[drolic]

It's a well known problem statement that fat rims and fat tires are lose fitting. More so with different tire / wheel combinations. This makes even Ghetto / Split tube tubeless susceptible to two issues. Burping and trouble getting tires mounted.

Here is a picture of my Moto Boris with its Vee Mission (folding) tires hanging slack of its Weinmann HL-80 rims. After one of its tubes went flat overnight. The bead pulls back and you can practically shake the tire off the rim.

So, filling the valley of the rim with a light weight filler like foam is used with both tape and split tube to avoid this. Its easier to seat the bead and is somewhat reported to reduce burping.


My solution was to use some Filter Floss. It's sold in bulk for aquariums and ponds. Mine is the two sided blue / white in 1" thick. Mine was off of a bulk role available in lengths longer than 80". Below is just an example of the product. Again, I tried 1" it can be had thicker or thinner.


Amazon.com: Puro-Kleen Kleen-Guard Pond & Aquarium Filter Media, 16" x 72", Pack of 2 (12 Feet Total): Patio, Lawn & Garden



This was then cut into a strip that fit the rim edge to edge. It's easy to cut with scissors, the challenge is a nice neat strait line.


My preference is for Schrader. Was easy to drill these single walled rims. So, I selected Schwalbe AV10 (24") because they have fully threaded Schrader stems.
Below you can see a long strip and a short strip that I cut. The short one is notched for the valve stem. I found it easy to put the long piece in first, then slip the shorter one in around the stem. No overlap was needed as the edges of floss matched up and created no gap under the split tube later.

Insert the stem with the lock ring only about half threaded on. Inflate the tube a little. This makes it stand out from the rim. It's now easy to tuck in the filter floss strip between rim and small tube. Let the air out of the tube keeping the tube aligned strait as it comes down to put pressure on the floss. You can now tighten the stem lock nut.


Carefully split the tube down the middle like any other split tube setup. Clean the powder out of the tube with soapy water. The AV10's were perfectly sized to overlap the rim just enough. No circumcision needed to be performed afterwards. Laid ontop of the floss the tube now sets about level with the rim edge.

Mounting the tire required a tire lever now. Keep the bead more or less centered in the valley and manipulate the split tube to center it again. I left the Schrader core in and used an air compressor. Bead popped into place without use of soapy water or sealant as lube. No strap or cord was needed to pinch the tire down. I believe a track pump could have been used, I just did not try.

Tire held air for 30 minutes before I pulled the core and added sealant though the stem. The bead held when core was pulled on both front and back. I used 3 cups of Stans in each.


It's been a week, still holds the original 10 lbs of pressure. I've rode maybe 15 miles on these some rocky trail and some intentionally jumping on / off curbs trying to make them burp. Have been unable to do so.


Initially I experimented with them at 5 lbs of pressure, could not make them burp but self steer was horrible. Went to 10 and stayed there. I would expect 7 or 8 lbs to be fine, thats just too low for my Clydesdale but.



I also tried to make them burp with the "c clamp test". I tightened the clamp as far as I thought safe then pulled / pushed on it. Was unable to make it burp. Ran this test at 20 and then again at 10 lbs. USE CAUTION if you try this, you can hurt yourself I wore a leather glove and eye protection.

Would be glad to hear if anyone else tried filter floss. So far I'm very happy with this method and was the easiest tubeless setup I've ever done. The benefits of tubeless have already been proven to me in ride quality and weight savings.


I do have the concern that the floss will eventually lose its thickness due to pressure unlike a closed cell foam. This could allow burping to happen. It would also then be hard to reseat in the field if needed. I intend to change out the original rim strip once I obtain a new one I want to try. But quite a few more test miles need to be logged first. Will report back here after more long term testing.


Weights measured on my digital kitchen scale.
Removed Vee Ruber tube : 460 gm
Installed 24" AV10 tube : 163 gm
Aprox 80 " of 80 mm Filter Floss at 1.0" : 44 gm

 

[mtbXCgeek]

Where exactly is your weight saving? You saved 300g in the tube but then added 800g of filter floss and sealant to each wheel. By my calculations, you are now 500g heavier per wheel

 

[drolic]

Admittedly, I should have weighed entire setup before and after but don't have a good scale for it. Also, stans isn't the same static load all the time. This is why I didn't show an overall calculation.

Care to show your 500+ gram calculations? Don't know how you got that even counting the sealant.

 

[mtbXCgeek]

You said three cups of sealant per wheel. One cup is 250ml so 3 is 750ml. Stans is mostly water so I made an assumption that 750ml of stans is 750g. Add in the 44g of filter and there is near enough to 800g. Subtract the difference in tube mass of 300g and there is 500g left. Admittedly, the stans is not always spinning with the wheel but a portion will be and that portion will get higher as your wheel speed goes higher.

When I used to race, we used to use 75-100ml of carpet latex per tyre for 2" tyres so I would think 200-300ml would work fine for fat tyres

 

[drolic]

Whoa no. I meant the red cup that comes with the Stans product. Not cup like the unit of measure.

Probably closer to 6 fl oz per tire than the 25 your 750 ml would come to.

 

[mtbXCgeek]

Ok, my bad. Sorry. To be fair, I never did see any weight savings ever in tubeless setups over a light tubed setup. Massive puncture resistance advantages though.

 

[drolic]

So, I decided that I 'needed' to replace my red rim strips with white. Ordered some Surley's as my Boris is slowly going storm trooper.

FYI.
Old Boris rim strips were 88 grms
New Surley rim strips were 92 grms.

In the process I had to tear down my tubeless setup. I was not that surprised to find that the filter floss I used as a rim filler had been crushed significantly under the pressure of the split tube.

Picture of the split tube resting on the depressed filter floss after removing the tire.

Picture of the filter floss after removing the split tube.

I'm not going to try and claim any improved burp protection from the floss. I just don't have enough miles on them to say that. I can say that to remount the tire with the crushed floss was a no-go. The tire gaped to much between split tube and bead to allow even a compressor to pop the tire into place.

I had already pre-cut a second set of floss inserts so I just replaced them and found that like before it was very easy to finish the job with the new floss keeping the split tube pressed against the bead. I even used a track pump this time with little effort.

Boris and its white strips.

Moral of the story... for split tube, the floss is a good setup aid. It's not reusable like I would like. I'm not convinced it gives any better burp protection that a good wheel / tire combination does. Foam as others have used can probably save you a few more grams.

Anyone want to trade something white for a set of red rim strips?

 

[drolic]

Longer term update...

I had to top off the Stans because it had been a few months and our AZ heat basically boils the stuff off. It's a 5 minute job if the beads hold. The split tube should ride ontop of the now crushed floss. The tires did hold their bead for me, so I just took out the schrader valve core and put in the two red cups of sealant. Done.

I'll say that the Schwalbe AV10 tubes are definitely the tubes you want for these Weinmann HL-80 rims. Could not be happier with where the split tube landed on the rim and the fully threaded schrader valves are a big nice to have.

We had some wicked rains here in AZ and the resulting mud ride was awesome. I went down to very low pressures for this (sub 5 PSI). No burping issues seen. I was sure I even snake bit it once, but had no issues.

I did eat mud a couple times. I blame these Vee Missions. You can't lean it over at all in anything remotely slick or that rear end will come right out from under you. I've only got 50+ miles on these Missions, but, I'm ready to put some Floaters on. I'm also trying out some platforms -vs- my preferred clip-less pedals. But, that's another post.

 

[Jisch]

When you have that gap that the air compressor can't overcome, you can put a ratchet strap around the tire, then tighten it just enough so it's putting pressure on the tire, but not so much that it's kinking it. I found most times with a ratchet strap on the tire I can use a floor pump to fill it up.

 

[watermonkey]

When you have that gap that the air compressor can't overcome, you can put a ratchet strap around the tire, then tighten it just enough so it's putting pressure on the tire, but not so much that it's kinking it. I found most times with a ratchet strap on the tire I can use a floor pump to fill it up.

There was no chance in hell that a strap (I tried) would help seat the bead on the Weinman hl-80, at least with my V Snowshoes. The gap was huge, strap did nothing. Ghetto tubless would not have been possible without a foam buildup.

 

[drolic]

I tried the ratchet strap when I replaced the rim stirp... I can see it maybe working.

However, I've been gun shy about doing it again since I popped a tire off the bead when using it with the compressor. After the loud boom that it made I got to wipe Stans off my face, change my underwear, and then answer some awkward questions that my wife had about what just happened in the garage.

So, ratchet strap + floor pump is my advice if you want to try it. For me, a good rim buildup is the way to go. It really does not take too much material.

 

[Jisch]

Interesting. I added Stans to my Floaters on Specialized rims a few weeks back - as soon as I deflated the tires, they jumped off the ridge and to the center, huge gap between the ridge and the tire bead. The ratchet strap put enough pressure on the tire to get the beads to touch the edges of the ridge and with a floor pump I got the beads to migrate out to the edge. I did the same with a Wienmann rim and a Floater when I had my FB4. I guess it's just particular tires and rims that play nice together.

I blew a floater off a rim with an air compressor trying to get it to move that last millimeter out. I've learned that it's much better to bounce the tire to get it to move the last bit (if necessary). My wife came running out to the garage after the explosion convinced I was going to be dead on the ground, instead I was just covered in Stans and deaf, it's a good thing Stants fluid isn't red.

 

[drolic]

So Jisch, does your post mean that you prefer the Floater over the Ground Control your Fat Boy came with?

If you've had them on long enough to need to top off the Stan's that is.

 

[Jisch]

I think the Ground Controls are better tires, but they cost 3 times what the Floaters cost. I figured for the summer I don't need that extra width and I'll wear out $50 tires rather than $160 tires.

So if money was no issue, I'd still be running the Ground Controls.

The Floaters are heavier and probably have greater rolling resistance, but I have had a great summer riding season on them, no complaints! Between the tread wear and the sidewall cracking, they are probably headed for the bin when the snow starts falling, but I never get more than 6 months out of a tire anyway.