V12 pulls to the left and right

[Funky]

God bless, 15 psi is way way way to low.. One unlucky day, when you accelerate or brake very hard... The tire will slip. Best case you will tear off only air valve. And you will have enough time to stop. Worst case tire slips off the rim and you go flying off..

Put in at least 20 psi.. Tire compression needs to be at least 1/3 not half.

[alcatraz]

1 hour ago, mrelwood said:

If it’s just an estimation, I guess there’s hope. But 15 psi is loose, and has been a cause for several torn tubes. Which of course ends up as a crash, because you can all of a sudden no longer steer.

 Your weight actually works against you here since you exhibit less pressure on the tire, so it’s easier for it to spin around against the rim.

 Be careful, and at least monitor the valve stem orientation and angle.

That's interesting. Never had a valve tear, but some pinch flats. Then I bring the pressure up to avoid the pinch flats.

So at least on two wheels it seems that I'm either riding too much like a granny or the pinch flats come before the valve tears.

...for me.

[alcatraz]

I should get a pressure gauge to confirm, but it's kind of a waste if I have a gauge that's inaccurate but at least repeatable.

The weight maybe doesn't matter because the wheel is torqued a lot less for the same acceleration, when the rider is lightweight. With less torque there's less of a chance to break the bond between rim and tire.

Also, how much is the pressure increase when you step on a wheel? Maybe not insignificant.

[alcatraz]

I was unable to ride the Chaoyang H5012 at my desired pressure because of unpredictability when turning. Squirrely or whatchamacallit.

The CST C1488 did the trick though.

Now I'm kind of curious what the actual pressure is so I can report it to you guys  

Edited June 29, 2023 by alcatraz

[mrelwood]

Separate analog and digital gauges can be had for very cheap here and there. They are definitely accurate enough to assess the pressure. +- 0-2 psi doesn’t really matter much.

[alcatraz]

I just got my pressure gauge. On my MSX 18x3.0in my favorite pressure that I've been running for 5000km is 11psi.

I've never had a snakebike or tear. Just sidewall fatigue. After 3000-4000km of 11psi I need to replace the inner tube because it has weakened at the sides.

What's amazing is that with the CST C1488, the wheel doesn't become squirrely at 11psi. I know that this pressure is impossible with some other tires.

My Tesla V1 with a 16x2.5in tire I'm running 17psi. I've ridden it for 14000km. Snakebit once or twice before I found my favorite pressure.

I don't so jumps. I'm very sensitive to pressure. When it drops 1psi below this I top it up.

I'm 66kg on the scale. 

I think the logic that lighter riders easier tear valves is flawed. It's probably the opposite. Much less torque is required to accelerate/brake.

[mrelwood]

8 hours ago, alcatraz said:

I think the logic that lighter riders easier tear valves is flawed. It's probably the opposite. Much less torque is required to accelerate/brake.

The same amount of difference is with the force the rider presses down on the tire. So it’s hard to say. I’ve heard of torn tubes for very lightweight riders as well when running at those pressures.

 The low pressure probably accelerate the wear on the tube’s sidewall, since it moves more on every rotation.

[Hellkitten]

10 hours ago, alcatraz said:

On my MSX 18x3.0in my favorite pressure that I've been running for 5000km is 11psi.

My rim would be toast after one ride at those pressures! 😩

[alcatraz]

Mm. Back when I had the V8 I was pumping it up hard. Still had most of my inner tube failures on the V8. On the Tesla I had 3-4 and the rim doesn't look great (you're right @Hellkitten) but I didn't use to top up every week.

So on the V8 with overinflation, I (my body) always "suffered" for 3 weeks, waiting for that pressure to get perfect. Then after ~3 weeks I get happy that the wheel feels great before getting a snakebite 1 week later.

Over the years I started honing in on the feel of that last week and just became sensitive to it. 

Before I couldn't tell the difference between 20 and 16psi. Now I can probably tell that it's 1 psi under target.

Also, I started using slime to try and reduce the leakage and stay in the great feel pocket for a while longer.

Still, I have to top up weekly. It's worth it though. On my bike I top up before every single ride so it's not a big deal. I use a foot pump. Often it's two pushes and I'm done. The gauge on the pump is way off but I can still use it to attain the pressure I need. 

The reason I'm explaining all this is because I think it's worth for someone like me to try it. You can squeeze out that last bit of comfort (with CST C1488 tire) before upgrading to suspension. The benefit is that you can save tons of money, and you don't need to carry 35-45kg up stairs.