Issues with tubeless set up on XT wheels

13 replies · 214 views

Lammark
23 posts
#1Apr 1, 2020, 7:27 PM
Killing time during the covid-19 lockdown by building my wife a new gravel bike (Niner RLT steel).

I bought a new set of Shimano XT (M-8000-TL) wheels (link below) for her. They have internal width of 23.9mm. I’m trying to set up 38mm Panaracer Gravel Kinds on them. I can’t get them to inflate at all. There is not even a hint of holding air. I”m using a compressor at about 75 psi, soapy water, the valve looks fine, but I also tried a Stans valve. Nothing. I also tried an old set of Conti mountain king tires, just to see. No luck.

What should I try next? New rim strip? If so, what do you all recommend?

Thanks.

https://bike.shimano.com/en-EU/product/component/deorext-m8000/WH-M8000-TL-R-29.html
0
shiggy
404 posts
#2Apr 2, 2020, 1:44 PM
Seat the tire with an inner tube.
Deflate, break loose one bead and remove tube. Leave the other side seated.
Install tubeless valve.
Spray some soapy water inside tire and rim.
Remount tire. Make sure bead is outside of valve.
Remove valve core.
Spray soapy water on outside of tire/rim junction.
Inflate to seat bead.
Deflate (will happen because the valve core is out).
Inject sealant.
Replace valve core.
Inflate.
Spin and shake.
0
shiggy
404 posts
#3Apr 2, 2020, 1:46 PMedited
If you did get the tire seated, but it will not hold air, yes, retape the rim. I have ridden GK SKs tubeless with no sealant—for a few hours
0
Lammark
23 posts
#4Apr 2, 2020, 8:17 PM
shiggy wrote:
Seat the tire with an inner tube.
Deflate, break loose one bead and remove tube. Leave the other side seated.
Install tubeless valve.
Spray some soapy water inside tire and rim.
Remount tire. Make sure bead is outside of valve.
Remove valve core.
Spray soapy water on outside of tire/rim junction.
Inflate to seat bead.
Deflate (will happen because the valve core is out).
Inject sealant.
Replace valve core.
Inflate.
Spin and shake.

Thanks. I tried all that last night (after posting my first message and after some googling). Didn’t work. I got a recommendation to add rim strip or gorilla tape to build up the center channel of the rim. Seems like that will work because the air seems to be escaping under the bead, so I need to make that fit a little tighter. I ordered gorilla tape. We’ll see. I’ve got them on there now with tubes just so I can keep building the bike.
0
shiggy
404 posts
#5Apr 2, 2020, 10:38 PM
don’t use gorilla tape. It absorbs moisture and fails
1
Perks Tooth
10 posts
#6Apr 4, 2020, 5:45 AM
With modern tubeless rims you wouldn't need to add a second layer of tape. If the rim is offset and the existing tape is dimpled, you may have a problem getting it sealed. If the rim is unused this shouldn't be an issue. I suspect the rim is too wide for the tire you are trying to use. At 23.9mm internal most rim manufactures are going to recommend a tire width of at least 2"/50mm.
0
Perks Tooth
10 posts
#7Apr 4, 2020, 5:48 AM
I am just looking at the spec on your wheel and it indicates a minimum tire width of 1.9". Your 38mm tire cannot be safely used on that rim.
0
Volsung
878 posts
#8Apr 4, 2020, 8:12 AM
Are the tires used? I'm pretty sure GK beads stretch. They're easier to mount the first time than any subsequent times. I would add a few layers of scotch 8898 tape (or any plastic tape really) just to build up the rim diameter.
0
shiggy
404 posts
#9Apr 4, 2020, 9:20 AM
Perks wrote:With modern tubeless rims you wouldn't need to add a second layer of tape. ...
...I suspect the rim is too wide for the tire you are trying to use. At 23.9mm internal most rim manufactures are going to recommend a tire width of at least 2"/50mm.

That is very outdated width recommendations. 24mm rims can easily accommodate 38mm tires
1
nellborg
142 posts
#10Apr 4, 2020, 4:53 PM
So, you alcohol'd the rim just to get any oils/residue off the tape-rim mating surface...
You're pulling the tape fairly tightly as you're putting it on the rim - and the tape goes all the way from sidewall to sidewall...
You used a hot nail to burn a hole in the rim strip for the valve stem...
You tightened down the nut on the valve stem with pliers a bit more than you could by hand....
You took out the valve stem from the valve core while you're trying to set the beads...
Does your air compressor have a high enough flow rate? 75 psi doesn't tell me if the flow rate is high enough... You need a big "whoosh" of air from the compressor into the tire to seat the beads.
0
Dino Sore
27 posts
#11Apr 6, 2020, 7:19 AM
nellborg wrote:
Does your air compressor have a high enough flow rate? 75 psi doesn't tell me if the flow rate is high enough... You need a big "whoosh" of air from the compressor into the tire to seat the beads.

I have a decent sized air compressor that could not get enough air flow to seat some tubeless tires. Not sure if it was the compressor per se, or the combination of the standard auto schrader air chuck and presta adapter. Most tires went on fine, but every once in a while I'd have a tire that just would not inflate. My solution was to get a Prestacycle Prestaflator. It has an air chuck that fits presta valves and a trigger handle to create that blast of air (plus a built-in air guage). Works great.
0
nellborg
142 posts
#12Apr 6, 2020, 11:08 AM
I recently bought that new Bontrager Flash pump and it works great. Yesterday, it seated both beads on my 41mm tires instantly even without soapy water.
0
heybrady
39 posts
#13Apr 7, 2020, 9:29 AM
shiggy wrote:

That is very outdated width recommendations. 24mm rims can easily accommodate 38mm tires
Agreed. They run road 25mm tires on 23mm wide rims. I have had 38mm GKSK on 25 and 28mm external rims without a single issue. Easiest tires to setup tubless I have ever seen.
0
Lammark
23 posts
#14Apr 7, 2020, 11:52 AM
Yeah, i”m not worried about the tire/rim combo. Researched this a lot and it’s common.

The compressor is getting old but it worked just fine setting up some Schwalbe 38 mm tires on my GRX wheels about three weeks ago.

The rim strip came installed. I think it’s fine but I’ll take a closer look.

Will probably try adding some table to build up the “height” in the middle. Doesn’t seem like it would do much harm. If that doesn’t work I’ll order some new tape and start over.
0

Related threads

NAHBs BikeBike Shows (NAHBS, Interbike, Eurobike...) · 3 replies · Apr 22, 2022
Wide clincher rim (rim brake) buying guideGravel Wheels (Wheels, Rims, Hubs, Etc) · 2 replies · Mar 12, 2017
2017 Lynskey Pro GRBikes · 56 replies · Jan 22, 2019
Roker Comp ReviewBikes · 128 replies · Sep 4, 2018
Amercian Classic Argent Disc vs Kysrium AllroadGravel Wheels (Wheels, Rims, Hubs, Etc) · 5 replies · Aug 17, 2016

Related threads

NAHBs BikeBike Shows (NAHBS, Interbike, Eurobike...) · 3 replies · Apr 22, 2022

Wide clincher rim (rim brake) buying guideGravel Wheels (Wheels, Rims, Hubs, Etc) · 2 replies · Mar 12, 2017

2017 Lynskey Pro GRBikes · 56 replies · Jan 22, 2019

Roker Comp ReviewBikes · 128 replies · Sep 4, 2018

Amercian Classic Argent Disc vs Kysrium AllroadGravel Wheels (Wheels, Rims, Hubs, Etc) · 5 replies · Aug 17, 2016