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MTB speed!!!(9 posts)

MTB speed!!!kingcobradv
Oct 1, 2003 6:56 AM
How fast can you guys do a 20 k time trial with a mountain bike?
Right now I am using a mountain bike for training on the road (since I havent bought a road bike yet) and I want to compare myself to others. Also how fast do you go over the same distance with a road bike?

thanks
no real answer for that, IMOoff roadie
Oct 1, 2003 7:35 AM
MTB's vary to much to really say. What tires are you using? Does it have suspension? What's the seating position? Some XC mtb's with slick tires and "fast" riding postions are nearly as fast as road bikes. Some even run 700c tires! Then again, with a heavy trail bikes with 5+ inches of suspension and nearly 3 inch wide tires- well, 20km on the road could be a real workout!

At a guess, I'd say a MTB is 5% slower if fully aimed at road riding, and as much as 50% slower if its "free-ride" built. Any bike you feel comfortable doing a 20km time trial on is probably in the lower range- say 10-25%.

A pretty good basic pace for 20km time trial would be 45 minutes. So on a MTB, you'd probably be looking at 50 minutes to an hour, depending on the bike maybe more.

A better judge might be, can you hang with a pack of road bikes? With them doing all the pulling, you should be able to hang on to a group that you normally would be pulling yourself.
Way too many variables!Zman
Oct 1, 2003 7:40 AM
Your question is loaded with what ifs and missing info.

Anyways I do have a example for you.

I trained with my Cannondale mountainbike in 2001. I ran Panaracer Pesala tires and could do my 15 mile "time trial course" at a very fast speed, around 20-21 mph.

I have never beaten that speed with my $5000 roadbike.

The terrain and conditions have a huge bearing on the equation.

All things considered I would say that a mountainbike with knobby tires is at least 5 mph slower.

Z
Seach the board for AARONTOY = ;-) nmpitt83
Oct 1, 2003 9:24 AM
OK, I'll biteGeardaddy
Oct 1, 2003 11:03 AM
Of course this can be radically different given the terrain, but most MTB races that I've done I'm happy to get 13 MPH average. This is over a course consisting of mostly singletrack with relatively short hills. I am definitely Cat 5 material on a road bike, where I'll do solo training rides in that average speed range of 18-20 MPH.

This year's Chequamegon Fat Tire 40 (Hayward, WI USA) race was won in record time with an incredible average speed over 19 MPH. It is known as a fast course, and many of the better riders will do it at 17+ MPH. An average Joe would be more like 14 or 15 MPH in that race.

So, do the math and read between the lines as you please.
22.3 km course with rolling hills and 2 long climbsBowWow
Oct 1, 2003 6:42 PM
I managed 42:55 on a Norco hardtail with a Duke fork and 1.5" (approx - I forget the actual size) Tioga City Slickers, drafting most of the way. The bike weighs about 24 pounds, I'm 205 and don't climb very well.

This year I switched to an old Centurion road bike and have cracked the 45 minute mark repeatedly - like almost weekly. But my personal best on this course on the Centurion is still only 41:45...

I just bought a Cervelo Prodigy (photos to follow!!) and am looking for a drop on the PB for this course before winter sets in... I'll keep you posted.

Steve (It's ALL about the bike!!!!)
re: MTB speed!!!kingcobradv
Oct 1, 2003 8:30 PM
Thanks for the replies!
I have a moutain bike that weighs about 35 pounds with 1.95" knobby tires. Usually I ride with baggy shorts and a t-shirt. My time for 20K is about 35 minutes at best on a course with some uphills and criterium type of turns.

Me and my cousin did 65 K going at about 28- 32 km/h most of the way this summer. His bike weighs much more than mine and his tires are 2" (knobby tires).

We both dont use clipless or toeclips.

Can anyone predict how fast we can go with the same effort using a "high end" road bike with a bike jersey/spandex and clipless pedals?

Thanks
Really!Zman
Oct 2, 2003 5:02 AM
I don't want to say that you are wrong because I don't know you, but I would like to ride with you some day.

I highly doubt that you are doing a 40 mile ride with a 40 pound full suspension mountainbike and 2" knobby tires at a average speed of 20 mph.

I did assume that it was a full suspension bike, maybe I was wrong.

My best guess estimate with a top of the line roadbike is that you could compete with Lance and Jan!

Z
Really!kingcobradv
Oct 2, 2003 5:13 AM
My cousins bike is full suspension, but mine only has front suspension. We put the suspension on the stiffest but there is still some bounce.