How do on-road mountain bike speeds translate to road bike speeds?
When cycling on roads on my mountain bike, I generally get around 10-12 miles per hour on a flat surface.
What sort of speeds can I expect to get on a road bike?
I think this is a slightly different question - it seems to be "If I can go X mph on bike A, and switch to bike B, what will my speed be?"
As @Gary.Ray points out, you seem to be asking how to estimate _your_ road bike speed based on _your_ mountain bike speed, but many answers seem to ignore this. Admittedly your title seemed to me to make it pretty clear, but I wonder if you might not emphasise this in the body of the question as well.
On my reasonably flat commute I average around 16 mph on my road bike, but your average speed is dependent on many different factors. A general rule of thumb is that if you are switching from a mountain bike with knobbies to a road bike you will be between 15-20% faster at the same watts/effort. Typically that's only a change of 2-3 mph.
I teach a bike commuting workshop, and one of the most common questions is whether to switch from a mountain bike to a road bike in order to increase speed. Typically, I tell people to try three things first:
- Swap out your knobby tires for high pressure slicks. You can find 1.25" -1.5" slick tires that fit mountain bike rims and run at between 75 - 90 lbs of pressure. These will dramatically reduce rolling resistance.
- If you have a suspension either lock it out, or set it as stiff as you can. Locking out your suspension will cause more of your effort to be transferred directly through the drive-train and translate into less loss of momentum from shock absorption.
- Try clipless pedals. Your pedal stroke will be more efficient, again resulting in an increase in speed.
If you do those three things the only real differences between a road bike and your mountain bike will be the weight (which matters a lot more when accelerating than it does when you are already rolling) and surface area resistance from riding in the drops. But most road bikers don't spend much time in the drops.
Finally, your weight and fitness make a huge difference. I frequently pass road bike riders while on my commuter rigid frame mountain bike with high pressure slicks.
I would also add that in a road bike I find that you can put power into the pedals easier than on a mountain or especially a cruiser bike.
I suspect the difference is even greater for someone in good physical shape. My touring bike, unloaded, is about 25lb and has 26x2.0 slicks. I find I cruise at 15mph on it, whereas on my racing bike it feels like I do 20mph+ without even trying. Don't underestimate the effects of weight, stiffness, and rolling resistance.
This answer ignores the primary difference between a road bike and a mountain bike. That's fine, for commutes or solo rides, but not so good if you ride with someone who's on a road bike while you're on a mountain bike. The difference is gear ratio. For instance, the typical top end MTB gearing, with a 44t big ring and a 12t rear, and a typical cadence of 90 RPMs gives you a speed of 26 mph possible. The same cadence in the top gear of a compact double road bike, a 50 x 11 usually, gives a possible top speed of 33 mph, at the same level of effort. Standard 53 x 12 is about 32 mph.
Of course, you need to be fit enough to maintain that pace. But since you're comparing the same levels of effort, that's a bit more than 2-3 miles an hour. More like 8-9mph faster. Which on a 20 mile commute = 46 minutes on the MTB, versus 33 minutes on a road bike, at the same level of effort. This is strictly a matter of gearing and mechanical advantage, for a roughly 30% increase in speed. BTW, all of the math here assumes the same tire diameter, which is not typical. The difference in wheel size alone, assuming high pressure slicks, is worth the 2-3 mph difference that @GaryRay claims.
I first read your post and was like "clipless pedals", huh? But then I came across this article which explains why they're called "clipless" (when they do actually clip in)... http://gizmodo.com/5990381/why-you-should-switch-to-clipless-pedals
One minor difference is the rider position. Most road bikes have drop bars so the rider is crouched over vs sitting somewhat upright. You can add drop bars to your mountain bike to help with that. I would say this is fairly important because at about 15 mph air resistance is a lot more dominant that rolling resistance.
Just a single data point but these are the speeds I would observe on flat ground for 3 - 5 mile rides- 1)Mountain Bike 26" with knobbies, no clips, suspension normal, bike weight >25 lbs very close 15 mph 2) Mountain Bike 26" flat tires, with clips, locked out suspension, bike weight > 25 lbs: about 18 mph. 3) Road Bike 700cc small flat tires, with clips, bike weight about 12 lbs: 19 mph. So most of the increase you get from flats and clips. But you still get a bit from the road bike.
Fitness is the biggest factor in how fast you can maintain. To provide a point of comparison, a local club here in the Seattle area holds an early spring Time Trial (race against the clock) every March. Looking at the results--and keep in mind, these are racers going all out, just short of barfing when they finish--those that competed averaged from 20 mph to 30 mph. Personally there is no way I can maintain 20 mph on the flats due to my lack of conditioning.
When The Fat Cyclist wrote about riding in the team car for a stage of the Tour of California, he got to follow one of Team Radio Shack's riders. His rider was planning on making it an 'easy' day, and was riding around 30 mph.
In conclusion...Your Mileage May Vary!
edit: btw, my personal speed (48-year-old dude, about 30 pounds overweight) is about 16.5 mph on smooth flats with no wind. Overall speed for a long ride, counting little stops to make a phone call, fill a water bottle, etc. averages about 13.5 mph.
Yeah, it's really about fitness. "Faster than without a road bike" is how fast you should go with a road bike. The exact numbers depend on you.
The biggest difference between a mountain bike and a road bike is gear ratio.
Any other difference can be overcome. You can change tires, increase pressure, lock out your suspension, and use clipless pedals, but if you are on a typical mountain bike, your gearing will still limit you to a speed which is roughly 30% slower than the same effort will produce on a mountain bike.
For instance, the typical top end MTB gearing, with a 44t big ring and a 12t rear, and a typical cadence of 90 RPMs gives you a speed of 26 mph possible. See the chart below for the speed of each gear combination with a typical MTB gearing.
The same cadence in the top gear of a compact double road bike, a 50 x 11 usually, gives a possible top speed of 33 mph, at the same level of effort.
Standard 53 x 12 is about 32 mph, with all else equal.
Of course, you need to be fit enough to maintain that pace. But since you're comparing the same levels of effort, that's a bit more than 2-3 miles an hour. More like 9 mph faster.
Which on a 20 mile commute = 46 minutes on the MTB, versus 33 minutes on a road bike, at the same level of effort.
This is strictly a matter of gearing and mechanical advantage, for a roughly 30% increase in speed.
BTW, all of the math here assumes the same tire diameter, which is not typical. (See the Charts for complete and accurate differences, with crank lengths, tire size, and gear spread accounted for)
The difference in wheel size alone, assuming high pressure slicks, is worth the 2 mph difference that @Gary.Ray claims in his answer above. This last chart is identical to the MTB chart above, except I've changed the wheel and tire size to match a road bike. RPMs, gearing, and pressure are identical to the first MTB chart. The difference in gearing from the wheel size change is 2 MPH.
By the way, the app I used to do the calculations and the charts here is called Gear Head, it's on the app store for iPhone and iPad, and it's the best tool I've found for these kinds of calculations. I like it, but I don't have any other connection to it, just for the record.
Zenbike, cool app. At first I was thinking you were off with those numbers, and then it occured to me you were talking in miles and I'm used to kms:) One thing you've remember though is that the gearing isn't the limiting factor most of the time. I mean, who spends 80% of their time at 90rpm in top gear? I even rode with my roadbike (an old one that weighs exactly the same as my hardtail MTB) gears locked at 53,18 and I was still noticeably faster than on my MTB (a decent entry-level) and that's even counting bumpy dirt roads and gravel. Stated simply, you can't gear your way to speed.
@Kevin, yeah, I use it a lot. I kind of disagree that gearing is not a limiting factor, though. Even if you are not in your top gear all the time, the gearing is radically different throughout the range. I am including wheel size and tire dimension in the drivetrain and gearing. Obviously, fitness and rolling resistance, and bike weight and many other things play a part, but gearing is the largest mechanical differential between mountain and road bikes.
If he is running 10-12 mph, he is probably in the middle of the gear range. Yes, the gear limited top speed will be lower due to lower gearing, but he has the gears he needs for his cruising speed.
You keep saying "the same level of effort". I don't think I understand your definition of "effort". The same cadence at different gearing is maintained by different pedalling wattages.
Resurrecting an old question and not really a bike pro, but my engineering guts say your "same level of effort" argument makes no sense. If you're riding the same bike at the same constant speed, your power output is the same no matter which gear ratio you use (equal to the sum of drag and other inefficiencies plus the climb). So aren't they only useful if you are already fit enough to max out the MTB? The gears just allow you to put in *even more* effort and they don't reduce the required amount of effort, unlike tires, riding position and stiff frame.
Nobody said the same speed. I said the same level of effort (power/wattage/work/whatever you want to call it, with different gearing, produces a different speed result. I’m not really sure why that seems to be controversial. Isn’t that the point of putting gears on a bike? Gears do not, by the way, allow you to “put in even more effort”. Effort (defined as the amount of energy you are producing with your legs) is controlled only and completely by the rider’s strength and endurance. Gears allow you to use that effort more efficiently to produce more speed from the same wattage, as I said.
Data points for your comparison: I switched from a 26" MTB with 3x7 speed to a 700 road bike, also with 3x7.
http://strava.com/ tells me that my ride speeds have increased by about 5 km/h on pretty much every segment.
My climbing times have dropped by 10%-20% but it wasn't any easier.
The aluminium road bike is 11 KG vs the 17 KG of the steel MTB.
Rank Date Speed Time 1 Dec 7, 2015 13.2km/h 1:11 <-- Road bike 2 Jul 18, 2015 9.7km/h 1:37 <-- Steel MTB 3 Jun 13, 2015 8.9km/h 1:45 <-- Steel MTB 4 Nov 23, 2015 8.3km/h 1:53 <-- Road bike-I stopped for some reason.
Rank Date Speed Time 1 Sep 24, 2015 37.3km/h 1:27 <-- Road bike 2 Dec 24, 2015 35.7km/h 1:31 <-- Road bike 3 Dec 22, 2015 35.3km/h 1:32 <-- Road bike 4 Mar 14, 2015 30.6km/h 1:46 <-- Steel MTB 5 Apr 18, 2015 29.0km/h 1:52 <-- Steel MTB 6 Jul 19, 2014 28.2km/h 1:55 <-- Steel MTB
EDIT Additionally - the MTB's bottom gear was 26/38 whereas the road bike is 26/27. Both are triples. So in the MTB its easier to drop another gear when the going gets tough, but on the road bike you have to keep going but at a lower cadence.
@Danielson the MTB had "combo" tyres, where the center was a long smooth bump all the way around the outside, and the shoulders had small blocks to the same height. So while riding straight ahead it was a slick, and while hard cornering it was a small block tyre. Pretend it was a road slick and you're close enough.
I am not surprised the large differences in average speed, especially on the flats as body position can have very large impact on your drag coefficient. You better be careful careful with these types of comparisons, before you know it you will start seriously looking at aero wheels, and slipstream kit for every advantage! Its a slippery slope.
@Rider_X Correct and accurate - I find the wind has a highly variable effect, and two or three times for each is probably insufficient data for a comparison. I have segments with 300 times, but the traffic lights make the data comparison less obvious. The two segments above are free of lights.
20 to 22 mph (32 to 35 kph) average over 40 miles (64 km) with a light road bicycle, bicycle shorts, clipless pedals, proper bicycling shoes, a helmet, excellent fitness, and a lot of practice. Peak speeds can be as high as 30 to 35 mph (48-60 kph) on the flats in a tight group of 6 or eight riders or so.
On my hybrid (think Mountain bike style but with thinner wheels) I average about 12-14 mph around Bolton (lots of hills) when I go out at my in-laws (in Doncaster where it's fairly flat) I average 15-18mph.
On a road bike you'll be faster still as it's lighter and built for speed.
As noted...It's mostly the motor... On nice flat roads with a good roadster...20+ even at my age. However, throw in some hills and a headwind and the average plummets. I have a 2-mile road course around the local park that incorporates 2 hills on each leg. When I was 15 years younger and in good shape, I could maintain 18 around that.
At those speeds on flat terrain there are other factors that will impact average speed far more than bicycle type.
In particular, stopping at intersections in an urban area will cause your average speed to plummet. 12mph average is actually reasonable for a dense city area and is not much slower than what cars average.
If you're talking about riding in areas without stopping, getting faster than 12mph average is easy with a little more experience.
The average speeds that can be attained on a road bike (or any bike) are determined by several factors:
- Distance covered
- Road surface
- Equipment, meaning the bike and components
- Age and fitness of the cyclist
Based on observation and considering all that, on primarily flat, non-windy, terrain, on a decent road bike, my estimates would be:
- Novice cyclist - a short distance (10-15 mi): 10 - 12 mph
- Casual, fit, cyclist - a short/medium distance (~25 mi): 15 - 16 mph
- Average club cyclist/fitness cyclist - a medium distance (+/-40 mi): 16 - 19 mph
- Experienced club cyclist/amateur racer - a medium/long distance (+/-55 mi): 20+ mph
- Pro cyclist - long distances: 25+ mph
Anecdotally... on one of my frequent rides through some farmland, there is a 12 mile, mostly flat stretch. With a tailwind, I'm a pro. A headwind, I'm a novice. With no wind, I'm somewhere in between, depending on the day.
Another anecdote... In my area I frequently use a particular paved bike path on both a road and mtn bike, mainly because it leads to a park full of single-track, and beyond that to nice countryside for road cycling. Anyway, I have 8 years of ride data for that route. Along that path there is a 6 mile, flat open, stretch that was repaved 2 years ago; originally it was very rough, chunky asphalt and upon repaving it was converted to very smooth asphalt. Lo and behold, after the repaving, my average speed on both bikes jumped up ~4 mph.