Rolling Resistance of bike tires...

man I have tested this so much. I had a long wheel base recumbent with a fairing and a hill I went down every day and I could test PSI and tires for speed. this is one reason I went tubeless so I could have less rolling resistance but good flat protection. going from the stock 2.4" tires on my trek at 60psi to 2" speed tires at 45 psi I gained 3mph faster and gained at least 8 miles more range. plus the ride was smoother.
 
BRR is a great resource !

the range from low to high is shocking -
12.6 watts to push a pair of veloflex records at high pressure
103.4 watts to push a pair of juggernauts at 8psi

basically the difference when using your own legs for power between “i’m going fast” and “why am i barely able to move” 😂😂😂
 
Nvreloader said:
Check out the special Articles, very interesting on what they have tested...
www.bicyclerollingresistance.com

Special Articles | Bicycle Rolling Resistance

Overview of all special articles about rolling resistance by bicycle rolling resistance
www.bicyclerollingresistance.com www.bicyclerollingresistance.com
Click to expand...
Very interesting results on the variation of coefficient of rolling resistance (CRR) in road-like tires with changes in ground speed, tire load, inflation pressure, temperature, and tire make and model. None of the tires tested are much like my 2.3" hybrids, but the takeaway is clear:

Contrary to conventional wisdom, CRR is NOT a constant for a given tire and surface. It grows slowly with speed and tire load and decreases with tire pressure.

However, the increases in CRR found among their the tested tires were pretty small. And the resulting increases in rolling resistance would be easily absorbed by an ebike motor with little impact on range.

No doubt a very different story with 4" knobbies.
 
Jeremy McCreary said:
Very interesting results on the variation of coefficient of rolling resistance (CRR) in road-like tires with changes in ground speed, tire load, inflation pressure, temperature, and tire make and model. None of the tires tested are much like my 2.3" hybrids, but the takeaway is clear:

Contrary to conventional wisdom, CRR is NOT a constant for a given tire and surface. It grows slowly with speed and tire load and decreases with tire pressure.

However, the increases in CRR found among their the tested tires were pretty small. And the resulting increases in rolling resistance would be easily absorbed by an ebike motor with little impact on range.

No doubt a very different story with 4" knobbies.
Click to expand...
it depends really. on our tandem going from marathon plus to the tubeless tires the same size 1.5" lower psi Schwalbe Marathon Almotion we sure noticed the better acceleration. I had forgotten how the bike felt when we did not have the marathon plus's on it. How much energy it takes may be a more subtle thing between tires. but you can notice acceleration handing comfort for sure. just adding a tube to the same tire you can notice how much harder the tire is with the same tire.
 
The BRR site is awesome, and I’ve used it often in my quest to hypermile and get the most out of my rides. My personal experience has been that the tire selection and pressure has made a tremendous difference.

Going to a low RR road tire made me feel like I had an extra turbo mode (whether e-bike or analog bike powered). Changing to only riding Continental Grand Prix 5000 tires on all my bikes (SS e-bike, analog SS bike, and geared analog bike) saved me 20+ watts and reduced rotating weight from my other tires.

Helped me to complete a 60 mile ride with my SS e-bike, and only it’s 250 wh internal battery. And ride analog majority of the time now, with SS and geared bikes, that would be so much more difficult with higher RR tires. Enables me to do ~50 mile club rides every weekend with my analog SS or geared bikes, where I would otherwise probably get dropped right away with worse tires rather than being able to hang with the pack most of the time.
 
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Plus showing how a motor does not overcome the difference. My older bulls bosch powered bike with 63nm of course and 1.5" marathon plus tires and my trek with 87nm of torque and 2.3" tires. the bulls would far out accelerate the trek and I averaged faster speeds. What I also noticed is I have a higher average hr and high average watt output. now trek with much better tires its much closer now. the trek will out climb the bosch no matter what. they both had the same gearing too. weight was pretty close to the same.
 
Important to keep in mind that acceleration involves way more than just rolling resistance. There, the tire radius (axle to tread) and total mass beyond the spokes (rim and tire plus any tube, insert, sealant) can be much more important.

These factors determine the rotational inertia of the wheels. The greater the combined wheel inertia, the more torque it takes to spin up or spin down the wheels at a given rate, and hence the harder it is to accelerate or decelerate the bike.

Worst common scenario for wheel inertia is probably a fat bike with heavy-duty 26x4" knobbies, tubes, and tire inserts.

The fairest way to compare rolling resistance by itself is at constant ground speed.
 
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Jan Heine at Rene Herse has put out a lot of good information about how tire type and PSI affect performance. Here's one good article with links to several others

www.renehersecycles.com

Myths Debunked: Higher Tire Pressure is NOT Faster

This used to be one of the first things you learned as a cyclist: If you want to go fast, make sure your tires are pumped up to the maximum pressure. The harder your tires are inflated, the faster they roll. We now know that…
www.renehersecycles.com www.renehersecycles.com
 
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bobf said:
Jan Heine at Rene Herse has put out a lot of good information about how tire type and PSI affect performance. Here's one good article with links to several others

www.renehersecycles.com

Myths Debunked: Higher Tire Pressure is NOT Faster

This used to be one of the first things you learned as a cyclist: If you want to go fast, make sure your tires are pumped up to the maximum pressure. The harder your tires are inflated, the faster they roll. We now know that…
www.renehersecycles.com www.renehersecycles.com
Click to expand...
Have seen that article before. Good one.

Tire type, tread, material, weight, width, pressure, road condition such as really smooth or bumpy, comfort desired, etc, are all considerations.

For me, as a roadie with smooth roads, a very low RR tire, at 28mm width, with moderate flat resistance, and pumped to about 15% below max pressure (“15% drop”), has been the best setup for me for speed and endurance for hypermiling.
 
I haven't read up on rolling resistance or even gearing much (just depended on the power of the motor), but it obviously matters a lot, both for speed and range. Something for me to consider over the winter break.
 
I am looking real hard at these road type tires for the summer, as I have just about got a slick on the rear now, with over 1200 miles on it. It's going to be a little hard for the snow which is coming , shortly.
I am hoping that these tires will increase the mileage per mile?
They are a little smaller at 4" as compared to my Kendra's 26x4.5" tires that came on the bike.
 
At first I thought that you were getting too much for your money with those tires, but then I found this,..

Screenshot_20231222-182706_DuckDuckGo.jpg




It looks like it's an old-school type tire like what we had as kids.
It weighs a ton but it's tough as nails.
It's old-school rubber that doesn't wear as well, but it's an inch thick to make up for it. 😂

I'd maybe just put one on the back like he did.
You'd use up more battery spinning those tires too.
 
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