Fat Bike Ghetto Tubeless 2.0

[TheElk]

Last year, I wanted to turn my Specialized Fatboy SE into a tubeless set up.  I failed because I could not secure the tube size I needed (https://community.bikehub.co.za/topic/167172-fat-bike-ghetto-tubeless-tubes/).

 

I just had a friend bring over some tubes from the U.S. and finally was able to pull it off.  I thought I’d post what I used and where I found it in case anyone else goes down this path.

 

First of all, there’s a lengthy thread here on converting Fatboy rims and tyres to tubeless:  http://forums.mtbr.com/fat-bikes/specialized-fat-boy-how-i-went-tubless-902936.html

 

NB: The older version of the rims was/is a PITA because it had a bunch of vent holes throughout the rim (in addition to the cut outs).

 

I considered the following options that could work for sealing the rims:

 

• Q-tubes 24x2.1-2.3 or 2.4-2.75 - split tube (“ghetto”) tubeless, reliable

• Spesh tubes 24x2.3-3.0 (a little heavier) - ghetto tubeless, reliable

• Pegasus tape (4") - seems fairly good but not perfect, 2-3 data points

• Zip Systems tape - seems good but almost nobody uses it, one data point

• Gorilla tape - seems to suck 50/50 with lots of data

• Tyvek tape - seems to suck 50/50 with not much data

 

I decided to go the split tube route because there seemed to be a lot of problems with the tape with my specific rims and tyres.  Unfortunately, I could not source either Q-tubes or Spesh tubes of the right size in South Africa.  I ended up ordering tubes from ChainReaction Cycles in the UK.  After being held up in customs for over a month, the tubes arrived….and were not the right tubes.

 

I gave up.

 

Last month, I had a friend coming over from the States and she brought some Q-Tubes 24x2.1-2.3 with presta removable cores.  I got them for US$8.99 each.  http://www.jensonusa.com/Q-Tubes-Standard-24-Presta-Tube   They came in Q-Tubes boxes but were marked Kenda 24 x 2.125 on the tube itself.

 

 

They worked perfectly.  That said, there is not a lot of room for error in aligning the split tube underneath the tyre so maybe go for the 24x2.4-2.7 if you don’t want to worry about precision alignment when inflating and seating the tyres.  There are parts of my tyre where the split tube only sticks out a few millimeters between rim and tyre on one side and more like 8mm on the other side.  The good part of this is that the split tube is barely noticeable unless you look closely and requires no trimming.  

 

Here’s how I did it:

 

Step 1: Remove tyre and old tube.  Wash rim and tyre with soapy water and let dry.

 

 

 

Step 1.5: I’m more worried about durability than weight, so I added weatherproofing foam around the cut outs on the inside of the rim for extra protection and to maintain enough edge of split tube sticking out between rim and tyre.  I purchased 2 rolls of 3mmx25mmx5m adhesive weatherstripping at Builders Express for R25 each and stuck it to the inside groove of the rim in two rows:

 

 

Step 3: Split the tube on the seam opposite the valve with medical or blunt-nose scissors. Insert valve through rim hole and stretch open tube around rim.  Be sure to wash off the powder on the inside and let dry.

 

 

Step 4: Pop tyre back on the rim, pushing tyre edge toward the center as you go and pulling out edge of the split tube, making sure that split tube sticks out between the tyre and rim on both sides:

 

 

Step 5: Add sealant (I added 250ml to each tyre) then inflate.  I used an air compressor and, once seated, made sure the pressure was not above 1.4 Bar (20 psi).  Some people had posted that their tyre exploded if they left it above 1.4 Bar.  I stuck to below 1.4 Bar and, thankfully, it seated and did not explode.

 

 

Step 6: Spin and shake rims/tyres and make sure pressure holds overnight.  I rode the tyres the next morning on tarmac at a high pressure to make sure all was good.  Checked pressure and they were holding.  Ridden it twice since and all is good.

 

 

[FDP]

Nice write-up!

[Butterbean]

Just adding my two cents,

 

Needed to convert my Surly Marge lite rims to tubeless... They're a little narrower than most fat rims and so I assumed a good gorilla taping would be fine... Leaked like a sieve...

 

So, grabbed some 20" BMX tubes which I've used on 26" wheels prior and came out with a flawless ghetto setup... I prefer the 20" tube because it tends to really stay in place well.

 

Had to drill the valve hole because finding presta BMX tubes is a pain... 10mm drillbit and a lot of apprehension. But it's done! Cleaned up the holes and then split the tube, fit it carefully (there's not much room for error with the narrow tube width), and fit the tyres. Pumped up without much hassle using a normal floor pump, popped some sealant in, and they seem good for now... Trimmed the very small overlap and took for a test ride.

 

Will obviously keep an eye on things but glad I did the drilling, it's opened the tube options up immensely!

[m-squared]

Very nice write up.

 

When I had my Whopper, I managed to get both tyres tubeless just using duct tape.  And it was a quick process too.  

 

I currently have a Fatboy Expert that that is tubeless using the method you described above.

 

Happy trails!