Scubaquarius

I've looked at some of the research and talked about this before... but I can't help but beat this "Dead Horse Question" one more time,
and then I promise I'll never ask again ! Here it is:

I'm doing my daily ride on my Liv Sedona with Hybrid tires, a tire which is wide, slightly knobby, and low pressure (50 psi mx). All these
riders on classic racer type bikes, "little skinny, high pressure tires (probably 90 PSI), are whizzing past me and I'm left in the dust.

So, here's my boggle: I can't believe it's not easier to peddle these little skinny, high pressure tires than it is my fairly wide, low pressure
Hybrid tires. Even though the research I've read on the subject argues against this.

Anyone out there see my point? Hey, it's OK I'm used to being in the lone crowd !

Opinions welcome,
Scubaquarius

Barry2 

If the racing bike "whizzes" by the Liv Sedona, then the Liv Sedona needs to go faster.

Tires will help. But an engine upgrade might help more.

Barry (who's bike also needs an engine upgrade)

Scubaquarius

Electric you mean?

Scubaquarius

Troul 

what's never talked about hardly is the type of air used & how it's put into the tires. If you put the air in gradually with a lower volume feed, the impact that it has on speed is governed.

Barry2 

Not electric... the engine you're already using..... YOU

stevel610 

Several factors would be involved, one of which are the tires. It is not only tire pressure but width tread pattern, rbber compound, casing materials and density. Also the bearings, number of spokes, and weight of wheel components.

ofajen

Those tires are pretty stiff and thick, so there is probably a good bit more energy required. Probably a bigger deal is that your bike is upright and you will have much more effect of air drag than you would on a race style bike at their speed.

If you wanted to do something about the tires, get some with more flexible casings. I get the fastest rolling tires I can, consistent with the tread and reliability I need.

But, with an upright bike, you will still have to pedal much harder to keep up with riders on more aerodynamic bikes at the same speed, even with better tires.

Does it matter? Do you want to adopt that riding position to increase your speed?

Otto

chaadster

I think you’ve probably misunderstood the research. On a smooth road, same comditions, a rider will be faster on a skinny, high pressure slick than on a wide, low pressure knobby. I’m not aware of any research, science, or credible evidence to the comtrary.

Now, add in the fact you’re dealing with comparing your speed on an upright cruiser with low pressure knobbies to riders you don’t know on road race bikes with probably all the go-fast and...oh, wait a minute, I get it now: this is a troll thread.

Scubaquarius

Hey Barry2,

I'm 65 years young and I'm afraid my "engine" has about as much output as it's going to get !

Looking for an "easy fix".....LOL,

Thanks Scubaquarius

Scubaquarius

Not looking to do the "Tour de France" riding position. I like sitting upright !

Thanks,
Scubaquarius

Scubaquarius

Chaadster,

Now that sounds more compatible with my line of thinking. All except the "troll thread", you lost me there.

Thanks, Scubaquarius

10 Wheels

Me at 67 y/o. NY to LA 4200 Miles

gear64

How knobby is slightly knobby? All this is purely anecdotal. Back in the day I felt like my higher end MTB with knobby tires was significantly slower than my low end ten speed. As such I would ride MTB with GF who wasn't a regular rider whenever she wanted to tag along. More recently I just got a new bike with 38s. Vittoria Zero. It's not noticeably faster or slower than my 25/28 bikes, but querying my database since 2019; two rides this year on 38s are in the top 10. The 38s eat bad road conditions for lunch though. I'm an average rider. I get passed as often as I pass. I like to think I pass more often, but I'm ok being blissfully wrong.

smashndash

Things that make me and my bike faster than yours:

Aero helmet
aero kit (jersey + bibs)
cleat pedals (I hate the word clipless)
"Tour de france" riding position
narrow handlebars
Waxed chain
expensive bottom bracket
aero carbon wheels
relatively low hysteresis tires with minimal tread
years of lifting/riding/racing experience

I'm not sure how you can see all these advantages and then conclude that the size of the tires is the problem. If you have the funds, I'd say buy some rene herse extralight tires of the same size you have right now + latex tubes and see what difference it makes. Those are about as fast as tires get.

10 Wheels

Me at 72 just home from Brain Surgery caused by a 16 MPH Crash.

Daniel4

Huh? Sorry but the double-negative is confusing me.

Who said peddling skinny high pressure tires were harder than wide low pressure tires?

Sy Reene

Rene Herse made a stab at making this 'research'. Not that I can say that I subscribe to its findings and conclusions though
https://www.renehersecycles.com/bq-tire-test-results/

just one chart from the article:

Scubaquarius

Thank you everyone for your replies to my post (Scubaquarius). It's a great forum with folks much
more knowlegeable than myself and I appreciate your taking the time to reply.

Have a great day and a great ride.... just finished mine ,

Scubaquarius

fredlord

Am I right in thinking that the more puncture-resistant a tyre is, the more slowly it rolls? And that faster rolling tyres are more prone to flats? I'm asking about normal tyres rather than tubeless, which I know nothing about. I've got Schwalbe Marathon Plus on most of my bikes, and I'm always hearing about how heavy and slow they are, but I get very few punctures, which is fine by me!

Retro Grouch 

Once you get above around 15 MPH, air drag consumes more power than everything else combined. The faster you go beyond 15 MPH, the more significant air drag becomes. If you want to ride faster, work on your aero position on the bike.

cb400bill

That would be an E-Bike.

OldTryGuy

65 years young >>

I have never met a person who has managed to be growing younger. In 2 months from TODAY I will be 71 YEARS OLD and will be proud to be every second of that age.

pdlamb

Heine's conclusions are widely and wildly mis-interpreted to mean wider tires are faster than skinny tires, period.

Wider tires may be faster than skinny tires if and only if:
Rider's posture is equally aerodynamic
Tire tread is similar (no knobs!)
Tire sidewalls are equally flexible
Tire thickness is similar
Tire tread is no thicker
Wide and skinny tires have similar flat protection (no extra layers)

In other words, the wide tire you're looking at needs to be like a Compass tire.

You want a tire that won't flat if you ride through sharp rocks, or one that will last for a really long time or distance? It'll be slower.

Pratt

To find out for your bike, with your tires, and you on it, get a friend and coast together at the same speed. Then, not pedaling, not changing your position, see who edges ahead. Then, you can let air out, put more in, change to skinnier tires, grease your whole body with margarine, etc. This will give you a new stick with which to beat the dead horse.

chaadster

Oh…thanks. I guess I need to eat some crow! I’ve not seen that RH/BQ compared knobby to smooth treads, though I know their take on wide tires generally. I’ll have to read the report and see what’s said. I do consider Heine and crew credible, though not infallible; that knobbies are as fast as smooth treads is a hard one for me to get my head around, I admit.