# Tubeless setup for MTB tandem



## ds2199 (Sep 16, 2008)

Ok, there's scattered information on this topic, so my questions are:

Who's running tubeless on their MTB tandem? 

1) What is the setup:
- Rim?
- Tire (UST, tubeless ready or standard)?
- Sealant/no sealant?

2) Share your results

Separate question - Is anyone running sealant with tubes?

Thanks

Dan


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## Trails4Two (May 12, 2008)

*tubeless experiment*

I'm in the slow process of a tubeless experiment. After two pinch flats on the Monarch Crest trail this past Fall, I decided to try tubeless and the biggest tire I had easily available. What I ended up with was a 2.4 WTB motoraptor (standard wire bead) on a Sun MTX rim (not tubeless ready). I did this with a ghetto conversion (20" split tube and Stan's sealant). We went out and pounded it as hard as we could for three weeks. I tried both moderate and and pretty low pressure and tried to run over as many rocks and ledges as I could find. It held up fine. Then we lost our babysitter and it has been sitting in the garage for over two months. It has lost some air but is still sealed.


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## PMK (Oct 12, 2004)

We are running this setup for local riding.

Slime tubes front and rear.

Front tire, Panaracer Smoke Classic / Kevlar, 2.1", 50PSI

Rear tire, Ritchey Zmax WCS / Kevlar, 2.1" 55PSI

While the pressures may seem high, mechanical grip is not a problem, but sidewall flex can be.

I've tried a wider 2.3" Continental on the rear, it's just enough to wide that it contacts the frame when cornering.

PK


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## TandemNut (Mar 12, 2004)

PMK said:


> We are running this setup for local riding.
> 
> Slime tubes front and rear.
> 
> ...


Are you running narrow(er) rims? I don't get sidewall flex at 40 PSI with MTX's and Mammoths. Of course we're running MotoRaptor 2.4's also, which are a beefy casing.
But we also run 2.4 Mutanos, with notoriously thin sidewalls, and still don't see a lot of flex.
But you do bring up a question I've been meaning to post here:
I recently built a demo (Ellsworth Witness) with 2.24 MutanoRaptors (for clearance). When we started riding, I tried running 30 psi in the tires. The rear did okay except for off-camber cornering. The front scared the crap out of me a couple of times in dip/turn situations where the fork got close to bottoming, as it felt like the tire was rolling off the rim. Sort of that real bad feeling when you discover, while trying to change direction, that you're halfway into a flat tire.
Now the tread is somewhat flexy on the 2.24 Mutano, but it wasn't until I took the tire back to 40 psi that the sideways rolling-off-the-rim sensation went away. 
So I'm curious how tubeless riders have addressed with this paricular phenomenon, given that lower pressures are one of the benefits of tubeless tires. Is this a heavily-loaded-tandem-only sort of problem?


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## PMK (Oct 12, 2004)

BigNut said:


> Are you running narrow(er) rims? I don't get sidewall flex at 40 PSI with MTX's and Mammoths. Of course we're running MotoRaptor 2.4's also, which are a beefy casing.
> But we also run 2.4 Mutanos, with notoriously thin sidewalls, and still don't see a lot of flex.
> But you do bring up a question I've been meaning to post here:
> I recently built a demo (Ellsworth Witness) with 2.24 MutanoRaptors (for clearance). When we started riding, I tried running 30 psi in the tires. The rear did okay except for off-camber cornering. The front scared the crap out of me a couple of times in dip/turn situations where the fork got close to bottoming, as it felt like the tire was rolling off the rim. Sort of that real bad feeling when you discover, while trying to change direction, that you're halfway into a flat tire.
> ...


We are running Sun Rhyno Lights, and we aren't petite nor weak.

For whatever reason, tire squirm, both sidewall flex and tread squirm, both front and rear, is a very noticable thing for me.

When we started with the tandem, I played with different pressure settings. The 50 / 55 is about 10PSI more than my single suspension bike on the same tires.

As for tubeless, non of our bikes have it. I am intrigued by using the methods posted here, just not sure it will be worth the effort.

I would like to run a larger tire, unfortunately it just isn't a good fit between the frame tubes.

PK

Forgot to mention the Zmax is installed opposite the labeled direction.


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## itsdoable (Jan 6, 2004)

BigNut said:


> ...But you do bring up a question I've been meaning to post here:
> I recently built a demo (Ellsworth Witness) with 2.24 MutanoRaptors (for clearance). When we started riding, I tried running 30 psi in the tires. The rear did okay except for off-camber cornering. The front scared the crap out of me a couple of times in dip/turn situations where the fork got close to bottoming, as it felt like the tire was rolling off the rim. Sort of that real bad feeling when you discover, while trying to change direction, that you're halfway into a flat tire.
> Now the tread is somewhat flexy on the 2.24 Mutano, but it wasn't until I took the tire back to 40 psi that the sideways rolling-off-the-rim sensation went away.
> So I'm curious how tubeless riders have addressed with this paricular phenomenon, given that lower pressures are one of the benefits of tubeless tires. Is this a heavily-loaded-tandem-only sort of problem?


First off, I'm not running tubeless on my own bikes, tandem or not. But we have a "fair" bit fo tubeless experience in the ride group.

Our main issue is not "roll off the rim", but roll the tire enough to burp it, causing an instant deflation and a "controlled flight into terrain" incident. For a while, it was not a ride until someone burped their front tubeless on a steep technical descent (slow speed, sharp turn, all the weight on the front type maneuver) resulting in an endo. Over time we played with tire model & pressure until we now have incident free rides, but it took some time, especially if you wanted to run the low pressures - it could have been avoided if we just pumped up the tire to tubed pressures, but then why use tubeless... Not sure I would recommend this technique of tire tuning for tandems....

As for squirmy thin side walled tires - maybe they are a good thing, since they potentially could avoid the above...


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## Trails4Two (May 12, 2008)

*ghetto tubeless effort*

Not really much effort involved in trying a ghetto set-up. Buy a couple of BMX tubes (schraeder) and a bottle of sealant. split the tubes around the outer diameter, stretch them over the rim (you might need to drill out the valve hole if your rim is presta only). Install the tire (rub a bit of water around the bead) and air it up with a compressor (this was the only slightly troublesome part). After it seats well air it up to about 50 to seat the bead really well. Then remove the core of the stem , put in about 4oz of sealant, air it up and vigorously shake it around a while. Trim off the excess tube if you desire. Done. You can also put in the sealant before you air it up the first time, but I accidentaly blew Stan's all over myself with the compressor when I wasn't careful. Overall, I was suprised at how easy it was.

If you really are sensitive to "tire roll" from low pressure, you probably won't gain much advantage from tubeless. (i.e. running lower pressure without pinch flatting) other than having sealant in there to avoid most flats.

Just my opinion


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## TandemNut (Mar 12, 2004)

Trails4Two said:


> Not really much effort involved in trying a ghetto set-up. Buy a couple of BMX tubes (schraeder) and a bottle of sealant. split the tubes around the outer diameter, stretch them over the rim (you might need to drill out the valve hole if your rim is presta only). Install the tire (rub a bit of water around the bead) and air it up with a compressor (this was the only slightly troublesome part). After it seats well air it up to about 50 to seat the bead really well. Then remove the core of the stem , put in about 4oz of sealant, air it up and vigorously shake it around a while. Trim off the excess tube if you desire. Done. You can also put in the sealant before you air it up the first time, but I accidentaly blew Stan's all over myself with the compressor when I wasn't careful. Overall, I was suprised at how easy it was.
> 
> If you really are sensitive to "tire roll" from low pressure, you probably won't gain much advantage from tubeless. (i.e. running lower pressure without pinch flatting) other than having sealant in there to avoid most flats.
> 
> Just my opinion


Well, I'm a sensitive kind of guy. Of course, I weigh as much as some teams, so that may be part of the reason behind the squirm problem (tire squirm, not captain squirm). Every time I've run tires at much less than 40 lbs on a tandem, I've run into this issue to a varying extent. I watched a team test-ride a tandem (not mine) with the front tire too low, and watched them do the slow fallover as they tried to do a tight turn in the parking lot. I suspect the tandem pushing the front wheel sideways so much magnifies the effect of the squirming.
I'll still probably experiment with the home-made tubeless setup just to get a feel for it. I like new technology when it's an improvement, but as stated above, I don't see major advantages for tubeless if lower pressures aren't part of the picture. Then again, It took a while for radial tire technology to catch on (us older guys remember that), so maybe tire designs havent' made the jump to utilize the tubeless advantage yet.


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## Sam Jones (Feb 25, 2005)

We have been running the following setup on our ECDM for the last several rides:

Sun MTX Rims
Stan's Rim Strips and Sealant
Kenda 2.35 Nevegal DTC with folding bead Front
Kenta 2.35 Short Tracker DTC with folding bead Rear


We are a 290# team with 185# in the front.
We ride were there are a LOT of rocks.
We don't ride fast/agressively down hill - just trail riders.
We've played with the pressure some (between 27 and 35) and are now using 30 PSI

Our reasons for going tubless are lower rolling resistance (we're a 130 year old team and are horsepower challenged) and better handling and traction in rocks, roots, logs, etc.

I have quite a bit of Tubless experience with Stans on my single.

My opinion so far is that we like the tubless on the ECDM, I believe that a WIDE rim does a LOT to eliminate the squirm - and it increases the tire volume. (I see Sun now has an even wider version of the MTX available). I have found on my single bike that use of the rim strips and making SURE they are all the way out to the corner of the rim so that the bead is on top of the strip all the way around eliminates burping.

Sam & GAIL Jones - Frederick Maryland


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## tf1958 (Sep 3, 2008)

I have been running tubless on our single bikes. I have found the key to trouble free tubless is using UST wheels and UST tires. Going to try tubless on our tandem this year. I am in process on building wheels using Mavic EX 823 rims and will be using Maxxis high roller 26 x 2.35 UST tires. If you once try tubless you won't want to go back, the ride and handling is well worth the switch and if you go with UST wheels and tires you will have no problems.


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## reamer41 (Mar 26, 2007)

I see this thread is a little old....

I've been running tubeless on our tandem for several years. It's been great. Initially I used Stans rim strips. They worked pretty well. I used standard tires and sealant as well as UST tires and sealant. I have since switched to the Maxxis rimstrips (in Mavic 521 rims) and find that the tires are a little harder to mount, but they seem to be better than the stans strips as far as sealing and burping is concerned.,

The thicker sidewall of the UST tires have proven to be much more durable than standard tires. We are a pretty heavy team.... 220 +155 + 50 = 425.... so there's a lot of load on the tires

If I were building up new wheels I would very much like to use a UST or otherwise tubeless rim. The tubeless setup has been nearly bombproof. Here in the land of cacti, and with both wheels bolted on (no QRs) that's a good thing


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