Tubeless Conversion: Gigantex Carbon Clincher w Ultremo ZX

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Miller
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by Miller

This is my winter for new technology I’ve decided. After building my disk brake bike (previously documented in the Gallery section) I thought I’d have a go at converting my carbon clincher wheels to tubeless. Some worries about this: tubeless tyres cost a bloody fortune, concerns about mounting, concerns about sealing, but curiousity won out.

Ultremo tyres are a favourite and hosts Starbike are offering the Ultremo Tubeless kit for €75.90, a discounted price because I think the Ultremo tubeless has been discontinued in favour of the Schwalbe One. With €15 of carriage and then another £27 in my LBS for Stans’ tape and valves the outlay was about £108. Ouch. This had better work.

The Ultremo kit contains two 23mm ZX tyres plus sealant fluid plus easy mount fluid. Here’s a tyre, quite weighty at 290-300g ish. The bead is rather pronounced.
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Here are the fluids. I had decided I would definitely be using the sealant.
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The Gigantex 20mm rim is narrow and not advertised as tubeless ready. It has a profile like an Open Pro.
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Now with two layers of Stan’s tape. I’d wondered how 21mm tape would fit into a rim that externally is 20mm wide. The tape is thin and quite rigid, you have to wiggle it side to side under tension to make it sit into the rim. It does fit, completely filling the rim well.
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Next, poke a hole through the tape at the valve hole and insert the valve. It was immediately obvious that there was not much space either side of the valve base for the tyre beads. This was an accurate assessment and to get the beads to sit into the rim I had to loosen the valve and let it slide up, then once the tyre was fitted, press hard from the outside and screw up the collar to hold the valve in place.
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Getting the tyre on was a struggle though not worse than other tight tyres I’ve come across. The easy mount fluid wiped along the beads was a big help. Before completely fitting the second bead I poured in about 30ml of Doc Blue at the side of the tyre then rotated it into the already seated tyre area. I did use a tyre lever to get the last section of bead across the rim.

Then the big moment, could I inflate the tyre? I attached the track pump and pumped furiously. Air hissed out at the valve. Damn. I tightened the valve collar more and shook the wheel to make sure the interior was coated with sealant, then tried again. Suddenly the indicated pressure was climbing! I whacked it up to 120psi. Some sealant leaked at the valve then... silence.
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For the second wheel I trimmed the base of the valve slightly in the hope it would be easier to seat the tyre. This did seem to help. On a wider rim this would not be an issue.
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The second wheel went up to pressure straight away. One thing though, it is sensitive to the force of the valve head on the valve, any movement here can provoke air loss. However an hour later both tyres are sitting silently at full pressure.

The inflated Ultremo tubeless runs out at a narrow 21mm width on these rims despite being nominally a 23mm. The tyre plus tape plus valve plus sealant adds 330g to the weight of the wheel. If it ever stops raining in Southern England I’ll take the bike out for a ride and see what the ride quality is like. So check back here in about May?
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by Weenie


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FIJIGabe
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by FIJIGabe

Welcome to the tubeless club! Great writeup, by the way. A couple of things I do differently, which may help you when you eventually have to mount a new tire on there:

Sealant: the Doc Blue is actually just Stan's sealant. There are better products out there, and in my experience, Stans does a good job on mountain bikes, but isn't very good at patching anything more than a pinhole in road tires. Instead, what I do is a buy a bottle of Slime (green, thick, nasty stuff), and dilute it (2/1 Stans/Slime). The beauty of Slime is that it actually has thick particles, which Stans doesn't have. This has saved me on road rides. Of course, once you are done with your ride, you should check the tire and patch it (with a normal tube patch kit).

Mounting: your wheels are about as wide as my old Reynolds, which means to say, they're narrow. This makes mounting the tires a bitch! Now, one thing I learned to do was to put the sealant in the tire, mount the tire, completely, then spin the wheel, while rotating my hands (picture it like you have one hand on each pedal, and are spinning the crank with both hands). This will get the sealant to coat the entire width of the tire.

Inflating: if at first you don't succeed, bust out a CO2 cartridge, and try, try again. Tubeless needs one strong blast of air (high volume, not necessarily high pressure). Some compressors will do that, others won't. However, if everything is properly mounted, a CO2 cartridge will save the day, if all else fails.

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Miller
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by Miller

Thanks for the tips, I'll bear them in mind. Just keen at the moment to know what the ride quality is going to be.

mattr
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by mattr

FIJIGabe wrote:The beauty of Slime is that it actually has thick particles, which Stans doesn't have.
Which stans fluid are you getting? The stuff I have is fairly full of latex particles. To the point it won't pour unless it's well shaken first.

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FIJIGabe
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by FIJIGabe

There's only one very of Stan's available at the moment. I usually just buy the large bottle, since I have so many tires to fill. You are correct, Stan's has quite a bit of particulate in it, but they are small particles, not large, like Slime. I don't like using Slime, which is why I dilute it, but the larger particles help with sealing.

Geoff
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by Geoff

Interesting. I have been running a tubeless test, but with tubeless-ready rims. I will be very interested in your results.

gravity
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by gravity

That is a one nice rim! Carbon weave looks A. Where did you get those?

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FIJIGabe
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by FIJIGabe

"Tubeless ready" wheelsets are a misnomer. Almost all clincher wheelsets can run tubeless tires, and utilize the full benefits of the tires (the exception is Mavic, which I have read has some odd clincher mating surface that, although it lets you inflate the tubeless tire, does not securely hold it in place, and can't prevent the tire from rolling off the rim in case of a flat). Case in point, I'm running tubeless tires on Zipp 303's and Reynolds 66's, and previously ran them on my Reynolds DV3K's.

To convert a wheelset, you need to seal, not just cover, the spoke holes. This is done by running a tubeless-specific tape, like Stan's, over the rim bed, not once, but twice (two revolutions of the wheel). With wider rims, like the 303's, you will need to use the 25mm "mountain bike" tape, which is just a wider version of the standard 21mm (not thicker). Once that is done, your wheels have been converted.

Last thing: be careful of your sealant and annodized rims. Some sealants (like Stan's) may contain ammonia, which will eat away at the aluminum surface of the rim. So far, I haven't seen any effect on the carbon epoxy, but I am keeping an eye out for that.

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Miller
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by Miller

gravity wrote:That is a one nice rim! Carbon weave looks A. Where did you get those?


Someone was selling them on this forum? Sorry, not a helpful answer for you. They are Gigantex and I am sure it won't be difficult to get something similar from the Far East. Many tips on how to do that on other threads in this forum.

pushstart
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by pushstart

FIJIGabe wrote:There's only one very of Stan's available at the moment. I usually just buy the large bottle, since I have so many tires to fill. You are correct, Stan's has quite a bit of particulate in it, but they are small particles, not large, like Slime. I don't like using Slime, which is why I dilute it, but the larger particles help with sealing.


This is good to know! One of my big disappointments with road tubeless was the sealant (Stans) unable to seal holes in the tire above 50psi. (The other disappointment was Hutchinson tires.) I will try this technique next time I give tubeless a try; I also plan to get a set of Schwalbe Ultremo or One tires. I so wanted to love tubeless on road as I do on MTB and CX.

Geoff
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by Geoff

While I get your point about conversions, the factory tubeless-ready rims may be a great many things (heavy, non-aero, expensive, etc.), but a misnomer is certainly not one of them.

I am told (by an engineer at one of the 'big factory' manufacturers - who admittedly had nothing to do with the design of the tubeless rim bead itself, but the manufacturing process) that the design of the tubeless rim bead is quite different than the conventional clincher offering. In any event, from a consumer perspective, with the tubeless-ready rims, it is a simple process to get on the road with tubeless. Simply install the valve and tire tubeless tire, throw-in some sealant, inflate and go.

I don't know about this whole tubeless thing yet. Are they better than clinchers? So far, I would say definitely, but that might not be saying too much. I don't mind the feel, but they corner like pigs. That must be down to the stiff sidewalls. Anyway, I am very interested in seeing how you guys get on with the conversion of carbon clinchers to tubeless after a few seasons. The idea of having deep tubeless as training wheels is interesting.

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FIJIGabe
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by FIJIGabe

Well, let's take a look. Stans, probably the leader in tubeless technology, still requires the use of tape to seal their wheels. Very few rims (tubeless ready and not) actually have sealed rim beds. Most wheels, Stans, Bontrager, etc, require that you use tape or a liner to effectively seal the rims from leaking. Now, many manufacturers are coming out with sealed beds (Easton comes to mind), but it isn't necessarily the case that tubeless-ready comes sealed, as you think.

Regarding the rim bead, there MAY be a difference (I haven't analyzed the shape, but will need more proof than "a friend of a guy on an internet board", sorry). However, that being said, I challenge you to remove a properly mounted tubeless tire from a "standard" clincher rim bed, using only one tire lever. The point it, tubeless tires on clincher rims seal on most wheels, just like on tubeless wheels (again, Mavic is the exception). I think the prime example is Shimano wheels, wherein the difference lies in the rim surface coating.

Finally, I've been riding tubeless clinchers for over two years. My first set of wheels (Reynolds DV3K's - 46mm) were very much up to the task. I converted my Zipps in October/November, once I got them. No issues with mounting the tires, and they aare ctually better than on the narrower rims. That being said, the Hutchinson tires aren't the most comfortable. However, the "stiff sidewalls" are a thing of the past. I currently run Fusion 3, which resolves the stiffness issue, and the Bontrager R3 TLR tires are supposed to be excellent in that respect. I will probably go that route sometime later this year, once my tubeless tire stock runs out. BTW, I run my tires 85/90 on my road bike and 100/100 on the TT bike (Reynolds 66 w/ Hutchinson Atom Galaktics).

VeloPixie
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by VeloPixie

Interesting thread, has anyone got any experience of converting Reynolds 32 clincher rims to tubeless or can anyone envisage any problems with converting them?

mattr
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by mattr

FIJIGabe wrote:Regarding the rim bead, there MAY be a difference (I haven't analyzed the shape, but will need more proof than "a friend of a guy on an internet board", sorry). However, that being said, I challenge you to remove a properly mounted tubeless tire from a "standard" clincher rim bed, using only one tire lever. The point it, tubeless tires on clincher rims seal on most wheels, just like on tubeless wheels (again, Mavic is the exception). I think the prime example is Shimano wheels, wherein the difference lies in the rim surface coating
if you go to the manufacturers websites and find the drawings you will see a significant difference between the profiles of tubeless ready (stans etc), UST and normal rims.
The difference is most readily noticeable when you let the tyres down, a UST will require a firm wiggle to disengage the tyre as it has a designed in locking feature, a stans type rim will merely require a bit of finger pressure as it's less of a locking feature and more of a tyre retaining feature, a converted conventional rim you will usually see the tyre just fall away from the bead. (This is all dependant on exactly which tyre you have fitted, and how you've set it up and which conversion you've done!)

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FIJIGabe
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by FIJIGabe

VeloPixie wrote:Interesting thread, has anyone got any experience of converting Reynolds 32 clincher rims to tubeless or can anyone envisage any problems with converting them?


32's, 46's, 66's, Assaults, etc., will mount the same. See the instructions above.

by Weenie


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