Tire failure modes.

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zerodish   10 µW

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Tire failure modes.

Post by zerodish » Apr 05 2021 8:47am

I'm a touring clydesdale I have done 100000 miles with 165 to 190 pounds on the rear wheel. Kevlar tires last 5 times as long as non Kevlar tires if the failure mode is glass cuts. There are 2 main types of these tires. There is the belt or fabric mesh under the thread used by most makers. There is also the chopped fiber used by Performance Geax brands. There is no reason why the 2 technologies can't be combined for a super tough tire. It's been my observation that tires 1.5 inch or 38 mm wide or less fail due to glass cuts. Tires wider than this fail from ripping at the bead. What we need if you want to run wider tires is an extra 2 plies. Attempts have been made to do this. Specialized Armadillo have have an extra 2 plies of flat plies. These tires were used by the Romp Family on their quad on their cross country trip. Details can be found on archive.org The problem with these tires is the rubber does not stick well to the flat plies and the tires delaminate. Continental has a light weight extra 2 plies called gator skins. The problem with these tires is the polyamide thread they use has a greater tendency to tear at the bead. We simply need to tell manufactures we want a tougher tire. They are making spokes for us now.

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Re: Tire failure modes.

Post by e-beach » Apr 05 2021 11:07am

Your thoughts about a tougher tires has been a long held dream around here.
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Chalo   100 GW

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Re: Tire failure modes.

Post by Chalo » Apr 05 2021 11:16am

These are bicycle tires, and the wasted pedal power and poor ride quality inflicted by extra plies and thick armor belts are unwelcome among most cyclists. I don't think we can expect that overall market condition to change in the near term.

That said, there are some very thick, very puncture resistant tires out there, and not all of them ride as badly as Specialized Armadillo tires. On my 29er e-bike, I'm using Kenda Kwick Drumlin 700x50 tires that are especially hardy. They fall in the category of "tires I wouldn't enjoy on a pedal-only bike". On my pedal bikes, I like Panaracer RiBMo, which is very puncture resistant but also relatively fast and comfy.

Any of the Continental or Schwalbe "Plus" models, Michelin "Protek" models, CST "EPS" models, WTB "Flat Guard" models, or comparable products from other manufacturers will feature effective anti-puncture layers. However much protection, rolling resistance, and tire stiffening you can stand, there is probably a tire out there for you. Some of the most flat-phobic members in this forum have even switched to motorcycle tires.

P.S. - Continental Gatorskins are brilliantly marketed, but lame flat protection. They are only armored compared to completely un-armored tires. And "polyamide" is a generic term for Nylon, which is a trade name belonging to DuPont. Almost all tires are made of it.

I'm curious what spokes "they" are making for us now that you think may be more suitable for us? When I build a wheel to carry 700 pounds regularly and 1000 pounds occasionally, I use 14-15ga double butted spokes because that's what works best.
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markz   100 GW

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Re: Tire failure modes.

Post by markz » Apr 05 2021 2:22pm

But is all that weight overtop of the hub motor, or are those setups front hub motors with all the weight on the rear?
Chalo wrote:
Apr 05 2021 11:16am
When I build a wheel to carry 700 pounds regularly and 1000 pounds occasionally, I use 14-15ga double butted spokes because that's what works best.

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Chalo   100 GW

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Re: Tire failure modes.

Post by Chalo » Apr 05 2021 3:02pm

markz wrote:
Apr 05 2021 2:22pm
But is all that weight overtop of the hub motor, or are those setups front hub motors with all the weight on the rear?
Chalo wrote:
Apr 05 2021 11:16am
When I build a wheel to carry 700 pounds regularly and 1000 pounds occasionally, I use 14-15ga double butted spokes because that's what works best.
They're not hub motors. They're 48 spoke pedicab wheels, and the loads I'm talking about are per wheel, not GVW.

I don't think a typical bicycle hub motor could do that duty, no matter how you build it. The flanges are too narrow and the side covers too weak.
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zerodish   10 µW

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Re: Tire failure modes.

Post by zerodish » Apr 08 2021 8:50am

The following information is from the Michelin truck tire data book. An 11R22.5 tire has a capacity of 6175 pounds and an 11R24.5 tire has a capacity of 6610 pounds. So a tire's capacity is proportional to it's diameter. Not much but I will take it. A tire's rolling resistance is inversely proportional to it's diameter again not much but I will take. However a larger diameter wheel is less strong unless you use a wider flange a larger diameter flange thicker spokes or stronger rim. Santana rates their 700c wheels at 700 pounds and their 26 inch wheels at 1050 pounds. No idea haw they came up with that.

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Re: Tire failure modes.

Post by Chalo » Apr 08 2021 10:37am

I was shopping for a replacement tire for my cargo bike day before yesterday, and I found a tire that might interest you:

https://bicycle.kendatire.com/en-us/fin ... lin-cargo/

The regular two-ply version of the Kenda Kwick Drumlin is already one of the toughest bicycle tires I've ever seen, but now there's a four ply Cargo version with higher load ratings and multiple 20", 24", and 26" sizes available. It looks like 700c and 650b sizes are not made with four ply construction, though.

Like almost all tires right now, availability is poor at the wholesale distributors I deal with. Most sizes can be bought directly from Kenda on their website, though.
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Re: Tire failure modes.

Post by e-beach » Apr 08 2021 12:02pm

Chalo wrote:
Apr 08 2021 10:37am
.......
The regular two-ply version of the Kenda Kwick Drumlin is already one of the toughest bicycle tires I've ever seen, but now there's a four ply Cargo version with higher load ratings and multiple 20", 24", and 26" sizes available. .......
Hummm now you got me thinking Kenda for my next set of tires.......
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Favorite Quotes:
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"At a certain point the entropy wins." Maria Helena Braga

Current Build: ProFlex 757 Expert full suspension. Yescomusa 36v 800w Rear DD, upgraded 10AWG solid core through axle phase wires. 15ah Headway, 1000+ cycles, 80% DOD 30A Tronsung controller.

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1992 Trek 800, Yescomusa 800w 36v front DD.

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Chalo   100 GW

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Re: Tire failure modes.

Post by Chalo » Apr 08 2021 12:11pm

There are three different versions that all look the same: K-Shield (2 ply, 3mm aramid/ceramic belt), K-shield Plus (2 ply, 5mm aramid/ceramic belt), and Cargo (4 ply, 3mm belt).

I want the Cargo version for the front hub motor wheel of my cargo bike.
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Re: Tire failure modes.

Post by amberwolf » Apr 08 2021 9:38pm

this one?
26x2.40 (60-599)
Part No. Compound Protection Tubeless Ready Bead TPI PSI WT (Grams)
214230 SINGLE K-SHIELD/4-PLY CARGO NO WIRE 60 80 1346±67
I wish they made it in a 29", and wider.

I don't see whether it is a "grippy" compound or not; so far all the Kendas I have had were pretty hard and skidded rather than gripping on many road surfaces in cornering and braking. :(

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Re: Tire failure modes.

Post by e-beach » Apr 08 2021 9:59pm

amberwolf wrote:
Apr 08 2021 9:38pm
this one?
.......so far all the Kendas I have had were pretty hard and skidded rather than gripping on many road surfaces in cornering and braking.....
At what speeds? Any added inertial force due to weight?


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Favorite Quotes:
"This is L.A., sugar. There is no 'over the top." Chris Erskine
"At a certain point the entropy wins." Maria Helena Braga

Current Build: ProFlex 757 Expert full suspension. Yescomusa 36v 800w Rear DD, upgraded 10AWG solid core through axle phase wires. 15ah Headway, 1000+ cycles, 80% DOD 30A Tronsung controller.

Past: Trek 4500 Yescomusa 36v 800w front DD.
Liahona, Yescomusa 36v 800w generic front DD.
1992 Trek 800, Yescomusa 800w 36v front DD.

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Re: Tire failure modes.

Post by amberwolf » Apr 08 2021 10:14pm

e-beach wrote:
Apr 08 2021 9:59pm


At what speeds? Any added inertial force due to weight?
Typically at 10-15mph or less, occasionally up to 20mph, on anything from a regular pedal bike with just me on it (back when I weighed only about 120-130lbs...feels like a LONG time ago!), to the first version of DayGlo Avenger, a mostly normal bike but with various motors on it (up to a 9C DD in front), with just me on it or up to a few dozen pounds of cargo in the rear cargo pod and deck.

The CST tires I've used in the same situations have all been softer compounds than the Kendas and gripped much better, even when they have very similar shapes and treads. They wear out a lot faster...but they keep me upright and on the road, whcih is worth it. ;)

The hardness of the Kendas and the problems I have had with their sidewalls disintegrating (in cargo situations, so probalby overstraining them...but other brands did not fail like that in the same circumstances!) drove me to stay away from them as a brand, for my usages.

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Re: Tire failure modes.

Post by fatty » Apr 09 2021 7:02pm

Check out the new 2-ply Schwalbe Pick-Up, similar to the Kenda Kwick Drumlin Cargo but I'd obviously trust Schwalbe over Kenda, and it's available in 27.5".
Rated 5/6 for road grip and 6/6 for protection.
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Re: Tire failure modes.

Post by markz » Apr 09 2021 7:56pm

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fatty wrote:
Apr 09 2021 7:02pm
Check out the new 2-ply Schwalbe Pick-Up, similar to the Kenda Kwick Drumlin Cargo but I'd obviously trust Schwalbe over Kenda, and it's available in 27.5".
Rated 5/6 for road grip and 6/6 for protection.

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Re: Tire failure modes.

Post by Santacruz » Apr 10 2021 3:54am

When I first got into eBikes it was with a folding Silent Force.
Within a month I was tuning it up, bigger motor, controller battery pack.
Along with the extra speed and weight came punctures. (Nearly all road and cycle path riding).
I tried all sorts of make for tyres including some BMX ones and self sealing inner tubes.
But still managed an average 2 to 4 punctures a month and for a few makes of tyres, they just wore out.
So I checked with a local bike shop, if they had any suggestions. They said I should use the Schwalbe Marathon Plus. These were more expensive to what I was buying before, but gave them a go and in a Year never had a puncture.
So I have stuck with this make since. Using Marathon plus on my MTB (26" wheel, 3000w rear hub).
Now using a Big Ben Plus on the front of my Stealth type build.
Never a problem for me with this make. But of course that also depends on the type and quality of roads you ride on.
These tyres do not seem to want to wear out and yet I find the grip very good wet and dry (and snow).
However, I think it is difficult to say if the grip is good or not as this depends on your riding style, bike, weather, road surface etc.
But wear rate and resistance (Flat battery or controller shut down, requiring pedal power) has me pleased and that includes my weight and bike weight being mostly over their recommendations.
They also handle speed well (again, over their recommendations).

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Re: Tire failure modes.

Post by zerodish » Apr 12 2021 7:55am

I took a 21 inch motorcycle tire and covered it with ink. Then placed it on a piece of paper to print the contact patch. The contact patch indicated the tire had 37 PSI in it even though there was no air in it. This tire would ride like a tire with 37 PSI in it if you could keep it on the rim. It is not obvious to me that a stiffer bead has more rolling resistance. The harshness would come only from the fact that it rides like a tire with a higher pressure rating in it. What I am saying is a tire with a Kevlar belt greater than 1.5 inch wide will fail by ripping along the bead before it gets enough glass cuts to fail at the tread. A lower pressure tire is more resistant to glass cuts. The extra bead does not have to run the full width of the tire it could only run near the bead or you could run it the entire width and reduce the thickness of Kevlar.

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Re: Tire failure modes.

Post by markz » Apr 12 2021 8:37pm

I rode with a flat 19"x3 knobby motorcycle tire and really did not notice a big difference. The tire is a normal dirtbike knobby tire, very stiff, very heavy. I will look into 22" bmx rim with 18" moped tire, but I wouldnt want to go much smaller then 24" bicycle wheel size. Going 21" motorcycle rim and tire will put the overall diameter more then 26" bicycle, closer to 27.5 or 29" bicycle. Might be good for my needs for the front.

Also of note, I had a moped tire that took a lot of abuse. It was on the same 19" motorcycle rim, 1.40" rim width. It would have lasted a very long time if it had not gouged into the rim brake mount and ripped the tire apart. I still got home with zero issues riding on the bare rim with tire off. Normally you'd go ultra slow and be ultra careful riding on a bare bicycle rim, but doing the same on a motorcycle rim I could be far less careful and still rode on the grass mostly.
zerodish wrote:
Apr 12 2021 7:55am
I took a 21 inch motorcycle tire and covered it with ink. Then placed it on a piece of paper to print the contact patch. The contact patch indicated the tire had 37 PSI in it even though there was no air in it. This tire would ride like a tire with 37 PSI in it if you could keep it on the rim. It is not obvious to me that a stiffer bead has more rolling resistance. The harshness would come only from the fact that it rides like a tire with a higher pressure rating in it. What I am saying is a tire with a Kevlar belt greater than 1.5 inch wide will fail by ripping along the bead before it gets enough glass cuts to fail at the tread. A lower pressure tire is more resistant to glass cuts. The extra bead does not have to run the full width of the tire it could only run near the bead or you could run it the entire width and reduce the thickness of Kevlar.

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