are E-rated tires slower than regular bicycle tires of the same tire model?

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prokyon
Posts: 92
Joined: Fri May 03, 2019 11:12 pm

by prokyon

I tried E-rated versions of regular road and gravel bicycle tires in the past and feel like they're slower.

I've been told that E-rated tires:
1) have sidewalls that are designed to flex when torque is applied to the wheel as to not overload the motor and transmission and have a smoother acceleration on an e-bike; needless to say this eats up energy when just pedaling
2) feature more functure protection than regular bicycle tires due to the added weight and speed of an e-bike

Are any of these two claims true?

Specifically I ride Conti 700x40 Terra Speed gen 2's now on pavement (E-25 rating) and I feel like they're a lot more supple and slower than the non-E-rated gen 1's I used to have (I could keep up with road bikes on pavement with those no problem).

jfranci3
Posts: 1605
Joined: Tue Jul 26, 2016 5:21 pm

by jfranci3

You mean "less supple"
https://www.bicyclerollingresistance.co ... -speed-e25

https://www.bicyclerollingresistance.co ... ection-e25

The tires are probably the same in reality. The margin for error/production variance on smooth road tires is probably around 1w. The difference is usually load (weight) rating. Conti might have just changed a few things to up durability or to accommodate more sizes.

by Weenie


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MagicShite
Posts: 455
Joined: Sun Jun 26, 2016 3:33 pm

by MagicShite

have you emailed Continental?

In the case of GP5000 clinchers 30mm e-bike rated...(the 30mms are oddly the only one e-bike rated and you can't buy normal 30mm GP5k clinchers)

Someone on Reddit Cycling subreddit emailed Conti and got the reply that e-rated are basically the same just that the tires went through additional "certifications" for ebike compliance.

I certainly did not notice much on the 30mms GP5k which I have been running on my LB WR45s for a while now.

prokyon
Posts: 92
Joined: Fri May 03, 2019 11:12 pm

by prokyon

I can't imagine any manufacturer responding with a resounding "yes, we intentionally made the new version slower to gain the E-25 rating". I just go by road feel and both Schwalbe Marathon and Conti TerraSpeed that I and a few other local riders have tried feel super sluggish in the E-rated versions.

I feel like the E-rated tires are also "more supple", i.e. softer in their roll, due to the added sidewall flex to bear higher loads - it's almost like the sidewall is designed to flex more to absorb motor torque as I mentioned above plus higher loads, i.e. it's a lot more springy and not as stiff, meaning it can take higher load without blowing out and rather expanding a bit more.

Greeners
Posts: 31
Joined: Fri Apr 26, 2024 10:13 am

by Greeners

I would have expected a stiffer sidewall to cope with the added weight/power. I am generalising as opposed to assuming facts about the models of high performance tyres typically spoken of on this forum.

Steve Curtis
Posts: 1359
Joined: Thu Jul 31, 2008 12:20 pm
Location: Hampshire UK, Dublin Ireland and Geneva Switzerland.

by Steve Curtis

I have the older non and current e-rated GP5000 30mm.
I have 6 of each and they weigh the same, feel the same in my hands, same flexibility, grip, texture etc
On the bike they feel the same too, no faster or slower to my non calibrates ass.

Nickldn
Posts: 2011
Joined: Mon Mar 25, 2019 12:35 am

by Nickldn

Greeners wrote:
Thu Jun 13, 2024 1:57 pm
I would have expected a stiffer sidewall to cope with the added weight/power. I am generalising as opposed to assuming facts about the models of high performance tyres typically spoken of on this forum.
I agree with your view. Would expect tyres for a heavier and more powerful vehicle to have stiffer sidewalls. More flexibile sidewalls would be overwhelmed by extra weight and power causing more deformation and vague handling/loss of stability. In the end the tyre would have a shorter life too.

BigBoyND
Posts: 1549
Joined: Mon May 31, 2021 1:51 am
Location: Berlin, DE

by BigBoyND

Why would you think that? The weight added by an e-bike is around 10kg. Meanwhile riders vary by 50kg+ in weight.

The torque difference is much more significant

by Weenie


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