2 punctures in 2 weeks

[kazbluesky2]

I love riding my ebike but I've had 2 punctures in 2 weeks (about 140kms a week), both of them by the heavy weight of me and the bike motor pinching the innertube on little bumps. Any recommendations?

Im losing tons of weight riding my bike to work and want to continue doing so but I cant be late to work - ebiking is great but it's not worth my job!!

I use a 700c 38 tire and am beginning to think that it just cant handle the weight.

 

[Zoot Katz]

Pinch flats are usually caused by too low tire pressure.
Try pumping up your tires to 10psi over their rated upper limit.
Maximum tire pressure is most often determined by lawyers instead of engineers.

 

[Russell]

I love riding my ebike but I've had 2 punctures in 2 weeks (about 140kms a week), both of them by the heavy weight of me and the bike motor pinching the innertube on little bumps. Any recommendations?

Im losing tons of weight riding my bike to work and want to continue doing so but I cant be late to work - ebiking is great but it's not worth my job!!

I use a 700c 38 tire and am beginning to think that it just cant handle the weight.

How much total weight are you carrying and how much is on the back end?

On my Raleigh E-bike I have Kenda Kwest 700C x 35 tires rated at 85 psi max and used to run them at 80-85 psi rear / 70-75 psi front but reduced that to 75-80 psi rear and 65 psi front for a bit smoother ride. I weigh 195 lbs and the bike is now close to 60 lbs as ridden for a total of 255 lbs or 116 kg. I also have a Kona Smoke which has Continental City Contact 700C x 47 tires that I run at 50 psi rear / 40 psi front. The bigger tires are wonderful.

The solution to pinch flats is of course to raise the rear pressure as Zoot Katz has said or preferably go to a bigger tire if possible. If you can't go bigger then try a tire with a harder, tougher sidewall like the Schwalbe Marathon or Marathon-Plus or use a thick thorn resistant tube.

-R

 

[morph999]

Get some specialized crossroads armadillo tires. They are puncture proof. And also get these
http://www.amazon.com/Pyramid-Thorn-Resistant-Bicycle-Tube/dp/B000AOA0KG/ref=sr_1_30?ie=UTF8&s=toys-and-games&qid=1243488458&sr=8-30

or the Avenir are also good...I've read good things about both of these

http://www.amazon.com/Avenir-Thorn-Resistant-Schrader-valve-1-95-2-125/dp/B00165Q99Y/ref=sr_1_31?ie=UTF8&s=sporting-goods&qid=1243488527&sr=8-31

 

[monster]

pinch flats can be caused by side wall damage to tyres which can be caused by the high torque on some of our motors in combination with poor tyre designs.
low pressure and curb jumping will cause side wall damage as well.

i had a sucession of punctures when i was trying to find the ultimate puncture proof tyre combo. i settled on big fat knobly 2.2 wide tyres with another tyre inside it and the innertube inside that with slime.

 

[Drunkskunk]

I had some pinch flats on my 700cX42 kenda tires. I went to Specalized 38c armadillos and never had a pinch flat again. I ran them at 90 pounds.

Normaly going smaller on the tire would increas pinch flats, but the Kendas were junk compared to the specalized.
I would recomend going for a bigger tire than the 38c regardless.

 

[needWheels]

I have not had a flat in several years, I use the self-sealing tubes by Bell @ Walmart for $6

Of course now that I've said that, you know what's bound to happen this week...

 

[kazbluesky2]

Thanks for your replies. I went down to the bike shop today to do something about it. Im using a nine continents motor in a 700c 38 wheel and found that I actually couldnt get a fatter tire on there because of the motor - the wheel is waaayyy over to the left. I looked for bigger thicker meatier tires but in a 700 c there just weren't any. Here in Japan a lot of the brands you mentioned haven't got a presence. So, I bought a new inner tube anyway and went home thinking Id put it on then get some slime (only to find out later that slime can't be put into this particular innertube arrrrgggghhhhh).

I then remembered what monster said about putting a tire inside a tire. To be honest I didn't think it could work (laws of physics and stuff) but to my amazement IT DID !!! It was tight (really tight) getting it back on but when I blew a bit of air in the side walls were really nice and stiff. Took it to the petrol station and really blew that sucker up and now it's as hard as STEEL . I've ridden it around a bit and it's great.

That was a great idea monster thanks,

I'll let you know how it goes next week, but I'm thinking it will be fine.

thanks again

Kaz

oh yup, my bike before the motor and batteries were put on was 19kg so maybe 50kg with motor batt and bike. I was 116kg when I started riding 5 months ago, now I'm about 100kg, so all told I recon the bike with me on it is about 150kg ( actually then you can add another 7-10 kg of books and stuff I carry in my rucksack). I don't know the pressure I blow them up to, basically - hard. One of the problems was (I think) that I don't keep an eye on how soft my tyres are getting on a regular basis, I just blow them up when they get mushy which in hindsight I know is a bit too late. I'll keep an eye on that from now on.

Again, thanks for the advice chaps.

 

[WonderProfessor]

I don't know the pressure I blow them up to, basically - hard. One of the problems was (I think) that I don't keep an eye on how soft my tyres are getting on a regular basis, I just blow them up when they get mushy which in hindsight I know is a bit too late. I'll keep an eye on that from now on.

They have this brand new invention that tells you the pressure in your tires. It's called a tire pressure gauge. Be careful, it might break your budget. In the States, we can buy them for about US$5. Before every ride, I check the pressure in my tires and I haven't had a "snake bite" flat in over a decade.

 

[dogman dan]

After thousands of miles on the commuter with no flats, using lots of slime, I suddenly get a flat on the new bike after less than 100 miles. Thinking WTF! I open up the thing and the hole is on the inside. Sure enough, a sharp peice of something in there between the tube and the rubber that covers the spoke nipples. Kinda like a rock in your shoe. Durn wallmart bike. :lol: Wierd that I rode 30 miles yesterday with no problems and then this morning it's sitting there with a big hole in the tube. I call it road karma, help out others and your car breaks down in the driveway instead of out there.

 

[Russell]

I don't know the pressure I blow them up to, basically - hard. One of the problems was (I think) that I don't keep an eye on how soft my tyres are getting on a regular basis, I just blow them up when they get mushy which in hindsight I know is a bit too late. I'll keep an eye on that from now on.

Yeah I think we all know THAT was your problem now :wink:

-R

 

[spinningmagnets]

Between my bikes and motorcycles down through the years, 90% of flats have been on the rear tire. Most recent bike I got a rear flat, one week after I got it. Bought a thorn resistant tube and a roll of "puncture-resistant" tire liner (kevlar?) for the rear only. 40 PSI and good luck so far.

 

[D-Man]

Most my flats were from thorns or "goat-heads" as they call them. I put on a new rear tire after my sidewall took a major blow but then got 2 immediate flats in 2 weeks also from thorns. I knew it was a freak occurance. Haven't had anymore in awhile. I run a double thick tube only in the back tire. Putting one up front would add another 1/2 pound which I don't want. Its true, 90-95% of the flats you get are the rear tire. Getting a flat is no big deal as I never take the wheel off. My tires don't require tire arms to remove so its easy to take tire off. If its a big leak, Its easy to find. If its a slow one, I'll spray the tube with soapy water again without removing the wheel. The only problem is with my tires is that you can't roll the bike too far with a flat tire as it falls off the rim. So you better be able to fix it on the spot. I've had at least 1 flat on the front tire and around 6 flats on the back over 4500 miles. Only one disabled me as it was a glass cut on a regular tube and I didn't have a patch kit on me. It was my first flat. I had a pump but couldn't pump fast enough. If I would have thought, I could have used some electrical tape that I had to put over the hole on the tube and get home on. I now carry all kinds of repair stuff on me.

 

[set]

krazybluesky2,

definitely sounds like pinch flats. Here's something to consider. Do you turn sharply? I used to have michelin city tires that were very skinny. They rolled very fast but were stiff. Riding with most of the weight on the back, I figured I wouldn't worry too much with the front's going flat. When I did get my first flat on the front tires, I broke it down and inspected the tire and the tube. Okay I thought, new tube and again, another flat. I then noticed that when I got the flats, I was racing home or to work and turning sharply. This was probably not good for the sidewalls. I went ahead and got bigger tires and tube. Kept the pressure medium and have not had a problem since. *Knock on wood*. Plus it feels more comfortable on the bumps. I think I lost like 2 MPH in top speed but it didn't bother me. The slight comfort and piece of mind was a fair trade.

 

[kazbluesky2]

when i think about it the last puncture was after i swerved across the road.

Since putting the tyre inside a tyre it feels very stiff and solid - i like it. Ive done about 70km on it now and it feels reliable.

But we'll see....

 

[Anonymous]

.

 

[kazbluesky2]

partially inflated? nope, i didn't know about that. When i think about it now you're right that would spread things out more evenly.

1 more thing ive learnt from chaps on this board, thanks.

 

[needWheels]

Sure enough :x :x
Because last week I said I have not had a flat in years, guess what happened this week?

Tonight I just went to check my tire pressure after charging the battery and the rear was FLAT !

Apparently I made it home only by the grace of the self-sealing tube which made the leak very slow.

Granted I have traveled more in the last month than I do in half a year because of the lifepo4 boost.

Upon examining the tread on the tire (trying to find the puncture) the tread looks like it's separating from the tire a bit.

This could not happen at a worse time financially.

I am looking at the Schwalbe Kojak Wire Bead 26x2 http://www.amazon.com/gp/product/B001IB3DSQ
specs http://www.schwalbetires.com/kojak

vs the Panaracer Tour Guard 26 x 1.5 Wire Bead
http://www.niagaracycle.com/product_info.php?products_id=13849

Any experience or feedback on either of those?
I would like to get the schwalbe but they are $25 each + shipping

 

[monster]

i had a flat from a piece of glass 2 days ago. the slime didnt work! probably too low pressure for it to work since i hadn't maintained my tire pressure? anyway i fixed the tube and put another innertube around the tire like a tire liner. i used 50 psi this time. the next day i get a massive puncture. it must have been a pinch flat because it was about 2 inches long and on the side wall. i noticed that there was tire damage also, the wire seem had come away from the tire at that point. maybe i was not careful with the tyre levers or the tyre had worn out? maybe adding extra diy tire liner into the tyre took up too much room and caused the tube not to seat properly? it happened when i put my bike into a bike rack, the ones that hold the wheel.

 

[dogman dan]

The tube likely went into the space when the tire pulled apart. The tire just wore out, though tire irons can damage stuff. I tend to need tires about yearly as they wear out.

 

[Joey]

I got a flat rear tire recently while riding my e-bike home from work. It is uphill most of the way, but fortunately, I was only a few miles from home when it happened. I was running Schwalbe Big Apples with slime-filled tubes. The rear tire went low very fast. Handling was pretty squirmy but I was still able to maintain sufficient control travelling at about 16mph for the first couple of miles. During that time I actually passed a biker going uphill while running on my obviously flat tire. I should have looked back to observe his reaction. It didn't occur to me how funny that situation was until some time later. I was too pre-occupied keeping my balance on my squirmy steed. My feet were pedaling at the time but not doing much of the work. 56V @ 30A was enough to push the e-bike fast even with a flat tire.

When I got home, I replaced the damaged tube with a double-walled slime-pre-filled tube. The Big Apple tire and rim seems none-the-worse for wear and no spokes were damaged. I have since commuted to work multiple times on the same tire and rim.

Joey

 

[Anonymous]

.

 

[John in CR]

... I need to change my riding style when loaded up that much, and run the tires at lower pressure. In the past I could hop cubs no problem, but with 60 prismatic cells and cargo load, no can do without getting flats, and bent rims!

What you need is motorcycle tires, spokes and rims. I've loaded my bike with over 500lbs with no problem. 9 months without issue...not even a loose spoke or the need to add air. They intentionally make bike tires run different sizes than motorcycle tire, so they can keep you buying that unrated untested junk all the time. How many times have you seen a motorcycle on the side of the road with a flat? Now think about just how common it is on bikes. It's so common that many guys carry spares with them. Ever see someone on a motorcycle carrying a spare?

John

 

[Anonymous]

.

 

[John in CR]

I use these bikes daily with motorcycle tires on the rear. The red one has a 2.75x17 tire, just over 23" diameter, and the blue one is a 2.75x14 and ends up a 20" wheel. I also have a 2.5x16 Pirelli (about a 21" wheel) and an aluminum motorcycle rim for it. It's is no fatter than a normal MTB tire, but it's a real tire with a 100mph and 300lb rating that's not going to be affected by glass thorns or pinch flats.

My hubbies are for small e-moto's and came with the spokes and rims. They have large drum brakes, so I didn't have to deal with the brake issue, though I have another one that I cut off the drum and added a disk brake mount to the cover. I did have to add freewheel threading to use a chain. I think the biggest issue for you could be holes for spokes but ???

John