Tyre Pressures: GP 5000 vs Gatorskin Hardshell

[MudLark]

Hi guys,

 

Hoping somebody can give me a few quick pointers here. I have in the past normally run Continental GP 5000 tyres with a pressure of around 5bar in the front and 6bar at the back. But those tyres are expensive, not perfectly puncture resistant (is anything?) and take one heck of a beating on Johannesburg's roads, what with the poor quality of the tar in various places, bits of glass, metal and all kinds of other things. So I eventually decided to get some Gatorskin Hardshell tyres for training purposes. They have an additional 10 W rolling resistance per tyre… And trust me, today I felt every one of those additional 20 watts between the two tyres. In any event, the question I want to ask is whether I should run these Hardshell tyres at the same pressure as the GP 5000s or whether I should run them harder or softer? Any pointers would be very welcome and gratefully received.

 

Cheers,

mudlark

Edited December 6, 2020 by MudLark

[Schnavel]

Hi mudlark, a few questions before an informed answer can be given:

 

1. What do you weigh?

2. Are you running both with tubes, or did you run the GP5000s tubeless?

3. What width tyres are running?

[MudLark]

Thank you Schnavel. Good points.

 

1. Weight: Around 82/83 kg, sometimes a bit less.

 

2. Both with tubes.

 

3. 28mm width.

[thisismyotherbike]

Hi mudlark, a few questions before an informed answer can be given:

 

1. What do you weigh?

2. Are you running both with tubes, or did you run the GP5000s tubeless?

3. What width tyres are running?

 

Edit: I see in the time it took me to post this you replied to Schnavel.

Edited December 6, 2020 by thisismyotherbike

[Jewbacca]

I think a 10w penalty is a 10w penalty.

 

I'm not sure there is a voodoo that can magically take that away unfortunately, especially if you are already around the 5 bar mark

[MudLark]

I think a 10w penalty is a 10w penalty.

 

I'm not sure there is a voodoo that can magically take that away unfortunately, especially if you are already around the 5 bar mark

 

Jewbacca, accepted. It's not necessarily about trying to reduce the wattage loss but just trying to figure out whether tyre pressures should be in the same range or whether they should be higher or lower given the different structure of the tyre concerned. My impression is that GP 5000s are designed to run at a somewhat lower pressure whereas possibly the Hardshell tyres are not designed to run at lower pressures. Ek weet eenvoudig nie.

Edited December 6, 2020 by MudLark

[Jewbacca]

Jewbacca, accepted. It's not necessarily about trying to reduce the wattage loss but just trying to figure out whether tyre pressures should be in the same range or whether they should be higher or lower given the different structure of the tyre concerned. My impression is that GP 5000s are designed to run at a somewhat lower pressure whereas possibly the Hardshell tyres are not designed to run at lower pressures. Ek weet eenvoudig nie.

hahaha

 

I think higher pressures have been shown to give kick back, so slow you down from the bumps as opposed to absorbing them.

 

I don't think any tire runs 'faster' while creating more chatter.

 

I kind of see it as a win as you get to work harder while training, then pop the 5000s on for race day and boom!

[MudLark]

hahaha

 

I think higher pressures have been shown to give kick back, so slow you down from the bumps as opposed to absorbing them.

 

I don't think any tire runs 'faster' while creating more chatter.

 

I kind of see it as a win as you get to work harder while training, then pop the 5000s on for race day and boom!

 

Okay, thanks. Completely different wheelsets, BTW for training and racing. Although in my case "racing" is a bit of a misnomer. It's more like "participating from the back half of the pack". :-)

[Al Allen]

I've ridden GP4000's and Gators (25mm Clinchers) and always have them at 7 bar for training rides and 8-8.5bar for events.

There's no point in having different pressures...pick one that you find comfortable. The tyres were designed to work at the recommended operating pressure. Pump them too low and you will be absorbing every stone and shard of glass you ride over (possibly why you've been eating through tyres).

I weigh 84kgs. Lighter riders can get away with lower pressures as they induce a lower effective bearing pressure on the tyre-road contact surface. 

If you find the data and nitty gritty interesting you can play around with this site below which allows comparison of various tyres, pressures and related rolling resistance:

 

https://www.bicyclerollingresistance.com/road-bike-reviews/compare/continental-gatorskin-2015-vs-continental-grand-prix-5000-latex-tube

 

 

[mikkelz]

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Edited December 6, 2020 by mikkelz

[MudLark]

I see that I am probably running things a bit too soft. Continental recommends 6.5 bar to 8 bar for both tyre types. 

[Edereese]

I weigh around 72kg, I ride both (25mm) gp range and gatorskin at 8 bar. Like they mentioned, a 10 W penalty is a 10 W penalty. For commuting and training rides, the gatorskins are definitely better.. special occasions I’ll pop on the Veloflex and WOW! Everything just feels so much better, but the constant thought of puncturing is exhausting. Will most likely go for the 5000 the day I can get it at a reasonable price + tubilitos, till then, gatorskins will have to do.

Edited December 6, 2020 by Edereese

[Andreas_187]

8 bar is crazy hard for an already hard tyre. 90psi/6 bar is perfectly fine, even a 28mm tyre I would run at 80psi/5.5psi

[Jewbacca]

8 bar is probably 'old school' thinking.... I haven't inflated anything harder than 5.5 bar on a road bike in quite a while.

[Schnavel]

I weigh around 72kg, I ride both (25mm) gp range and gatorskin at 8 bar. Like they mentioned, a 10 W penalty is a 10 W penalty. For commuting and training rides, the gatorskins are definitely better.. special occasions I’ll pop on the Veloflex and WOW! Everything just feels so much better, but the constant thought of puncturing is exhausting. Will most likely go for the 5000 the day I can get it at a reasonable price + tubilitos, till then, gatorskins will have to do.

 

Why on earth would you run the tyres at 8 bar, especially at your weight?!

[Edereese]

I

Why on earth would you run the tyres at 8 bar, especially at your weight?!

I honestly don’t have an answer for you. I was thinking 5,5 front and 6,5 rear, will see if I feel any difference.