UMA 90 experiences ?
For those that have UMA 90"s, can you share your experiences regarding tire mounting and those that have gone tubeless.
How well do they 'tubeless' compared to say Stans tubless rims ? Are they difficult to get to bead up or difficult to get a tire to hold air to get to the point of beading up because of the width ?
I am a tubeless convert from the begining and like the advantages of the system but see mixed thoughts when it comes to the fatties.
I understand UMA's are designed with short bead sidewalls and a larger than normal bead ridge. does it work that much better tubed or tubeless than the other rim designs.
Pretty easy to set up tubeless. Just mount the tire put a strap around it and tighten. Mine aired right up using an air compressor, deflate(don't break the bead), inject sealant and air them back up.
I wouldn't even try to put air in them without the strap, even with a compressor the air comes right out.
Good point, I have been using the strap method for years but hadn't considered for this. Do the UMA's allow tires to go over the bead without excessive pressure, lets say, not over 30 psi ? And can I assume they hold the bead well at 6psi or so ?
Originally Posted by GTR2ebike
Yeah mine set up easy as well. The only thing is I had the seam on the rear leak a little but the Stans sealed it. I used an air compressor as well but no strap. These rims hold the tire very well.
Are you speaking of the welded seam ? Not actually sure if they are welded, I know the Surly rims are.
Originally Posted by bdundee
Regardless, If it is the seam of the rim, does that mean the tape you are using is not under the tire bead like one would do on a stan's rim ?
Mine did the same thing out of the seam and it sealed as well.
Originally Posted by danaco
The seam isn't welded on the uma's. the tape goes on the rim just as stans tape does but I'm guessing their is enough "space" for air to leak before the stans does it's job and seals the tire to the tape.
They are not welded, pinned or someting. The tape goes just under the bead using Stans tape, I think I was just off a little on my installation of the tape. If I did it again I wouldn't start and stop the tape at the seam even with 6" overlapped, I would start at the stem.
Originally Posted by danaco
Love mine, and once the initial learning curve was achieved, not any more hassle than a Stans rim set up.
Haven't bothered with the strap, though I could see it helping.
New tire? Mount it with a tube and ride it a few times. They need to stretch and settle into shape. All caved in on themselves as new ones are? Good luck.
Once formed, I carefully break one bead off, remove the tube, toss in some sealant, and up she goes.
Yep, minor seam leak here too, sealant nailed that down quickly.
Worth noting, take the time to ensure that the drain holes at the valve hole and seam are fully taped (I used 4" sections of "regular" Stans tape for it), the wide tape doesn't really reach them.
I don't know if this helped but I put a dab of epoxy on every drain hole.
I'm not tubeless but my 90's are awesome and very solid. Well recommended
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