Following on from the recent discussion on 'how fast have you been?', I wonder what the panel think the rough difference is in MPH between a typical racing tyre and a typical knobbly 2" MTB tyre when used on a matching typical bike with a typical rider in a typical riding position wearing a typical helmet etc (obviously there are lots of variables - hence the 'rough difference'😉.
I can get to about 28mph on a reasonably flat road on my typical MTB with 1.9" tyres but I can't sustain that for more than half a mile or so. 20mph might be more of a cruising speed. I have never had the opportunity to try a racing bike with those super thin tyres and large chain ring so I was wondering what an equivalent speed for effort on a racer might be estimated at?
Completely impossible to gauge? Or is there a +10mph difference between 2" knobbly tyres and slick racing tyres?
Completely impossible to gauge? Or is there a +10mph difference between 2" knobbly tyres and slick racing tyres?
I don't know what the quantitative difference is, but qualitatively it's /huge/. Even the difference between a proper mud-plugger and a relatively wide touring tyre is instantly noticeable, and I don't ever like to have knobblies on tarmac if I can help it because they're such hard work.
So whatever the answer is in terms of numbers, Executive Summary is it's well worth getting slicks if you're spending much time on the road.
Pete. -- Peter Clinch Medical Physics IT Officer Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital Fax 44 1382 640177 Dundee DD1 9SY Scotland UK net [email hidden] http://www.dundee.ac.uk/~pjclinch/
Following on from the recent discussion on 'how fast have you been?', I wonder what the panel think the rough difference is in MPH between a typical racing tyre and a typical knobbly 2" MTB tyre when used on a matching typical bike with a typical rider in a typical riding position wearing a typical helmet etc (obviously there are lots of variables - hence the 'rough difference'😉.
I can get to about 28mph on a reasonably flat road on my typical MTB with 1.9" tyres but I can't sustain that for more than half a mile or so. 20mph might be more of a cruising speed. I have never had the opportunity to try a racing bike with those super thin tyres and large chain ring so I was wondering what an equivalent speed for effort on a racer might be estimated at?
Completely impossible to gauge? Or is there a +10mph difference between 2" knobbly tyres and slick racing tyres?
Umm.. get a road bike and sign up for a few time trials.. You won't be embarassed.
Typically I'd expect a difference of about 5kph going from knobblies to slicks on the same bike. You'll get a big improvement from a more aero position as well. The faster you go, the less of a difference the tyres will make (due to wind resistance rising as an exponential of speed).
I can get to about 28mph on a reasonably flat road on my typical MTB with 1.9" tyres but I can't sustain that for more than half a mile or so.
Bleedin' 'ell! I don't think you really need to worry much about the difference. Freewheeling down a steep hill on tarmac the bike "flats out" at about 35mph with knobblies (albeit 2.2"😉. Pedalling on the flat, my legs "flat out" at about 18-20mph. I do only have a 36/11 top gear though.
Typically I'd expect a difference of about 5kph going from knobblies to slicks on the same bike.
ISTR about 2mph when I switched from knobblies to slicks on my ATB a decade or so ago. I got a similar improvement when I later switched from City Slickers at 60psi to S-Licks at 90psi.
-- Danny Colyer <URL:http://www.colyer.plus.com/danny/> Reply address is valid, but that on my website is checked more often "He who dares not offend cannot be honest." - Thomas Paine
20mph might be more of a cruising speed. I have never had the opportunity to try a racing bike with those super thin tyres and large chain ring so I was wondering what an equivalent speed for effort on a racer might be estimated at?
Get a racer, do time trials!
Quoted message said:
Completely impossible to gauge? Or is there a +10mph difference between 2" knobbly tyres and slick racing tyres?
It depends on lots of things, but you can fiddle around with lots of things here:
<url:www.kreuzotter.de/english/espeed.htm>
The difference is around 1.5 to 2.6 kph. Doesn't sound a lot, but as a percentage of your speed it is very significant.
Following on from the recent discussion on 'how fast have you been?', I wonder what the panel think the rough difference is in MPH between a typical racing tyre and a typical knobbly 2" MTB tyre when used on a matching typical bike with a typical rider in a typical riding position wearing a typical helmet etc (obviously there are lots of variables - hence the 'rough difference'😉.
I can get to about 28mph on a reasonably flat road on my typical MTB with 1.9" tyres but I can't sustain that for more than half a mile or so. 20mph might be more of a cruising speed. I have never had the opportunity to try a racing bike with those super thin tyres and large chain ring so I was wondering what an equivalent speed for effort on a racer might be estimated at?
Completely impossible to gauge? Or is there a +10mph difference between 2" knobbly tyres and slick racing tyres?
There's usually said to be about 5% difference. But if you're sustaining 20mph on knobblies you're already up to the point where air resistance starts to get serious, and it might be a bit less than 5% for you.
Completely impossible to gauge? Or is there a +10mph difference between 2" knobbly tyres and slick racing tyres?
There's usually said to be about 5% difference. But if you're sustaining 20mph on knobblies you're already up to the point where air resistance starts to get serious, and it might be a bit less than 5% for you.
Though slim racing tyres on slim rims are going to have an aerodynamic advantage over 2" tyres on top of the rolling resistance advantage of high pressure smooth tyres over knobblies.
"Noel" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Following on from the recent discussion on 'how fast have you been?', I wonder what the panel think the rough difference is in MPH between a typical racing tyre and a typical knobbly 2" MTB tyre when used on a matching typical bike with a typical rider in a typical riding position wearing a typical helmet etc (obviously there are lots of variables - hence the 'rough difference'😉.
I can get to about 28mph on a reasonably flat road on my typical MTB with 1.9" tyres but I can't sustain that for more than half a mile or so. 20mph might be more of a cruising speed. I have never had the opportunity to try a racing bike with those super thin tyres and large chain ring so I was wondering what an equivalent speed for effort on a racer might be estimated at?
Completely impossible to gauge? Or is there a +10mph difference between 2" knobbly tyres and slick racing tyres?
Knobblies are slower. Except for a nearby hill, which I can rocket down at 40+ on the MTB, but the road bike scares you half to death at 30.
No-one has mentioned how much better a road tyred bike handles, especially how much quicker it can corner than one with knobblies.
"Noel" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Following on from the recent discussion on 'how fast have you been?', I wonder what the panel think the rough difference is in MPH between a typical racing tyre and a typical knobbly 2" MTB tyre when used on a matching typical bike with a typical rider in a typical riding position wearing a typical helmet etc (obviously there are lots of variables - hence the 'rough difference'😉.
