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since i'm mostly going to be riding xc this year, i switched out my minion/high-roller combo for racing-ray/racing-ralph - and i've been very happy with the massively reduced rolling resistance and largely satisfied with traction
...but...
the last couple of rides the racing-ralph (on the back) has burped significant quantities of air
yesterday it lost so much over a short rooty section that i had to stop and pump it up - it really broke my flow
maybe relevant detail: there's about 90kg of me, and i'm on 27.5"x30mm rims. i've got the addix-speed/evo/super-ground version of the racing ralph, and i've been running about 40psi
is there anything to be done about this, or should i move on and try a different rear tyre ?
What width? 40PSI seems rather high, you must bounce all over the place.
For the last 12 months I've been running Ralph Addix Speed 29 x 2.1 at the rear on 25mm internal, 25psi, tubeless, 85Kg kitted up, never had a burp.
ralph full spec is: 27.5 x 2.25, addix speed, evo, super ground
i chose 40psi because it was bang in the middle of the 26<->54psi range schwalbe give in the ralph specs
there is no noticeable bounce (although there was some pretty horrible squirming and noise when it was actually burping) and handling has been fine - no traction issues or other weirdness
i've got a matching racing ray on the front, 27.5x2.25 (addix speedgrip, evo super ground) and same 40psi pressure, but haven't had any burping at all there
40 psi is wayyyyyyy too high. Pop your details and riding style into here and it'll give you a better indication of what pressures you need to be running - https://www.schwalbe.com/en/pressureprof
Amazing tyres btw. I run the Racing Ray / Ralph combo on my backup XC bike but am even thinking of getting some for my Transition Spur this summer as the Ray grips way above its paygrade.
Perhaps a section the rear rim is slightly bent, allowing some momentary detach/reattachment of the bead?
ah, thanks @devash , pressureprof is recommending 2.2bar/32psi for me
although if i switch:
terrain:mixed -> terrain:rocky (reasonable)
style:trail -> style:cc (reasonable)
ability:intermediate -> ability:pro (lol)
it goes back up to 2.7/bar/39psi
anyway, sounds as if i should try a lower pressure
and these tyres are on my canyon spectral trail bike - (apart from the burping) it's all the fun of a squishy bike with the rolling resistance of an xc bike
Perhaps a section the rear rim is slightly bent, allowing some momentary detach/reattachment of the bead?
hmm ... could be @jacobyte - worth a look
Is it loosing any pressure while it's sitting in the shed? That might also suggest you need to check if the bead is properly seated. I'd only expect it to be burping with lots of sideways stress, not in normal running.
not losing any more pressure than i would expect in the shed @susepic - the burping was very noisy and very obvious yesterday, while hooning it over a load of roots
reduced my pressures down to 30psi, and had no burpage on a 40km ride last night, so 🤞 it's sorted
that reducing pressures can prevent burping breaks my mental model of tyres though 🤯 - i previously thought increasing pressures would always lead to less burping 🤔