How much of a difference do hills make for average speed?
 

Yeah, yeah, don't look at your average speed and just ride blah blah...

But I'm looking at it anyway and am slightly miffed at how low it is compared to everyone else's on here. Some new guy posts and says he's averaging like 19-20 on a mountain bike for 40 miles, or someone who claims to only be a commuter says they were cruising at 22 mph for a 20 mile ride or something.

I would say I am in pretty good shape and I have been riding for awhile, yet my all out effort on a 23 mile route only gave me about 18.4 mph. I've been training a decent bit for competition purposes so I'm a little discouraged when I see commuters averaging 22 or more. I'm riding a road bike too (CAAD10) so it's not a bike issue.

I wouldn't think hills would make more than a 1-2 mph speed difference (avg) but I don't know... has anyone done a comparison between their average on hilly terrain (eg North Georgia) vs flat (Florida)?

Oh, and my speedometer is calibrated correctly as it matches my phone's GPS as well as stopwatch + Google Maps.

All I can say is that some people exaggerate numbers a bit.
In closing, I wish I could do 18mph on my normal 21 mile route...

Depends on a lot of factors like wind, distance, elevation gain, temperature, etc

On that course I mentioned, when I time-trial it, I average about the same regardless of wind or temperature. (At least I'm consistent...) Well, actually, it hasn't been very windy lately, but that probably would affect it if there was a lot.

Everyone on BF can do >20 mph average.

It's different in the real world.

Bob

Depends on how steep the hill is and how long it lasts.

On flats with no wind, I can ride at around 19-20mph on my road bike fairly easily (high Z2/low Z3)*. On hills, my 180lb carcass means that I slow down to well under 10mph depending on the slope - on one extended 10% climb, I had to lower the auto-stop speed cutoff of my Garmin, so that it could record my moving trackstand.


*Converting from imperial mph to BF Mph, this means that on BF, I can ride at a recovery pace for several hours at 20mph. On a mountain bike. With rubbing brakes. Uphill.

I find that hilly terrain does take my speed down 1-2mph (you make some time back coming down hill, but you dont make it all back). Of course "hilly" is very non-specific, so take my comment it for what its worth.....nothing.

Given my experience among the general biking public in my local area, 18mph+ pretty much will have you passing 97% of everybody on the bike paths and streets. The other 3% will be more experienced riders, and probably also people who are into cycling enough that they'd be posting on the internet more often than the slower 97%, making it look like everybody is faster than you. The reality is probably very different.

Anyway, if you really want to quantify your performance, get a power meter. It will tell you exactly how strong you are, and then you can look it up on the infamous chart in the power meter book to see how big your e-wang is.

Riding for 36 miles in 2:10 magically becomes 40 miles in 2:00 when you get on the interweb.
The garmin connect thread is revealing.

I'm not sure it's helpful to just use a generic term like "hills".

A "hill" could be gentle incline, it could be a short sharp pull, it could be a monstrous great thing. Obviously a hill that is long and steep will have a much bigger difference than a hill that is short and gentle. It also depends on how well an individual rider copes with hills, and the overall elevation profile of a particular ride (a return journey will, by definition, end up at the same elevation it started while a one-way trip could conceivably be downhill all the way).

There's a road near me that's a long incline but a gentle gradient. As a rule of thumb I reckon on maintaining 15-16mph going one way and 19-20 going the other way. There's another road fairly near me where if I reach the top without dropping below 5-6mph I'm pleased about it, and coming down I routinely hit 30-35mph without even pedalling.

On my bike on the flats I aim to cruise around 15-20mph and pass most other cyclists at that speed. Every once in a while I come across a guy on a road bike dressed in Lycra who smokes me like a kipper. On occasion I keep pace with a roadie in Lycra, although whether that's because I'm pushing and they aren't or I'm as fit as they are remains unknown.

Of course for good measure you need to throw in the tendency of some folks to exaggerate their achievements online.

It Depends
 

Hills have a huge effect because you lose more on the climb than you get back on the descent.

As an example, making a few simplifying assumptions, 30 kmh over a course with an average 2% grade (equal up and down) requires the same constant power output as about 35 kmh over dead flat course.

To make a 30 kmh average on a course averaging 5% is equivalent to 44 kmh on the flat. That one's a bit unreal because very few of us would pedal at full power on a 5% descending grade, partially because doing so gives you a very small net gain.

If you change the model and say that coasting the downhills allows you 20% more power output on the uphills, 30 kmh over a course with a 5% average grade is still the equivalent of over 40 kmh on the dead flat course.

You're in North Georgia, so I'm going out on a limb here and stipulate there is pretty much no flat ground around there. Hills and constant direction wind never help your average speed on a course that ends where it begins - there are few absolutes but that is one of them.

If you are just transitioning over to cycling from running and averaging mid-18 mph on a solo ride with a lot of rollers, as stated above you would be riding 90% of the cyclists you meet on the road off your wheel.

Note also there is a change in your pedal stroke and the muscle development of your legs as you change over from running to cycling, especially on hills. When I had to give up running and picked up cycling, I found myself sliding to the back of the saddle to use more hamstrings as they were much more developed from running. After a few thousand miles and as the quads started developing more, I tended to stay more to the center.

I used to do a 50 mile route and had two options - one was the shoulder of highways that was mostly flat and the other was two lane roads with lots of rolling hills and a bike trail that was filled with steep ups and downs. The hills added at least 2 mph.

Since I live in a somewhat hilly area I'm not sure what I can do on a flat course.

But I can average around 19 to around 19.5 on a 40 mile ride. This is a pretty good exertion for me too.

Here is a ride that you can see I have some hills in with speed. This one had about 3000 feet of climbing in 41 miles.

http://connect.garmin.com/activity/84048404

Average speed is useless. Internet posts all lie about average speed (except speed in races, but that's in a race with a pack, which is very different). I bet that the "22 mph" commuter took his "average" speed by looking at his computer while riding with a tailwind or on a slight downhill, or both.

Hills make more of a difference than you think. I've done races that had a 10 mph average speed because they were all up hill.

If you want to race, forget average speed and internet lies and read this: http://www.bikeforums.net/showthread...s-a-tip-or-two

All out only 18? Should be able to hit 20+ on flats with a decent bike.
I'm currently averaging just over 13 mph on 20 mi rides in SF, with lights and stop signs everywhere, and generally not safe to be over 20. And I just started riding after a 3 year break. I do wonder how some people get so high of an average by "cruising." Maybe if most or all their miles ridden have no stops or slowing.

Your question can be closely answered by using the Garmin data from my 305. Once I download the data after a ride onto my desktop Garmin software, it gives me the time spent on each 1 mile lap. Now, I could have set the lap distance to something less like a half mile per lap. That might make it more finite.

I go on Excel and construct the formulas to calculate the average speed after removing the slowest laps. Suppose I go on a 20 mile ride and 2.5 of those lap miles were the slowest. Then I know that 12.5% of that ride can be removed to arrive at an adjusted average.

That way, I can isolate the average speed to the warm up miles and the riding in stop and go traffic, and the long climbs.

The Garmin software also allows me to see the route on Google Earth. That is, the actual ride is mapped out.

For starters take posts about average speeds on BF with a grain of salt. Average speed is affected by a lot of variables and unless you know what conditions were for someone who you're trying to compare your effort with it won't mean much.

Please be aware that if you can't average 24 mph plus on hilly rides with an average grade of 20 per cent and 50 mph head winds, you don't belong on BF.

Double those numbers if on a recumbent of CF bike.

Why does 22mph have to be an exageration or a lie?
It's perfectly possible even on hilly terrain.
I do about 22mph on 10 to 30 miles on a hybrid with suspension fork and 35mm tyres.
The hills aren't very long here though ... one K per hill max.
That may sound incredible to you and aparantly it does ... but to others having better lungs, legs, blood vessels and heart, it may be normal.

About the hills slowing down the average ... it is indeed so but just a bit.
On the flat I cruise at about 23mph ... on a 5% not too long hill I keep at about 18mph using anaerobic power ... then on the way down I get to about 32mph while pedalling in high gear.
Overall the average is only slightly affected by hills, assuming that they are not extreme hills.
Wind direction and power is far more important in this regard.

Yeah slowing down and stopping a lot will definately kill your average.
An average should be measured over at least 10K without any stops.

Adjusted averages are even more irrelevant than averages in general.
An average should be measured over a long distance and without any stops or rules to discard data, otherwise it is not an average but just a number popping out of a formula.

I think hills lower your speed at least 2mph compared to a shorter flatter commute, more if you're like me and run out of steam pretty quickly. I was happy with 16.5 mph last weekend, 30 miles on North Georgia hills. If I went 40 or 50 it would creep down to closer to 15. In town, shorter and flatter routes that I'm accustomed to, 3-4 mph faster. I think it's impossible to accurately compare speeds with someone else unless they're covering the same ground at the same time (ie, riding with you).

Flat, no wind: 20mph
Flat, moderate wind: 18mph
Moderate hills (50 feet elev. per mile): 17.5mph
Hilly (100 feet elev. per mile): 16mph

All above based on a 40 mile ride. This is the difference hills make, for me at least.

With competition in mind though: it's good to have fitness, but more important to race smart and be able to draft well, do as little work as possible when not necessary, follow the right wheels etc.

For typical races, average speed is indeed irrelevant.
For Timetrials though, the only thing that counts is your average speed :)

I think you are the guy OP was talking about :-D

My averages drop 4-5mph on my very hilly course >100' per mile vs my flat course. Perhaps some of this is because I cannot acheive maximum speed (would be over 50mph) on the way down due to stop signs, curves, and running out of gear.