Problem with Powertap?

Alhana

While training I notice that the current watts display on the top row of my powertap goes to solid dashes and the elapsed time on the bottom stops, sometimes for 15-20 seconds at a time. I have never seen this before and it is kind of annoying having the display just feeze for that long. Have any of you with powertaps experienced this and is there a fix?

lanierb

This means that the CPU is not receiving the signal from the hub. Some comments:

Non wireless PT: this usually means one of three things, (1) the hub batteries are weak and need replacing, (2) the sensor is not installed close enough to the hub or in the right position, or (3) some older (non sharkfin) sensors did this due to a vibration issue, usually while coasting downhill -- if this is the problem they will send you a new sharkfin sensor for free I think. There's also (4) possible RF interference from some near source of RF, but in my experience this is rare for the non-wireless version.

Wireless PT: (4) becomes cell phone tower/cordless phone/etc interference, and is more common for the wireless than wired PT. You can recognize this because it always drops out in the same locations on a ride.

Alhana

Thank you for the tips. My powertap is the wired kind. You mentioned the hub batteries might need changing, is this doable for someone or is it best to send the hub back to saris? Can you even get batteries for the hub locally?

I think the computer also runs on batteries, should those be changed too? If so, I'm sure the computer batteries would be a cinch to switch.

Bikeridindude

The batteries can be purchased locally, and changed yourself. Just remember to put some grease on the threads when you scrow the hub back together to keep it watertight. The owner's manual says for sure, but I think the computer batteries last at least twice as long as the hub, depending on the recording setting you have it on.

Alex Simmons

and search these forums for tips on removing the hub cover on the SL hub if you have an SL hub that is. It can be a bugger to get off first time.

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Alhana

I double checked the powertap and remembered it is the PT Pro model rather than the SL. I would guess the hub isn't too different, as far as taking it apart, from the SL model.

As for the grease, I figure something from the bike shop should do the trick. THe hub batteries are something like #457 or EPX76 Oxide type. An electronics store should have these.

Thanks for the tips guys.

grv

If the battery holder on the pro is anything like the sl, be really gentle putting it back in the hub, and stop if you encounter much resistence. My sl has this flexible tab that sticks out of the hub, which the battery holder connects with when it slides in. The first time I changed the batteries, I guess it was not lined up just so, and I bent the tab a little.

Still, if you're not a klutz like me, it'll be fine.

Tim Lamkin

What I have found, ( I have four wheels with PT's) change the bats every two months in summer, every month in winter, my riding is 600/800 a month (yours may vary), I have tired all different schedules to changing and found this to be the best.

I ride down to about 29/31 degrees F, after that It is too damn cold to ride, PT's have some issues at that temp, the better the bats the better the data as for less drops.

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Alhana

Tim, I have to ask...you said 'my riding is 600/800 a month', you don't mean hours do you??? If you do then I might as well quit the sport for being a slacker

Yeah, riding at temps much lower than 25-30 is a darn exercise in torture. Well for me at least.

Something kind of unexpected I found was I noticed a prominent drop in what seemed like a similar location. Sure enough, I went around the corner a half block or so and realized there is an array of towers of some sort there, maybe radio, maybe something else.

Regardless, I will check out some batteries locally, maybe radio shack can hook me up.

Chipotle

Me too. My PT Pro computer has now gone to heck.

Why me, Lord?! Not now! Big race Nove 11. I was mid come - back after a broken clavicle (Ti plate and 10 screws). Everyone wrote me off for the season. I was getting strong the scientific way. Now I may have to train with a HR monitor, argggggh...

Seriously, I went to zero out the torque and got numbers then dashes. I adjusted the wired shark fin and briefly got numbers again, then dashes. I have two hubs and 3 harnesses. Tried em all. Dashes. All the batteries have been changed. Dashes. Saris said $ 200 for a new one. No help.

Has anyone heard of the CPU's just dying? Anyone ever bring one back from the dead by installing updated firmware? Any suggestions?

ric_stern/RST

i change my hub batteries about twice a year -- this is for the new Pro units (that look like an SL), the SL and the 2.4. I ride about 550 - 600 hrs/year.

I think i've needed to change my computer battery once so far this year.

The batteries in the old style Pro hubs last pretty much forever! mine were still working fine one unit that was 3 y old, at which point i just changed them anyway!

In answer to the dashes issue. Check the receiver unit is the correct one and correctly placed, and check that the cones on the axles are tightened correctly.

Lastly, if you or anyone has the *old* style Pro hub, please remember the allen key bolts should only be turned 7 times when placing the hub cover back on, else you'll likely break the hub.

ric

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Tim Lamkin

OK tell me more my friend

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ric_stern/RST

Turning the allen key bolts more than seven turns can crack the PCB circuit board and ruin your hub. (i think it's the circuit board, anyway, you'll ruin the hub)

ric

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Tim Lamkin

Cool...tanks

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