Powertap harness question

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I recently got a 2nd powertap sl for racing and it came with a new harness, the "sharkfin" one. Mounted it on my bike and it worked fine no problems with either the SL wheel or the powertap pro wheel. Then one day i take it out and when i plug in the head unit it says "host" just like it does when i plug it into my pc to download data. Tried another head unit with the same result. Is there a way to fix this or is the harness shot? Any chance of Saris replacing the harness considering i didn't use it in the rain or anything adverse and the harness is only a month old?

Try switching wheels and replicating the problem.

If it still does this (you've identified that the problem is in the harness) call Saris. This is a new one.

Having the head show "host" when on the bike is definitely an indication of a harness problem. The cradle you use to download from the head connects the two electrical connectors on the right side of the unit together. This is how the unit knows it is in the cradle and puts it into the "host" mode. If you see host on the bike that means that those two wires in the harness are shorted together. Most likely because the tie wraps have chaffed through the inner insulation. They will replace the harness no questions asked.

I got rid of the tie wraps and used tape after the same thing happened to me.

Thanks for the speedy reply guys, i figured it was the harness by trying different wheels and different head units. Just thought there might be some reset button or something, at $70 a pop these harnesses need to be built a little better.

I seem to remember that two of the computer pins get shorted together to switch it to Host mode (don't remember which two, unfortunately). You've either got a short between two wires in your harness, or possible the little copper contacts in the computer cradle have gotten smashed close enough together that they touch when the computer is installed.

I'd check the contacts in the cradle, and the tightness of your zip ties before scrapping that harness.

Edit: or just read what Flapsupcleanup said, above...:o

I seem to remember that two of the computer pins get shorted together to switch it to Host mode (don't remember which two, unfortunately). You've either got a short between two wires in your harness, or possible the little copper contacts in the computer cradle have gotten smashed close enough together that they touch when the computer is installed.

I'd check the contacts in the cradle, and the tightness of your zip ties before scrapping that harness.

Edit: or just read what Flapsupcleanup said, above...:o


Check across the length of the wire from the mount to the fin looking for knicks, cuts or pinches in the cable. I had this same problem a few weeks ago and found that my mechanic had accidentally run a new rear drealleur cable across my powertap cable, severing it in the process.

When I got my replacement unit few weeks ago, first time I tried it I got the same result (Host). I hooked it to the download unit once, then put it back on my bike and it was fine.

When I got my replacement unit few weeks ago, first time I tried it I got the same result (Host). I hooked it to the download unit once, then put it back on my bike and it was fine.Replacement unit for which? The harness or the computer? There's a pretty good chance you have a pinched wire in your harness, which shows up randomly.

Replacement unit for which? The harness or the computer? There's a pretty good chance you have a pinched wire in your harness, which shows up randomly. No. In fact it was just the onbike computer. But the first time I hooked it on the bike, I too ended up with the 'Host' behaviour.

But thanks for the info.

BTW, I haven't sent the 'hr receiver defective unit' yet. I like the fact that it can serve as a backup unit. Do you think Saris will care about not receiving back the defective unit?

I don't want to endup on the FBI's 10 most wanted man on the planet :D :o

Saris said they would send me a new harness, so i guess problem solved. It stinks having to have a spare sitting around at 70 a pop

BTW, I haven't sent the 'hr receiver defective unit' yet. I like the fact that it can serve as a backup unit. Do you think Saris will care about not receiving back the defective unit?

I don't want to endup on the FBI's 10 most wanted man on the planet :D :oOooh, good question. I'm nearing the end of my warranty period, too, but was procrastinating getting mine ready to send back. I didn't know they will send one out based on a phone call, without having the defective one in hand.

Oooh, good question. I'm nearing the end of my warranty period, too, but was procrastinating getting mine ready to send back. I didn't know they will send one out based on a phone call, without having the defective one in hand.
psst(!)... Don't tell anyone, but they didn't even ask me about date of purchase ;) Seems like as soon as you prononce the password (hr receiver), the unit is already in the mail.

And for the record, I am going to call them and see how much they'd charge to allow me to keep both units.