 215/65R15 tires we've installed will hit the fender. So, why does yours? Wheel travel is physically limited by shock travel. I am wondering if you have destroyed the rubber shock piston shaft bumper. Hard bottoming, over time, can split this bumper and it can even fall off. This would give the shock about 1" more travel which would translate to more than 1" at the axle. Increasing wheel travel by this amount would certainly give you the issue you're having. Making it unlikely that a 60 series tire is going to solve the problem.

It is also possible that the shock is worn out hydraulically. Rough terrain will wear a shock out much more quickly than running on a smooth road surface.

The picture below is not your shock. But it does show the shock bumper. (Yours will be black) They do make a much better bumper using polyurethane. But I don't believe the OEM bumper can be replaced or not. I would definitely look into this before spending more money on tires. Your solution may be shock replacement.

Shock.jpg