How much faster is a road bike than an FS MTB?
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Except that for the same pressure a wider tyre has a lower rolling resistance, so big oops I'm afraid.Rolling resistance for one, a major one, unless you have 23C tyres on the MTB as well as it being 19lb! 8)Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0 -
Except that for the same pressure a wider tyre has a lower rolling resistance, so big oops I'm afraid.Rolling resistance for one, a major one, unless you have 23C tyres on the MTB as well as it being 19lb! 8)
A wider tyre of the same tread on the same rim at the same pressure up to a point will have a lower rolling resistance until that is outweighed by the aero disadvantage. Hence the peloton has gone from 23's to 25's in recent years but unlikely to jump to 28's or more unless for a cobbled classic. A treaded tyre above 32mm on a wider rim at a lower pressure....yeah right oops.
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Rolling resistance for one, a major one, unless you have 23C tyres on the MTB as well as it being 19lb! 8)
Completely aside from the point the Rookie raises that is irrelevant. You'd not get slower over time because of rolling resistance. There would be a power number associated with overcoming that, which would be a constant, and would mean you'd go slower, but that rate wouldn't change, unless you had a slow puncture. I'm still not sure I get your point. Or, rather, I don't think you get mine. Or you don't get physics.0 -
Rolling resistance for one, a major one, unless you have 23C tyres on the MTB as well as it being 19lb! 8)
Completely aside from the point the Rookie raises that is irrelevant. You'd not get slower over time because of rolling resistance. There would be a power number associated with overcoming that, which would be a constant, and would mean you'd go slower, but that rate wouldn't change, unless you had a slow puncture. I'm still not sure I get your point. Or, rather, I don't think you get mine. Or you don't get physics.
Firstly, very quick time up the Box Hill zig zag!
Your power output in doing on that on your mtb would mean the same power output on your road bike would be a quicker time. It really is that simple.0 -
Edit: I'm not explaining myself well. I suspect the speed differential would change because fatigue from needing to hold a less comfortable aero position on the MTB would become a factor. Physics dictate that an additional power output would be required to get over the extra rolling resistance, but it's not a physical given that the speed differences would diverge. Time, yes. Distance, yes. Both as a function of going faster. but just because there was a 1mph difference in average after 5 miles doesn't mean there'd be a 10mph difference after 50 miles. I stand by what I said.
And thank you, I don't ride it that often, my Leith hill one is better, comparably 0 -
Ahem but you said rolling resistance and have now corrected it to aero to try and dig yourself out your whole ...so that's a double oops....you should now PUT THE SHOVEL DOWN.
Except that for the same pressure a wider tyre has a lower rolling resistance, so big oops I'm afraid.Rolling resistance for one, a major one, unless you have 23C tyres on the MTB as well as it being 19lb! 8)
A wider tyre of the same tread on the same rim at the same pressure up to a point will have a lower rolling resistance until that is outweighed by the aero disadvantage. Hence the peloton has gone from 23's to 25's in recent years but unlikely to jump to 28's or more unless for a cobbled classic. A treaded tyre above 32mm on a wider rim at a lower pressure....yeah right oops.Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0 -
Ahem but you said rolling resistance and have now corrected it to aero to try and dig yourself out your whole ...so that's a double oops....you should now PUT THE SHOVEL DOWN.
Except that for the same pressure a wider tyre has a lower rolling resistance, so big oops I'm afraid.Rolling resistance for one, a major one, unless you have 23C tyres on the MTB as well as it being 19lb! 8)
A wider tyre of the same tread on the same rim at the same pressure up to a point will have a lower rolling resistance until that is outweighed by the aero disadvantage. Hence the peloton has gone from 23's to 25's in recent years but unlikely to jump to 28's or more unless for a cobbled classic. A treaded tyre above 32mm on a wider rim at a lower pressure....yeah right oops.
I think me and njee20 reached a point of understanding. I realise some people need to put a dash on their forum arguments won chart, you go for it. 0 -
All I know is, roadies always overtake me.All the gear, no idea and loving the smell of jealousy in the morning.
Kona Process 134 viewtopic.php?f=10017&t=129946070 -
All I know is, roadies always overtake me.
That's just because you're old, fat and slow.Transition Patrol - viewtopic.php?f=10017&t=130702350 -
All I know is, roadies always overtake me.
That's just because you're old, fat and slow.
Seems reasonable. I overtake plenty of roadies on my MTB.0 -
I overtook someone once.
A small girl on a pink glittery bike. And she had go faster tassels.I don't do smileys.
There is no secret ingredient - Kung Fu Panda
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Parktools0 -
I overtook the local (read elderly) road cycling club once - on the road (from one muddy path to another), up a hill.
I was on my MTB and mud was flying off my tyres all over the place.. The look on their faces was priceless. I still said hello and they did, to their credit, say it back. They were significantly redder than I was by the time they got to the top though..
Boardman HT Team - Hardtail
Rose Pro-SL 2000 - Roadie0 -
You presumably knew that because you stopped and waited at the top...? Kinda nullifies your awsums.0
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Nope... They were crimson by half way up - at which point I lost sight of them as I was over the peak.. Didn't take a genius to work out how much redder they would be at the top
Tbh though, it wasn't hard. They actually state on their website that they aim to average about 12mph when out on the road.. That's really not a lot ) and therefore they go even slower up a hill.. (I average 16-18mph when out on the road on my roadie - when I aim for the hills )
bob6397Boardman HT Team - Hardtail
Rose Pro-SL 2000 - Roadie0 -
You looked back over your shoulder just to see how red they were'. I think so me of that mud on your tyres was bovine excrement! It sure smells like it.Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0
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So you beat a bunch of guys who advertise doing slow rides? Yet I find myself on the verge of a swoon at your average speeds. I'm conflicted.0
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I'm terribly unfit. But dragging my FS 29r around to commute was horrible. Picked up an old hybrid that my old man doesn't use and it's helped me immensely! Makes riding my MTB on the trails much easier too!!0
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We should note that faster riders get more benefit from aero gains than slower riders.Meh. There are a few hills around here I've ridden dozens of times on my road bike and my MTB and the MTB is the fastest. Aero is the biggest difference. People want to think it's more of a difference than it is IMO. 30% gains are complete tosh if you've got a vaguely XC focuses MTB.You only need two tools: WD40 and Duck Tape.
If it doesn't move and should, use the WD40.
If it shouldn't move and does, use the tape.0 -
Aero benefits increase exponentially with speed yes.0
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Its similar to riding on the drops on a road bike compared to the hoods / bar. At slow speed no real difference but as you go faster a much more marked effect. To over take someone on a road bike riding at speed on the drops on a mountain bike and keep ahead of them you would need to be seriously fit.
I am not that fast but can cruise at about 18mph with no great effort on my road bike in the drops but keeping the same speed going on my xc MTB on road would cripple me.0 -
Rubbish. Hands either side of the stem is more aero. If you're getting dropped its because they're fitter. Drops gives a lot of control, but isn't necessarily the most aero position.
Caveats in there about type of MTB etc to make folk feel better.0 -
Rubbish. Hands either side of the stem is more aero. If you're getting dropped its because they're fitter. Drops gives a lot of control, but isn't necessarily the most aero position.
Caveats in there about type of MTB etc to make folk feel better.
Surely tri bars would be more aero, hand either side of stem means an upright body position and more drag??0 -
Bend your elbows - I was assuming this hypothetical rider didn't have clip on tri-bars to hand!0
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Rubbish. Hands either side of the stem is more aero. If you're getting dropped its because they're fitter. Drops gives a lot of control, but isn't necessarily the most aero position.
Caveats in there about type of MTB etc to make folk feel better.
Clearly none of this is based on fact? Drops is more aero as it puts you're torso in a lower position, width when on the drops has a lesser effect on overall frontal area. To hold the near the stem and stay low would be too uncomfortable to hold for a decent length of time hence why tri-bars are used when allowed.
Loads and loads and loads and then a bit more than that is the answer to the original question and its about the sum of the variables. Position; rolling resistance due to hard, narrow tyres; weight (especially uphill)...etc,etc,etc.. Anecdotes about how so and so beat a roadie on his mtb are pointless. Two equally fit riders, one on a road bike the other on an mtb (even if it was an xc 29er hardtail never mind a fs), the road bike rider would disappear up the road never to be seen again.0 -
Clearly none of this is based on fact? Drops is more aero as it puts you're torso in a lower position, width when on the drops has a lesser effect on overall frontal area. To hold the near the stem and stay low would be too uncomfortable to hold for a decent length of time hence why tri-bars are used when allowed
Define "fact"? Drops put you lower because folk have no core strength and just fall onto their hands. I go faster for a given power by bending my elbows on the hoods, even better is "imaginary aero bars", but yes, hard to do for more than a few minutes. The drops have a place for sprinting and descending, where handling is better, but if i want to get/close a gap in a road race I'll not use my drops.
Never disputed that a road bike is quicker, but the answer to the question in the OP is, IMO, less than folk think.0 -
http://www.bikecalculator.com/
If you are averaging 150 watts of power, then 14.8 mph for a MTB and 17.86 for a road bike on the hoods, and 19.34 for a road bike on the drops.0 -
I don't see any option for MTB tyres.....
And of course an 'dale Fsi will be a lot faster on road than a Giant Glory....all in all that added nothing.Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0 -
What a crock of shit, it's hardly that straight forward. As I said, it's entirely possible to be more aero on the hoods, and I'm more aero on my MTB than half the people you see on road bikes with 800mm head tubes!0
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This thread is certainly doing some hard miles. Perhaps this needs to be posted on the Road Bike forum and we all meet up for a big race!? 8) 0
