Powertap SL -- Works in the cold?

[EpicriderGMAC]

I have a newish (2 months old) Powertap SL hub built up 3x to a Speedcific Niobium 30mm rim by Mike Garcia. For the first 3 weeks of use, the PT was great and I had zero signal drops in all conditions and temperatures. I did one ride in 28 degree, snowy, rainy weather for 4 hours and the PT was fine.

After all wet rides, I have been wiping down the contact points for the computer and wires with alcohol, and I've been opening the battery cover for 15-20 min to let any moisture in the hub evaporate.

HOWEVER--for the past 3 weeks my PT SL has been permenantly dropping signals after the first 10 min of my ride. The hub works great for the first 10 min, then I start to get some dropped signals, and within 5 minutes, the screen simply does not read wattage or speed and my PT computer shuts off.

I have the new SL version of the wiring harness, aka "sharkfin" reciever, and I have the reciever installed vertically (sharkfin pointing up towards the saddle) on my chainstay. I have a small piece of very thin foam under the reciever to dampen the vibrations from the hub freewheel.

WHAT'S UP WITH MY PT? Other riders on my team don't have any problems with their PT pro and PT SL on the same rides that I get no signal. I have ruled out the problem being the battery since I don't have more than 100 hours on the hub yet.

I want my Power Data...what should I do? It works fine on my indoor trainer..

 

[rmur17]

I have a newish (2 months old) Powertap SL hub built up 3x to a Speedcific Niobium 30mm rim by Mike Garcia. For the first 3 weeks of use, the PT was great and I had zero signal drops in all conditions and temperatures. I did one ride in 28 degree, snowy, rainy weather for 4 hours and the PT was fine.

After all wet rides, I have been wiping down the contact points for the computer and wires with alcohol, and I've been opening the battery cover for 15-20 min to let any moisture in the hub evaporate.

HOWEVER--for the past 3 weeks my PT SL has been permenantly dropping signals after the first 10 min of my ride. The hub works great for the first 10 min, then I start to get some dropped signals, and within 5 minutes, the screen simply does not read wattage or speed and my PT computer shuts off.

I have the new SL version of the wiring harness, aka "sharkfin" reciever, and I have the reciever installed vertically (sharkfin pointing up towards the saddle) on my chainstay. I have a small piece of very thin foam under the reciever to dampen the vibrations from the hub freewheel.

WHAT'S UP WITH MY PT? Other riders on my team don't have any problems with their PT pro and PT SL on the same rides that I get no signal. I have ruled out the problem being the battery since I don't have more than 100 hours on the hub yet.

I want my Power Data...what should I do? It works fine on my indoor trainer..

sorry to hear you're having trouble with the SL. I'd definitely contact Saris Customer Support and see what they advise ... but FWIW I've read the SL batteries are not as robust as the Std. or Pro's in <0C temps so that just could be your issue.

rmur

 

[EpicriderGMAC]

I do live in Madison, WI...so Saris is only 2 miles away...perhaps I'll do that.

I just don't want to give up my new PT hub to the service department for 2 weeks in the middle of training!

 

[RapDaddyo]

I don't have the "Sharkfin" receiver you referenced, but dropouts are typically caused by one of two problems with the SL: (1) weak batteries in the hub, or (2) vibration problems with the receiver due to the receiver mount. Both problems can be isolated indoors. If the hub batteries are weak, you get a flashing hub transmission icon (upper left corner of computer display). Even if you aren't getting a flashing icon, it's worth it to replace the hub batteries and test it. The batteries are pretty cheap. The second issue can be tested on a trainer. If you get the pawls screaming (spin the wheel and backpedal the crank), you should get the dropouts (dashes on the displahy plus loss of hub transmission icon). After experimenting with various types of spongy material, I finally went to free hanging my receiver from the chainstay -- see photo and discussion here http://www.cyclingforums.com/showpost.php?p=2556738&postcount=13. I have not had a single dropout since I made the change, even when I've tried to get dropouts by backpedaling on descents. Hopefully, one of these two issues will work and you can avoid the trip to Saris. Good luck.

 

[palewin]

HOWEVER--for the past 3 weeks my PT SL has been permenantly dropping signals after the first 10 min of my ride. The hub works great for the first 10 min, then I start to get some dropped signals, and within 5 minutes, the screen simply does not read wattage or speed and my PT computer shuts off.
I want my Power Data...what should I do? It works fine on my indoor trainer..

I've had precisely your problem; changing the hub batteries cured it. My "assumption" (with all the dangers of making assumptions) is that the batteries in the hub had enough juice for normal conditions (so no blinking icon) but in the cold weather just ran out of power about 10 minutes into the ride (at which point there wasn't enough power left for the blinking icon). Anyway, even though the old batteries only had about a month's use, I swapped them out, and last week my SL was operating at 29F again. By the way, I've never come close to the 250-300hours mentioned in the manual, I think that referred to the Pro, and for some reason the SL goes through hub batteries a lot faster; I had to replace one pair (excluding the recent cold weather problem) after about 170 hours and I think the second pair closer to 140 hours.

 

[EpicriderGMAC]

Hmmm...where do I get a new battery? How much do they cost?


I'm sure that I'm not dropping signals due to freewheel vibrations...it never happens indoors or outdoors (in the warm) while coasting. The "sharkfin" reciever was designed to cure that problem, and with my foam mounting strip, I've had no issues with that.

But 140-150 hours battery life--that sucks! I'll bet the new wireless model is even worse!

 

[RapDaddyo]

Hmmm...where do I get a new battery? How much do they cost?

#357 Silver Oxide, only $3.00 each here http://www.beiterbattery.com/dl303-357.htm, about $3.50 at Radio Shack. For some reason, the ones that ship with the hubs seem to have a short life, but replacement batteries seem to have a longer life.

 

[Sprint2Win]

Have you tried one of your teamates hubs(wheel)?
If it works with someone else's, it's your hub, if not, look at the receiver or wiring.

I have a newish (2 months old) Powertap SL hub built up 3x to a Speedcific Niobium 30mm rim by Mike Garcia. For the first 3 weeks of use, the PT was great and I had zero signal drops in all conditions and temperatures. I did one ride in 28 degree, snowy, rainy weather for 4 hours and the PT was fine.

After all wet rides, I have been wiping down the contact points for the computer and wires with alcohol, and I've been opening the battery cover for 15-20 min to let any moisture in the hub evaporate.

HOWEVER--for the past 3 weeks my PT SL has been permenantly dropping signals after the first 10 min of my ride. The hub works great for the first 10 min, then I start to get some dropped signals, and within 5 minutes, the screen simply does not read wattage or speed and my PT computer shuts off.

I have the new SL version of the wiring harness, aka "sharkfin" reciever, and I have the reciever installed vertically (sharkfin pointing up towards the saddle) on my chainstay. I have a small piece of very thin foam under the reciever to dampen the vibrations from the hub freewheel.

WHAT'S UP WITH MY PT? Other riders on my team don't have any problems with their PT pro and PT SL on the same rides that I get no signal. I have ruled out the problem being the battery since I don't have more than 100 hours on the hub yet.

I want my Power Data...what should I do? It works fine on my indoor trainer..

 

[EpicriderGMAC]

Have you tried one of your teamates hubs(wheel)?
If it works with someone else's, it's your hub, if not, look at the receiver or wiring.

Good point. I'm going to order a few sets of new batteries, and try swapping wheels with a teamate on my next ride.

Thanks for all the help. One of these things has to be causing my problem, so I'll figure it out here very soon I hope.

By the way...the PT does not work below a certain temperature correct? What temperature is that (much below 32 F I hope!)

 

[palewin]

Good point. I'm going to order a few sets of new batteries, and try swapping wheels with a teamate on my next ride. ...
By the way...the PT does not work below a certain temperature correct? What temperature is that (much below 32 F I hope!)

Epic: first, the #357 silver oxide batteries are pretty common. Radio Shack carries them, but here in NJ so do most supermarkets and CVS pharmacies, so you don't have to "order them", you can get a pair locally (the hub requires two). Saris says the PTs are not reliable below 30F. Its the batteries that have trouble with the temperature, not the hub itself. On my previous set of batteries, I was good to about 25-26F. Then I replaced those with a pair from Radio Shack, and as mentioned earlier, had to replace that set after only one month when my SL was shutting down even when it was mid-30s. Put in a new set of EverReadies (from the pharmacy) and everything is running fine down to 29F (hasn't been colder, and today we got close to 2 feet of snow, so riding outside is temporarily suspended...) I mention the brands not because they necessarily mean anything, just that batteries themselves seem to have a lot of variability (like how long they've been in the store?) and the SLs are sensitive to that variability.