Please help me. . . need suggestions
 

Hi, I'm new here.

I weighed 380 lbs this time last year, and I'm down to 325 from walking walking walking.

My knees started to hurt, someone suggested biking. Wasn't sure it'd work at my weight, so I was suggested a fuji crosstown 4.0 as a good beginner bike and was told it would support my weight, I'd just need to ride at higher pressures.

Got the bike. First thing that didn't work was the spring loaded seat post as it bottomed out. It was exchanged with a nice solid post and now the seat is fine.

3rd time I rode, I was going down a flat road - suddenly - bulge wobble and BAMMMMM! the back tire blew. Upon inspection the tube came apart at seam. They replaced - said it shouldn't happen again. Rode home (2 miles) - nearly home - front tire - wobble - I stopped instantly this time - and about the time I stopped - BAMMMMMM! like a gun shot. Same deal - tube came apart at seams.

So given my weight - is this doable? Are there some 'special tubes' I can get? Thanks for honest and frank advice. I suppose I'm stuck with the bike, so try to work with me on what I have, and please realize I can't drop a 'ton' of money.

Thanks, I hate for this to be the first post - but I hope someone can help recommend something to me.

Looks as the tubes were improperly installed.
Get a good floor pump and air up the tires before each ride.
The tire pressure listed is on the side of each tire.

Hi, I guess I should have said that. Before my rides I did check my pressure they were just over 90 psi each. Thanks for more suggestions before I go back to the shop. . .

Another thing - let me describe the tubes after the burst.

Near the valve steam location - the 'seam' of the time looks as if it were cut with a razor for a distance of around 3 inches . It looks like a clean slice. Not like a puncture, etc. Looks as if the tube just peel apart for a while.

You are heavy, sure, but you're not as heavy as two full size men riding a tandem, and they don't pop tubes like that unless something causes it, not just the weight.

I could be wrong, but I don't see how a tube could explode/ rip from the inside unless it was caught between the rim and the tire, there was a defect, or if there were a sharp area on the rim somewhere starting the failure. The tire is so much stronger than the tube, and inside that tire, how could the tube expand enough to pop without some sort of external thing acting on it?

Where, exactly, on the tube is that seam and rip?

Inner surface where it contacts the rim?
Outer surface where it contacts the tread part of the tire?
Side surface where it contacts the sidewall of the tire and/or where the bead of the tire seats in the rim?

I was going to suggest that you get the largest tires you can fit on that frame, but again, that isn't necessary for normal tandem riders, so it shouldn't be for you. But. what size tires are you running now? A larger tire might help.

Hi, thanks for the reply
 

It is 700 x 28

The 'slice' or 'separation' is near the valve stem along the side of the intertube that faces outward towards the tire itself.

The second time when it was on the front tire - let me describe. I was 'pedaling' up a hill leaning my weight into my strokes, not standing though, just in a lower gear slid a little forward on my seat. I clear the top of the hill. I was just about to rest on the seat from my legs. Suddenly, the front tire started to wobble a little (just as the rear did before). A visible bulge grew from the left side of the tire (from my riding perspective) I slowed down. It happened so quick, I could not tell exactly, but it was as if I lost the 'bead' to the tire. Not sure of the technical term - but you know when the tire does not seat righ. Just as I came to a complete stop - the bulge area blew with a deafening noise.

I've mentioned 'wider' tires to the shop guy, and he keeps saying it shouldn't be necessary (it seems logical to me that wider would be 'better' though). Does getting wider tires require different rims?

Anyway, thanks for what you've given me so far, hopefully I answered your questions so you can tell more. I'd take a pic and post it but, I just dropped the bike back by the shop waiting for the 'boss' to come in and look at it. . . When I was there, the guy at the shop said that we might even need to air it up past 100 psi.

Is it safe to air up the tires so much? Thanks for any perspectives, etc. . .

Would the gatorskin tires I keep reading about that have great review make a huge difference with this kind of deal?

First, go up a couple sizes to 32c or 35c.

A word about size. A lot of companies will call a tire 35, but it will really be 32.
This complicates matters, as you might guess.

Ask your bike shop about how large a tire can fit.

I suggest getting the Panaracer Pasela TG folding 35c.

I think camilo hit a very important point dead on. You are only 325. Most tandem loads outweigh you. More than a few well laoded touring setups are heaver.

Having high preasure is to avoid pinch flats. 10 wheels pointed out checking the advised preasure for the tires. Too high could lead to losing the bead. Try the top end of the reccomended range. If you do not get pinch flats (2 small holes from the tire pinching in ht erim when it bottomes out, like a snake bite, think of what yuo can imagine happening if you hit a pothole).

Or it could all be a bad batch of tubes, very likely both yuor tubes are from the same batch. And on that one other point, for you cheap tubes may be better. In cycling often cost is because of trimming weight and in tubes that means expensive tubes have less rubber to an exact tollerance. That is NOT what you need yet. Cheaper usually means thicker. I hope you get to the point where grams in tube weight makes a difference. But that surely is not now. (I would really have hated to have wasted money and more important increased the chance of tube failure going with the idea of buying better, meaning more expensive tubes).

Hi, if a pinch flat looks like two small holes, these are not pinch flats. I'm going to try the suggestion of that tire (any good links to get it cheap from?) and the higher pressure plus whatever else the bike guy says when he comes back in tomorrow.

If anyone else has any suggestions - I'll keep checking this thread. I really appreciate it.

hey, just figured out that the clydesdale forum existed for ppl like me :P, I'm going to post this there too as well

Thanks for help!

Congratulations on the weight loss, did you see the article previously published in Bicyclist Magazine about the guy who was 501 pounds before he got healthy? It's in their archives and worth the time to find and read.

Nice job losing 55lbs. But don't fool yourself that the walking was responsible. Cutting back on eating is the real key. Walking a mile burns about 100 Kcal, but eating a candy bar can easily add 300-400.

I encourage you to keep losing to prevent damage to the joints. We're really not made to carry that much weight.

Best wishes for a healthy future. :thumb:

last week my rear tire blew out like a gunshot and had cuts as if someone slit it with a razer. i was riding on a clean, smooth, paved road. lbs said that i skid the tire and the rubber was thinner at those points and so finally at some point it failed. this combined with the fact that i inflated the tire to max pressure + 95 degree heat + my 220 lbs of heavy weight caused the tire to explode. air expands with higher temperature and this increases pressure. if you inflate your tires to 90 psi on a 80 degree day but then ride it in 90 degree weather, the psi will be greater than 90 (don't know the exact numbers). i reduced my tire pressure and no problems now. my advice to you is to get tires with high psi capacity, inflate them below the max psi, and make sure to avoid skidding on them as much as you can.

Interesting... I also frequently lost the bead on my 700x23c road bike tire back when I started riding. It actually turned out that I was losing the bead because I was UNDERINFLATING the tires.

Back then, I only had an el-cheapo Schraeder-valve tire pump made by Bell. It was leaky and it had no gauge, so I was simply pumping the tires up until I can feel it get "firm" by squeeze-feeling it with my fingers. Turns out that was not enough-- I would hit a bump, feel my wheel wobble, come to a stop, and see part of the bead dislodged from the rim. I then had to deflate the tire to get the bead to seat again, and reinflate with my portable pump.

All that time I thought getting the tire pressure to "firm" was good enough. NOT EVEN CLOSE. "Firm" was only 70 PSI when the 700x23c tires had a MINIMUM recommended pressure of 110PSI (printed on the sidewall)!

I bought a new Specialized floor pump with a pressure gauge, and now I inflate my tires to 120PSI before every ride (5 PSI below the 700x23c tires' maximum rated pressure), and I've never lost the bead since then.

In your shoes, I'd get some thick tubes and always inflate to the recommended pressure range using a pump with gauge.

RE: the larger tires: the limiting factor will be how big a tire the frame and brakes of your bike will acomodate. I'm a pretty small guy (5-8, 165) and ride 32 mm tires on my commuter bike. They are very comfortable, and for recreational riding, don't feel slow at all. I wouldn't hesitate to put 32-35 mm tires on my bike if I were your size, and pump them to the max on the side wall (I pump to the minimum on the sidewall, but that's because of my weight). To me, for a guy your size, for recreational riding, a 28mm tire is just not practical and serves no "go fast" purpose at all.

Just for reference: 28mm = 1.1"... 32mm = 1.25" ... 35 mm = 1.4-1.5", etc. 700c tires are measured in mm, 27" and 26" tires are measured in inches. But there are equivalent sizes across the board.

Our tandem has 1.5" (~35mm) tires about mid-way between min and max on the sidewall for my wife and I who combine to about 270 pounds. I've seen racing tandems with two adults on them with narrower tires. There is NO WAY a 32 or 35 mm tire pumped up within normal sidewall range should fail you. it will certainly be a lot more comfortable and probably feel more stable for you than the 28mm.

Just to talk about the width of your rims and how it might impact tire size (note - this is in addition to the bike frame and brake clearance): I put my 32mm commuter tires on very normal, fairly narrow road rims (Mavic Aksium), which previously had a 23mm (.9") tire on it. I put the tandem tires on a fairly broad rim that previously had the equivalent of 50-55 mm (2 or 2 1/4") tires on it. I doubt if your bike came with rims that are either too narrow or too wide for 32-35mm.

If I were you, I'd buy brand new tubes (plus one spare), brand new, tires 32-35mm, and start fresh.

As for source: I found that many bike shops are now carrying wider 700c tires, but generally for the popular "cross" type of bike which means they have pretty signficant tread. Tread ONLY helps if you're riding on soft surfaces (i.e. mud or grass). Tread doesn't help you at all, in fact reduces traction on pavement. Therefore, these knobby tires are not only noisy and cause vibration, they aren't at all optimum for pavement riding. I haven't found any smooth, wide 700c or 26" tires in my town (4 bike shops). So, I ordered mine (Michelin City, 32mm) online from Performance. They have a bunch of wide, smooth tires in both 26" and 700c from $12 - $30, take your pick. No questions asked return policy too, in case you order them and can't make them fit on your bike.

i would recommend a bike than can fit schwalbe big apples. they will give you a soft, smooth ride without having to worry about pinch flats.