Bring on the fat(ter) tyres
-
- Posts: 536
- Joined: Fri Apr 17, 2009 5:18 pm
- Location: Northcote
Bring on the fat(ter) tyres
Postby misterhorsey » Thu Oct 20, 2016 10:13 am
And the lower pressure.
Not sure if this has been posted before. Long podcast. Worth a listen.
I've let a lot of air out. Plush ride. Seemingly no loss in speeds.
- silentC
- Posts: 2442
- Joined: Mon May 05, 2014 5:24 pm
- Location: Far South Coast NSW
Re: Bring on the fat(ter) tyres
Postby silentC » Thu Oct 20, 2016 10:29 am
- Me
- g-boaf
- Posts: 21217
- Joined: Mon Sep 26, 2011 6:11 pm
Re: Bring on the fat(ter) tyres
Postby g-boaf » Thu Oct 20, 2016 12:00 pm
- Thoglette
- Posts: 6599
- Joined: Thu Feb 19, 2009 1:01 pm
Re: Bring on the fat(ter) tyres
Postby Thoglette » Thu Oct 20, 2016 12:14 pm
Thought I had. (Oh yes, over here) But worth it's own thread. Not surprisingly Zipp and Compass actually make wide, supple tyres in 700C. Almost as expensive as wide, handmade tubulars toomisterhorsey wrote:Not sure if this has been posted before. Long podcast. Worth a listen.
Unfortunately for me, I moved from 622 to 630 a decade ago when that was the only way to get a 32mm wide tyre (bar 26"). Next time I wear the brake tracks out.....
"People are worthy of respect, ideas are not." Peter Ellerton, UQ
- cyclotaur
- Posts: 1782
- Joined: Wed Jan 26, 2011 1:36 pm
Re: Bring on the fat(ter) tyres
Postby cyclotaur » Thu Oct 20, 2016 3:29 pm
My old blog - A bit of fun
"Riding, not racing...completing, not competing"
-
- Posts: 37
- Joined: Mon Oct 17, 2016 1:36 pm
- Location: Brisbane, Queensland
Re: Bring on the fat(ter) tyres
Postby bobbythebrit » Thu Oct 20, 2016 3:52 pm
I thought the idea of installing wider tyres was so that you could dramatically drop the pressure needed (to around 80 or so). Am I wrong on this subject or is there more to it than just that?g-boaf wrote:I've got two near identical bikes, one with 23mm tyres running 110psi, and one with 25mm running 100-110psi (occasionally less if I don't check them). The one with the 25mm tyres is 6.6kg because of the wheels it has, but I don't notice much difference between them on hills. They are both quick. But the one on 23mm tyres with alloy wheels is very, very harsh over bumps.
I'm considering putting some 25mm tyres on when I next need some.
'99 Gary Fisher Aquila
'97 Corratec 3004
- silentC
- Posts: 2442
- Joined: Mon May 05, 2014 5:24 pm
- Location: Far South Coast NSW
Re: Bring on the fat(ter) tyres
Postby silentC » Thu Oct 20, 2016 3:58 pm
Yesterday I got a pinch flat and my crappy little pump couldn't get more than about 60psi into the back wheel, so I rode home on that. It felt a bit spongy on the climbs but otherwise not really that noticeable. I suppose I'd be much more a candidate for pinch flats running very low pressure like that.
- Me
-
- Posts: 536
- Joined: Fri Apr 17, 2009 5:18 pm
- Location: Northcote
Re: Bring on the fat(ter) tyres
Postby misterhorsey » Thu Oct 20, 2016 4:23 pm
The ride is plush. And although I'm a bit out of shape, on certain segments of the Yarra Boulevard Strava is telling me I'm nearing times I used to achieve when I was much fitter.
The podcast gets into the nitty gritty. But a higher psi = a stiffer ride (which may feel more rigid and faster) basically means more energy is transferred into your body, and thus your body has to counteract those forces. Having a lower psi allows the tyre to deform and absorb more of that energy for a net savings of energy you put to achieve an equal speed. Or something like that.
A lower psi does feel more comfortable, and also actually feels slower . But the data suggests that the feel is misleading.
Anyway, it's worth experimenting. It's also cheaper than upgrading your frame for a significantly more comfortable ride.
- Thoglette
- Posts: 6599
- Joined: Thu Feb 19, 2009 1:01 pm
Re: Bring on the fat(ter) tyres
Postby Thoglette » Thu Oct 20, 2016 4:58 pm
There is more to it than just that. Tyre carcass construction counts. A non-vulcanised tyre with high thread count will be more supple than a vulcanised and/or armoured tyre of the same size. So a 23mm tyre can be faster than a 32mm tyre.bobbythebrit wrote: I thought the idea of installing wider tyres was so that you could dramatically drop the pressure needed (to around 80 or so). Am I wrong on this subject or is there more to it than just that?
I'm considering putting some 25mm tyres on when I next need some.
And traditionally that was the case, with wide tyres tending to "touring" or "puncture proof" construction and "open tubular" construction only available in narrow tyres (or actual tubulars). Cheap tyres tended to be universally stiff.
But, IMHO, it is size that dominates. The change from 19mm to 23mm (yes, I used to ride 19mm tyres) or 23mm to 28mm is a 50% increase in volume. Going 23mm to 32mm is doubling the volume and drops the pressure for my rear wheel from 100psi to 60psi.
I'm now firmly in the school of "the fattest tyres you can fit" as purchasing additional suppleness is always more expensive than just going wider.
Frank Berto's chart (from Jan Heine's article on pressure) is included below
"People are worthy of respect, ideas are not." Peter Ellerton, UQ
-
- Posts: 37
- Joined: Mon Oct 17, 2016 1:36 pm
- Location: Brisbane, Queensland
Re: Bring on the fat(ter) tyres
Postby bobbythebrit » Thu Oct 20, 2016 8:20 pm
Interesting, thanks for the info!Thoglette wrote:There is more to it than just that. Tyre carcass construction counts. A non-vulcanised tyre with high thread count will be more supple than a vulcanised and/or armoured tyre of the same size. So a 23mm tyre can be faster than a 32mm tyre.bobbythebrit wrote: I thought the idea of installing wider tyres was so that you could dramatically drop the pressure needed (to around 80 or so). Am I wrong on this subject or is there more to it than just that?
I'm considering putting some 25mm tyres on when I next need some.
And traditionally that was the case, with wide tyres tending to "touring" or "puncture proof" construction and "open tubular" construction only available in narrow tyres (or actual tubulars). Cheap tyres tended to be universally stiff.
But, IMHO, it is size that dominates. The change from 19mm to 23mm (yes, I used to ride 19mm tyres) or 23mm to 28mm is a 50% increase in volume. Going 23mm to 32mm is doubling the volume and drops the pressure for my rear wheel from 100psi to 60psi.
I'm now firmly in the school of "the fattest tyres you can fit" as purchasing additional suppleness is always more expensive than just going wider.
Frank Berto's chart (from Jan Heine's article on pressure) is included below
'99 Gary Fisher Aquila
'97 Corratec 3004
-
- Posts: 8
- Joined: Mon Sep 12, 2016 3:59 pm
Re: Bring on the fat(ter) tyres
Postby richard.allan » Fri Oct 21, 2016 8:50 pm
I bought a Giant Defy Advanced 2 about 18 months ago. The rear tyre didn't last long because of a sidewall split and I replaced it with a 28mm Continental GP 4000S II. I don't know if it's a bit odd to run a different size tyre front and rear but it suits me. The original tyres are 25mm. I did the whole weighing thing again (there are also apps to do this) and I'm now running 75 psi in the front and 100 psi in the rear and I'm pretty happy with that.
-
- Posts: 763
- Joined: Wed Oct 28, 2009 11:31 pm
Re: Bring on the fat(ter) tyres
Postby hamishm » Sat Oct 22, 2016 1:24 pm
Why so much in the rear? I am putting 70-80 psi in my 28mm 4000s II. It's comfortable, reliable and I'm just as fast (or faster) than I was on 25mm until recently.richard.allan wrote: The rear tyre didn't last long because of a sidewall split and I replaced it with a 28mm Continental GP 4000S II. I don't know if it's a bit odd to run a different size tyre front and rear but it suits me. The original tyres are 25mm. I did the whole weighing thing again (there are also apps to do this) and I'm now running 75 psi in the front and 100 psi in the rear and I'm pretty happy with that.
-
- Posts: 8
- Joined: Mon Sep 12, 2016 3:59 pm
Re: Bring on the fat(ter) tyres
Postby richard.allan » Sat Oct 22, 2016 2:38 pm
My partner now rides the hybrid I mentioned in my previous post & I'm also going to decrease the pressure for her & even soften the front forks a bit.
-
- Posts: 1176
- Joined: Fri Mar 22, 2013 4:58 pm
Re: Bring on the fat(ter) tyres
Postby vosadrian » Wed Oct 26, 2016 2:04 pm
Going by that rationale, surely thinner tyres/ more pressure is faster on smooth surfaces, as less "energy" goes to body as there is less energy for the tyre to transmit. On a perfectly smooth road there would be zero energy the body has to counteract. This being the case, would not thin tyres and high pressure be fastest on smooth roads, and fat tyres with less pressure on bumpy roads (chip gravel/dead road), and there would be some crossover in the middle.misterhorsey wrote:The podcast gets into the nitty gritty. But a higher psi = a stiffer ride (which may feel more rigid and faster) basically means more energy is transferred into your body, and thus your body has to counteract those forces. Having a lower psi allows the tyre to deform and absorb more of that energy for a net savings of energy you put to achieve an equal speed. Or something like that.
Personally I am 70kg and run about 110psi in 23s. Suppleness does not really bother me too much, but a squirmy tyre does. There is no indication my setup is slow.
- RonK
- Posts: 11508
- Joined: Mon Aug 24, 2009 2:08 pm
- Location: If you need to know, ask me
- Contact:
Re: Bring on the fat(ter) tyres
Postby RonK » Wed Oct 26, 2016 2:54 pm
Heretic!vosadrian wrote:Going by that rationale, surely thinner tyres/ more pressure is faster on smooth surfaces, as less "energy" goes to body as there is less energy for the tyre to transmit. On a perfectly smooth road there would be zero energy the body has to counteract. This being the case, would not thin tyres and high pressure be fastest on smooth roads, and fat tyres with less pressure on bumpy roads (chip gravel/dead road), and there would be some crossover in the middle.misterhorsey wrote:The podcast gets into the nitty gritty. But a higher psi = a stiffer ride (which may feel more rigid and faster) basically means more energy is transferred into your body, and thus your body has to counteract those forces. Having a lower psi allows the tyre to deform and absorb more of that energy for a net savings of energy you put to achieve an equal speed. Or something like that.
Personally I am 70kg and run about 110psi in 23s. Suppleness does not really bother me too much, but a squirmy tyre does. There is no indication my setup is slow.
You would dare to question the opinion of the infallible Jan Heine?
You should be burned at the stake.
- Thoglette
- Posts: 6599
- Joined: Thu Feb 19, 2009 1:01 pm
Re: Bring on the fat(ter) tyres
Postby Thoglette » Wed Oct 26, 2016 4:27 pm
We get close to smooth roads at an indoor velodrome. White lines on fresh hot mix come close, too.vosadrian wrote:This being the case, would not thin tyres and high pressure be fastest on smooth roads, and fat tyres with less pressure on bumpy roads (chip gravel/dead road), and there would be some crossover in the middle.
RonK wrote:You would dare to question the opiniin of the infallible Jan Heine?You should be burned at the stake.
Actually, if you read/listen to what Jann says, you'll find he agrees with vosadrian. He has provided a fair bit of data about the where and when of the cross over points too.
It's when people (like me ) turn it into a dogma ("the fattest tyre that will fit") that the nuances get lost.
"People are worthy of respect, ideas are not." Peter Ellerton, UQ
-
- Posts: 1176
- Joined: Fri Mar 22, 2013 4:58 pm
Re: Bring on the fat(ter) tyres
Postby vosadrian » Thu Oct 27, 2016 9:39 am
I didn't read the source, but it makes sense to me. About half my riding is on pretty smooth roads and the other on pretty ordinary road including some pretty dead chip gravel roads. Most of the bad roads are in bunch rides, so not too fussed to lose a few Watts on a non-ideal surface when I have no problem staying with the bunch anyway.Thoglette wrote:We get close to smooth roads at an indoor velodrome. White lines on fresh hot mix come close, too.vosadrian wrote:This being the case, would not thin tyres and high pressure be fastest on smooth roads, and fat tyres with less pressure on bumpy roads (chip gravel/dead road), and there would be some crossover in the middle.
RonK wrote:You would dare to question the opiniin of the infallible Jan Heine?You should be burned at the stake.
Actually, if you read/listen to what Jann says, you'll find he agrees with vosadrian. He has provided a fair bit of data about the where and when of the cross over points too.
It's when people (like me ) turn it into a dogma ("the fattest tyre that will fit") that the nuances get lost.
I have never actually tried wider tyres. I have had people tell me how good they are, but I never noticed them suddenly get faster or slower. They tell me how much smoother it is, but I have no issue with how smooth my setup is so no need to try. Most of my wheels seem to be designed for 23s so I use 23s. I am sure there are some aero considerations using wider tyres on aero wheels that are not specifically designed for wider tyres. Swissside do a lot of aero testing of wheels and they seem to recommend Conti GP4k 23s as the ideal tyre for their wheels.
-
- Posts: 908
- Joined: Mon Sep 09, 2013 5:33 pm
Re: Bring on the fat(ter) tyres
Postby koshari » Thu Oct 27, 2016 9:46 am
- silentC
- Posts: 2442
- Joined: Mon May 05, 2014 5:24 pm
- Location: Far South Coast NSW
Re: Bring on the fat(ter) tyres
Postby silentC » Thu Oct 27, 2016 9:55 am
I run 25s because that's what my new bike came with and I didn't see any reason to change. I'm happy with them and I see a lot of the other guys are changing to 25s too.
- Me
- Thoglette
- Posts: 6599
- Joined: Thu Feb 19, 2009 1:01 pm
Re: Bring on the fat(ter) tyres
Postby Thoglette » Thu Oct 27, 2016 10:51 am
"People are worthy of respect, ideas are not." Peter Ellerton, UQ
-
- Posts: 8
- Joined: Mon Sep 12, 2016 3:59 pm
Re: Bring on the fat(ter) tyres
Postby richard.allan » Thu Oct 27, 2016 4:29 pm
A lot of people are adverse to change. Personally, I like to give new ideas a go & then make up my own mind. Otherwise we'd all just be stuck in the past...
- singlespeedscott
- Posts: 5510
- Joined: Sun Jan 20, 2008 4:35 pm
- Location: Elimbah, Queensland
Re: Bring on the fat(ter) tyres
Postby singlespeedscott » Thu Oct 27, 2016 5:30 pm
-
- Posts: 8
- Joined: Mon Sep 12, 2016 3:59 pm
Re: Bring on the fat(ter) tyres
Postby richard.allan » Thu Oct 27, 2016 7:54 pm
- Thoglette
- Posts: 6599
- Joined: Thu Feb 19, 2009 1:01 pm
Re: Bring on the fat(ter) tyres
Postby Thoglette » Fri Oct 28, 2016 12:10 am
Yes, but some people are "too time poor" to actually access and comprehend the articles.richard.allan wrote:Well that's a tad simplistic.
"People are worthy of respect, ideas are not." Peter Ellerton, UQ
-
- Posts: 8
- Joined: Mon Sep 12, 2016 3:59 pm
Re: Bring on the fat(ter) tyres
Postby richard.allan » Fri Oct 28, 2016 8:16 am
- General Australian Cycling Topics
- Info / announcements
- Buying a bike / parts
- General Cycling Discussion
- The Bike Shed
- Cycling Health
- Cycling Safety and Advocacy
- Women's Cycling
- Bike & Gear Reviews
- Cycling Trade
- Stolen Bikes
- Bicycle FAQs
- Serious Biking
- Audax / Randonneuring
- Retro biking
- Commuting
- MTB
- Recumbents
- Fixed Gear/ Single Speed
- Track
- Electric Bicycles
- Cyclocross and Gravel Grinding
- Dragsters / Lowriders / Cruisers
- Children's Bikes
- Cargo Bikes and Utility Cycling
- Road Racing
- Road Biking
- Training
- Time Trial
- Triathlon
- International and National Tours and Events
- Cycle Touring
- Touring Australia
- Touring Overseas
- Touring Bikes and Equipment
- Australia
- Western Australia
- New South Wales
- Queensland
- South Australia
- Victoria
- ACT
- Tasmania
- Northern Territory
- Country & Regional
- The Market Place
- Member to Member Bike and Gear Sales
- Want to Buy, Group Buy, Swap
- My Bikes or Gear Elsewhere
- Cycling Brands
- Cannondale
- Garmin
- Giant
- Shimano
- Trek
Who is online
Users browsing this forum: No registered users
- All times are UTC+11:00
- Top
- Delete cookies
About the Australian Cycling Forums
The Australian Cycling Forums is a welcoming community where you can ask questions and talk about the type of bikes and cycling topics you like.
Bicycles Network Australia
Forum Information
Connect with BNA
This website uses affiliate links to retail platforms including ebay, amazon, proviz and ribble.