Tubeless conversion disaster

Thanks both for replying.

There is sealant in the rim. I put the tape on the same for both wheels so that’s odd…

I’m trying to establish if the wheel is faulty or user error

80 psi seems high for tubeless tyres. What’s the max limit on the tyre?

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80psi would be high for riding it. But the Schwalbe Pro One as well as the Flo wheels (they are hooked?!) should easily survive being pumped up to 80PSI!

OP: Can you maybe specify which wheels and which tires (width) you used? Are you sure that your pump / compressor shows the right pressure?


Flo 60 carbon
Schwalbe pro one with max psi of 110
Yes they are hooked

Width of tyres 25

80psi should have been absolutely no problem for that combo. (See Tubeless on FloCycling Wheels & Flo website)

Were the wheels new or used? If used there might have been previous damage. If new: Contact Flo. If the pressure was just 80psi it’s probably a manufacturing fault.



I bought them in 2017 and have been running with a tube set up. Just now tried to convert to tubeless.

I guess they could of been damaged by my use.

It is reasonably possible that the wheel itself had some damage from use with the standard tyres, that you were totally unaware of (inside crack or something similar) and then when you pumped up using the tubeless the damage was a ‘weak spot’ that led to the failure.

The inner tube taking the majority of the pressure previously may have been why the wheel didn’t fail until now; at which point having the ‘direct’ pressure was unfortunately enough to create the failure.

Perhaps you were fortunate it happened now while just pressurising the tyres rather than at 20mp on a downhill. :open_mouth:

Likely to be something you would have had no chance of spotting visually beforehand with an inspection so will be hard to identify what the actual ‘cause’ was. Do you recall ever having a back ‘knock’ on that wheel at any point?

I think the manufacturer may well take that stance as you have had the wheels a fair while now, but no harm in asking them to see what they say.

Good luck :+1:t2:


Thanks all for your sage advice

Did you have issues installing the tire and/or use tire levers?

Very difficult to get the tyres on. I used plastic tyre levers and the schwalbe mounting fluid. Strangely the back was hardest and that’s fine.

The front was easy but still a challenging

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At the risk of asking an incredibly stoopid and basic question…was a 2017 FLO carbon wheel designed to accommodate tubeless? I know they are now, but have no idea about a 2017 model…

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Not a silly question, but apparently yes. Flo confirmed before I started.

They have a hook on the rim too


Great news, Jon Thornham at Flo has offered me a new wheel.

However, the Flo 60 has been discontinued so it would be the new Flo 64 AS.

Does it work to have a new Flo 64 AS on the front and an older Flo 60 on the back? Is the size difference material and what about the different wheel type?


That is some good customer service…they would have been in their rights to say “sorry…out of warranty and not a warranty issue anyway”. Good for them!

Other than the visual, you’ll never notice the difference. Having a slightly deeper front may look at little odd, but will ride just fine.


Mixed wheels is fine if the mis-matched look doesn’t bother you, but it might be a good opportunity to just upgrade both wheels and send a little goodwill back at them. I’d bet they would make you a deal on the rear if you asked to get the matching pair.


Ditto. You are getting a replacement for a toasted wheel, which is “free” considering you were most likely headed down the road to buy a new one.

Toss the now unspent money in to complete the upgrade. :stuck_out_tongue:


That should not happen at 80psi. Francis Cade made a YouTube video testing tyres pressures before the rim pops and they were almost twice as you before something happened.

How would this be possible?? I’m not saying it couldn’t be but how would you not design a kind of bleed port into your rim if there was a possibility that you could start pumping air into your rim. If this is actually the case then this seems like an extreme oversight from an FMEA perspective.

Without looking at the damaged wheel in person, it’s hard to say exactly what happened in this particular case. The pics above look like the rim blew out.
Out of the 5 different wheelsets I’ve got banging around, only 2 have obvious pressure equalisation ports in the rim. The ports are only small anyway so it wouldn’t be too hard to have one seal up whilst trying to seat a stubborn tyre.
I suppose the others rely on air escaping past the valve (provided you haven’t sealed the outside with the o ring and some sealant).

IME with TL rims it’s quite common to have sealant leak into the rim where the valve is tightened against the rim tape/rim. Every valve seems to have a different design and some fit better than others.
The other area that can leak is where the tape covers the spoke access holes. Some TL rims don’t have these holes, or the need for tape of course, so that one’s rim dependant.