On 7/27/2018 3:13 PM, wrote:
On Wednesday, July 25, 2018 at 10:15:02 PM UTC-7, John B. Slocomb wrote:
On Wed, 25 Jul 2018 17:39:49 -0700 (PDT), wrote:

A couple of months ago I was struck by a car that decided four way stop intersections were not what they meant. I had come to a complete stop and allowed ALL of the traffic to pass and started across. I got 2/3eds of the way across and the woman who had been behind a pickup I let pass rolled the stop sign and accelerated directly into me. She was obviously distracted but the old bat might have been having her first clear shot at a bike for all I know.

In any case perhaps I should start from the beginning - back around 2008 I bought a new Time VX Elite carbon fiber bike. With the normal 120 psi 23 mm tires it was completely un-ridable. It was so stiff it would hammer your balls through your skull on the first bump. So it went up on the shelf. I removed the components and used them elsewhere and that frame just sat there. Anyway I decided to put it back together and since the latest fad is fat tires I put 28 mm Michelin Krylon Endurance on them. What an F-ING difference! With the fat tires it is one of the best rides I've ever had.

My Pinarello Stelvio was the one I was riding when I was hit and while the frame and fork came though OK every component on the bike was broken.

I had Campy Scirroco CX wheels on it and I discovered that I HATE aero wheels with a passion. Since her insurance company was paying for it I bought a set of Fulcrum Racing 3 wheels that were last year's and on clearance. When they arrived they were already set up for Tubeless. Well, I had been wanting to try that as well.


The older steel bikes won't fit fat tires so the largest that would fit are 25's. I installed the tires on the wheels. I had bought 4 ounce bottle of Orange sealant which was the best in the tests I read.


Now the tires will not go onto the rims because they are a bit tight. So first I put the filler at the bottom and using a Park Valve Tool I removed the valve head. Pumped in 2 ounces of Orange then turned the wheel perhaps 1/8th of a turn so that when you release the squeeze bottle it doesn't suck the sealant back in. Then I hit it with a CO2 cartridge. POP!!! it was on and I rotated the wheel while laying it on one side and then the other since initial leaks are from the tire and rim not being a perfect fit.


Every morning I had to pump the tires up until I finally took it for a ride and that fit the tires well onto the rim and the bumps packed sealant into any voids.


Now the tires with tubes would normally run around 110 lbs and be not very easy riding. But now I ride between 60 and 80 psi (letting the pressure go down over a week before refilling).

The ride is exceptional. With the higher pressure they are sort of bouncy so fast downhills can be scary. With the lower pressure the rolling resistance doesn't seem to increase detectably. Riding with guys with the high pressure tube tires I find myself coasting while they are pedaling.

Not to mention they cannot get a pinch flat and with the sealant they cannot get flats. So I can leave that damn 2 lb flat kit at home and just take a multitool and a CO2 cartridge and filler just in case I get a large enough hole that the tire gets too soft before sealing. And I doubt I'll ever need that.

So if you've had any questions about how tubeless works I am quite satisfied with it after a couple of months.

Now I ride sport bikes and I don't know that this would be a good idea for 32 mm commuter tires. Though probably, because they talk about using them for CX tires which have a lot of pinch flat problems. But these normally run higher pressures than you would with a tube in it. There's always the possibility of it blowing the tire off of the rim unless you're using Mavic tires and rims specifically designed to work together tubeless. As far as I know Mavic are the only people to have "systems" designed.

One, off topic comment. Regardless of what a tire says on the side
there are optimum inflation pressures that are usually lower then the
numbers on the side walls - 110 psi - 120 psi.

Look up one of the numerous weight/pressure tables and try the
recommended pressure. You'd be surprised how comfortable they are.

I'm a little guy, 61 Kg and I usually run ~75 psi for the usual city
streets.

1. The tire manufacturer supplies a list of advised pressures for rider weight.
2. The advised pressure for my weight on a 25 mm Michelin is 108-110 psi.
3. And with over 80,000 ft of climbing and over 2,500 miles so far this year despite a couple of prime months lost to weather or medical problems leaves me at over 82 kgs.

I have a problem understanding what sort of riding you people are doing. Joerg and I seem to ride in the same manner as does (or did) Joy. 32 mm tires are for Cross or Gravel bikes. Why would you ride a high rolling resistance tire on a commuter which operates in the speed regime where rolling resistance is the prime source of friction?

I'm not certain, but you seem to be implying that 25mm tires must roll
easier than 25mm tires. I don't believe that's the case.

https://road.cc/content/feature/1825...ch-wider-tyres

https://janheine.wordpress.com/2018/...es-are-slower/

https://www.schwalbetires.com/tech_i...ing_resistance


--
- Frank Krygowski