Is there a web site or document available that shows this power curve? I’ve love to be able to enter my weight and watts to see what my approximate speed would be (or vice versa.)
The power curve states that at 30 mph you should be pushing somewhere around 700 watts…
Here’s the Kurt power curve.
I have heard the same thing (release the tension after each ride) and been told the same thing by bike shops. It will create a bald spot and contribute to tire slippage.
Nope, it’s just misinformation. I’ve had the Road Machine for several years and just left the bike on the trainer. A year or so ago I asked Carl, their head engineer, several questions, including leaving the bike on the trainer and he said it was no problem. And logically, how could it create a bald spot? Like the bikes I ride on the road I periodically check the air pressure, and if the air pressure and resistance remain constant then there will be no slippage.
again…I have seen tension (which can be attributed to tire pressue) make a huge difference, even with no slippage. I actually almost sent one back because I thought the resistance unit blew. After a month of normal riding it lost all resistance; no matter what gear I was in, it was just spinning freely. Felt like an idiot when I turned the tension screw a few times. Had no problem for the last 200 hours since.
As for de & retensioning between rides: I think that is a waste of time and unnessecary. I ride a trainer ~3,000/yr and have never had any problem. Granted I use dedicated bike for my trainer, but I have never experienced any of the problems mentioned with keeping the resistance unit tight against the wheel.
To properly tension, bring the wheel into contact with the tire (just touching) then do 2 full turns. After riding, back off 2 full turns, and reset (2 full turns) before next ride. Make sure tires are properly inflated (I think they recomend 110 psi).
NO
Depending on the tire, 2-5 full turns, and you do not need to back off between use (assuming it’s left on the trainer). Multiple compound tires may squeek, but that is because of the multiple compounds and not lack of tension.
If you have any technical questions talk to Carl at Kurt.
Here’s the web site & formula:
http://www.kurtkinetic.com/powercurve.php
Kinetic Road Machine:
P = (5.244820) * S + (0.01968) * S^3
30 mph equates to ~689 watts. I free spun my rear wheel to 50 mph for 2722 watts - now that was impressive.
If you’re hearing a lot of squealing/squeaking noise while riding the Kurt (pull your cat’s tail out of the resistance unit), and you’re getting black specks of rubber all over the floor & on the bike ---- get an orange Continental Hometrainer tire. Huge difference in the noise level, no tire slippage, & no black residue.
Once the resistance wheel is in tension against the tire, the tensioner spring is useless.
If your trainer speed seems way too high, check the circumference value & the k/hr, m/hr selection. If it’s correct, and your speed on the road looks OK, make sure the tire isn’t slipping. Otherwise, check the orientation of your magnet. If it’s sideways, you may be getting double pulses each wheel revolution.
Maintaining a certain speed on the Kurt is definitely more difficult than a normal ride on a flat road. Don’t believe me? Try riding at 20 mph for 10 minutes on the Kurt, then on the road. 19 mph is ~234 watts on the Kurt. I rode a Computrainer for an hour at 21 mph at ~220 watts.
If you’re really bored, go to analyticcycling.com and determine how much power it would take for each segment of some hilly bike route. Then work these numbers backwards in Excel (or algebraically) to come up with speed values for the Kurt. If you’re bored.