This month, hookless rims have come under intense scrutiny as a result of Thomas De Gendt's blow out on stage 5 of the UAE Tour. 

There are articles and videos popping up hourly, on top of a huge history of Hooked vs Hookless debates on forums and the usual places online.

LOWMASS' advice and view on the use of hookless rims and tyres for cycling is as follows;

Hookless rims and tyres are well suited to off-road applications where the tyre is significantly wider than the rim, and the tyre pressure used is significantly lower than the maximum standard for hookless rim/tyre systems (73psi). 

We only offer MTB, Gravel and CX hookless wheelsets, and we continue to be confident in their use off-road with hookless compatible tyres which meet the minimum tyre size stated. 

Our carbon road wheelset is purposely specified with hooked rims. 

Should you use your LOWMASS hookless off-road wheelset with road hookless tyres, you must observe the minimum tyre size, and maximum psi specifications, and use hookless compatible tyres (*LOWMASS hookless MTB wheelsets are compatible with all MTB tubeless tyres)

Until further notice, LOWMASS do not recommend the use of cotton / poly-cotton carcass / hand made road tyres with hookless rims.

The manufacturing variations and stretching that we have seen with hand made CX and gravel tyres have not caused any safety issues with our off-road hookless rims (observing the miniumum tyre size and maximum psi). However, we assume that hand made road tyres have similar dimensional variations and stretching to hand made CX and gravel models, and suspect that this may be a factor in the current safety concerns related to road hookless rim/tyre use.  

LOWMASS hookless rim model = minimum tyre size

SL-CX = 25mm 
GC26-370 = 32mm
SL-GR = 32mm 
*Carbon XC Race MTB = 2.25"
*SL-XC = 2.25"