Load Rating Bontrager Standard Tube

markz

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Got stranded huge, my fault for not carrying for fix, but it was a fresh tube, triple checked how it sat, I used one plastic lever ever so slightly to plop bead back on, and checked to see tube wasnt misaligned nor pinched with lever, it 26" Shraeder 2.00-2.40 on 2.0 tread.

Not having any luck with tubes, can that mofo tube hack 388lbs + 22lbs motor + 11lbs battery + Townie 21D

I looked for loose spokes but the depth is huge at ~30mm, looked for chamfered rim, sharpies on rim, I look for sharpies on the inside and outside of tire

Yet I keep getting flats.

Maybe what I need is a cargo tire, and a cargo tube. While I wait for my motorcycle spokes to come in the mail.
 
What specific flats are you getting, in what specific places on the tube?

Different kinds and places of flats are caused by different things.
 
I'm going to place my bet on pinch flats.
A 2" wide tire might have to be inflated to over 160lbs to fully support a 400 pound weight, and that's for normal riding. If you hit something smaller than the contact patch of tire to road, like a stick, the edge of a pot hole, or a curb, you will need even higher pressure to avoid a pinch flat.

The problem is the size of the contact patch. the smaller the tire, the smaller the contact patch, and so the higher the pressure needed to support the bike. You may be able to get the pressure high enough for a while of normal riding on a 2" tire, but any road obsticles like potholes, uneven seems between pavement, or larger snones could still cause a pinch flat on a skinny tire.

The answer is to go to a wide enough tire that lets you run at a lower pressure. 2.75" to 3" Is probably what it will take to support 400+ lbs of load
 
Thanks!

The rim is a 31mm wide Downhill Crystalyte rim from Justin. And I make sure when installing tire that its seated properly.

This is my routine.

1) Inflate new tube and let the air out so there is a little air still inside.
2) Install tire so that one side of the tire bead is on the rim.
3) Slip new tube in, and put the valve through the rim.
4) Carefully sliding the tube inside the tire all the way around, double checking that its correct.
5) Carefully slipping the tires other bead over the tube until it reaches that point where a bit of it cant slip on with hands alone.
6) I try using my hands to push the bead up the rim wall on the outside to see how close I am, if I am close I put more strength into it, if I am a long ways off I use plastic levers trying not to pinch the tube. Sometimes I slip my finger up into the tire to see where the tube itself is.

My fix today, the tire went on easily with just the hands. Front tire went on the back, new tube in the back. Inflated to 45psi, normally I inflate to 52psi which is right in the middle of the tires recommended 40-65psi.

Here are some pictures of the questionable damage to tire.
Right on the seam. BTW I put a bit of duct tape on it, and pumped it up and checked for any other leaks under water at the sink, no other leaks were found. This is what I envisioned I'd see from the sound I heard. This one was at 52psi. I inflated new tube to 45psi, but maybe I should be going up to 60 or 65psi whatever the sidewall of the tire states. The tire is a 2.0.
Tire Bead.jpg
View attachment 2
hole2.jpg
hole3.jpg

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This particular flat was eventful.

After a short 10 minute walk from the river into a residential neighborhood, with google maps and cell phone found the bus stops. I got lucky, choice of 4 buses. The bus stop headed south only had one bus, the bus stop I was at, heading north had 3 buses and it was 5pm so buses every 15 minutes. My calculations were in 45 minutes of waiting, there would be 8 buses rolling by. I sat at the bus stop with 3 choices, but the other side of the road, the bus came within 5 minutes with a bike rack. My bus stop, by the 3rd bus and in 15 minutes a bus with a rack came. I was lucky! For now on I gotta carry a pump, a tube, levers and a patch kit. Imagine riding and being stranded out in no mans land, imagine an industrial area after about 6pm there are no buses. Even then, if its peak rush hour like 4 or 5pm that route might only be a small bus and they never has a rack on it, or its a one bus route and that normal sized bus has no rack on it. Royally F'd! Been there, exact scenerio, but on a Sunday, so short bus. Called a taxi, and they guy wanted extra cash because I had a bike, he made several lie's to me in which I kept my mouth shut, and explained I understand, yes I will pay you extra. Got to the train station and I never gave him extra! :lol: Is that good, is that bad. Who cares, he lied, there is no extra fee for a bicycle, plus I did all the work. The bike was ready to go, front wheel off, seat off, pannier bags off. One downside is if I ever call a cab again and that mofo shows up. I've had it where it was 3am, in front of a business, well lighted, called taxi, had bike, taxi rolls in, does a loop around right near where he came in and rolls out. As I was at the other end, 250ft away, very visible.
 
I have found that of locally available tubes, the most reliable has been the thick flat resistant bontrager tube.

But nevertheless, occasionally you get a stinker, in my case usually weak around the stem. This is what happened to you. I've seen it perhaps 10% of all bontrager tubes I've bought. Its not tube creep either, it happens fairly quick after you install it, before any thorns could cause low pressure creep.

I have not had them fail by just ripping somewhere else along the tube, but I have seen that failure a lot on other tubes, that are thinner at the top.

Regardless of what the tire says, go to at least 60 psi. That will help with potential pinch flats later.

Its possible you did not have the bead set perfect at the stem, adding to the strain of that area of the tube. Or the tire itself had pinch damage there.
 
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