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I have converted my fat bike rims to tubeless. Mulefat rims, huskar du tyres, gaffer tape on the rim beds over the orginal tape that covers the holes. Stans sealant.
They go up fine, shake them around and no obvious air comes out - leave them for a day they are flat, pump them up again and dip them in the bath - air pouring out of the rim holes and they go flat in minutes. do the stans shake and they seal up again and no air visible coming out of the tyre or rim when dunked in the bath
I have now been thru this cycle 4 times! I don't get it. surely when they are sealed the stans should turn solid in the holes nd seal it up virtually permanently.
a function of low pressures? Should have put more gaffer tape on? something else I have done wrong?
Help me out please - I am confused as to why a tyre that is ealed up one day is nothing like sealed the next day
Ah, the mysteries of tubelessing a fatbike rim with 32 spoke holes and then the big holes to make the rim lighter...
In that situation maybe the split tube ghetto method would be better and leave the rim tape in.
Apparently Mulefoot rims are easy........
I'm still an innertube luddite :o)
Bruce has an excellent video showing his ghetto tubeless method and setup. Explains everything.
D.
Thing is they do stay up for a while - its just when they do go flat after a day or two then just pumping them up does not work - air pours out until I give them a good shake again - then they seal up
Sounds like your rim strip is leaking, although no idea why it stays up initially.
What rim strip did you use? Or did you just use some tape from the garage? Rim strips important IME.
thats the issue steve - clearly its leaking out of the rimstrip but then a shake seals it up and it stays sealed for a couple of days until it goes flat - then its not sealed again
molgrips - gaffer tape over the existing rimtape - a recommended method
Is that Gorilla or gaffer tape? Don't think gaffer tape is waterproof?!
I'm not a fan of gaffer or gorilla tape because the sealant causes them to become unstuck
Ah - that will be it then shermer. there is not a huge overlap where the gaffer tape is stuck to the rim rather than the reinforced plastic tape that covers the holes - so when the pressure drops beow a critcal level the tape is lifting. Get the pressure up again it reseals with fresh sealant shaken onto it.
Buggeration - might have to redo it
gorrilla tape is a brand of gaffer tape the stuff I used is airtight
@shermer75 - over what period? I've got some rims that I gorilla taped over a year ago and they are still fine.
NOw sealed up again - dunked in the bath and no air coming out that can be seen!
I've known it take quite a few rides before the tyres start to stay up. It takes time (a few minutes) for the sealant to seal a hole, depending on size - so riding it keeps the hole bathed in sealant for a few hours, rather than just for a few seconds if you are shaking it.
Have you actually tried riding it? I find tyres always need a good ride when first setup.
Its been ridden a bit but not a lot. Was going to go for a long ride today but worried about flatting. Its just odd that it stays sealed for a day or two - then goes flat, pump it up and air comes out everywhere - shake it and it seals again.
Is the tubeless sealant able to wet the surfaces properly? That's the most annoying issue i've had with people using odd combinations. (Gaffer tape etc) is the sealant won't actually wet then stick to the surface. So it'll never seal.
Also an issue with certain brands of tyre. Clean and scrub first......
It seals well for a while then leaks like a seive. shake it and it seals again
Now held pressure to 1/10 of a lb for an hour so I shall risk the ride
Make sure the tape is wide enough to cover the bead seats too. The 3" (? 78mm?) wide Gorilla tape was just too narrow for the 80mm Mulefut rims on my bike. Went with 4" waterproof duct tape, with about 1/2" slit off it in the end, and it's been fine for over 2 years.
Two wraps of Gorilla tape might be better, but I'm always wary of leaving an edge for the sealant to get under.
I did two wraps overlapped to get the tape right to the edge of the rim. Perhaps thats the issue - the sealent is getting under that edge.
Lost 1/2 a psi in an hour and a bit riding.
I used split tubes to make my fattie tubeless, saves using miles of gaffa tape and prevents leaking through the rim tape. There is a little downside but it's only cosmetic:
If you were really keen you could trim that down. Start with a 24" tube for a 26" wheel, cut it around the circumference to yield a strip of rubber with a valve in it.
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Two wraps of Gorilla tape might be better, but I’m always wary of leaving an edge for the sealant to get under.
How does only having one wrap avoid having an edge?
(Or have I misunderstood your statement)
wide tape that only needs to go once round rather than narrow tape that needs to have a strip each side leaving a seam down the middle was how I understood it
Can you not get dedicated rim strips then?
almost certainly molgrips - I am just a cheap barsteward and the gaffer tape option is nice and light
front has now lost a couple of PSI, rear is flat again. 12 miles riding not enough? I think I will have to redo them
How does only having one wrap avoid having an edge?
(Or have I misunderstood your statement)
Statement wasn't very clear - I was assuming at the time that he'd used one wrap of 3" tape which isn't wide enough to span the bead seats, therefore two wraps of 3" tape, staggered, might be better. Best of all is to use wider tape that will span both bead seats with one wrap (the 4" duct tape cut down to ~3.5").
ETA: With wide tape, the edges are under the tyre beads, so held in place and protected from the sealant. The only edge that is exposed to the sealant is where the ends of the tape overlap, but you can make that overlap as long as you like to help with the seal.
almost certainly molgrips – I am just a cheap barsteward and the gaffer tape option is nice and light
I bet the rim strips don't leak though 🙂
I've always wanted to give a split inner tube a go-to I might try it!! 🙂
Do you still need rim tape if you are using a split inner tube? 🙂
I was hoping to avoid the split inner tube method for two reasons - weight and the tyres are tight on the rim anyway - an extra layer of rubber will make them very tight indeed.
Split tube has advantages because the tyre and the tube get glued together by the sealant so if the tyre does roll a little it is less likely to burp.
<span style="font-size: 0.8rem;">You don't need tape over and above what you would use for just a regular inner tube.</span>
<span style="font-size: 0.8rem;">I would expect the weight weight difference to be minimal.</span><span style="font-size: 0.8rem;"> </span>
<span style="font-size: 0.8rem;">It becomes more of a faff when you come to change tyres however.</span>
I would cut the tube back to the rim.
FFS this ****ing forum is a clustering ****
Tj, do the split tube thing and ride the bike not faff. Plus the cost of time and sealant... do it once, do it properly.
You have a rim with 32 spoke holes, then the cutouts.... That's a lot of holes to seal with tape. I tried Gaffa / Duc tape and it just came unstuck when wet. My rims only have small spoke holes and they sealed with small squares of clear 3M parcel tape after cleaning with brake cleaner.
For your rims, Fatty Strippers / Split Tube is Shirley the way to go. Its a bit of weight but offset that against the fact you can actually ride your bike.