Did I install it corectly

Did your Dad's bike have a computer on it too?  Did you compare the distances/speeds between the two computers?

Because if you KNOW that road bike is correct then you would only have one bike to look at for installation errors...the mountain bike.

But I would also say that you should not expect to go as fast on your mountain bike as on your road bike.

That could be the problem.  Probably the quickest way assuming it tracks miles for the ride is to check the distance against the route tracker and see if there is a big discrepancy in miles for the ride. 

Typically though, most people are slower for the same effort on mountain bikes.  I can't say this because I have experience, but the people I pass in races on mountain bikes seem to be working just as hard as I am.

Edited by kenj 2009-06-25 3:52 PM

Going from a road bike with slicks to a MTB with knobby tires could make a fairly big difference depending on where your are riding. Also the computer you are using might not be completely accurate. Make sure that you have positioned the magnet exactly where the manufacturer recommends, if the magnet is to far away or too close so that it is rubbing, it might give you a false reading.  

2mph increase from a mountain bike to a road bike is not outside expectations.

7 mph increase, even riding 2-man time trial, might be a little too much to attribute to just the bike.


Usually statements like "maintained a good 18 to 23 mph rate for about an hour and a half" are at best subjective and lean toward exageration.

Edited by the bear 2009-06-25 3:58 PM

one other possibility - did you/can you set the computer to wheel size?

I know with my cateye there is a code that needs to be put in depending on what wheel size you are using. It all affects the reading on the comp if you don't set it correctly.

34 miles in 1.5 hrs = 22.66mph...wish I could average that in a race...

x2. I did just over 40 in just under 2 couple weeks ago, and was pleased with myself.

John

Agreed, may not have calibrated the cyclometer right.

Also, if you have the trainer on a really setting or if it is a fluid trainer the harder you go the harder it gets.

Too many factors to say whether there is an installing issue.