wired powertap sl

Discussion in 'Power Training' started by Mac_Biker, Oct 8, 2012.

  1. Mac_Biker

    Mac_Biker New Member

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    I have a wired powertap sl that does not transmit power readings anymore.
    The cadence works. Occasionally the powertap will send some data, but then stop.
    I recently changed the batteries in the hub, because it wasn't working earlier.
    I don't really use the powertap except for the winter. So I've just put the bike on the trainer with the powertap.

    Any ideas?
    Thanks.
     
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  2. frost

    frost New Member

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    Do you have a separate cadence sensor or is the cadence measured from the hub?

    If you are using a separate cadence sensor then I would double check the hub batteries and make sure the receiver "fin" is close enough to the hub. If it doesn't work or the case is that the hub transmits cadence but not power, then I'd contact Saris/Cycleops. At least in my experience they have an excellent customer service.
     
  3. RapDaddyo

    RapDaddyo Active Member

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    If you have fresh batteries in both the hub and handlebar computer, you should be able to test the hub by giving the crank a quick turn on a stand or in a trainer. If you don't get power data from the hub, check your wired harness for kinks or breaks. It's possible that your hub is okay but your wired harness needs to be replaced. These are pretty cheap. If your wired harness wire looks good and your batteries are fresh, you probably need to return the hub to Saris.
     
  4. An old Guy

    An old Guy Member

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    My PowerTap gave me some problems recently. It turned out to be moisture and dirt on the contacts at the head unit.

    I replaced the wire harness becasue I had a spare. No problems since.
     
  5. Yonni

    Yonni New Member

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    This started happening to me this week (wired SL secondhand). The HR and speed were OK but watts are dropping in and out. I've changed batteries in the yellow CPU and tonight I'm changing hub batteries. I'm also leaving the hub open in the airing cupboard to see if it's moisture.

    I've heard people talk about brushes in the hub wearing out but can we see these or is it a specialist service only thing?

    Also would like to know how the signal works i.e. does the hub transmit to the sensor and the sensor run by the handlebar yellow CPU batteries. I mean if the hub batteries were low that would explain why I'm getting HR but not Watts but I don't understand why I am getting speed as well, which surely has to come from the hub too. Or is there a magnet in the hub that the sensor uses to detect speed like an old school bike computer? I'm just worried that there is a fault with the hub that is more serious /costly than aquick service.

    I'll update on how I get on but in the meantime any technical explanations, in laymans terms, would be welcome.

    Thanks
     
  6. upstateSC-rider

    upstateSC-rider New Member

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    My wired unit had a similar problem and it turned out to be the harness also.
    I think I had the plastic tie wraps too tight which cut the wires on the inside of the insulation causing my intermittent issues.
     
  7. AdamW

    AdamW New Member

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    I had a similar problem. Not only check the wiring, but also check how secure the battery holder in the hub is. Mine was loose and that's why power and speed were intermitttent yet cadence and HR were fine. I replaced the battery holder with a new one and haven't had any problems since.
     
  8. RoyalDutchShell

    RoyalDutchShell New Member

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    Ugh- after 5 years, my wired Powertap is doing the same thing. It's worked brilliantly- many KMs and even multiple diy bearing-replacements, but perhaps it's finally died.

    Just replaced the hub batteries, and now the unit says "0" power while stopped, yet "- - -" while pedaling. Like the others here, it gives cadence, speed, etc. from the hub... tested it with second bike (different wire harness) and get the same problem.

    Any updates or further advice?


    to note: Cycleops doesn't service these older wired units anymore, so the options are basically to fix-it yerself or ditch-it.
     
  9. daveryanwyoming

    daveryanwyoming Well-Known Member

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    Sounds like your unit is toast but I'd still call Saris about service. I'm pretty sure they've switched from repairing these units to giving a very attractive offer on upgrading to the newer units. I had a team mate that did that recently and as he described it the deal was so good it was almost worth buying a broken unit off of ebay just to cash in on the upgrade.
     
  10. RoyalDutchShell

    RoyalDutchShell New Member

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    Thanks for the idea, Dave. (btw, I love reading your posts- thanks so much for sharing your knowledge on these forums!!)

    Although I should have tested more before posting here: by re-inserting the battery holder into the hub again (as AdamW suggested), it started to function again!!


    But it's great you can pick up old wired PTs second hand for cheap out there. It makes training by power so much more accessable to people starting out (ie. people we're coaching).
     
  11. mobix

    mobix New Member

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    Hello,
    I also have a powertap wired and cannot get any transmission icon since a couple of weeks.
    Tried to change the batteries, tighthen the battery holder with no luck.
    I suspect the problem is on the wired harness but I wonder how to check this since I don't want to spend money on a new harness and then realize that perhaps the problem is on the hub.
    I went on test mode 2, should be the receiver, and cannot see any 88 signals.
    Can someone confirm that I should get 88 signal with a certain frequency with a working harness?

    Also if you have a spare harness to sell please contact me.

    Thanks
     
  12. ambal

    ambal Active Member

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    The batteries are usually very easy to change, maybe drop it into a bike shop if you can't do it again?
     
  13. Mac_Biker

    Mac_Biker New Member

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    I saw that this thread is still alive.
    The problem with my powertap was the batteries in the hub.
    Apparently I had sucky ones. Just got new ones and they worked.
    I get cheap batteries from microcenter. They're about 1-2 dollars a piece.
     
  14. touringmn

    touringmn New Member

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    I am hoping that some of you using the older models are still around and interacting with each other.

    After one year off my bike, I am now back on my road bike and had the powertap wheel showing me that I still can show some effort.

    But I did get back home and wanted to upload the results again into PowerAgent. We have to log our activities to show that we are making progress. But now it seems that my USB cradle is not connecting. It will not go into host mode. I have validated that my USB ports are good.

    Any similar problems or suggestions?

    My PC is a Windows 8 LT, fairly new. I downloaded the latest PowerAgent software.

    So I am afraid that something is awry with the cradle.

    HELP
     
  15. daveryanwyoming

    daveryanwyoming Well-Known Member

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    Yes, it's likely in the cradle itself as the CPU will display HOST if you simply short out the appropriate two pins on the back of the CPU. IOW, displaying host does not require USB connectivity it just requires the appropriate pins shorted on the CPU.

    I'd start by making sure the contacts on both the cradle and the back of the CPU are very clean. Try rubbing them with a pencil eraser to remove any oxidation and then wipe them with a clean cloth to remove the eraser shavings. That and of course make sure you really click the CPU home into the cradle as sometimes that can take a bit of force. If that does not work I'd either try a different cradle which may mean buying a new one or short of that try pulling the battery from the CPU, flipping it over and reinserting it momentarily to reset the CPU then reinstall the battery and see if things work better which assumes it's some sort of firmware lockup issue in the CPU but realistically it's more likely dirty contacts or the cradle.

    -Dave
     
  16. MElsaied

    MElsaied New Member

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    where and how do i replace my wired harness ?
     
  17. RapDaddyo

    RapDaddyo Active Member

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    The wired harness is a single part, with the hub receiver at one end and the handlebar computer bracket at the other end. You should be able to order a replacement part from Saris.
     
  18. MElsaied

    MElsaied New Member

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    could you kindly send me a link
     
  19. RapDaddyo

    RapDaddyo Active Member

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    Saris has now set up their PowerTap products as a separate company. I looked on their website and found the CPU for the hub you have:
    https://www.powertap.com/product/little-yellow-cervo-lyc-cpu
    If you click on the product options, you will find that you can get either the wired or wireless CPU. But, it wasn't clear whether the replacement part comes with the wired receiver and harness. So, I called PowerTap Support (the number at the bottom of the above link) and asked the support representative to check the detailed part list for that replacement part. He checked and said that the CPU does not come with the wired receiver and harness and that they are out of stock of that part (part # 7022). However, he told me about a program they have for people in your situation (i.e., obsolete hub). They have a hub overhaul program whereby you send in your wheel (with the obsolete hub) and they replace all of the internals of your hub with the G3 internals. This program costs $350 and you set it up with them directly by contacting PowerTap Support. You would need a new CPU, but he intimated that they will give you a discount on one of their CPUs that will work with the G3 electronics.
     
  20. MElsaied

    MElsaied New Member

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    thanks for your help,
    so do you have an idea where else i can get the wired reciever and harness, because i cant afford the overhul program at this time
     
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