Weight Weenies

120psi is not a normal pressure these days. 80-90, maybe a touch higher is the normal range for common 23-25mm tires. 60-70 would be running 'lower pressures'.

Anyway, does tubeless really allow lower pressures? There still is some minimum pressure people will want to use to protect the rim and prevent bottoming out. I use 75/80psi and it really feels like the minimum on GP4000s (25mm). If I switched to the GP5000TL I don't see myself going any lower.

Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com

Even if you use the same pressure as a clincher it's like riding 10psi less because of the lack of tube.

Had a good one yesteday. During a long ride I hot something that damaged the rim cretaing a sharp notch which then damaged the tyre above the bead and also sliced the sidewall. The tyre was a rather old IRC (about 4 years old). The slice was fixed by teo maxalami 3.5mm plugs and the bead damage was fixed by a maxalami 1.5mm plug. it held 25 psi but I was carrying so much load in my panniers probably about 15 to 20kg) that the I was riding on the rims anyway. because the tyre remained seated I was able to ride the the bike to the nearest shop and buy a tyre. all they had though was a schwalbe lugano but it got me home. If I had not had the pannier I could have riden that the remainder of the way with a bit of care, although the rest of the way would have been 70 miles but I have gone further on about 25 psi before.

All the fears are simply lack of experience.

AJS914 wrote: ↑

Mon Jul 29, 2019 2:44 pm

120psi is not a normal pressure these days. 80-90, maybe a touch higher is the normal range for common 23-25mm tires. 60-70 would be running 'lower pressures'.

Anyway, does tubeless really allow lower pressures? There still is some minimum pressure people will want to use to protect the rim and prevent bottoming out. I use 75/80psi and it really feels like the minimum on GP4000s (25mm). If I switched to the GP5000TL I don't see myself going any lower.

I never went as low as 75psi on 25mm GP4000s because I got a load of pinch flats and the rolling resistance went up a couple of watts.

I was a bit bigger back then I suppose ‍♂️

I've only had one pinch flat @ 80psi rear over thousands of miles and that was a gigantic pothole. Still, I do think I'm at lower limit for my weight (195lbs).

AJS914 wrote: ↑

Mon Jul 29, 2019 2:44 pm

120psi is not a normal pressure these days. 80-90, maybe a touch higher is the normal range for common 23-25mm tires. 60-70 would be running 'lower pressures'.

Anyway, does tubeless really allow lower pressures? There still is some minimum pressure people will want to use to protect the rim and prevent bottoming out. I use 75/80psi and it really feels like the minimum on GP4000s (25mm). If I switched to the GP5000TL I don't see myself going any lower.

My use of them seems to show it. I’m running Vittoria corsa 2.0’s. 700x25 (probably closer to 27mm on 19mm ID rims however) and have settled on 70f/75r psi and I weigh 82kgs.

I still dont carry a spare tube. I puncture a lot. For PBP I will carry a spare tyre. If it goes pear shaped I will mount a new tyre and pour in some sealant. Infalte with CO2 and bingo away I go fairly quickly.

The problem with fitting tubes to tubeless tyres is you really got to make sure you get all the bits of sharp stuff out that you did not know about. Given you are more likely to punture whe its wet, that also when your more likely to make an error.

As for tubeless standards, they already exist. Schwalbe, IRc and hutchinson (conti and vittoria too I suppose) seem to follow them and many rims/wheels match. Its like they talked to each other. Most of the issue people find are self inflicated. take the wheel I rebuilt to today. the valve and tape were installed badly. I am surprised it held air.

I’ve only been on tubeless for a few months and this was my first experience. Last Saturday, I ran over a screw with a large head and it lodged in my rear tire. I stopped, gently pulled out the screw and watched in utter astonishment as the sealant closed the puncture within seconds. Yes, seconds. From stopping to riding off again must have been no more than 30 seconds. The tire continues to hold pressure as if nothing happened.

The details are: Schwalbe Pro One tire in 28mm, Orange Seal sealant, 62 psi pressure , Enve 4.5AR disc wheels

I’m never going back to tubes.

groover08 wrote: ↑

Tue Jul 30, 2019 2:46 am

I’ve only been on tubeless for a few months and this was my first experience. Last Saturday, I ran over a screw with a large head and it lodged in my rear tire. I stopped, gently pulled out the screw and watched in utter astonishment as the sealant closed the puncture within seconds. Yes, seconds. From stopping to riding off again must have been no more than 30 seconds. The tire continues to hold pressure as if nothing happened.

The details are: Schwalbe Pro One tire in 28mm, Orange Seal sealant, 62 psi pressure , Enve 4.5AR disc wheels

I’m never going back to tubes.

bm0p700f wrote: As for tubeless standards, they already exist. Schwalbe, IRc and hutchinson (conti and vittoria too I suppose) seem to follow them and many rims/wheels match. Its like they talked to each other. Most of the issue people find are self inflicated. take the wheel I rebuilt to today. the valve and tape were installed badly. I am surprised it held air.

Some time ago Josh Poertner of Silca mentioned in the Marginal Gains podcast a tubeless ERTRO standard was being worked on by rim and tire manufacturers, and it should become official in the near future. I can't remember whether a timeline was mentioned, but I think it was implied model year 2020 products should already carry that standardization.

Jugi wrote: ↑

Tue Jul 30, 2019 4:05 am

bm0p700f wrote: As for tubeless standards, they already exist. Schwalbe, IRc and hutchinson (conti and vittoria too I suppose) seem to follow them and many rims/wheels match. Its like they talked to each other. Most of the issue people find are self inflicated. take the wheel I rebuilt to today. the valve and tape were installed badly. I am surprised it held air.

Some time ago Josh Poertner of Silca mentioned in the Marginal Gains podcast a tubeless ERTRO standard was being worked on by rim and tire manufacturers, and it should become official in the near future. I can't remember whether a timeline was mentioned, but I think it was implied model year 2020 products should already carry that standardization.

The ETRTO standards come in two parts, tire bead shape/dimensions and rim shapes/dimensions. The tire standard is basically set...it’s UST. There is still squabbling over the rim standards...for example whether hookless should be included, but also bead hook dimensions and rim bed shapes. The rim situation might it be resolved for years.

Also nobody is forcing manufacturers to adhere to ETRTO guidelines. In a CyclingTips interview, the Continental guy was very cagey about why they chose not to step in line with UST, creating some potential compatibility issues.

groover08 wrote:I’ve only been on tubeless for a few months and this was my first experience. Last Saturday, I ran over a screw with a large head and it lodged in my rear tire. I stopped, gently pulled out the screw and watched in utter astonishment as the sealant closed the puncture within seconds. Yes, seconds. From stopping to riding off again must have been no more than 30 seconds. The tire continues to hold pressure as if nothing happened.

The details are: Schwalbe Pro One tire in 28mm, Orange Seal sealant, 62 psi pressure , Enve 4.5AR disc wheels

I’m never going back to tubes.

100%.

Once the trick of how to mount the tyre is mastered (get both beads in the centre channel) and you experience the above (or you learn to use a dynaplug if the above doesn’t work) you realise that only under extreme circumstances will you ever have to install a tube. For me i carry a set of dynaplugs and that is it. Even on gravel rides. Never been stranded yet. So much better than tubes.


Sent from my iPhone using Tapatalk

How often does the sealant need to be refreshed or replaced? Saw one sealant mfg recommend 2-3 months for road tubeless?

Considering going tubless on one wheelset. But because of multiple bikes/wheelsets, I might go a couple weeks before the tubeless one rotates in. Wouldn't be worth it if I only get a handful of rides and have to refresh again

bm0p700f wrote: ↑

Mon Jul 29, 2019 5:29 pm

All the fears are simply lack of experience.

... I thought burning band width was the goal.. sorta a smallish camp fire.. to warm the hands on a chilly am.

Anyone pissing on tube-ass NOW in just trying to drown a gopher in his hole.. takes one hella lotta brew to accomplish that. Few... very very few.. could stand long enough to accomplish that. And of those.. only 1 in 10 could hit the hole.

eric01 wrote: ↑

Tue Jul 30, 2019 1:07 pm

How often does the sealant need to be refreshed or replaced? Saw one sealant mfg recommend 2-3 months for road tubeless?

Considering going tubless on one wheelset. But because of multiple bikes/wheelsets, I might go a couple weeks before the tubeless one rotates in. Wouldn't be worth it if I only get a handful of rides and have to refresh again

Depends on the sealant, temperatures and tire/wheel combo. On my UST rims Bontrager sealant which is watery lasts 6 months or so (25-30c temps). It also depends how much of the sealant will be used to seal the tires on the rims (if needed).

Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com