PowerTap Hub cut up and how it works

[@gplama]

Powertap have a 30% off trade in at the moment, you've taken 25% off that one in just a few minutes! Too easy! :) We love your work mate. Thanks again for putting this together.

[@DiegoCattaneo]

Great stuff! Thanks. In the video where Shane brought the powertap, you mentioned the wrong bearing preload.. It's still present in the newer versions with the bigger axel?

[@glennoc8585]

Can't get enough of 'how it works'. I like to know what's inside.

[@LuescherTeknik]

You have come to the right channel for that!

[@askebendtsen2473]

Production quality is getting really good!

[@LuescherTeknik]

Thanks, I have been working on this, so it is nice to get good feedback.

[@mas465190]

Ultra-cool!! Genius the way you did the quarter section. Never would have occurred to me. Would have just cut it in half. Many thanks.

[@hrevyaga82]

Great disection to show how the torque sensors works.

[@mccreadygossard]

The best youtube channel ever. I wish i could go to Australia one day just to visit your workshop! Thanks for this again, i really love your work.

[@simonbrewer891]

Great video. I have thought about getting an Powertap Hub in the past, and was always curious why they were so large. From your video it now becomes clear. The layers are axle, bearings, inner (torque hub) and outer spoke hub which creates the bulky appearance, and allows for servicing. I wonder if anyone ever considered building a power metre between the ratchet and the axle? That seems a obvious interface where torque is transferred through to the spokes/rim.

[@markwhite4182]

Excellent video. Thaks Raoul and of course Shane for the 'donation'!

[@kevina6587]

The Wheatstone bridge was invented by Samuel Hunter Christie in 1833 and improved and popularized by Sir Charles Wheatstone in 1843. My wired powertap is not quite that old, but nearly !

[@RixterNow]

Thanks for the review. Shane, thanks for making it possible

[@johntrussell7228]

Amazing stuff!! Thank you for making these, I am learning so much about the equipment in the sport I love. :)

[@stevenellis8365]

Thank you ! Love your work.

[@ClarkS963]

EXCELLENT VID! Loved the sound of the narration. It was very Pro!

[@TheDarkInstall]

Clark S No, that is his natural sawing speed.

[@RobPennefather]

Great video as always. Looks good with the new camera too!

[@dblazquez]

Super cool. Thanks.

[@garym5218]

Excellent vid, thanks to you and Shane ! Just a thought on the magnet...wondered if that was for rpm of wheel for speed rather than for cadence since cadence would depend on what gear was selected. Think PTap hub estimates cadence via equating 2 power spikes (left and right downstrokes) being equal to 1 rpm of the cranks, but may be wrong :-). Anyway, very interesting and keep them coming !

[@blackdidi]

Gary M agree with you about the rpm part. I also like to know the purpose of the floating part where the strain gauge installed on.

[@LuescherTeknik]

Definately for RPM of the wheel, as it cannot know what the legs are doing directly. Having the wheel speed and the power spikes and hence cadence, it would be possible to calculate the gearing.

[@fat2fit691]

love this stuff, good job.

[@nagev7239]

potentially the best channel on YT aaaaand i learned a NEW WORD today!!!! #lubricity

[@PeakTorque]

The wear pad is a nasty solution. I bet it gives rise to a bit of stick/slip hysteresis being so close to the gauge. A bearing would have been better! Great video though Raoul.

[@TheDarkInstall]

Yeah mate! Good video. Interesting to see the wear pad... I wonder how the wearing down of that over time affects things?

[@LuescherTeknik]

Good point, it is quite well sealed however friction at this interface could change the torque values slightly, the torque tube could also fatigue over time and fail.

[@tk38]

great content again. better with the camera as well!

[@bacazterchovej2235]

well but how they made that metalic foil /strenght gauge/ to not be damaged by changing hubs strain ?

[@886014]

Great video, thanks to both of you for making this available. I have one that has also failed and got it apart as far as the hacksaw. I figured I had nothing to lose and could gain some education by pulling it apart. I wondered whether it was pressed/bonded together and was considering trying to press it apart, but had a bad feeling about it and can see now that wouldn't have worked so that was a good hunch. Have you ever disassembled/reassembled one without the hacksaw?

[@LuescherTeknik]

I have not, however it is not difficult as the torque tube is just screwed into the hub shell, you just need the correct tools to unscrew it.

[@886014]

Awesome, that's how it looked in the cutaway, thanks very much. I have a machine shop so it's normally no trouble to make up a tool to suit. I'll put that on the To-Do list. I'm just curious if I can track down the cause of failure. I used to dislike that wheel so no great urgency to get it working, just natural curiosity.

[@DudidumMusic]

@@886014 Hi Pete, I know I'm replying to an old post, but maybe you're still around. Did you manage to fabricate a tool to remove the power-meter core from it's hub? I need to replace the flex cable that connects the batteries to the board. It's a left-handed thread, right?

[@bullwhipjohnson8247]

I just wondered if the blue wire could be used to tie the batteries together? The cutaway is interesting because it shows the exact position of the bearings inside the hub body. They appear to be somewhat offset in their alignment. Unusual because it may not support the weight of bike and rider in a straight vertical line.

[@LuescherTeknik]

I checked the blue wire and it does link the two batteries. With the bearing position I would imagine that they are positioned in this way to accomodate the other components.

[@bullwhipjohnson8247]

Glad I could help. I chuckle to myself. I've had a little experience with electronics so, that was an easy guess. I've watched a couple of the older cutaway videos and they're quite an eye opener. Great work.

[@macolganjames3356]

If only to link the batteries, it would be a much tidier and more professional job than that. I suspect you're both correct. the ugly blue jumper to also assist in removal/replacement of the battery housing in that confined space. also keeps sweaty salty fingers from touching the batteries. Another great vlog Raoul :)

[@michaelmason1979]

Do you know what size the bearing right inside the freewheel hub is?

[@Offgrid531]

any ideas how to reset the torque tube as mine will not zero when calibrating it with my garmin. its reading 7.22 with the wheel out of the bike? thanks for the great video.

[@LuescherTeknik]

Hi Chris, there may be a component failure in the board or other causes for this, I would recommend sending it back for refurbishment. Sorry I can't help you with this

[@literoadie3502]

Are you gonna do any machining on the Myford? Which model Myford do you have?

[@LuescherTeknik]

I use the Myford all the time, I have an old ML7, I got it in 1990.

[@literoadie3502]

It'd be cool if you could show some machining!

[@zygmuntthecacaokakistocrat6589]

Bearings aren't any good any more . . .