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Old 11-01-09, 11:07 AM   #1
Old Town
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Comparing bike speed

A while back I asked if anyone knew what the speed difference was between bike types: road, hybrid, mountain. I didn't get a good answer so I did some testing of my own. I post the results here because it showed the MTB to be much better than I would have guessed. Had I posted this in the hybrid/road section someone might have sought me out and hunted me down in my bed.

I used an old, but sound, Cilo steel road bike circa 1986 with 23X700 slicks for a road bike.
My Kona Dew Deluxe with 30X700 slicks for a hybrid.
Mountain bike was a Kona Fire Mountain hardtail. This bike has Kenda 2.25X26 road tires with very fine tread. (no mountains in Key West)

All tires inflated to full pressure. Over a weeklong period I ran all three bikes over an 8 mile up-and-back course early in the day when traffic was very light. Not once did I have to really slow down for cars at intersections. I did not try to race. This is important. I can no longer go real hard for 8 miles because I never do it. So it was my effort to take the course at an average commuting pace. The same level of effort I normally ride. Each bike was ridden 3 times. All speeds posted are averages. Remember I am 52 years old and not related to Lance Armstrong.

Road bike average speed was 16.7 mph.
Hybrid average speed was 14.0 mph.
Mountain bike average speed was 13.3 mph.

I was very surprised to see how relatively quick the MTB was compared to the road bike and especially the hybrid. Funny thing was I felt fast on the hybrid. But it was no big impovement over the MTB. The road bike was riden from the drops. (this nearly killed me - my lower back)

You can't compare a MTB to any road bike but they give away little to hybrids with the right tires. And they do it in greater comfort with the fat tires and front suspension.

Last edited by kenhill3; 11-01-09 at 12:45 PM.
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Old 11-01-09, 01:01 PM   #2
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Mountain bike was a Kona Fire Mountain hardtail. This bike has Kenda 2.25X26 road tires with very fine tread.

All tires inflated to full pressure. Over a weeklong period I ran all three bikes over an 8 mile up-and-back course early in the day when traffic was very light.

The road bike was riden from the drops. (this nearly killed me - my lower back)
Fixed it for ya (I hope) , Old Town.

Was that 8 miles total or each way?

What were the max. pressures on the tires?

I'd be interested how the bikes compare on longer rides, say 30 or 60 milers.

I ride road but I'm no 'roadie'. I spend little time in the drops (usually just descents), must be my MTB cellular memory.

That would bother my back, too, it's hard enough doing longish road rides and sitting relatively stationary. MTB is moovin' and groovin'.
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Old 11-01-09, 01:38 PM   #3
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Also can you lockout your front shock on your mountain bike? It would be interesting to see how much speed if any speed is lost with the front shock open.
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Old 11-01-09, 01:54 PM   #4
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Nicely done, but you're measuring particular bikes - and the way they are set up- rather than bike types. Speed is determined by air and tyre resistance. Change the stem length or top tube length - which certainly varies a lot on MTBs* - and aero will be transformed. And at the speeds you report, tyre resistance will matter a lot - totally slick tyres with thinner walls made out of lower hysteresis energy rubber would add quite a bit of speed.

The current Fire Mountain looks like a "sit up and beg" vicars' and old ladies' bike compared to the classic Joe Murray designed Konas and their contemporaries. But for this reason the air resistance was distinctly lower. A long top tube MTB with, say, 1.5 Rubino Pros, will handle quite differently from your Fire Mountain. In fact even the WIDTH of your bars will alter aero! I think you'd probably have found my 88 Lava Dome - or the Shogun Prarie Breaker I used for courier work - would have out paced your Dew quite comfortably, and would even keep up with a performance hybrid like a Sirus - or a racing bike fitted with flat bars.

Otoh, even big savings in air resistance get eaten up in small speed increases - because aero goes up with the CUBE of speed. So you'd have to cut air resistance by a factor of EIGHT to double speed (neglecting tyre resistance). I think it was for this reason your speed differences were so small - and would have been even smaller with faster tyres on the MTB.

MTBs - and hybrids - are very diverse groups of designs. They're marketing rather than engineering or performance categories. And who knows where you put a bike like, say, the Cotic Roadrat, which can be built with flats or drops and 26 or 700c wheels and which has competed in cyclocross and MTB races?
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Old 11-01-09, 02:38 PM   #5
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Fixed it for ya (I hope) , Old Town.

Was that 8 miles total or each way?

What were the max. pressures on the tires?

I'd be interested how the bikes compare on longer rides, say 30 or 60 milers.

I ride road but I'm no 'roadie'. I spend little time in the drops (usually just descents), must be my MTB cellular memory.

That would bother my back, too, it's hard enough doing longish road rides and sitting relatively stationary. MTB is moovin' and groovin'.
I accept all offers to improve my spelling and grammar. (Man, you gonna be busy.)

It was 8 miles total - four up, four back.

23X700 @ 110lbs, 30X700 @ 85lbs, MTB 26X2.25 65lbs

I have no doubt a man pushing all out would see a greater difference in speeds as the more efficient bikes came into there own. Still, just bopping along the MTB is little different than the hybrid.
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Old 11-01-09, 02:50 PM   #6
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meanwhile: Agree with all you have to say. I was simply curious as to how my own bikes set up as I use them would behave. You mention air resistance and an upright position. A while back I asked members to tell of their fastest bike speed. I had once done 49mph on a road bike down hill. Many others had similar results. Two days ago I tried to haul down the only real hill I have down my way(Seven Mile Bridge leading out of Marathon) with the Dew Deluxe. In its biggest gear I got up to 33 mph before I got on the binders. The wind was lifting my chest and the front wheel was getting light and very squirrely. Have never experienced this before but have never gone over about 26 mph or so on a hybrid. It was eye-opening. Body position is one very important thing on a bike at speed unless you want to lift off. Shall not do this again with a situp bike.
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Old 11-01-09, 05:19 PM   #7
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Two days ago I tried to haul down the only real hill I have down my way(Seven Mile Bridge leading out of Marathon) with the Dew Deluxe. In its biggest gear I got up to 33 mph before I got on the binders. The wind was lifting my chest and the front wheel was getting light and very squirrely. Have never experienced this before but have never gone over about 26 mph or so on a hybrid. It was eye-opening. Body position is one very important thing on a bike at speed unless you want to lift off. Shall not do this again with a situp bike.
Ouch. I did courier work in San Francisco and never had this problem with my stretched-out riding position Reagan Era mtb, despite all the "Bullet" descents. And all the bike demanded in return was the willingness to support about half my body weight on my hands and the neck flexibility of a contortionist!
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Old 11-01-09, 05:26 PM   #8
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Ouch. I did courier work in San Francisco and never had this problem with my stretched-out riding position Reagan Era mtb, despite all the "Bullet" descents. And all the bike demanded in return was the willingness to support about half my body weight on my hands and the neck flexibility of a contortionist!
Reagan Era MTB. I like that. I'm gonna steal it.

My first real MTB was a model called the "Mount Washington". I think Ross made it. That was 1984. The Mt. Wash was a non-suspension pig that was all chrome all over. It looked like a magnesium fire when you had it out in the Florida sun.

But I liked it.
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Old 11-01-09, 05:28 PM   #9
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I think we're missing the important question here. What color were the bikes?
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Old 11-01-09, 05:40 PM   #10
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Too many variables. Useless comparison.
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