Inaccuracy of Pro 300PT indoorbike with powertap due heating up flywheel



PaulMD said:
I have had a good conversation with Robb Zbierski from Cycleops. The problem I have with my powertap in the flywheel is quite unique and Cycleops is investigating the problem. They are very helpfull and they send me a new flywheel. When they receive my faulty flywheel they will test it why the torque is off after an workout because a normal flywheel won't have this problem.

I knew Robb would take care of you... :D
 
PaulMD said:
I have had a good conversation with Robb Zbierski from Cycleops. The problem I have with my powertap in the flywheel is quite unique and Cycleops is investigating the problem. They are very helpfull and they send me a new flywheel. When they receive my faulty flywheel they will test it why the torque is off after an workout because a normal flywheel won't have this problem.

So does this suggest that my flywheel/PT is "defective" and I should call Robb as well?
 
Here is what I posted to a couple other forums:


I had root canal on Wednesday an I was not quite able to perform my test has planned -- I could not maintain FTP for the workout so I stopped. However, I backed off a bit and at least did 20 minutes at L3 to wake my legs up a bit. Thankfully, I saw zero drift during this brief workout:

Start:
Torque: 0
Flywheel: Room Temperature
Hub: Room Temperature

After 10 minute Warm-up:
Torque: 0
Flywheel: Slightly warm
Hub: Room Temperature




After 20 minutes at 260 watts:
Torque: 0
Flywheel: Warm
Hub: Maybe a bit above room Temperature

After 20 minutes at 260 watts, there was no really temperature increase at the hub and all my torque zero readings were rock solid.
 
cPritch67 said:
So does this suggest that my flywheel/PT is "defective" and I should call Robb as well?
I received my new flywheel pretty fast (on tuesday morning). But I had no time to post here or to install the flywheel. Yesterday I installed the flywheel and did a 20 minute ride and I had no torque drift! Before and after the ride the torque was 0 inch pounds.

So my defective powertap hub is replaced with a good one :D

The downside of a accurate powertap is that my power is lower. I will post my new FTP when I have done a 60 minute timetrial on the Pro 300PT with the new flywheel.

@cPritch67: Torque drift is not normal for the 300PT. I think you should contact Saris.
 
PaulMD said:
I received my new flywheel pretty fast (on tuesday morning). But I had no time to post here or to install the flywheel. Yesterday I installed the flywheel and did a 20 minute ride and I had no torque drift! Before and after the ride the torque was 0 inch pounds.

So my defective powertap hub is replaced with a good one :D

The downside of a accurate powertap is that my power is lower. I will post my new FTP when I have done a 60 minute timetrial on the Pro 300PT with the new flywheel.

@cPritch67: Torque drift is not normal for the 300PT. I think you should contact Saris.
sweet. Did THEY pay for shipping? !
 
PaulMD said:
I received my new flywheel pretty fast (on tuesday morning). But I had no time to post here or to install the flywheel. Yesterday I installed the flywheel and did a 20 minute ride and I had no torque drift! Before and after the ride the torque was 0 inch pounds.

Most excellent. Be sure to post your results on all of the lists you've posted this issue to.

-Andy B.
 
That's great news! I hope your 1 hour ride of truth goes well for you...striveth for the mastery...:)

PaulMD said:
I received my new flywheel pretty fast (on tuesday morning). But I had no time to post here or to install the flywheel. Yesterday I installed the flywheel and did a 20 minute ride and I had no torque drift! Before and after the ride the torque was 0 inch pounds.

So my defective powertap hub is replaced with a good one :D

The downside of a accurate powertap is that my power is lower. I will post my new FTP when I have done a 60 minute timetrial on the Pro 300PT with the new flywheel.

@cPritch67: Torque drift is not normal for the 300PT. I think you should contact Saris.
 
PaulMD said:
I received my new flywheel pretty fast (on tuesday morning). But I had no time to post here or to install the flywheel. Yesterday I installed the flywheel and did a 20 minute ride and I had no torque drift! Before and after the ride the torque was 0 inch pounds.

So my defective powertap hub is replaced with a good one :D

The downside of a accurate powertap is that my power is lower. I will post my new FTP when I have done a 60 minute timetrial on the Pro 300PT with the new flywheel.

@cPritch67: Torque drift is not normal for the 300PT. I think you should contact Saris.


PaulMD
Thanks for the update. I'll be on the phone with Saris Monday morning.

Chris
 
cPritch67 said:
The reason I had to cut my test ride short was that UPS showed up with my just ordered 2.4 on Zipp 303 wheelset. :D I had to open the boxes and oogle for a bit. I will probably not have the 2.4 installed on the bike for a few weeks - hopefully I'll be one of the problem free (no drops) 2.4's.

I agree, we need to confirm that ??? is looking at torque, not watts.
Oh Zipp 303 with the SL 2.4, nice nice!
I think I am going to order Zipp 404 with the SL 2.4 in april.
 
Paul;


Good to read that all ended well. However, still check your torque each time before use. I am more religious with my PT hub as well.

John