Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More • Hacker News Board

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#141

Post by mnky9800n » Fri, May 17, 2024, 11:34 AM UTC

garphunkle wrote: post #94

cogman10 wrote: post #76

Earlier quoted context omitted.

To add to this, unless you are actually competitively cycling (you probably aren't) this sort of thing makes pretty much no difference for someone that is using cycling for transport. It's a bit like obsessing over the lightest frame possible. Yeah, we can get a 1lb frame made of space materials but at the end of the day it's basically something that will reduce a cyclist's average speed by like 0.1mph. For anyone do…

I'm not sure if steel frames make a significant difference in comfort. If we measure comfort as deflection or vibration, then tire choice will have orders of magnitude more importance. When you have two springs in series, the combined spring constant is dominated by the weaker spring. I race on a carbon frame with 30mm tires, and commute on a steel frame with 38mm tires for what it's worth. Bike weight is irrelevant…

I think the difference between aluminium and steel is easier to feel than carbon to steel.

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#142

Post by seadan83 » Fri, May 17, 2024, 6:04 PM UTC

bluecalm wrote: post #130

seadan83 wrote: post #120

Earlier quoted context omitted.

Salsa cut-throat is a gravel bike, fits 2 inch tires. Personally, I find having drops to be more comfortable because you can change hand position. Look to tour divide bikes for gravel bikes optimized for comfort and fatter tires. I don't understand your prediction for an imminent transformation.

My prediction is that gravel bikes will have wider forks and people will put MTB tires in them instead of 40mm "gravel" tires they do today. It will be faster, more comfortable and safer. Drop bars are great, they will stay. You don't need an MTB bar for your typical light off-road terrain.

Gravel bikes with wide forks and MTB tires already exist. That was my point with the salsa cutty example.

Classic gravel tires do not have very aggressive knobs, but there are some that do.

Gravel is odd as that can be hard packed dirt, small rocks, larger, up to mountain road (babyheads). For some of those conditions, the sidewall of a MTB is overkill and there is a stronger desire for a supplier, faster tire. Basically a cross country MTB tread.

So, there are already wide forked gravel bikes, and there are conditions where a 38 tire is plenty. To fit a 2 inch or 3 inch tire also requires trade offs for the down tube. Which is to say, it's arguably different bikes you want fir some Kansas gravel compared to northwest mountain passes.

As well, the upper limit will probably be at 2.5 inches.

Last, a lot of MTB tires are designed for folks that drive up to a trailhead and then ride down a trail. Those tires need to be solid, and just solid. So, I think it will be the variety of tires that change. More tires suitable for "light" cross-country MTB and ranging in between the spectrums.

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#143

Post by giuliomagnifico » Sat, May 18, 2024, 2:16 PM UTC

Oh I’m reading this website (and subscribed) since lots of years. It’s very interesting and used for cyclists like me! Love it.

Re: Bicycle Rolling Resistance: Tire Rolling Resistance Tests and More

#144

Post by arghwhat » Sat, May 18, 2024, 10:32 PM UTC

ActorNightly wrote: post #135

arghwhat wrote: post #83

Earlier quoted context omitted.

Quoting the article posted in another comment ( https://www.renehersecycles.com/12-myths-in-cycling-1-wider-... ) > The German magazine TOUR built a sophisticated setup with a motorized dummy rider and found that a 28 mm-wide tire had the same wind resistance as a 25 mm tire when the wind was coming from straight ahead. With a crosswind, the wider tire was very slightly less aerodynamic. Even then, the wider tires re…

25 and 28 are basically same width. Also wind tunnel testing is not really representative of real world condition given real world turbulence, but I dunno if that would really affect results. Im just against the general saying that wider tires are faster. This implies that fat bike smooth tires are the fastest, but we know that this is ridiculous. 25 to 35c probably doesn't matter too much aero wise at regular cyclin…

The issue is that narrow tires have a very, very inefficient suspension behavior, and road surface and rider movement causes it to be constantly exercised. That does not mean that you gain anything from going nuts - there are diminishing returns just like there is for slimming the tire for aerodynamics.

What tire is best depends on the surface, the rider and the speed. On a perfectly paved road at high speed and with a light, stable rider, 25 might be right. On regular roads, 35 might be faster. On a bumpy mess, "smooth fat bike" tires would indeed be faster still - assuming you can stay upright without the tread. There's a reason you don't take a road bike with 25mm tires to do downhill mountain racing.