# Replacing Powertap Hub Bearings



## Cyclin Dan (Sep 24, 2011)

I am thinking it's about time to replace the bearings in my Powertap Hub. I have the Pro+, and I bought it last May. It's making some interesting sounds, I know the bearing suck to begin with, and I was caught in a really dirty super heavy rain on dirty roads for about 3 hours last weekend...can't be good for bearings.

I saw this video online: Replacing your PowerTap axle in a pinch. - YouTube

The video is helpful, but it only shows one bearing being replaced. Isn't there at least 2? Does anyone know how the drive side bearing is replaced?

What bearings would you all suggest I order to replace the existing ones? I was looking at these (Bikeman ABI Enduro Zero Ceramic Grade 3 6902 Sealed Bearing 15 x 28 x 7mm) but honestly have no idea if that is a good bearing or a good price.

I have Campagnolo freehub, but it is less than one year old (switch from Shimano to Campy late last year) so I am thinking the bearings in it are fine.

If anyone could clarify those few points I would really appreciate it.

Thanks!


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## Cyclin Dan (Sep 24, 2011)

Look at the huge variety of prices on the bearings found online.

6902 ceramic bearing | eBay

Can anyone help clarify which are good, which are bad, etc...? I want to get good bearings, but don't want to spend more than I need to.

Thanks in advance.


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## Kontact (Apr 1, 2011)

Powertaps are not user serviceable. You might be able to get part of it apart, but the power measurement won't be accurate after that. You send them to Saris for service and calibration.


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## Cyclin Dan (Sep 24, 2011)

Kontact said:


> Powertaps are not user serviceable. You might be able to get part of it apart, but the power measurement won't be accurate after that. You send them to Saris for service and calibration.


I realize that is what Saris said, but my LBS is willing to do it and there are LOTS of people on "that other forum" that have done it, as per the threads I've seen. I posed the same question there...hopefully it gets some action.

Everyone says it's very easy to do. I just need to make sure I get the right bearings.


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## rbart4506 (Aug 4, 2004)

Wrong! You can change the hub bearings...It's easy...

Watch the video to get the axle and non-drive side out...Then pop the drive side out...I used a socket that fit within the hub and lightly tapped it out...

You can press the drive side bearing in using a threaded rod with the olf bearing and some large washers...Pretty straight forward...

The don-drive side bearing gets pressed in as shown in the vide0...

6902 - drive side bearing and 2 more of those in the freehub,,,
6802 - in the non-drive side...

Everything to measure power is within the hub, you do not disturb it...

Saris doe a good job of scaring users into sending their PTs in for service when all they need is a simple bearing change...

Do a google search and you'll find lots of info on the bearing replacement process and successes....

Now if there are other issue with the PT, then by all means send it in...But, to replace bearings that is for sure a DIY...


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## Cyclin Dan (Sep 24, 2011)

rbart4506 said:


> Wrong! You can change the hub bearings...It's easy...
> 
> Watch the video to get the axle and non-drive side out...Then pop the drive side out...I used a socket that fit within the hub and lightly tapped it out...
> 
> ...


Thanks for the help. Does this look like a good bearing?

S6902-2RS Ceramic Bearing ZrO2 Stainless Steel Sealed ABEC-5 15x28x7: Amazon.com: Industrial & Scientific

That's the 6902, which it sounds like I need two of for the drive train side...correct? And the NON drive train side is 6802 it sounds...do I need 2 of those as well?

I am not going to replace the bearings in the freehub because they're less than a year old...or should I just do them all at once?


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## Justinbinny (Oct 29, 2013)

At least the G3 hub has a different design. The axle might still be captured by the main hub bearings, but the NDS cap no longer presses against the bearing inner race (instead it just presses on the axle end), and the freehub has a little lateral play, so those aren't captured either. Should be more more forgiving. 

If looking for 6902 bearings :- 
*​*6902 - Buy 6902 / 6902-2RS / 6902-ZZ Online @ Bearings.uk.com


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## Kenrow (Dec 21, 2010)

Do you need ceramic bearings, you could get the Enduro Max bearing for as little as 6 bucks each? (Enduro does make high quantity bearings)


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## Tunnelrat81 (Mar 18, 2007)

I realize that I'm resurrecting an old thread here, but I just wanted to post that I just replaced the bearings in my G3 Powertap hub this evening. The video often linked in these powertap bearings threads is for an older PT hub with a slightly different design. The G3 hub is different in that the magnet that's on the axle does not fit out of the opening on the non-drive side of the hub shell. What this means is that if you follow the directions in the video, the bearing will come partially out and then stop. If you try to force it, you will likely damage the inside of the hub, as the magnet simply won't fit out. I had to reverse the direction and press out the DS bearings first. After some light tapping with the rubber mallet, I realized that I could use my bearing press with some random sockets and spacers to slowly push the bearing out more gently. Next time I do the job, I will avoid the hammer and simply press it out.

I did have to lightly tap the NDS bearing from inside once the axle was removed, but that's because I don't have one of those cheap and clever bearing pullers. I'll try to pick one up before I do this job again. Once the NDS bearing was removed and the new one pressed in (I used the wheelsmfg press and drift set), I cleaned the axle and re-wrapped the magnet with a fresh application of electrical tape and slid it back into place. 

From this point, the only thing left is to find the right set of drifts/sockets/spacers that you want to use to press the DS bearing in, realizing that the axle has to go in first, so you can't use the normal 6902 drift with it's alignment collar. I used the 6902 *flat* drift and then stacked a 3/4 in drive socket (you'll have to search for the appropriate size to fit inside ratchet teeth and rest gently on the bearing drift) and then simply press the bearing into place. I re-installed the PT battery unit, slid the axle end caps back in place and put it back onto the bike. 

The hub immediately connected with my Garmin 520, and seems thus far to be reading correctly. I'll spend much more time this weekend on the bike and will get a better idea of whether or not the calibration drifted. I doubt it will have, but if so, I can always send it in. It is out of warranty anyway, and since their service is a 'complete' one, there seemed little risk for me trying to replace the bearings myself.

I still spent less than the Powertap service, and I now have the bearing tools for my other cartridge bearing wheelsets.

-Jeremy


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## yuanja888 (Mar 17, 2008)

Jeremy, that's good to hear. I am in a jam and need to replace two G3 bearings. I am trying to visualize your instructions and need some help. 

So how did you get the the axle out? U said u started on the ds bearing by pulling it out. How was that done exactly? Did you tap on the axle from the nds?


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## Tunnelrat81 (Mar 18, 2007)

Yes, you can either tap on the NDS of the axle, or you can use some sockets/spacers to use the bearing press to do the same thing. That all depends on what random bits you have laying around that you can use to space it out appropriately to use the press for removal instead of the rubber mallet. 

-Jeremy


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