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How to wire up the PT... elegantly?

Started by Aztec · · Last activity · 21 posts · 5,051 views

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Power meters
Published
6 July 2004
Last activity
25 July 2004
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Aztec
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21
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  1. My Power Tap Pro is now finally all built up (28h, on Ritchey rims, Sapim Cx-ray spokes, Record front hub).

    I didn't realize that it isn't wireless. How the heck do you run those wires -- which are way long for a 56cm -- cleanly? I've wrapped them around the cable casings up front, but since I have internal cables, I ultimately have to run them down the frame tubes somewhere. Yuck.

    If anyone has any pics of how you did it, I'd love to see them. Right now I have the receiver wire running under the top tube, and the cadence wire running down the front edge of the down tube.

    Learned a quick power lesson today already on the trainer... my power faded from 175w at a steady 'endurance' heart rate all the way down to about 145w over the course of just an hour! I'm going to learn a lot from this toy.

  2. I ran into the same problem for a Polar Power system. I think running the cables under / in front of the tubes as you did is a good choice. I used a narrrow width of very sticky black duct tape to fix the cables, they are practically invisible unless you look at the bike from below.

  3. Quoted post said:

    Originally posted by Aztec
    My Power Tap Pro is now finally all built up (28h, on Ritchey rims, Sapim Cx-ray spokes, Record front hub).

    I didn't realize that it isn't wireless. How the heck do you run those wires -- which are way long for a 56cm -- cleanly? I've wrapped them around the cable casings up front, but since I have internal cables, I ultimately have to run them down the frame tubes somewhere. Yuck.

    Two quick tips: Clip the cadence sensor or buy a PT standard harness. Cadence is pretty much a red herring for training and the standard PT measures it well enough for most purposes. Unless you've got some other reason for it, ditch it.

    I also used electrical tape the same color (that's colour Ric) for one bike and clear electrical tape (try and find that!) for my other bike running the wire up the seat stay and across the top tube.

    Good luck and prepare to have your eyes opened.

  4. Quoted post said:

    Originally posted by Aztec

    Learned a quick power lesson today already on the trainer... my power faded from 175w at a steady 'endurance' heart rate all the way down to about 145w over the course of just an hour! I'm going to learn a lot from this toy.

    P.S. Yea, training by HR kind a sucks eh!

  5. Quoted post said:

    Originally posted by beerco
    Two quick tips: Clip the cadence sensor or buy a PT standard harness. Cadence is pretty much a red herring for training and the standard PT measures it well enough for most purposes. Unless you've got some other reason for it, ditch it.

    I also used electrical tape the same color (that's colour Ric) for one bike and clear electrical tape (try and find that!) for my other bike running the wire up the seat stay and across the top tube.

    Good luck and prepare to have your eyes opened.

    can't you guys learn to spell 😄

    i use the little sticky tape strips that come with the PT.

    Up the rear triangle and then using black insulation tape (to match the brake cable colours) i tape it behind the brake cable, then using the PT sticky strips place it under the top tube and then carefully wrap it around the brake cable at the front. looks fairly neat.

    i actually use the cadence function -- i can't be bothered to cut the cable. anyway, beerco is correct (even if he can't spell :eek🙂 the PT standard cadence is pretty good. generally seems to be spot on (on average).

    ric

  6. I prefer to mount the receiver on the chain stay instead of the seat stay, then run the cable up the bottomside of the downtube under some color-matched electrical tape. Any excess cable can either be wrapped around the chain stay or around one of the cable housings at the handlebar (I prefer the chainstay).

  7. i hadn't thought of that! it'll be like one of those timing chip things on the pro's bike in the TdF!

    and, Andy, it's "coloUr" ;-)

    Ric

  8. Thanks for the ideas -- sounds like I'm close to what others do. I'll have to take up the challenge for finding clear electrical tape! My frame is mostly red, so it's not too bad, but I can't imagine trying to hide this thing on my multi-coloUr Colnago!

    When you refer to 'PT standard cadence'... um, what is that? Are you telling me that there's another way of getting a cadence reading without that wire???? I don't know that I really 'need' cadence, especially since I've never had it, and you can't display it at the same time as HR anyway (unless you kludge it by putting HR in the middle display). Maybe after awhile I'll clip the cadence wire off.

  9. Quoted post said:

    Originally posted by Aztec
    Thanks for the ideas -- sounds like I'm close to what others do. I'll have to take up the challenge for finding clear electrical tape! My frame is mostly red, so it's not too bad, but I can't imagine trying to hide this thing on my multi-coloUr Colnago!

    When you refer to 'PT standard cadence'... um, what is that? Are you telling me that there's another way of getting a cadence reading without that wire????

    The regular PT calculates cadence by counting the time between "power pulses" from the hub. This method is not perfect and has some artifacts, but I find that for the most part it's "good enough".

    In some cases where you're back calculating gear selection or maybe some other stuff a very accurate cadence is required, but for the most part it's not.

    I don't own a PT pro, but it's my understanding that it will revert to the old way if the cadence signal is missing.

    p.s. I'd rather look at cadence than HR!

  10. No kidding, it has redundant systems??!!! I LOVE IT!!!!

    I don't want to look at HR either... w/ that upward drift (or downward, holding power constant) yesterday, it makes longer workouts too easy at the end (or, using power will make me overtrain ;-)).

  11. My electrical tape keeps coming unstuck, even though the frame is clean!

  12. Quoted post said:

    Originally posted by Aztec
    My electrical tape keeps coming unstuck, even though the frame is clean!

    Here are a couple of tips:

    1) clean the frame with some isopropyl alcohol and then allow it to dry completely before applying the tape. This will ensure that that there is no residue of grease or oil to interfere with the adhesive.

    2) be careful to not stretch the electrical tape when you are applying it. Instead, gently unroll more than you need, allow it to spring back to its original length if you've stretched it at all, then apply it over the cable and finally cut to length.

  13. Wouldn't be nice if the people at Graber "got" it and provided wireless. Not too difficult in the 21st century. 🙄

  14. jimh2 said:

    Wouldn't be nice if the people at Graber "got" it and provided wireless. Not too difficult in the 21st century. 🙄

    I guess you think that the battery life of your PT is too good eh? Ever design an embeded device with wireless capabilities?

  15. Aztec said:

    Thanks for the ideas -- sounds like I'm close to what others do. I'll have to take up the challenge for finding clear electrical tape! My frame is mostly red, so it's not too bad, but I can't imagine trying to hide this thing on my multi-coloUr Colnago!

    When you refer to 'PT standard cadence'... um, what is that? Are you telling me that there's another way of getting a cadence reading without that wire???? I don't know that I really 'need' cadence, especially since I've never had it, and you can't display it at the same time as HR anyway (unless you kludge it by putting HR in the middle display). Maybe after awhile I'll clip the cadence wire off.

    I unhooked the crank magnet and Voila! the cadence still 'works' as it did before. I put that in quotes because it worked pretty poorly. Now I know why -- it's using the virtual calc rather than the intended way. I think I need to stick a spacer between the receiver and the magnet since my chainstays are curved and far from the crank. That is, if I want to use the official cadence method. I dunno, it would be nice to chop off that wore and clean the whole thing up!

  16. Aztec said:

    I dunno, it would be nice to chop off that wore and clean the whole thing up!

    One thing I thought of if you decide to chop off the cadence sensor: Make sure you somehow isolate the two wires and seal them off. I don't know what their cadence circuit looks like, but a short between the two could reduce battery life. Use a sharp wire cutter to sever the line, then inspect to make sure the wires don't short. Finally, wrap in tape or put a drop of RTV on there to keep any moisture etc out of there.

  17. beerco said:

    One thing I thought of if you decide to chop off the cadence sensor: Make sure you somehow isolate the two wires and seal them off. I don't know what their cadence circuit looks like, but a short between the two could reduce battery life. Use a sharp wire cutter to sever the line, then inspect to make sure the wires don't short. Finally, wrap in tape or put a drop of RTV on there to keep any moisture etc out of there.

    prior to cutting it off, if you do want cadence then you need to manually change settings on the CPU, to collect crank cadence only.

    ric

  18. Aztec said:

    I unhooked the crank magnet and Voila! the cadence still 'works' as it did before. I put that in quotes because it worked pretty poorly. Now I know why -- it's using the virtual calc rather than the intended way. I think I need to stick a spacer between the receiver and the magnet since my chainstays are curved and far from the crank. That is, if I want to use the official cadence method. I dunno, it would be nice to chop off that wore and clean the whole thing up!


    I hooked up the crank cadence properly this time... WHAT a DIFFERENCE in how it works. Wow. Nice and smooth reading, spot on what I *think* my cadence is, etc. Way better than reading it at the hub. I think I'll hold off from clipping that wire just yet.

  19. Ric, dude, Color's the right spelling for Americanized English. It started back when Webster was developing the first dictionary for English for the colonies and Ben Franklin encouraged him to make some changes such as changing the spelling for words like theatre to theater and colour to color. (grins wryly) Just so you know, you're dealing with a slightly different written dialect than your normal English.

    Thomas Davis

  20. tomdavis80 said:

    Ric, dude, Color's the right spelling for Americanized English. It started back when Webster was developing the first dictionary for English for the colonies and Ben Franklin encouraged him to make some changes such as changing the spelling for words like theatre to theater and colour to color. (grins wryly) Just so you know, you're dealing with a slightly different written dialect than your normal English.

    Thomas Davis

    i know that, it was humour or humor. obviously lost on you ;-)

    ric

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