Sat at home licking my wounds after an unplanned off on my commute into London this morning.. Was about 12 miles in and giving it some beans down a nice smooth wide road when I entered a roundabout at 20mph ish. Carved nicely left and then as I leaned it over to the right there was an almighty bang and the next thing I know I am sliding along the tarmac… Thankfully no cars were close so I picked myself and looked at my bike to see the rear tyre tangled in the frame and stans jizz all over the place!

Limped to the side of the road and range the wife to come and pick me up. Skinned my right arse cheek, elbow and ankle and tore a large hole in my Assos bibs which is annoying.

Unsure what went wrong – the tyres (Vittoria 40mm jobbies on Stans rims) don’t hold their pressure over a week or so, but I’d inflated them to 60 psi before I sent off (they’d dropped to 25 ish after a week) – wonder if maybe it wasn’t seated properly and my extreme G force cornering technique was too gnar?

Will console myself with some online bib short shopping and mull over whether to go back to tubes…

Tubeless tyres or just the rims? I suspect the side loads deprssurised the tyre. Hope you heal fast.

Tegaderm for road rash, scrub it hard to get the dirt out in a hot shower, then apply. Amazon is a good supply. Buy large! Not cheap, but the best there is.

stans jizz all over the place

Olly feels your pain.

Stans rims

+

Vittoria 40mm

+

60 psi

Set alarm bells off for me…

Which rims exactly? (EDIT – I am sure now I’ve checked) Stans rims have some fairly low max pressures when running tubeless tyres due to possibilities of tyres blowing off under high load…which is doubly worrying with your comments about them not holding pressure as maybe the bead isn’t seated/sealing that well with your chosen combo.

FWIW with tyres that big 60psi is waaaaay too high anyway.

Oh dear. Another anecdote that makes me less keen to go road tubeless, and yet I’m still curious! I think at higher pressures (60psi is sort of in-betweeny) there is a chance of the bead coming over the rim, sort of the opposite of burping.

If they were going down to 25psi over a week I doubt they’d be at the point of falling off through burp.

Which Stan’s rims? If they’re 29er rims, they won’t hold a tubeless pressure above 50psi without exploding off the rim. I know this from painful experience with Crest rims.

Which rims exactly? I’m pretty sure Stans rims have some fairly low max pressures when running tubeless tyres due to possibilities of tyres blowing off under high load…

I agree with this, I think it’s 3 bar on my Mavic rims – I’m fairly certain this is to stop the tyre blowing off rather than for rim strength against pressure (as otherwise a smaller tyre could run far higher pressures without an issue)

road biking…40mm trye width….60 psi….

does not compute! 😀

philjunior – Member
Oh dear. Another anecdote that makes me less keen to go road tubeless, and yet I’m still curious! I think at higher pressures (60psi is sort of in-betweeny) there is a chance of the bead coming over the rim, sort of the opposite of burping.

I’ve been using road tubeless at pressures ranging from 50-90psi for over 2 years without incident even when the rims aren’t strictly tubeless rims (i.e Archetype, SL42, Pacenti SL25, Nextie Carbon, etc…)

I always try to avoid jizz and jobbies on my commute but I know londoners are a bit crazy.

Could have been a lot worse, hope you heal quickly

I’ve been using road tubeless at pressures ranging from 50-90psi for over 2 years without incident even when the rims aren’t strictly tubeless rims (i.e Archetype, SL42, Pacenti SL25, Nextie Carbon, etc…)

I’m sure it’s possible, but there’s a risk. I think I’ll probably stick with Mavic if I go down the tubeless route on the commuter.

It was on my GT Grade so they’re Stan’s Grail road rims – rated up to 115psi and the tyres are rated at 70psi max so well within tolerance. The tyres are quite loose on – I can get them on easily by hand, so maybe I need tighter bead tyres if I want to go tubeless?

Stan’s Grail road rims – rated up to 115psi

Key words being ‘up to’, it’s tyre size dependant.

Max Pressure with 23mm Tire: 116psi
Max Pressure with 28mm Tire: 100psi
Max Pressure with 32mm Tire: 45psi

therefore…
Max Pressure with ~40mm Tire: probably less

from here

tyres are rated at 70psi max so well within tolerance

That’s almost irrelevant in this case, that’s the max pressure for the tyre, but that’s not taking the rim into account.

Well that’ll teach me not to RTFM… Thanks for showing me that – feel an even bigger t*t no!

I suspect the tyres aren’t tubeless either – tubeless tyres have reinforced beads and sidewalls to cope with the additional stresses

A combination of loose tyres and way too high pressure, I’d say. I run my 28mm Schwalbe ones at 90psi on Grails and never had any issues.

In reality I reckon you’ll be OK with ~40ish psi with big tyres, but it can be very dependant on the fit and how well the bead seats Vs how baggy/stretchy the tyres are.

The point still stands though, 60psi for tyres that big seems awfully high even if the rims can take it (or you were using tubes).

Hope your injuries heal up quick, it’s the ones that catch you off guard like that that really hurt 🙁

Just checked and the tyres are Vittoria Voyager Hyper 700 x 35 (funny how I know every detail about my MTB but sod all about my other bike!) so I guess I could probably run them at 40ish? My commute is 25 miles each way half of which is along the grand union canal so I prefer fatter tyres.

Should I look to change them for something better suited to the Grail rims? Any tips?

road biking…40mm trye width….60 psi….

does not compute!

oldtalent – Member
road biking…40mm trye width….60 psi….

does not compute!

yes, the benefits of hindsight!

Any tips?

Try tubeless tyres for running tubeless

Get well soon Hugh, best of luck

Haze – Member
Any tips?
Try tubeless tyres for running tubeless

Maybe a good place to start! I read about loads of people using these tyres tubeless so (foolishly) assumed they’d be OK! They were cheap as chips at On One so no loss (injuries aside)… Buy cheap, buy twice never rung truer!

Aye, never mix your jizz with your jobbies.

These are only 32mm but I think they could be a sensible option? Any alternatives?

https://www.sigmasport.co.uk/item/Bontrager/AW2-Hard-Case-Lite-TLR-Tubeless-Ready-Clincher-Tyre/D8QZ

or these at 30mm

https://www.sigmasport.co.uk/item/Mavic/Yksion-Elite-Allroad-Tyre/9P5N

commute into London this morning

That was the first in a series of bad things happening.

funkmasterp – Member
commute into London this morning
That was the first in a series of bad things happening.

LOL – I only do it once a week as it’s 25 miles and takes up too much valuable MTB time otherwise. The first 12 miles is through the ‘burbs and then there’s 11 miles along the Grand Union Canal and then a mile from Paddington to the office so it’s quite a nice run as a rule. Today’s off happened about 11 miles in and looks horribly like it was totally my fault for fitting non Tubeless Ready Tyres and over inflating them too!

FWIW with tyres that big 60psi is waaaaay too high anyway.

Depends on rider weight. At 230 pounds and assuming 60% of weight on the rear wheel this chart suggests around 68psi for a 700×37. 60psi would be around the right place for me on a rear 700×40.

https://janheine.wordpress.com/2016/03/09/tire-pressure-take-home/

I’m 75kgs so 170lbs ish and they turned out to be 40mm tyres but as stated above, NOT officially tubeless ready although a lot of people claim to run them tubeless without issue.

I can’t afford to risk it again so will buy some with a big fat TLR sticker on the side.

Try some tubeless ready Schwalbe G One speeds. Not the cheapest, but very good on the road, and I’d happily ride them on a canal towpath. The wider G Ones are even better, but not as fast on the road. Just be sure than any tyres you do mount are tubeless.

I ride wire beaded CX Pros tubeless at 25 PSI, but these are on a cross bike. On mud. On Stans Crests. For road use, it’s tubeless tyres. Always.

As said upthread – watch out for the max rim pressure. Stans quote a max 45psi for some if not all their rims with wider than 32mm tyres. . fitted So either tubed or 45psi max with wider than 32mm?

The broader pressure range of our BST-R Series rims and wheelsets means they’re optimized for tubeless use with tires in the 32mm to 50mm range at pressures of 45psi or lower, as well as 25mm to 32mm tires specifically designated as “tubeless” that feature reinforced beads designed for pressures up to 115psi. Both BST and BST-R rims and wheelsets may be used with tubes.

https://www.notubes.com/crest-mk3-rims

Why is it that Stan’s, the archetype of tubeless in the mainstream, have such utterly woeful prsssures for 32mm tyres? To me, it sounds like a design clock up covered with a safety sticker.

Why is it that Stan’s, the archetype of tubeless in the mainstream, have such utterly woeful prsssures for 32mm tyres? To me, it sounds like a design clock up covered with a safety sticker.

See my edit. Decent/high pressures for up to 32mm wide tyres. Wider than 32mm tyres max 45psi.

That link is still 40 psi. Nothing in the Stans rims catalogue allows for tubeless, 32mm or greater and more than 40psi… that’s pretty rubbish

I’ve had Pacenti SL25, Archetype, Nettie carbon 29er and SL42s all running 32mm or more tyres including 37mm Hypers at 60 psi for over 2 years.

I run those tyres at 45 psi with tubes.

I run schwalbe g-one speeds at about 45psi on iron Ross rims with no issues and are fantastic for road and a bit of farm track / fire road

I’m using Specialized Sawtooth 42mm on Specialized rims at around 50psi tubeless but if I know I’m sticking to the road I’ll up to to 60-odd. No problems at all.
I’ve seen these low pressure recommendations for Stan’s rims before and found it a bit odd. If I was buying the rims I’d use Mavic every time. Their 419 rim is/was fantastic. I did many many miles on those set up tubeless with Marathon Plusses at 60-70 psi no problem at all. They come with a really good tubeless rim strip.

As I am clearly ignorant on all things gravel/road, would I be ‘safer’ to just fit some tubes in these tyres and run them at circa 45psi or change them for some proper 700×32 Tubless Ready tyres and run these tubeless at 45psi?

I’m inclined to just spend a tenner on a couple of tubes given that I only use the bike for ad hoc commuting but don’t want to risk this happening again?

Schwalbe 40mm GOnes.
100kg rider plus laptop and change of clothes in panniers
20 mile commute

Stans Flow 29er at 50psi on the front – emailed Stans and they were fine with that

Hope 20Five on the rear at 90psi – again Hope ok with that.

Tyre pressure depends on weight (!) and some of us are heavy.