Vredestein here I come.

[ST Gui]

Second report on this tire. I just got back from the Heart of Texas Rally putting on about 4500 miles over the last 5 days.

No evidence of the tire rubbing in the swingarm? A credit card's thickness (or two) would give me pause.

Plus I'd like the option of running at recommended tire pressures for comparison. Whatever works - works. But I'd like to explore a range. I guess that would mean a bit of grinding.

 

[Willsmotorcycle]

No evidence of the tire rubbing in the swingarm? A credit card's thickness (or two) would give me pause.

Plus I'd like the option of running at recommended tire pressures for comparison. Whatever works - works. But I'd like to explore a range. I guess that would mean a bit of grinding.

#16
Danno is right-on this one, I would be very cautious if I ran my CT at 42 psi. Not sure there is a recommended tire pressure for a car tire on a MC, assuming the recommended pressure you refer to is for the bike. Mine seems very happy around 30 psi hot.

 

[ST Gui]

Not sure there is a recommended tire pressure for a car tire on a MC

I'm referring to the numerous recommendations from Dark Siders on this forum and not implying there are any manufacturer's recommendation for same. I assume possibly mistakenly that there are none. Well maybe other than "Don't Do It".

 

[jodog]

No evidence of the tire rubbing in the swingarm? A credit card's thickness (or two) would give me pause.

Plus I'd like the option of running at recommended tire pressures for comparison. Whatever works - works. But I'd like to explore a range. I guess that would mean a bit of grinding.

The tire does not rub. I didn't actually stick a credit card in there, I was just saying that there isn't a whole lot of extra room.

 

[ST Gui]

I was just saying that there isn't a whole lot of extra room.

I thought it was probably hyperbole but who knows. Good to know that it didn't rub in all that distance. Not that I'd go Dark Side but the appeal of much longer tread life with by all accounts very reasonable handling is interesting. And the "does this fender make my tire look fat" factor is pretty cool. Or is it "does this tire make my fender look skinny"? No matter.

This probably has been addressed but not that I can remember — how does this tire height compare with the factory recommended size? Is the speedo affected? Seat height?

 

[Sadlsor]

I can still easily put the 1300 on the centerstand... but the rear tire is on the ground. And so is the front.
I will have to jack it up if I need to spin the rear tire for anything.
Double Dark with a Bridgestone BT38(?) means I have to lay the front fender between the forks, before I can remount the front wheel, then bolt it on. The front must be taller than my usual Michelin or Dunlop sport rubber.
But I LOVE the handling, and @jodog
experienced the very same feelings I did when I first rode on this setup... tentative and unsure what to expect, but after a couple hundred miles, I stopped thinking about it / them at all.

 

[jodog]

I can still easily put the 1300 on the centerstand... but the rear tire is on the ground. And so is the front.
I will have to jack it up if I need to spin the rear tire for anything.
Double Dark with a Bridgestone BT38(?) means I have to lay the front fender between the forks, before I can remount the front wheel, then bolt it on. The front must be taller than my usual Michelin or Dunlop sport rubber.
But I LOVE the handling, and @jodog
experienced the very same feelings I did when I first rode on this setup... tentative and unsure what to expect, but after a couple hundred miles, I stopped thinking about it / them at all.

The Bridgestone 120/80 on the front is definitely a taller tire. Like Sadlsor I can easily put the bike on the centerstand but both tires touch. The saddle height only changes by half what the tire adds, so about 3/8 inch. What I noticed most was the lean angle when on the side stand. Normally, when parking on the right side of the road, the camber of the road would make the bike sit precariously straight up with worries about wind blowing it over. Taller tire means more lean on the stand and it parks more stable on the right. But where the ground falls away to your left, it's going to take more effort to right the bike when you get on. It's not a problem, but it's different. The front tire height gain did NOT result in a lighter front end which can happen when you either raise the front or lower the back. This becomes evident when you are behind a semi and the front feels less planted. At first I thought that this might have been the case but turns out I had a heavy head wind and oddly shaped semi-loads (car carriers and the like) that created much more dirty turbulent air. It was all good in normal wind with normal trucks.

YMMV

 

[jodog]

#16
Danno is right-on this one, I would be very cautious if I ran my CT at 42 psi. Not sure there is a recommended tire pressure for a car tire on a MC, assuming the recommended pressure you refer to is for the bike. Mine seems very happy around 30 psi hot.

Most days my CT starts out around 37 psi in the garage. Depending on the ambient temps it climbs to 40 or as much as 42 psi on the road. I cannot tell any difference in the feel between tires at 37 and 42. If you are setting your tires at 32 in the garage, you are likely running them at 37 on the road. Since everyone thinks I'm addled for running a CT at 40 (as well as crazy for running one at all), I'm going to drop my pressure for a ride this week and see what all you low pressure guys experience. We'll call it an experiment. How low should I go?

 

[W0QNX]

27.5 Really I'm not kidding one bit. Go for a range of between 25 to 30 if you want. And never ever exceed 100 mph. Really I'm 1000 percent not kidding on that either.

Lower pressure will let the sidewall flex which will result in better handling and lower pressure will reduce the abnormal wear around the middle tread area of the tire.

My testing has gone as low as 20 psi with no issues.


FYI the sidewall is no more likely to rub the swingarm at 20 psi than at 40 psi. The tire sidewall can't rotate 270 degrees and maintain the flexed shaped it has at the road contact point. It's pretty much the same shape at 20 psi as it is at 40 psi in the sidewall. The center is what crowns out at 40 psi.

 

[jodog]

27.5 Really I'm not kidding one bit. Go for a range of between 25 to 30 if you want. And never ever exceed 100 mph. Really I'm 1000 percent not kidding on that either.

Lower pressure will let the sidewall flex which will result in better handling and lower pressure will reduce the abnormal wear around the middle tread area of the tire.

My testing has gone as low as 20 psi with no issues.


FYI the sidewall is no more likely to rub the swingarm at 20 psi than at 40 psi. The tire sidewall can't rotate 270 degrees and maintain the flexed shaped it has at the road contact point. It's pretty much the same shape at 20 psi as it is at 40 psi in the sidewall. The center is what crowns out at 40 psi.

I have been advised by many "experts" that MC tires should be kept at the highest pressure to prevent the cupping and scalloping of the sides. Personally I think that blaming my inability to air a tire is simply a way for them to deny my warranty claims. As far as the rear CT goes, I have never seen greater wear in the middle of the tread than across the entire tread patch. That includes days in summertime west texas where the pavement will fry your eggs and the heat pushes the tire pressure up to 48 psi. After many CTs I have never seen uneven wear. As for reaching 100, I wouldn't even do that in a car.

Has anyone advocating lower CT pressure ever actually encountered an issue by running a high pressure? Personally, after probably 300k+ on a CT, I've never encountered any issue. I have felt the tire get squishy and want to "move around" in corners when down around 28-30 psi.

 

[Sadlsor]

I'm running 32-34psi on my V-tire out back, and it feels steady, planted, and confidence-inspiring in the curvy bits.
And cushy-comfy on the superslab, but it's not mushy.
I've yet to feel it slip, even on wet roads.
Data point: there's some big fat Bridgestone BT38, or BT46 in the front, I don't even remember. It's the same setup as @970mike suggested.

 

[Art Franz]

I run a Pirelli ct, my 4th now. 28 psi cold, closer to 30 when leaving on a trip fully loaded. 42 on the front, Michelin PR, whatever the current flavour is. And I have a good 1/4 inch between the swingarm and the tire.