weight times power plus tired legs equal the delta of ???
September 29, 2010 11:07 AM Subscribe
I rode in a century ride last Sunday, It took me 11:34 on a mountain bike, with a 20lb frame, if everything else was equal how much faster could I have completed the ride, if I had a top of the line road cycle?
I don't know. The biggest advantage a road bike has is riding position, aerodynamics and tires. All those can be overcome by changing some parts out on a mountain bike to get yourself more comfortable/aerodynamic and lessen the energy you're losing to those knobby/low pressure tires.
I suspect that over a century a 1970's road bike will still be within sight of a brand new titanium lightweight, all else being equal. Unless it's hilly, the weight isn't much of an issue.
posted by pjaust at 11:13 AM on September 29, 2010
I suspect that over a century a 1970's road bike will still be within sight of a brand new titanium lightweight, all else being equal. Unless it's hilly, the weight isn't much of an issue.
posted by pjaust at 11:13 AM on September 29, 2010
That is amazing! That must have been very difficult.
My entire steel-framed road bike, with wheels, weighs in at around 20lbs. It's impossible to say how much faster you could have been, but I can tell you that the difference between riding on knobby Velociraptors and my Continental 700/23's on pavement is night and day. The contact area of the tire plays a huge part in how much effort it takes to stay rolling.
posted by tmt at 11:14 AM on September 29, 2010
My entire steel-framed road bike, with wheels, weighs in at around 20lbs. It's impossible to say how much faster you could have been, but I can tell you that the difference between riding on knobby Velociraptors and my Continental 700/23's on pavement is night and day. The contact area of the tire plays a huge part in how much effort it takes to stay rolling.
posted by tmt at 11:14 AM on September 29, 2010
You averaged about nine miles per hour, which is pretty good, considering. A skilled amateur cyclist could double that on a road bike.
Since I've never done distance riding on a mountain bike, and I don't know how skilled you are, it's impossible to say how fast you'd do it.
Check out this forum thread on century times.
posted by supercres at 11:18 AM on September 29, 2010
Since I've never done distance riding on a mountain bike, and I don't know how skilled you are, it's impossible to say how fast you'd do it.
Check out this forum thread on century times.
posted by supercres at 11:18 AM on September 29, 2010
A couple weeks ago I did a mini tour doing close to 100 miles in a day. I think we averaged about 16mph on our not-top-of-the-line road bikes. 100 mi / 16 mph = 6:15 without breaks, but we took breaks.
posted by domnit at 11:19 AM on September 29, 2010
posted by domnit at 11:19 AM on September 29, 2010
Hard to say, depends a bit on the course, your fitness level and how long you dilly-dally at the stops. I would say that a road bike will be faster no matter what. It's more efficient for what you're doing, lighter, etc. How much faster? Too many variables. And I don't think "good road bike" versus "top of the line" is going to have much bearing.
My husband did a century earlier this year, he has a nice road bike and is very fit. He did it in under 7 hours. However, the first hour and a half was a steep uphill which he said was very challenging. There were rollers in there but he said it was a total beast. If it had been flat for that 20 or so miles, he probably could have shaved another 30 to 40 minutes off his time. And, of course, after the hill, he sat around at that first stop and recovered a bit longer than he might have.
The funny thing about cyclists is they are always trying to get a lighter bike. Now, if you're already a skinny guy with no fat to lose, sure, go lighter on the bike with more expensive, carbon fiber components. However, you could lose ten pounds off your body and have more effect. My point being: it's not all about the bike.
However, the jump from mountain bike to road bike is a biggie and worth pondering if you want to do a lot of these longer rides. Go take a few for a spin!
posted by amanda at 11:19 AM on September 29, 2010
My husband did a century earlier this year, he has a nice road bike and is very fit. He did it in under 7 hours. However, the first hour and a half was a steep uphill which he said was very challenging. There were rollers in there but he said it was a total beast. If it had been flat for that 20 or so miles, he probably could have shaved another 30 to 40 minutes off his time. And, of course, after the hill, he sat around at that first stop and recovered a bit longer than he might have.
The funny thing about cyclists is they are always trying to get a lighter bike. Now, if you're already a skinny guy with no fat to lose, sure, go lighter on the bike with more expensive, carbon fiber components. However, you could lose ten pounds off your body and have more effect. My point being: it's not all about the bike.
However, the jump from mountain bike to road bike is a biggie and worth pondering if you want to do a lot of these longer rides. Go take a few for a spin!
posted by amanda at 11:19 AM on September 29, 2010
Congratulations! Good for you for competing the ride. If by a 20lb frame you mean that the whole bike weighed 20 pounds, that's really not very heavy if you consider that even a significant weight loss on the bike (say five pounds or 25 percent) is going to be proportionally smaller compared to the total weight of rider + bike. What might make more of a difference is tires—does your mountain bike have wide, knobby tires? Smooth road tires would speed you up—they don't have to be super skinny 23mm tires; as long as they're smooth, then 28mm or 32mm road tires would have a much lower rolling resistance than knobbies. You can easily put this kind of tire on your mountain bike without having to splurge on a top of the line road bike.
Anyway, all that said, a decently fit cyclist on a decent road-oriented bike can ride a century in about 6.5 hours of pedaling time—about 16 mph average—again, not counting stoppage time. That would be for a mostly solo ride, and of course could vary somewhat depending on how fit, and the course and wind conditions, etc. Riding in a paceline or group will speed up that time somewhat, as you can really save a lot of energy due to lowered wind resistance in the group.
posted by chinston at 11:20 AM on September 29, 2010
Anyway, all that said, a decently fit cyclist on a decent road-oriented bike can ride a century in about 6.5 hours of pedaling time—about 16 mph average—again, not counting stoppage time. That would be for a mostly solo ride, and of course could vary somewhat depending on how fit, and the course and wind conditions, etc. Riding in a paceline or group will speed up that time somewhat, as you can really save a lot of energy due to lowered wind resistance in the group.
posted by chinston at 11:20 AM on September 29, 2010
Anecdotaly, when I switched from a mountain frame to a road one, I saw my cruising speed jump from the low 20s to the high 20s-low 30s, say a difference of 7-8 km/hr, perhaps a 25% improvement. How much of that was from the switch in fame and/or improvements to aerobic capacity because I was riding more, I couldn't say.
posted by bonehead at 11:36 AM on September 29, 2010
posted by bonehead at 11:36 AM on September 29, 2010
I did a couple centuries this year on my 20lb steel road bike (Surly Pacer) at just under 6 hours. The main difference, I think, is the high-pressure skinny tires. A mountain bike just isn't made for going that far, and the soft, knobby tires move slowly and sap energy.
If you like the way your mountain bike feels, you'd get improvements from 26" slick tires.
posted by M.C. Lo-Carb! at 12:02 PM on September 29, 2010
If you like the way your mountain bike feels, you'd get improvements from 26" slick tires.
posted by M.C. Lo-Carb! at 12:02 PM on September 29, 2010
When I switch from summer slicks to winter studs, I lose 2-4 km/h. Pushing hard on a nice clear straight, I can hold 35km/h, but if I crouch and bring my arms in I can push that up at least 4km/h. I'm riding a 30+lb rigid frame 26" wheel bike (the winter bike is actually a little lighter, and it has 700c wheels, so the tire switch might be worse than my number above).
The thing you have to remember is, friction losses increase linearly with speed, but aerodynamic losses increase by the cube of the speed. That means up to 20km/h your riding position hardly matters, by the time you hit 30km/h it is fairly important, at 40km/h it is everything.
Also, while losing fat is good for the weight of the vehicle, it is also good for the aerodynamics. When you lose a couple of inches from your waste, you make a smaller frontal area on your vehicle, and that let's you go a lot faster. For people travelling fast and level, reducing the frontal area is far more important than weight.
posted by Chuckles at 1:01 PM on September 29, 2010
The thing you have to remember is, friction losses increase linearly with speed, but aerodynamic losses increase by the cube of the speed. That means up to 20km/h your riding position hardly matters, by the time you hit 30km/h it is fairly important, at 40km/h it is everything.
Also, while losing fat is good for the weight of the vehicle, it is also good for the aerodynamics. When you lose a couple of inches from your waste, you make a smaller frontal area on your vehicle, and that let's you go a lot faster. For people travelling fast and level, reducing the frontal area is far more important than weight.
posted by Chuckles at 1:01 PM on September 29, 2010
Pushing hard on a nice clear straight, I can hold 35km/h, but if I crouch and bring my arms in I can push that up at least 4km/h.
Err.. What I mean to say is, on a nice clear straight where I feel like 35km/h is the speed I can hold, if I bring my arms in and crouch I can get to 39km/h comfortably enough.
I'm not really sure what my actual fitness is right now :) The absolute numbers aren't the point though.. The point is how much difference the riding position change makes at roughly what speed.
posted by Chuckles at 1:06 PM on September 29, 2010
Err.. What I mean to say is, on a nice clear straight where I feel like 35km/h is the speed I can hold, if I bring my arms in and crouch I can get to 39km/h comfortably enough.
I'm not really sure what my actual fitness is right now :) The absolute numbers aren't the point though.. The point is how much difference the riding position change makes at roughly what speed.
posted by Chuckles at 1:06 PM on September 29, 2010
Yeah most people will average about 15mph on a road bike on a century, if you're in pretty good shape. Much faster than that and, wow, but 6-7 hours is pretty reasonable.
posted by rachelpapers at 1:34 PM on September 29, 2010
posted by rachelpapers at 1:34 PM on September 29, 2010
Other who say 6-7 hours are right on. You will find the experience of road cycling to be a bit different, but I think it is a positive difference. Any reasonable road bike will yield a considerable speed gain over 100 miles, so don't get too worried about top of the line. The engine (you) has a lot more to do with the speed until you find you are regularly cruising ~25mph.
posted by dgran at 2:13 PM on September 29, 2010
posted by dgran at 2:13 PM on September 29, 2010
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Had you ever ridden anything near this long before?
posted by RustyBrooks at 11:10 AM on September 29, 2010