Really Confused and MAD

OK, I have the Nimbus 29 Muni, the knobby tread seems to getting worn down FAST. Ezas gave me a tire from the 29 touring…
I see no damage in the wire bead, and the only thing I can tell that went wrong is:
Listed on the side of the Duro Easy rider it says 35 -65 PSI
That same tire on UDC says 30 PSI max
The tire size is 28 x 2.35 where the stock Kenda Muni is 29 x 2.2

At 45 PSI the tire jmped off the rim, and before I could grab my valve tool the tube shot out and EXPLODED… Left ear has been silent for 10 - 15 minutes now…
Good news is the LBS has a tube for $5.25 but they are closed for the night.

Did I assume incorrectly that this tire should fit this Uni? It’s right off of the Nimbus 29 touring… Did I over inflate by believing the side wall?
Am I over worried about how fast the knobby muni tire is wearing? I seem to be doing alot of around town (street and asphalt) and “crushed and compacted stone bike path” riding which shouldn’t need a knobby.

On an upnote, on my ride earlier, a local newpaper guy took my picture for “future use” and I had to sign a release, a Father / Deacon at the church next door blessed my MUni for saftey, and at the LBS, looking for a small tire pump and stuff, they gave me a free reflector :smiley: :sunglasses: and even mounted it… When I just called about a tube price, they knew who it was! LOL

A knobby tire will wear much faster on hardpack than a smoother tire. If you ride on the street, you may want a road tire instead.

There aren’t many things that can make a tire jump off the rim. One would be if you pinched the tube in between the tire and the rim, and it somehow didn’t cut the tube. The other is waaaay too much air pressure. But if it says 35-65 psi on the tire, you should have been fine, unless you took it off of a 5 foot drop : P sounds like the former happened considering what you mentioned. Put the new tube in, same tire, but be careful to make sure it’s seeded properly and doesn’t pinch the tube, some people cover the tube in flower or something to make it less prone to pinch flats.

I have a bald spot on my duro because I was practicing idling on a cement sidewalk. maybe the street would wear your knobby tire. I wonder if there is a comparison chart for the tires’ durometers…

on the subject of the tire popping off the rim:

no tire should pop off the rim from only 45 PSI

A few things I would check is to see if

  • the bead is broken (especially if it has a wire bead)
  • your pressure gage is way off (an explosion at 45 PSI shouldn't be that loud)
  • if there is damage to the edge of the rim

If anything is damaged don’t use it again. I have a feeling that your pressure gage is off.

On the tire wearing extremely fast:

  • unicycles wear out tires more than twice as fast as bikes. It is just the nature of the beast.
  • Mountain bike tires tend to be made of soft rubber.
  • Soft rubber wears quickly on pavement.
  • turning on pavement will make knobbies "scrub" which will quickly wear them out
  • even when you are going in a strait line your unicycle is turning a bit with every pedal.

don’t ride a knobby on pavement and expect it to last.

Is this the second tube that has blown the tire off the rim? If so there could be damage to the bead on the tire that you can’t see. If it is blowing off in the same spot on the tire each time that is the best indicator that there is a tire problem. If this is the case then a new tire is the only real solution. I have seen brand new tires blow off, and then never seat again. If you are committed to making this tire work you can sometimes get it to hold with a bit of contact cement on the bead of the tire.

As for the tire size I would pay more attention to the ISO size. You will see it on your tires usually between parenthesis, and it will be something like (59-622). Both of the tires have a bead seat diameter of 622 mm’s. That means that they will both fit a 700c rim. 28" is normally used in reference to tires between 45 mm’s and 60 mm’s or thereabouts, and 29" refers to tires bigger than 60 mm’s. The problem is that there are other tires that don’t have a 622mm BSD, that are also called 28", and they wouldn’t fit.

Ok the ISO is 60-622 so I guess that sounds right…
A customer from work talked to me on the phone, he thinks that I am seating the bead wrong, or rushing to fill it right up to fast… I guess I am used to old school 20" bike tires and these are different…
Gonna take both tires and uni rim to the LBS and let them see if they can fit it without the blow out… Maybe they can show me how, or I’ll hit the library…

thanks for all the help

Reallly sorry you are having problems with that tire. I will say that tire fits loose on the rim. Taking it off the rim was like taking gift wrapping off a box.

Tom, UDC has a misprint the Duro Easy has a spec of TPI of 30 and UDC picked that up as 30 PSI

To the other posters that is tire that shipps standard on the 29" Touring and is the right size. I rode it a few days before I decided that I would be happier with the Big Apple (and I am, much) So I offered it up to anyone for the cost of shipping.

I had that tire at and rode at 70 PSI. Nothing extreme just parking lot riding trying to get used to a 29" wheel.

When I got BA from Universal Cycles it was folded in half (by some web sites a sure way to kink the bead) and I massaged the kink out. When I mount a tire I always check the bead at about 20 psi. If you look tires actually have a line near the rim to use for checking the bead is even all around.

Yesterday I rode my BA at 80 lbs, 10 PSI over the sidewall spec.

So back to your tire:

I followed these instructions for folding a wire bead tire to try to get the tire to you in good shape:

That’s why the tire was folded in thirds, but it wasn’t easy with a fat tire like that.

I bummed if it didn’t work out for you. Hopefully you just didn’t have it on the rim right. Did you inflate with compressed air or a track pump? I only use a track (basic floor) pump and maybe since that inflates the tire slowly it has time to work into the right position.

Good luck, I hope that tire works out for you. If the tire is damaged I will credit you back 1/2 the shipping, is that fair?

Maybe an internet search on Duro Easy mounting problems or blow off? will show if this tire is prone to that.

One more thing, while ISO is the final word, 28" = 29" just a different way of measuring/specifying tire size.


I don’t think you are supposed to fold tires unless they are “folding” tires specifically. Whenever I have bought any “non-folding” tires they have come unfolded in a big box.

Eric, not mad at you at all, you’ve done nothing wrong! The tire bead looks fine… I am fairly certian through here and a serious road biker friend over the phone that I did it wrong…
I possibly had the tube pinched, BUT I never stopped to check the mounting at intervals, went straight for the gusto…
And I think Saskat (cant you pick a simpler name? LOL) was right… My wally world pump gauge is off…
gonna pay the LBS $10 for the tube and mounting, then buy a new pump. And NO YOU WILL NOT send any money back to me!!! :smiley:

Not to be too picky, but I just want to make sure that the right info is out there.

28=29 as long as the iso size is 622. A 28x1 1/2 tire has an ISO bead seat diameter (BSD) of 635, and will not fit on the same rim as a 29x2.5, or even as a 28x1.5. So the ISO is the thing that really matters. The red flag for whether or not it will fit should be if you see decimal numbers or fractions. Even though 1.5, and 1 1/2 seem like they are the same, they generally indicate a different BSD in the bicycle industry.

If you look at those web sites they are specific to folding wire bead tires.

But from what I read they are supposed to fold in thirds not half (like my BA came from Universal cycles)

finding a box for a 29" tire would have been a bit of work and I wanted to keep the shipping cost down for Tom. Truth be told I didn’t want to spend a ton of effort on sending someone a free tire. (tom to his credit rounded the shipping cost to the next $5. Little gesture but it was appreciated.

Good luck with that tire i’m looking forward to waking up to good news from you. I only had one blow off and it was so long ago I don’t remember the circumstances, I only remember it was a rear tire on a BMX bike. I do remember that loud sound!

I know money is tight for both of us so if the tire didn’t work out and I didn’t want you to eat the shipping for a tire you can’t use but I’m not going to beg to send it!

I got my fingers crossed for ya.

I have had good luck with folding steel bead tires, and never had a problem getting them to seat on a rim. I don’t think your folding is the culprit if you folded it in thirds, and made sure to twist the bead rather than to bend it.

Of course you’ll never get a wire bead tire to fit into the same space as a folded “folding tire,” but you can get it much smaller without hurting it.

Heads up for Tom (hope he sees this).

I got a hole in my tube from the 4 little drain holes near the valve stem on the rim. I filed, sandpapered the burr down a bit on all 4 holes before putting the the tire back on.

I am pretty amazed at how loose these tires are on the rim. But as usual no problem seating the bead and no special effort to get it to seat.

With fat wire bead tires, you twist it into a figure 8, put the ends together to form a circle and that’s it. road tires you can fold into thirds. Usually whom ever had the tube slip out of the tire bead and has a blow out, owes everyone in earshot a round of drinks. it happens.

SO not buying my 4 and 1 year old a round of drinks! ROFLMAO
But the 1 year old musta jumped about 2 feet when it went

I trust your knowledge having read some of your posts.

My experience is that my 2" BA came from Universal Cycles in a figure eight and and had a nice kink in it. I massaged it out and all has been good even up to 80PSI. I can still see slight remnants of the kink when the tire is off the rim.

I only posted two sites, but three sites said and demonstrated thirds. I can’t remember which sites cuz I looked at many but there were sites that admonished not to fold in half and not one site advised it…

I think next time I need to ship a tire like this I’ll ship it flat since there doesn’t appear to be a good way to ship them folded.

yeah, why stress it when it’s gonna get beat up in shipping. I think I’d do the same after this thread.

Everything is going to work out just fine…Many of us have already been through this movie. Bigger wheels are fussier to mount tires on. The tire is going to live…And if the tire really turns out to be actually damaged I have another one sitting in my garage.

Having said all of that I don’t know what kind of rim you have and what JTROPS wrote could apply to your situation.

Well, most of you were right…
the tire is fine, mounted right up for the LBS. And it rides SO SMOOTH!
the guy asked me to show him how I tried to do it and well I learned a few things

DONT go straight for the high pressure! 10 psi then check- 25 psi check and then bounce and recheck - then 40 psi, last check and bounce, the go for it.

Also, it is SO much better for the tire and tube AND your luck if the tire is NOT touching the ground when your doing this except for the bounces… Your putting a load and changing the shape of an area which can make the bead hop over or pinch the tube… Hang it… I plan to make up some hangers from all thread and coat them with rubber dip… This will even give me a means of storage

Guy didnt charge me for the mounting, just smiled and said “Stop buying everything on the internet! Come to me for the small stuff at least and we’ll get along…”
So tomorrow after I sell my telescope stuff finally, I am going there to buy my bike shorts and the 20 " uni for my son that he has in his shop collecting dust, and a small handfull of other things…