Go off heart rate, as a direct MPH is not realistic. Also, because you are not having to balance you are essentially doing muscle isolations. So bring down your HR about 10% to account for this.
Another vote for KK. I have 2 and use them year round almost daily. Never a problem.
Go off of power or HR. My vote is for power. MPH on a trainer is pretty meaningless. Do yourself a favor and pick up a cheap PT wheel from the classifieds or competitive cyclist. You can thank me later.
jamie
Did you have a different tire on the zipp? It also depends on your tire pressure and how tight you get the rear tire.
You should get pretty a pretty consistent offset if you keep the tire clamped down the same and the pressure the same.
If you are looking at a trainer, consider a CycleOps Indoor Cycle as an option - micro-adjustable, watts, cadence, smooth road-like feel, no bike set-up, smaller footprint, easier to incorporate standing into your workout than a trainer.
I have about 40 of these and am selling various units -
http://forum.slowtwitch.com/gforum.cgi?post=3587538;search_string=300%20pt;#3587538
I also have the CycleOps Fluid II which I use when I go to my son’s baseball tournaments. I ride it with my powertap wheel and find the power curve to be manageable, but dissimilar enough that I generally cruise while I take in the game - much prefer the CycleOps Indoor Cycle which I use 2-3x/week.
Concur with Steve Woo on having a lot of air on you for more comfort and ultimately a better workout (watts).
There you go.
Michael McCormack
www.m2rev.com
be sure to add fans and ventilation to have any real usage on effort.
to make the resistance harder you just shift and pedal harder.
the resistance will be similar to an average person on an flat road on an average road bike, at any given rear wheel speed.
to simulate a hill, shift to a harder gear and pedal hard.The KK power curve is supposed to match a 165lb rider with a 23lb bike going up a 1% grade on rough asphalt. Mine is generally within <5% of powertap measured power.
+1
From my experience, the power curve on the Kurt Kinetic can be surprisingly accurate as long as you do more than 5 FULL turns.
I have two KK trainers and two powertaps and all permutations of the set-up can either read ~215 watts @ 20 mph at ~3 full turns (which is what others report as well) OR ~260 watts @ 20 mph at >5 full turns, as per the KK curve.
+1
From my experience, the power curve on the Kurt Kinetic can be surprisingly accurate as long as you do more than 5 FULL turns.
I have two KK trainers and two powertaps and all permutations of the set-up can either read ~215 watts @ 20 mph at ~3 full turns (which is what others report as well) OR ~260 watts @ 20 mph at >5 full turns, as per the KK curve.
Interesting. I haven’t seen anybody quantify the effect of greater/lesser tightening. I don’t have a powertap, so I have no way of verifying the calibration, beyond aiming for the coast down times that I have seen in threads on cycling forums.
So I’m curious: do you know what the coast down times are from 20 mph for the 3-turns and 5-turn scenarios that you mention? I have seen 13.4 seconds quoted elsewhere as the right time to target for accurate calibration.
Treat yourself to a trial of TrainerRoad.com. Indoor training will never be the same (unless you already have a computrainer that is). Can’t wait for winter this year!
Yeah, I remember that 13.4 second number somewhere as well.
I haven’t thought of going hardcore scientific with coast down times, because I left my race wheel with the trainer back home this year and the other set-up is in my dorm room… so my observations are just from my constant staring at my cpu. What I can tell you is that once you really crank the resistance unit down past 5 fully turns, it doesn’t make much of a difference.
I like the KK a lot. Someone once told me the power curve makes it equivalent to riding a 3% grade … which seems about right to me. I can do tempo pace in the small ring. And out of the saddle in a 53x11 at climbing cadences is not easy (and harder than doing the same on the LeMond trainer)
I have more of a slick on the Zipp and the Cyclops wheel has more of a tread pattern on sides, slick throug the middle. Neither tire is anything special though. Tire pressure was same on both at 100. Not sure how I had tension set between the two.
Does flywheel weight make a difference then too? The KK road machine I got was the one that came with the heavier flywheel that you can either put on or not. It’s been on for a while now but when I was switching between the two, it didn’t seem to make alot of difference on or off, but I didn’t have a PT at the time. Guess I can try it both ways and see if there’s a difference. Think I just left it on because it was on when I was done comparing the two.
The tire tension makes a big difference. I see a 20 watt difference between my wife’s VirtualPower watts and mine with the same trainer and the same power tap wheel. It’s because I tighten down my wheel more than hers.
I don’t have any experience with the heavier flyweight, but I don’t think it affects the watts/speed as the actual resistance by the fluid unit is unchanged. It will affect acceleration and deceleration though, so the amount of energy to “get up to speed” should change a bit.
I agree. You’ll get some automatic smoothing with a heavier fly wheel too. When compared to a power speed reacts a lot slower. So you might be jumping up and down 10 watts with a power meter, but because of inertia your speed would stay pretty constant. With a heavier fly wheel that would be even more consistent.
We are working on roll down calibration though, and it would definitely mess with that :).