Advice for going tubeless on 2018 Scalpel SI with carbon wheels- Mtbr.com
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  1. #1
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    Advice for going tubeless on 2018 Scalpel SI with carbon wheels

    I have a 2018 Scalpel SI Carbon 2 bike which I purchased last year. Been getting lots of flats and tired of constantly replacing tubes on the trail, so thinking about going tubeless.

    The wheels are "Cannondale C-Zero, Superlight Hi-Impact Carbon, Tubeless Ready, 28hole, 23mm inner". Does tubeless ready mean I don't need new rim tape? Or if I need to purchase new rim tape, I presume I'll have to remove the old one?
    My stock tires are getting worn, so I'm gonna replace those with some tubeless capable tires.

    Has anyone here done the tubeless conversion with these wheels? Any advice?
    Last edited by howardv; 06-15-2019 at 05:05 PM.

  2. #2
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    Just install valves and you are good to go. Your current tires are also tubeless compatible.

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    Quote Originally Posted by TurboKoo View Post
    Just install valves and you are good to go. Your current tires are also tubeless compatible.
    Awesome! Thank you!

  4. #4
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    Yeah but the rims will need a sealing tape applied. Not all the 2018 models shipped with the spoke bed sealed.
    Just get a NoTubes Tubeless conversion kit and have it fitted by your local bike shop if you don't know how. The tyres were tubeless ready so that shouldn't be a problem but if they need replacing then opt for the Pirelli Scorpion H or M. I hav no idea where you're situated so the hard terrain or mixed terrain tyres are safe bets

  5. #5
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    Thanks Brad. I've decided to wait and see what my local bike shop has to offer on their annual 4th of July sale. If the right deal comes along, I may just dump my Scalpel and get a new bike. If not, then I'll proceed with the tubeless conversion. And I'd like to learn and do it myself.

    Thanks for the advice!

  6. #6
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    Recently set up my Scalpel-Si tubeless with Schwalbe Thunder Burt tires, Stan's yellow rim tape, Stan's tubeless valves, and Stan's sealant. Excellent results, very pleased with performance. Also did three sets of tubeless tire setups for others this week. Tried and true method is important, have seen several tubeless setup attempts fail immediately or on first trail ride.
    Remove any stock rim tape, clean rim well with isopropyl alcohol, install Stan's yellow rim tape stretching tightly and pressing firmly down center as you go, twice around the rim with a few inches overlap, carefully pierce tape through valve hole and insert tubeless valve. Install first side bead, then second side leave bead unseated a few inches. Be aware high quality tubeless ready tires are often a very tight fit at the bead requiring careful full strength levering to install. With just a few inches of bead still unseated, pour in well shaken liquid sealant - recommended amount or a little more - then complete seating bead. Slosh and spin wheel to distribute sealant inside. Fill with enough air to just get bead seated onto rim both sides - compressor highly recommended - then spin and slosh tire to distribute the sealant well around the inside of tire. Then fully pressurize 60-80psi mtb, 80-100psi road bike - should hear bead POP onto rim fully (not for the nervous). Spin, slosh, and bounce tire on hard surface several times around its circumference to fully distribute sealant and seat bead. Inspect bead 360 degrees both sides that bead is correctly seated. Reduce pressure to correct riding psi and ride tubeless!

  7. #7
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    Quote Originally Posted by Cannosseur View Post
    Recently set up my Scalpel-Si tubeless with Schwalbe Thunder Burt tires, Stan's yellow rim tape, Stan's tubeless valves, and Stan's sealant. Excellent results, very pleased with performance. Also did three sets of tubeless tire setups for others this week. Tried and true method is important, have seen several tubeless setup attempts fail immediately or on first trail ride.
    Remove any stock rim tape, clean rim well with isopropyl alcohol, install Stan's yellow rim tape stretching tightly and pressing firmly down center as you go, twice around the rim with a few inches overlap, carefully pierce tape through valve hole and insert tubeless valve. Install first side bead, then second side leave bead unseated a few inches. Be aware high quality tubeless ready tires are often a very tight fit at the bead requiring careful full strength levering to install. With just a few inches of bead still unseated, pour in well shaken liquid sealant - recommended amount or a little more - then complete seating bead. Slosh and spin wheel to distribute sealant inside. Fill with enough air to just get bead seated onto rim both sides - compressor highly recommended - then spin and slosh tire to distribute the sealant well around the inside of tire. Then fully pressurize 60-80psi mtb, 80-100psi road bike - should hear bead POP onto rim fully (not for the nervous). Spin, slosh, and bounce tire on hard surface several times around its circumference to fully distribute sealant and seat bead. Inspect bead 360 degrees both sides that bead is correctly seated. Reduce pressure to correct riding psi and ride tubeless!

    after installing the tubeless rim tape i'd fist t]make a coffee, while brewing install a tube and tyre and inflate to 50psi and leave overnight for the rimtape to seat without any edges lifted. The rim tape stays down much much longer this way and therefore isn't affected by ammonia based sealants

  8. #8
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    True, if you have the luxury of extra time and labor, bedding in the rim tape with pressurized tube and tire can help improve the seal, but if you clean well with alcohol first and install the tape firmly and tightly, centered nicely in the rim, you should have no problems with "No Tubes".

  9. #9
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    the adhesive backing needs time to cure as its urethane based. If you get sealant under any little spot that has not yet stuck down properly, that area will lift and the lift will run further under the tape till it creates a leak. Applying constant pressure to the tape till the adhesive backing cures properly is necessary if you want a long lasting reliable rimtape.

    Ah the other step I add is once the tape is stuck down and I've refited the tyre tubeless with sealant added, I inflate the tyre back up to 50psi and check for proper sealing of the bead and make sure the tyre is airtight using a mild solution of soapy water. I'll leave the tyre inflated check the pressure and record it. Come back an hour later and check again and repeat everyhour. By the time the owner/customer comes to collect the wheel(s), i've got a few hours of pressure records. If it's lost more than 2psi in an 8hour period then somethings wrong. Often it's just required to be ridden and then settles. Mostly I find that its a leak at the valve stem or core or the tyre has a slight ridge on the bead due to the way they're folded when being packed at the factory. Ideally one should inspect the tyre and rim before starting the conversion process to make sure theres no latent defects that going to undo all your hard work.

    Anyway this is more for the benefit of @howardv since he wants to attempt the conversion himself.

    PS: take note of the maximum pressure the rim is rated to. Some hookless rims don't allow the tyre to be pressurised to more than 40psi so when seating the rim tape take this into account

  10. #10
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    Quote Originally Posted by howardv View Post
    Thanks Brad. I've decided to wait and see what my local bike shop has to offer on their annual 4th of July sale. If the right deal comes along, I may just dump my Scalpel and get a new bike. If not, then I'll proceed with the tubeless conversion. And I'd like to learn and do it myself.

    Thanks for the advice!
    but have you checked if they are already fitted with tubeless tape?

    mine were

  11. #11
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    Just to keep this thread updated:

    Over the weekend, I went tubeless! If anyone has the same bike (link in original post above), you do not need any tape. The install was very simple and straight forward. Actually, couldn't believe it was this easy!

    My bike was one year old and I needed new tires. Bought Onza Ibex tires (tubeless ready), Stan's 44mm stems, and Stan's regular sealant. Didn't use any other tape - just the ones that were already installed on the wheels from factory. Installed new tire, poured in sealant, and was ready to go.

    To note, could not seat at first with a regular pump. Had to use CO2 inflator to seat tires. Then I used a pump after it was seated.

    So far, holding air. Thanks for all the help and suggestions! Can't wait to go on my first trail ride today or tomorrow.

  12. #12
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    if you used the CO2 inflator with sealant in the tires there is a good chance it froze the sealant and it is now just sitting in one lump in the tire..

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    Quote Originally Posted by howardv View Post
    Just to keep this thread updated:

    Over the weekend, I went tubeless! If anyone has the same bike (link in original post above), you do not need any tape. The install was very simple and straight forward. Actually, couldn't believe it was this easy!

    My bike was one year old and I needed new tires. Bought Onza Ibex tires (tubeless ready), Stan's 44mm stems, and Stan's regular sealant. Didn't use any other tape - just the ones that were already installed on the wheels from factory. Installed new tire, poured in sealant, and was ready to go.

    To note, could not seat at first with a regular pump. Had to use CO2 inflator to seat tires. Then I used a pump after it was seated.

    So far, holding air. Thanks for all the help and suggestions! Can't wait to go on my first trail ride today or tomorrow.
    Congrats! Now join the mafia and tell all of your friends that mountain bikes should be tubeless! I rode road bikes for years and I can't believe they even still sell bikes with tubes.

  14. #14
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    Quote Originally Posted by guidodg View Post
    if you used the CO2 inflator with sealant in the tires there is a good chance it froze the sealant and it is now just sitting in one lump in the tire..
    Oh no! On one wheel, I can still hear the fluid sloshing around but not on the other. Is that what happened? So I can still get a flat with a thorn from a plant? Is there a fix for this? Should I inject more sealant through the stem?

    Was really looking forward to not having to carry a spare tube with the tools going forward.

  15. #15
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    just add some more fluid....50-60ml will do

    You will still have to carry a tube and a pump though especially in more remote areas...if you cut your tire the sealant will do very little

  16. #16
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    Quote Originally Posted by guidodg View Post
    just add some more fluid....50-60ml will do

    You will still have to carry a tube and a pump though especially in more remote areas...if you cut your tire the sealant will do very little
    Oh it gets better! I took my bike out for a ride and found I'd contaminated my rotors with sealant (just the rear)....which has now also contaminated my pads. Had to come back after one block of riding. Frustrated, I went for a ride on my road bike. Will take everything apart again tomorrow. My tires are brand new, so I'll just remove it and see what it looks like inside.

    Then I'll make a new thread warning newbies of "what NOT to do when going tubeless".

  17. #17
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    no need to take everything apart...if they are holding air just add another 50ml and go ride....

    a bit of rubbing alcohol to clean rotors and pads and you are good to go

  18. #18
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    They're holding air fine. Just worried about the blotches of dried up sealant throwing off the balance. So I may take the tires off to check. In one tire, I can hear the sealant splashing around, so I won't remove that one. And I 'm gonna clean the rotor with alcohol and sand the pads a bit.

    One thing that concerned me was that the handling of the front seemed way off. Not sure if it's because of the sealant or this is how the new tire feels. It was a short one block ride, so I need to test further. The steering felt materially different.

  19. #19
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    the sealant will have no effect on handling....are these new tires that you have never used before?

    just a question,,,,you fitted Onza Ibex tires which according to what I found are 2.4 tires for Enduro/DH...not really a great choice for a Scalpel esp on the rear in my opinion...super heavy and quite wide and not ideal on a 23mm internal width rim

  20. #20
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    Glad to hear sealant shouldn't have any effect. This is the first time I'm using this kind of tire, so I'm probably not used to it. And I still need to see how it feels on dirt.

    These are 29x2.25 - same size as the previous factory tires.

  21. #21
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    Ibex on the front will feel squirrelly, especially on grass

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