Tyre Pressures: GP 5000 vs Gatorskin Hardshell

[devocean]

I ride 23mm hardshell gatorskins at 8-9 bar and I weigh 67kg...because I don't know any better. I bought GP4000's once and punctured every other ride so went back to gatorskins.

[MudLark]

I ride 23mm hardshell gatorskins at 8-9 bar and I weigh 67kg...because I don't know any better. I bought GP4000's once and punctured every other ride so went back to gatorskins.

 

GP 5000s also puncture quite a lot if you run them fairly hard. Anything from say 7 bar upwards. Run them at 6.5 and lower and they very rarely puncture. Don't ask me why – just how it is.

[WIPEOUT 1000]

Try SILCA Professional Pressure Calculator

 

https://info.silca.cc/silca-professional-pressure-calculator

[Schnavel]

Another great source of information:

 

https://www.enve.com/en/tirepressure/

[buckstopper]

I have ridden tubeless 25mm schwalbe Pro 1 (racing tyre), 25/28 since Feb 2017, almost 5 years and 8000km on the front tyre, which needs replacing now. I have never removed it, only topped up. Yesterday I rode at about 3 bar,I'm 78kg.

[buckstopper]

I'm not anal about my tyre pressure unless I'm doing a race (Vets cat). I would pump to about 5bar max. Haven't had a puncture since I went tubeless.

[MudLark]

Try SILCA Professional Pressure Calculator

 

https://info.silca.cc/silca-professional-pressure-calculator

 

Very interesting. For the same overall system weight there is roughly about a 2 bar difference between a 23 mm and a 28 mm tire.

[Edereese]

Dropped the pressure to 6 front and 6.5 rear. Took a quick spin, road feel is definitely softer

[mikkelz]

~62kgs running 25mm GP4000S II @ ~90psi (6 bar) on Fulcrum Racing 5 LG wheels.

 

I used to run 120psi on my previous Shimano wheelset with 23mm tyres (Gatorskins).

 

After moving to the 25mm tyres on the new wheelset, I don't know how my body survived all those years at 120psi. Harsh!

[Patchelicious]

85kg (no mocking!!) running GP5000 28s at 6.5 front 7 at the back.

 

Front has punctured twice in the last 2 rides.

 

On the 10watts difference between GP and GS, that seems a lot?

[JohanH]

GP4000s 25mm front and back around 6bar generally. I weigh in at 76kg. Decided to inflate to 8bar.

 

First ride this morning after higher pressure = first puncture for the year. Deflating back to about 6.5 as soon as I get home.

[MudLark]

85kg (no mocking!!) running GP5000 28s at 6.5 front 7 at the back.

 

Front has punctured twice in the last 2 rides.

 

On the 10watts difference between GP and GS, that seems a lot?

 

I suggest you go about 5.5 in the front and 6.5 at the back. See here: https://docs.google.com/spreadsheets/d/10878Rq_wnurkcdIyhklZ0Y6ARx6xxdLMZ_9Xj9hgmZ4/edit#gid=1388801070

 

10 watts difference is per https://www.bicyclerollingresistance.com/. Don't know anything more accurate.

[DieselnDust]

Rn the tyres within the recommended pressure range moulded into the side wall.. Work out what percentage of the GP5000 pressure range you are at then apply the same to the Gatorskin. It will still feel harder than the GP5000 due to the stiffer construction but it also isn't designed to be flexed as much or it will start to crack up. 

[MudLark]

Rn the tyres within the recommended pressure range moulded into the side wall.. Work out what percentage of the GP5000 pressure range you are at then apply the same to the Gatorskin. It will still feel harder than the GP5000 due to the stiffer construction but it also isn't designed to be flexed as much or it will start to crack up. 

 

Hello Diesel – always good to have you chiming in on a discussion. So the interesting thing here is that both tyres have the same pressure range on the Continental website – 95 to 116 psi (6.5 bar to 8 bar) and both have the same moulding on the side wall – a maximum pressure rating of 8 bar/116 psi. Yet, if you use these online tyre calculators, for my weight range they seem to indicate about 5.5 bar in the front and about 6.6 bar at the back. So quite interesting.

[DieselnDust]

Hello Diesel – always good to have you chiming in on a discussion. So the interesting thing here is that both tyres have the same pressure range on the Continental website – 95 to 116 psi (6.5 bar to 8 bar) and both have the same moulding on the side wall – a maximum pressure rating of 8 bar/116 psi. Yet, if you use these online tyre calculators, for my weight range they seem to indicate about 5.5 bar in the front and about 6.6 bar at the back. So quite interesting.

 

 

Yes I also find that interesting. 

There could be a few reasons. The 23c and 25C versions use the same pressure range. That is likely because the orientation of plies, ty[re of rubber compound and bonding techniques are the same across all three sizes. The only difference is the width. Between 23C and 25 C I find myself running them at closer to 105psi for the 23C, 100psi for the 25 and 95psi for the 28. Still within the specified range but different pressure to compensate for the increase in volume.

When I drop any of those tyres outside of the specified range the sidewalls start to open these diagonal lines much like MTB tyres that are underinflated.

If I use the SRAM tyrewiz app I also get a very low pressure even for a 25C tyre yet for my MTB the pressure recommendation is more or less spot on but still a little on the low side. 

recommendation is 1.3 F and 1.4 Bar rear and I run 1.4 front, 1.6R and still bottom the rim.

 

I'm not sure what algorithm the apps use to work out the pressure or what assumptions they are aking but it always comes out lower than Were I set the tyre pressure to. If I follow the recommendations I always have  wrecked sidewalls.

 

PS:  I suspect that the pressure recommendations on the tyres also come from ERTO that sets the standards relating to tyre size /per rim width and governs other dimensions relating to rim and tyre dimensions relative to each other.

Edited December 7, 2020 by DieselnDust

[Andreas_187]

The Max Pressure printed on the sidewall is a warning and not a guideline. Just like the tyres on your car, do not inflate to the max pressure.

If you inflate to 110psi and then fly down Kloof Nek Road you will be way over 115psi. Hit the brakes, the rim gets hot, the air expands and now you're at 125psi. BOOM!