New Vittoria Corsa Pro!!

[GONE4ARIDE]

For me, these are race day only / special ride tires, but that's the way that I have always treated tires like this. These tires ride and perform so well that it's tempting to ride them everyday, but that's not what they are intended for. For everyday tires, Conti GP 5K are tough to beat ATMO.

[LanceLegstrong]

For me, these are race day only / special ride tires, but that's the way that I have always treated tires like this. These tires ride and perform so well that it's tempting to ride them everyday, but that's not what they are intended for. For everyday tires, Conti GP 5K are tough to beat ATMO.

If you're saving them for race day only, you're really missing out. That's like buying a Ferrari then leaving it in the garage all year. What's the point of having it?

[Requiem84]

This really is a briliant tire. Only issue is that pressure keeps dropping. Easily lose 1 bar on 4-5 hour rides...

My 30mm Corsa Pros might go from 65psi to 60psi over a 24 hour period… either you’re using bad sealant or have a small leak somewhere. It could be the tape, the base of the valve or even the valve core.

On the same rims and same valves, sealant etc the GP5000 and the Pirelli Zero TLR's didnt lose pressure as fast as the Corsa Pro's.

[TobinHatesYou]

On the same rims and same valves, sealant etc the GP5000 and the Pirelli Zero TLR's didnt lose pressure as fast as the Corsa Pro's.

I just checked... My Corsa Pros were inflated to 4.5bar on Thursday and they were at 3.4bar 4 days later. Your tires are losing air at >20x the rate mine are. Accept that something is wrong with your setup and work on fixing it.

[Requiem84]

On the same rims and same valves, sealant etc the GP5000 and the Pirelli Zero TLR's didnt lose pressure as fast as the Corsa Pro's.

I just checked... My Corsa Pros were inflated to 4.5bar on Thursday and they were at 3.4bar 4 days later. Your tires are losing air at >20x the rate mine are. Accept that something is wrong with your setup and work on fixing it.

In exactly the same set-up these tires lose pressure much more easilly than other tires. Sure, perhaps going for 100ml sealant will fix this, but why should I when P Zero's work fine with 40ml?

The conclusion for me is that these tires just require much more fiddling and (pro) work to get them right. When they are right they are awesome, but for everyday training I'll be going back to P Zero's.

[TobinHatesYou]

On the same rims and same valves, sealant etc the GP5000 and the Pirelli Zero TLR's didnt lose pressure as fast as the Corsa Pro's.

I just checked... My Corsa Pros were inflated to 4.5bar on Thursday and they were at 3.4bar 4 days later. Your tires are losing air at >20x the rate mine are. Accept that something is wrong with your setup and work on fixing it.

In exactly the same set-up these tires lose pressure much more easilly than other tires. Sure, perhaps going for 100ml sealant will fix this, but why should I when P Zero's work fine with 40ml?

The conclusion for me is that these tires just require much more fiddling and (pro) work to get them right. When they are right they are awesome, but for everyday training I'll be going back to P Zero's.

I'm using 40mL of sealant too, bro. Check around your valves and/or use a better sealant. I doubt anyone else in this thread is losing 1bar per 4-5 hours.

[Requiem84]

On the same rims and same valves, sealant etc the GP5000 and the Pirelli Zero TLR's didnt lose pressure as fast as the Corsa Pro's.

I just checked... My Corsa Pros were inflated to 4.5bar on Thursday and they were at 3.4bar 4 days later. Your tires are losing air at >20x the rate mine are. Accept that something is wrong with your setup and work on fixing it.

In exactly the same set-up these tires lose pressure much more easilly than other tires. Sure, perhaps going for 100ml sealant will fix this, but why should I when P Zero's work fine with 40ml?

The conclusion for me is that these tires just require much more fiddling and (pro) work to get them right. When they are right they are awesome, but for everyday training I'll be going back to P Zero's.

I'm using 40mL of sealant too, bro. Check around your valves and/or use a better sealant. I doubt anyone else in this thread is losing 1bar per 4-5 hours.

4-5 hours of riding that is.

Still pretty hard for you to understand that with all external factors exactly the same these tires simply lose more air than others.

Edit: I should rephrase that to be fair: it seems you can get these tires right, but it also seems it is more difficult than with other tires. This also comes back on BRR:

Conclusion BRR:

What our data doesn't show is user-friendliness, as the Corsa N.EXT is much more of a set-and-forget tire, while the Corsa Pro is going to need pro-level attention to unlock its performance.

Another user on BRR experienced even more severe pressure dropping than I did:

I’ve put a pair of 30mm ones on my Zipp 303 firecrest hookless wheels. The feel and grip is superb, but getting them to hold air is almost impossible. They are dropping from 60 to 40 PSI in 6 hours. I’m using Stan’s sealant, which works perfectly with all my other tires across road and mountain bikes. Has anyone had success with other sealants with these tires?

[Nereth]

I agree with Tobin - you're an order of magnitude out on leak rate - this is not "working fine" as you can't get to the end of a lengthy race without your tyre turning into a marshmallow.

If you've tried that exact rim with a different tyre and not had the same problem (i.e. took the Corsa Pro off and put a GP5000 or similar on and it doesn't leak), then try a different Corsa Pro, in case your actual tyre has a flaw in it, and if that also doesn't work, I'd be looking carefully at your bead seat on your wheel to see if it has a flaw in it that is interacting with the shape/hardness of a Corsa Pro tyre bead but wouldn't interact with the same features of a GP5000 bead.

All else fails, this might be something repeatable like the corsa pro has a very hard or poorly shaped bead that isn't going to easily seal on a lot of wheels, but even that should be solveable with adequate use of sealant - Put enough on and shake the tyre to get the sealant onto the bead until it seals properly, and then suck out the excess through the valve hole if you don't want that much in your wheel.

[LanceLegstrong]

Another data point. I pump mine up once a week. Maybe 5-10 psi loss over the course of a week of riding. Occasionally I'll have more air loss which I figured was a small puncture that lost air before sealing. But I wouldn't say I'm losing more air than other tubeless tires. Perhaps the same as latex tubes.

[TobinHatesYou]

I just checked... My Corsa Pros were inflated to 4.5bar on Thursday and they were at 3.4bar 4 days later. Your tires are losing air at >20x the rate mine are. Accept that something is wrong with your setup and work on fixing it.

In exactly the same set-up these tires lose pressure much more easilly than other tires. Sure, perhaps going for 100ml sealant will fix this, but why should I when P Zero's work fine with 40ml?

The conclusion for me is that these tires just require much more fiddling and (pro) work to get them right. When they are right they are awesome, but for everyday training I'll be going back to P Zero's.

I'm using 40mL of sealant too, bro. Check around your valves and/or use a better sealant. I doubt anyone else in this thread is losing 1bar per 4-5 hours.

4-5 hours of riding that is.

Still pretty hard for you to understand that with all external factors exactly the same these tires simply lose more air than others.

You haven’t quantified how much air loss your other tires experience, only that they exhibit less overall. How much pressure drop do you experience with GP5Ks? Also riding does not have a noticeable effect on air loss rates in any of my tires.

[Requiem84]

So I just checked again for fun.

Pumped up the the front and rear to 5.0 bar yesterday for a 2 hour ride. Tire pressure 5 minutes ago was 3.9 front and 3.7 rear. Typically the pressure now drops at a much slower rate, like 0.2 - 0.4 a day when not cycling.

The GP5K's dropped very little during/after a ride. Something like 0.3 - 0.4 max. And then when idle they dropped like 0.2 day.

The Pirelli Zero TLR's dropped basically nothing during/after a ride and dropped very very little when idle.

So sure, I see from all the experiences here that it seems to be possible to fix my pressure issue with the Vittoria's. But personally I prefer the convenience of the Pirelli's. Now that the 28's are apparently fixed again, I'll be going back to them for everyday riding. I'll keep the Vittoria's for races though, as I really like their feel, speed and also the relatively low weight.

[Jaisen]

Bicycle Rolling Resistance has the casing width, thread width, and casing-thread ratio for size 28 at: 73mm, 30mm, and 41.1% respectively.

Anyone have the measurements for sizes 30 and 32?

[TobinHatesYou]

Bicycle Rolling Resistance has the casing width, thread width, and casing-thread ratio for size 28 at: 73mm, 30mm, and 41.1% respectively.

Anyone have the measurements for sizes 30 and 32?

30mm = 32mm tread, 78mm casing = 41%

[Jaisen]

Bicycle Rolling Resistance has the casing width, thread width, and casing-thread ratio for size 28 at: 73mm, 30mm, and 41.1% respectively.

Anyone have the measurements for sizes 30 and 32?

30mm = 32mm tread, 78mm casing = 41%

Thanks Tobin!

[LanceLegstrong]

I have some 32s.
- Weight was 292g and 313g.
- 85.7mm wide measured flat. Tread 30.8mm flat.
- Mounted on 21mm internal rims, they measure 32.3mm at 70psi. Tread mounted is 27.6mm.

And yes, the flat tread is correct.