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puncture resistance of Big Boats?

Started by handlebar, October 03, 2023, 07:18:19 AM

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handlebar

At 3,000 miles I've had my second puncture of my rear Radrunner tire. The first took me months to find because it was a whisker-thin wire.

This was also strange. A quarter inch of wood less than 1mm in diameter, like 20 gauge copper wire. I thought maybe it was the tip of a thorn, which can be very hard and sharp. No this was blunt, and it felt soft, like broom straw. How in the world could it penetrate the tread of a tire?

I find it ironic that the sidewall of the OEM Kendra tire says "puncture resistant casing." The 30 TPI count means low puncture resistance, and the rubber must be especially easy to penetrate.

The green is showing through on the right of the tread. I guess I corner harder on right turns. I've read here about CST Big Boats. Are they the only other option? How are they for puncture resistance?

santacruzpaul

I thought the lower the TPI the more puncture resistant, And that wire bead was better than the folding tires, Please educate me,
Thanks, Paul


Quote from: handlebar on October 03, 2023, 07:18:19 AM
At 3,000 miles I've had my second puncture of my rear Radrunner tire. The first took me months to find because it was a whisker-thin wire.

This was also strange. A quarter inch of wood less than 1mm in diameter, like 20 gauge copper wire. I thought maybe it was the tip of a thorn, which can be very hard and sharp. No this was blunt, and it felt soft, like broom straw. How in the world could it penetrate the tread of a tire?

I find it ironic that the sidewall of the OEM Kendra tire says "puncture resistant casing." The 30 TPI count means low puncture resistance, and the rubber must be especially easy to penetrate.

The green is showing through on the right of the tread. I guess I corner harder on right turns. I've read here about CST Big Boats. Are they the only other option? How are they for puncture resistance?

handlebar

#2
Quote from: santacruzpaul on October 03, 2023, 11:25:32 AM
I thought the lower the TPI the more puncture resistant, And that wire bead was better than the folding tires, Please educate me,
Thanks, Paul


I don't know about folding tires. Some of my info on TPI came from Schwalbe. It was a paper on their site. I read it more than a year ago, so it may not even be up any longer.

I did find this: https://www.schwalbetires.com/technology-faq/

Under Tire Construction, you can scroll down to "What does EPi mean?" EPI seems to be TPI. They say that years ago they quit producing anything less than 50 because the coarser stuff has poor puncture resistance and high rolling resistance. They say 67 is best all around, but sometimes a manufacturer will add up the counts of layers so they might have 3 layers of 67 TPI and call it 200 TPI. Schwalbe says a single layer of 200 would have threads too small to resist punctures.

The last time I  looked into it, nobody mentioned less than 60, and that was too coarse in terms of rolling resistance and puncture resistance. Maybe 60 was 2 layers of 30 or 3 layers of 20.

JimInPT

Quote from: handlebar on October 03, 2023, 07:18:19 AMI've read here about CST Big Boats. Are they the only other option? How are they for puncture resistance?

I can't speak definitively, but the Big Boats that came from the factory for my 2021 MiniST2 have never had a flat and after 700 or so miles still have a lot of tread left.  I like the durability and handling so much that I tracked down a spare set this summer, because they're not easy to find, at least in my 20" size.  I keep them right at 30 psi and check/top them up about every 2-3 weeks; they're usually down only to about 29 or so at most.  I hit both front and rear with Slime shortly after purchase and although I've never seen any sign of green weeping that plugged a hole, I can't say for sure they've never been attacked and punctured.  Have some FlatOut for next time, but so far there's been no next time.

However, I also ride a lot of hard-packed woods and dirt trails with occasional blackberry thorns but nothing truly vicious, about 30%, in addition to pavement riding on occasionally bombed-out rutted streets, so they're not being babied either.

Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.

handlebar

The CST tires on my Radmission state maximum and minimum pressures. Do your sidewalls show that?

(Schwalbe has a 4" tire that good down to 5 psi. I'd get a kick out of that, but I'd need a tubeless 26" rim.)

CST has a 4" tire that seems to be the same kind as the Big Boat. The 4" version is easier to find. I believe my 55mm rims will do fine with a 4" tire. Think I should try one?

JimInPT

#5
Quote from: handlebar on October 05, 2023, 05:12:13 AM
The CST tires on my Radmission state maximum and minimum pressures. Do your sidewalls show that?

No range; it just says "Inflate to 30 psi" and I keep them there because I mostly ride on dry packed dirt and dry pavement, so the lower rolling resistance is great, they grip fine with good handling and are very quiet.  If I regularly rode soft surfaces I might drop it a few psi, but I'm sure there are others here with more experience to judge that.
Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.

SemperVee


Unreal..  Tires wear out Dude! Be proactive to change sooner not later.  3000 miles and you are complaining? 

handlebar

#7
Quote from: SemperVee on October 05, 2023, 09:57:34 AM

Unreal..  Tires wear out Dude! Be proactive to change sooner not later.  3000 miles and you are complaining?

I'd sure have something to complain about if I had to buy another 3.3 inch Kendra!

I'm glad I've worn the tire down on one side from cornering because it's an excuse to get something better, and I want to find the best option.

In the middle if the tread, where I normally ride, the knobs are plenty thick, and the blunt stick went through the casing between knobs, where there is no wear. It happened because it was a low-quality tire the day I bought the bike.

I was lucky to go 3,000 miles before it happened. It could just as well have happened in my first 10 miles.

Can you suggest a better tire?

handlebar

Quote from: JimInPT on October 05, 2023, 07:59:10 AM

No range; it just says "Inflate to 30 psi" and I keep them there because I mostly ride on dry packed dirt and dry pavement, so the lower rolling resistance is great, they grip fine with good handling and are very quiet.  If I regularly rode soft surfaces I might drop it a few psi, but I'm sure there are others here with more experience to judge that.

The DOT requires maximum pressure on the sidewall to prevent injuries and damage from excess inflation. I've read that they pump a tire up until something gives, and half that pressure is the rated max.

Bias tires would often have a pressure range on the sidewall. I don't remember seeing it on a radial. I think I'm catching on. Radials can operate on less pressure than bias-ply tires, but low pressure could make a car or truck handle poorly. I think tire manufacturers decided to leave recommendations up to vehicle manufacturers.

Schwalbe publishes the maximum weight, maximum pressure, and minimum pressure for each model and size tire they sell. They have tires enough like the CST tires on my Radmission that I can guess I should run 50 in the rear and 40 in the front. I'll have to try it.

I haven't seen the maximum weight or minimum pressure for the OEM Kendra or the Big Boat. Underinflating a fat tire on the front of a bike could cause squirrelly steering. I think lawyers told Kendra, CST, and Radpower to state only the maximum pressure so somebody with a broken helmet can't sue.


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