came to set up my sram roam 40’s as tubeless and heard air hissing out, soapy watered them and they were leaking from a couple of spoke nipples? first time setting up rims that are classed as UST, from the looks of it, its just rim tape? any ideas?

cheers

Leaking through the rim tape, re tape the rims.

You need proper stans tape on the rims, ust is about the rim profile, you still need to seal the spoke need properly.

Cheers guys. Do I need to buy the stans tape with the valves attached or just the tape?

The yellow tape should be OK as they’re ust.

Electrical insulating tape if you want a cheaper solution

Done my roam 50s with electrical tape after running out of yellow tape. Works the same don’t think I will bother using the proper stuff again!

awesome, ill give that a go cheers everyone!

If they are proper ust you don’t need to tape them. Im guessing air is escaping into the rim through the valve hole. One of the points of a ust rim is that you don’t need any other method of sealing. Another benefit is that the spoke fixes from the outside so there are no holes for air to leak from on the inside (apart from the valve hole) I ran mavic ust wheels and schwalbe ust tyres with no sealant for over a year and I never had any leaks. I only added a drop of sealant after getting my first puncture.
Check your valves are seated correctly as it should be the only place air can escape.

You can have a ust rim with spoke holes in it.

I thought that was the point of UST over tubeless ready? UST is a sealed rim, is it not?

Is more about the rim profile, you can have a ust rim that needs tape to seal.

http://www.pinkbike.com/news/To-The-Point-UST-Rims-Tires-2013.html

Just wrap some electrical tape around the rims (works as well and much cheaper) and reinflate using the valves you already have.
Or the yellow Stans tape is good as well.

Tom KP

Apologies I never knew that. I thought all ust were completely sealed apart from the valve hole.

Apologies I never knew that. I thought all ust were completely sealed apart from the valve hole.

They are. Your advice is sound – a UST rim leaking through the spokes is either damaged, faulty or most likely leaking through/around the valve. Where that article says ‘sealed by rim tape’ thats a bit of a misnoma. The tape must be factory installed. The Roams use a UST certified plastic strip (not tape) and so don’t need taping.

I thought so. I purposefully bought ust rims to avoid faffing with tape. I have mavic 819’s and 823’s which have no spoke holes or tape and have both been brilliantly. As much as I tried to avoid buying rims that need tape I also have some stans crest and some light bicycle carbon rims that I have taped with one wrap of proper stans. These have both been fine but I still prefer the proper ust. I think the better bead sealing makes for a better seal that doesn’t rely on sealant which in turn means the sealant last longer.
I keep reading about people’s success and equally failures with insulation tape and other bodges but never fancied trying it. Stans tape is hardly expensive and seems to work fine for me.

Edit: although the link above does say that some rims do use tape so just ignore me again.

The last attribute of a UST rim is that it must be airtight, which
means that any spoke holes must be fully sealed with tape or plastic, or the rim bed is
left intact and not drilled at all.

hey guys, sorry for the late reply, been away in somerset with zero signal and wifi visting family!

i have the mavic 823’s on my 26′ zesty. thats why i was confused with these roams on my strive. i have just tried taping with electrical tape and 3 out of the 4 spokes that did leak have stopped but one is still doing it, ill try again later.

Bear in mind that air leaking out of the rim through the spoke holes isn’t necessarily leaking into the rim through the spoke holes- Once you’ve got a lean from the tyre into the rim it basically pressurises the rim and then it’ll leak out by the route/routes of least resistance. Spoke holes tend to be fairly airtight after a little use because of the tight fit and pressure so this usually works the other way- spoke hole leaks into the rim then vents at the “outer” valve hole which is unsealed.

TL;DR- it’s not as simple as “leak at this spoke hole means this spoke hole leaks”