Why do I keep blowing tire tubes @ 30mph...

[nukezero]

This is the second time today, that I blew my tire tube in less than a week.

The first tube, had a strange hole in the inner side (facing the rim) but I found that the spoke/rim did not have anything sharp to suggest how it got there. The first time I got my Mac motor kit, within 5 minutes was when the tire went flat.

Next up, I upgraded to Slime's 26 in. inner tube from walmart. I got a good 40-50 miles out of it then today, while on a bike trail (flat road, not dirt), my rear tube gave out. The strangest part is I'm not sure if it is a thorn because nothing is apparent from the outside. When I got home, I tried to pump it up and at first, I could hear that the leak was coming from the shrader valve. And ironically, I can feel some slight air coming out of the shrader valve? Could it be that the valve system blew or something? I sure was traveling pretty fast when it all went flat on me. When I try to pump it up for the 4th time, funny thing, it started to hold pressure! Up to 50psi again. But when I went back to the garage about an hour later, it already leaked out all the air again....

So tomorrow I'll be taking it apart and figuring out where it blew or where the leak is. Can anyone recommend what tire/inner tube combo to go with for high speed mac motor (30mph)? I'm looking at the Sclhwalbe Marathon Plus HS440 but nobody has this thing in stock in the USA. Then I'm not sure if I should spend $12 bucks and buy the super thick inner tire tube at Walmart.

The interesting thing is, I have a Mr. Tuffy tire liner brown in there, 26 x 1.95 and it looks like it served no purpose. But of course, the jury's still out as to how I got the second flat.

Oh, by the way, bicycle is a 2013 Electra Townie 21 speed with 26 x 1.95in tires. Yes, these tires are probably not designed for such high speed and the tread pattern isn't exactly aggressive. My last motiv ebike was using Kenda Small Block 8 tires and I never had a flat in that for the 9 months that I owned it. So perhaps I should try those tires again since i had some good luck with those? Same bike trail/path. Just a different bike and tire.

*** EDIT: 7/1/2014 - Found the problem, posted down below.

 

[melodious]

I'm thinking it's the tuffy liner. If it's not positioned right, it can bind on your inner tube. I like the thick slime tubes personally, and wish they were available for MTB 29ers.

 

[Hugechainring]

I don't have the answer, but may have some procedures that might help you. You mentioned the spokes, but if you have a good rim strip, the spokes/nipples shouldn't be a hazard. There is a rim strip, right? I have used 26 X 1.95 tires and slime filled tubes with much success , but my old bikes didn't go 30mph. Regardless, I found three things which were important. First is the quality of the tube, secondly, the size, and third the installation.

Not all tubes are created equal. I'm not an expert, but I have had success with Kenda and Maxxis products. My personal opinion is the rubber products out of Taiwan are better than the Chinese stuff.

The size is important. Many tubes are sold with a range, especially at stores that want to limit their inventory like Walmart, and you can get tricked into installing an oversize tube in your tire. This excess material can more easily get folded or end up under the bead, promoting pinch flats. Pick a tube whose upper range is at or slightly above your tire size.

I install my tires using the proper tools, plastic tire spoons. If I'm in a pinch (no pun), I'll use the back end of a kitchen spoon. If at all possible, I'll mount and dismount my tires using only my fingers. Assembly is easier than dis-assembly. This helps prevent pinches from tools.
Once it's together, I put just enough air in the tire to swell it up and get it on the bead. Then I go around the tire, manipulating it by hand to make sure it on the bead and the tube is not trapped. I then remove the valve stem and let all the air out. I then pressure it up one or two more times, and depressurize it. I feel this lets the tube find it's "happy spot" This will also help with valve stem alignment. If the stem is cocked , you can shift the tire a little on the rim. Once everything looks good. I reinstall the valve stem and put a few pounds in it, do another visual, then go to full pressure.

Based on what you are saying, I would be running your tires at very near their rated pressure. E-bikes are heavy and the extra speed makes heat, which is bad for tires. High pressure will reduce your rolling resistance, reducing heat, and also make your tire stiffer, reducing the possibility of a pinch flat when rolling over obstacles.

Flats ruin the experience. I hope you have better luck

 

[BLUESTREAK]

The first flat that you had was on the inside of the tube and was most likely caused by the tube pushing down into the spoke hole even if you had the not-so good rubber rim strip.throw that rubber strip away and go get a couple of rolls of the white medical tape that has been around for over 100 years and make at least (2) but maybe (3) complete raps around the rim and you wont have the inside hole happen again, the other flat maybe a little harder to figure out, but the first flat problem will be solved.

 

[Avitt]

I just solved a similar problem with a wheel built by EM3EV. It's a high quality wheel, but it used a cheap, thin rubber band in place of rim tape. As others have suggested, the tube was bulging into the spoke holes, and blew out in one spot. (I run my tires at about 90 psi, so lots of pressure). This weekend, replaced the rubber band with some proper, Velox style rim tape...Don't expect to have this particular issue again.

 

[MadRhino]

Quality components and proper installation, that is all that you need to ride safely.

A good rim strip is plastic, not rubber or cloth. I recommend Michelin, and take it the proper width for your rim.

A good tube is DH rated, it is much thicker than other tubes. Slime is needed only if you ride arid areas with square stones and lots of thorns, otherwise you might want to fill some once your tire is worn out and still want to ride it further more. A wheel rides much better without slime, and with better acceleration performance too.

A good tire is made with 2 ply and a wire bead, inflated within the spec pressure range written on it. A tire should be no more than 3 times the width of the rim, and no less than a third wider than the rim. Soft compound is much safer but wears much faster too. Use only soft compound tires if you have the habit of hard cornering for they might save you and your bike a lot of bruises.

 

[r3volved]

A leak from the valve, I would suspect your tire is slipping on the rim. Draw a line on rim and tire and see if the tire's crept after a ride (ie lines wouldn't line-up)

 

[dogman dan]

Slime in the tube yes, slime brand tubes no.

I use the best I can find in my town, in my case a bottranger tube from a place that turns them over a lot.

 

[nukezero]

THE JURY IS IN! The same thing that happened to my first tube happened to my second tube. Except the second tube with slime lasted 40-50 miles longer, while the first tube just decided to bail out after 5 mins. There is a 4mm slit or cut on the inside of the tube again.

This is em3ev's rim with Mac motor. I don't blame em3ev. It's a great hub/motor and rim and he's wonderful to deal with. But yeah, it does have a REALLY thin rubber rim tape as you guys call it. And when you press your fingers down, I can see how it can squeeze itself into the spoke hole. You guys are right, that was the problem.

So now I'll be canceling my tire order since it really wasn't a bad tire at all. So I won't blame the tire nor Mr. Tuffy.

So I wonder if the local bike shop sells quality plastic rim tape? I guess this time, I should buy the "THICK" Tire tube as well. Those things should last quite a bit.

 

[cal3thousand]

THE JURY IS IN! The same thing that happened to my first tube happened to my second tube. Except the second tube with slime lasted 40-50 miles longer, while the first tube just decided to bail out after 5 mins. There is a 4mm slit or cut on the inside of the tube again.

This is em3ev's rim with Mac motor. I don't blame em3ev. It's a great hub/motor and rim and he's wonderful to deal with. But yeah, it does have a REALLY thin rubber rim tape as you guys call it. And when you press your fingers down, I can see how it can squeeze itself into the spoke hole. You guys are right, that was the problem.

So now I'll be canceling my tire order since it really wasn't a bad tire at all. So I won't blame the tire nor Mr. Tuffy.

So I wonder if the local bike shop sells quality plastic rim tape? I guess this time, I should buy the "THICK" Tire tube as well. Those things should last quite a bit.

So the spoke ends protrude enough that they are cutting the tube? EM3EV build that wheel for you?

 

[Ykick]

Either the spoke or "pinch flat" IMO. What size tire, rim, vehicle/rider weight, air psi? Riding any curbs or rough terrain?

Even well-built motor wheels can rub spokes into tubes so for that reason I insist on 2.5mm DH tubes and Hockey tape for rim liner.

Unless you use a large amount, Slime does little to nothing for slowing interior punctures IME.

 

[nukezero]

Either the spoke or "pinch flat" IMO. What size tire, rim, vehicle/rider weight, air psi? Riding any curbs or rough terrain?

Even well-built motor wheels can rub spokes into tubes so for that reason I insist on 2.5mm DH tubes and Hockey tape for rim liner.

Unless you use a large amount, Slime does little to nothing for slowing interior punctures IME.

EM3 ev's wheel/hub. DH19 , standard spokes. 155lb rider. 50PSI tire. 26x2.00" tire. No rough terrain. No hopping off curbs. Was mostly bicycle lane and paved bike trail, but bike trail sometimes bumpy asphault. Especially at 30mph, the vibration is there but not that bad like mountain biking.

 

[nukezero]

THE JURY IS IN! The same thing that happened to my first tube happened to my second tube. Except the second tube with slime lasted 40-50 miles longer, while the first tube just decided to bail out after 5 mins. There is a 4mm slit or cut on the inside of the tube again.

This is em3ev's rim with Mac motor. I don't blame em3ev. It's a great hub/motor and rim and he's wonderful to deal with. But yeah, it does have a REALLY thin rubber rim tape as you guys call it. And when you press your fingers down, I can see how it can squeeze itself into the spoke hole. You guys are right, that was the problem.

So now I'll be canceling my tire order since it really wasn't a bad tire at all. So I won't blame the tire nor Mr. Tuffy.

So I wonder if the local bike shop sells quality plastic rim tape? I guess this time, I should buy the "THICK" Tire tube as well. Those things should last quite a bit.

So the spoke ends protrude enough that they are cutting the tube? EM3EV build that wheel for you?

yep, he built the wheel. The inside rim tape does move around though. It does seem to be sliding side to side so I'm not sure if it was supposed to be glued in place or what not.

 

[Chalo]

Rubber rim strips are for single-walled rims ONLY. Chinese manufacturers have been putting them on double-walled rims because they are cheaper, even though they do not work. You have to use a fabric or hard plastic rim strip on double-walled rims, to prevent the kind of puncture you have been getting. It should either be wide enough to fill the inside of the rim, or else attached with adhesive, so as not to uncover any rim holes when the tire is mounted.

Mr Tuffy type tire liners are nowhere. They cause flats (chafing the tube) as they prevent flats, and they make the tire ride like crap in the process.

Slime is a necessary evil if you live in goathead country, but it can easily foul your valves and either make them leak or make them difficult to pump up or deflate.

Use a tire with as much protection as you need, then use a normal tube. That's the best way to go, hands down.

 

[nukezero]

Rubber rim strips are for single-walled rims ONLY. Chinese manufacturers have been putting them on double-walled rims because they are cheaper, even though they do not work. You have to use a fabric or hard plastic rim strip on double-walled rims, to prevent the kind of puncture you have been getting. It should either be wide enough to fill the inside of the rim, or else attached with adhesive, so as not to uncover any rim holes when the tire is mounted.

Mr Tuffy type tire liners are nowhere. They cause flats (chafing the tube) as they prevent flats, and they make the tire ride like crap in the process.

Slime is a necessary evil if you live in goathead country, but it can easily foul your valves and either make them leak or make them difficult to pump up or deflate.

Use a tire with as much protection as you need, then use a normal tube. That's the best way to go, hands down.

How does Mr Tuffy make it ride like crap? I can't seem to tell the difference.

The rim is a Alex Rims DH19, double walled. 18mm width I believe. What size rim tape should I use? My local bike chain, Jax Bicycles, says they carry Velox rim tape in 17mm, 10mm for $4.99.

Also, does anyone know if it's safe to put 26x2.10 Kenda Tires on my Alex Rims DX19 which is of the spec: 26", 559X18, 520g, ERD: 540

 

[Avitt]

You see the football shaped I pattern around the hole? That's the shape that's made when the inflated tire pushes itself and that cheap rubber band into the spoke hole. I actually had a whole row of these "footballs", and one finally failed. High quality rim tape will solve your problem.

 

[cal3thousand]

Rubber rim strips are for single-walled rims ONLY. Chinese manufacturers have been putting them on double-walled rims because they are cheaper, even though they do not work. You have to use a fabric or hard plastic rim strip on double-walled rims, to prevent the kind of puncture you have been getting. It should either be wide enough to fill the inside of the rim, or else attached with adhesive, so as not to uncover any rim holes when the tire is mounted.

Mr Tuffy type tire liners are nowhere. They cause flats (chafing the tube) as they prevent flats, and they make the tire ride like crap in the process.

Slime is a necessary evil if you live in goathead country, but it can easily foul your valves and either make them leak or make them difficult to pump up or deflate.

Use a tire with as much protection as you need, then use a normal tube. That's the best way to go, hands down.

How does Mr Tuffy make it ride like crap? I can't seem to tell the difference.

The rim is a Alex Rims DH19, double walled. 18mm width I believe. What size rim tape should I use? My local bike chain, Jax Bicycles, says they carry Velox rim tape in 17mm, 10mm for $4.99.

Also, does anyone know if it's safe to put 26x2.10 Kenda Tires on my Alex Rims DX19 which is of the spec: 26", 559X18, 520g, ERD: 540

They affect the wheels more if you're a weight weenie and have ultra light 700c wheels. For (moderately powered) ebikes, they don't have much effect

 

[mvly]

I use double layer cloth rim tape. Never had a problem after that. I also run a tufty lining and thick thorn resistance tube with slim inside it.

 

[cal3thousand]

I use double layer cloth rim tape. Never had a problem after that. I also run a tufty lining and thick thorn resistance tube with slim inside it.

My trick for this is Hockey Tape. It is SOOOOO much cheaper than real rim tape and is the same stuff. You can get rolls and rolls for the same price and any sporting good store in North America should have it.

 

[nukezero]

You see the football shaped I pattern around the hole? That's the shape that's made when the inflated tire pushes itself and that cheap rubber band into the spoke hole. I actually had a whole row of these "footballs", and one finally failed. High quality rim tape will solve your problem.

oh i didn't even see that, until you pointed out. I definitely see it in my picture, that football shape cutout. Real funny.

 

[nukezero]

I use double layer cloth rim tape. Never had a problem after that. I also run a tufty lining and thick thorn resistance tube with slim inside it.

My trick for this is Hockey Tape. It is SOOOOO much cheaper than real rim tape and is the same stuff. You can get rolls and rolls for the same price and any sporting good store in North America should have it.

And does the hockey tape contain adhesive? Otherwise, how do you make it stick to the rim so it stays in position? One of the problem I had with this thin rubber strip is that it actually shifts side to side, and potentially exposes the eyelit holes.

 

[Drunkskunk]

Those rim strips are ok in wider rims and lower pressure tires, but for narrow rims and high pressure, there is only one choice.

Every good bikeshop will carry it. Nothing works as well.

You should de-bur the edges of your spoke holes, as their shouldn't be a sharp edges on those holes. that can be done with a file, or even just running the flat edge of a screwdriver around the rim of the hole will dull the sharp edges.

After that, a single layer of Velox should be used. If you need more, fix your rim. Velox provides a soft bed for your tube, and a strong resistance against being pushed into the spoke holes. unlike rubber strips, the fibers in the rim tape won't stretch and allow the tube's pressure to force the tube down the hole.

Hocky tape can stretch more than Velox. It could work if you use multiple layers, but Velox is better.

It also more resistive to slipping than those plastic and rubber rim strips, so if you have a cut valve, Velox can help prevent that.


as for other issues, Tire liners are junk. The don't flex the same as the tire and tube, so eventualy wuill rub and chawe through. Slime tubes, Also junk. Sadly they use a cheap tube and try to rrely on the Slime inside being enough to make the difference. it isn't.
Slime + DH tube = Win. Of course, if you don't live in a place where you have many flatss, it has many drawbacks, like added weight and maintenance. You have to remove the valve and clean it sometimes, and you'll notice the heavier wheel. But when you need flat prevention, it works better than anything else, when combined with a good tire.

get a good 2 ply tire. There a lot of places where you can cut corners, buy cheap, and make due on an ebike. But there are 3 places you shouldn't if you want a successful ebike. Batteries, brake pads, and tires. Ge4t the best of these you can afford and you'll have no regrets.

 

[Chalo]

Mr Tuffy type tire liners are nowhere. They cause flats (chafing the tube) as they prevent flats, and they make the tire ride like crap in the process.

How does Mr Tuffy make it ride like crap? I can't seem to tell the difference.

Okay, first ride a sweet tire like Panaracer Pasela (non-Tourguard), and then a crap tire like Specialized Armadillo anything. Then you'll know the difference I'm talking about. Tuffys make a good tire like Pasela ride as if it's an awful tire, e.g. Armadillo. And they chew grooves through your tubes while they're at it. It has nothing to do with wheel or tire weight; I don't even have any lightweight stuff to compare against.

The Pasela is easy to puncture, the Armadillo not so much. But there are tires, like Panaracer RiBMo, Panaracer T-Serv, and Schwalbe Marathon Supreme, that offer a nice ride quality along with excellent puncture protection. Their protection is way better than a Tuffy stuffed into a junk tire.

26 x 2.1" tires will fit fine on your rims, though that rim width is ideal with a tire about 1.5" wide. Most (not all) Kenda tires are junk, for what it's worth. Modestly priced tire brands that don't make junk are CST, Freedom, and Tioga. There are also plenty of reputable makers that offer both economical and overpriced tires: Continental, Michelin, Panaracer, Schwalbe, Maxxis, etc.

 

[cal3thousand]

I use double layer cloth rim tape. Never had a problem after that. I also run a tufty lining and thick thorn resistance tube with slim inside it.

My trick for this is Hockey Tape. It is SOOOOO much cheaper than real rim tape and is the same stuff. You can get rolls and rolls for the same price and any sporting good store in North America should have it.

And does the hockey tape contain adhesive? Otherwise, how do you make it stick to the rim so it stays in position? One of the problem I had with this thin rubber strip is that it actually shifts side to side, and potentially exposes the eyelit holes.

It's tape, of course it has adhesive. That's how they keep it on the hockey stick :wink: