New PT - Why all the dropouts?

Biker Joe

This week I received a new Zipp wheel with a PT 2.4.

During the inagural test ride, a easy 11 mile jaunt around the neighborhood I found that the display would go into the searching mode at almost every traffic light. After a few seconds it would come back on.

However, the bigger issue is that I have done this ride several dozen times and know that the exact distance is 10.62 miles door to door. The new PT display indicated that the ride was 9.02 miles. At one point 3/4 through the ride, the display went to all dashes for about a minute or so. In viewing the graph, the recorded data show a speed spike to over 1,000 MPH!

There are a number of traffic lights on the graph and a bridge climb about 1/3 of the way into the ride. I am attaching the file for anyone interested and who can provide their opnion and comments.

Wondering if the Hub or Computer is defective?

Biker Joe

Almost forgot,


When I scroll through the data on the compter head itself, the distance for the ride shows 10.62 miles!

What's up with that? How can the computer head differ from the downloaded ride file?

Joe

mr_mojo

Make sure the receiver is very close to the hub.

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Biker Joe

The receiver is mounted on the bar stem.

Terry Ferguson

What setting are you using in the cpu to stop recording (i.e. no speed or no HR)? What software are you using to download? - TF

fstrdr7

I am not for sure if this is the same, but I got my PT about a little over a month ago, and for the first 2 weeks, anytime i touched it, or bumped it, or hid a rough part of the road it would stop reading and would show dashes. I had to make sure it was firmly situated in the mount to get it going again, but I am no longer having those issues. Don't know if it was a breaking in period or something, but it sounds kind of like what you are experiencing.

lanierb

You probably should tell us what kind of PT. E.g., is it wired or wireless? Regardless, probably the biggest source of dropouts is weak hub batteries. Try changing them and I'd bet your dropouts will go away.

jbvcoaching

Disagree. My experience is that hub batteries (on an SL hub, wired or not) will go 6 months to a year, while the CPU battery lasts roughly half that time or less. So I always recommend the order of steps to be:

1) Change CPU battery

2) Change hub batteries

3) Start isolating components to see where the problem is.

For a wireless, I might move step 3 up to step 1 since there's no receiver to deal with.

mr_mojo

Then move the shark-fin closer to the hub. I guess you mean you have a wireless PT...

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my wattage blog: Sufferfest

Biker Joe

ve both

Sorry, should have been more clear. This is a Powertap 2.4 wireless hub. No shark fin. The stem mount has no electronic connections.

I have both Saris Power Agent and Training Peaks WKO+

Biker Joe

I have the computer to stop recording with speed.

lanierb

I agree that the CPU battery lasts less long than the hub, but the first sign of a weak CPU battery is usually downloading issues, not data dropouts on the ride. Data dropouts are usually a sign of a weak hub battery (in my experience).

Biker Joe

Just wanted to give everyone and update and explain what has happened.

I wrote Saris and explained the problem. The called and emailed me several times over the past 2 weeks as I tried to work through a few of their suggestions. Once it became apparent that the problem was definitely with either the hub or the computer, Saris asked me send both the hub and computer back to them.

Within a few hours I received a RA (Return Authorization), to my amazement it was prepaid and they asked which shipping carrier I would prefer to use. The wheel was picked up at 5PM and on it's way.

It has only been gone for two days, but I feel completely satisfied that Saris treated me with the utmost of concern and professionalism. They have assured me that the hub/computer repair will be expedited.

For any of you experiencing any problems, give Saris a call. Their support and attention to the customer is second to none. I also have to say that I have two computers and three wheels with PT hubs. This has been the only one with an issue. I am confident that Saris will take care of the issue.

bubsy

Sounds like they have great customer support I'm having major dropout issues with my 3 month old wireless as well as rediculus fluctuations in power even when not pedaling usually this settles down after 10 mins and then l stop and recal torque
and if l'm lucky l can sometimes get a 1 hour session with only a handful of dropouts but not always, l need to contact saris and proly send it back, but in Australia that could be quite a wait for the repair. lnterested to see how you fair in your wait for their repair or assesement of your PT. For 2 grand $AU l hoped l would get something more reliable.