Hi all, My PowerTap Pro+ hub was squeaking. I took it into my LBS and they didn't have any experience with messing with this hub. I called the Saris cust svce and they said I have to mail the wheel in to them to get it serviced at a cost of $180. YOUCH! And I have a 60 mile ride scheduled for Sunday that I REALLY don't want to miss. Does anyone have experience with this hub and how to swap out the bearings--or even just squirt some lube in there, for that matter?
As always, thoughtful, well-informed replies are most appreciated.
--David

Yup, I paid the $180 to have my PowerTap G3 hub serviced a couple years ago, though I now forget exactly what the problem was. But "grinding" while coasting rings a bell. I now have about 13,000 miles on that hub, and that was the only service it ever needed, or received.

A serious cyclist (with an expensive power meter) really should have a 2nd set of wheels (or a 2nd bike!), for times like these. Nobody likes to train for, and then miss an event, because of a mechanical issue.

A power-meter hub is not the first arena you want to play in with regards to changing bearings. I would take them up on the offer and grab a loaner from a friend.

Thanks for your comments. I have to say I'm a bit annoyed with Saris for claiming, in their documentation, that those are 'sealed bearings' that 'do not require replacement'. That was a lie . What's more, they have decided to not allow customers to even try to replace the bearings--or have a local expert do it, forcing us to cough up a minimum of $180 to have Saris do it, and lose 2, 3, 4 or 5 weeks use of the power meter. (And it's $350, if it's the other kind of hub--the earlier version, I believe.)

I *do* have a spare wheel for that bike but, of course, that means no distance, power, or speed data... I'm going to call around to some more LBSs tomorrow in the hopes someone somewhere knows how to at least squirt some lube in there. I think that's all it is--it just needs some grease.

Thanks again.

Update: I found a local bike shop that might be able to do the work. They have various tools for various PowerTap hubs, have done the work before, but it depends on my hub and their tools. We'll see...

I have a friend with an older model and I changed the bearings for him. One side was a radial bearing and the other was a cup and cone.. I thought that was a poor design.

A $20 wired cyclometer will give you speed, distance, ride time, maximum speed and perhaps some other data. It won't give power but it will fill in most of the gaps while your Power Tap is being serviced.

Here is what I tell all my customers get your work done a month or so before your big ride. Waiting till the last second is never a good idea because if something goes wrong which can happen even under a skilled mechanic who has done the process before for various factors and reasons, you don't have time to get it fixed. You will also not have time to ride the bike and make sure all is good. You want to allow time to ride the bike and bring it back in, if it needs to be touched up and some places cannot always do under 24h turn around especially on specialty items that need parts they may not stock and also because other people have come in beforehand.

I would just ride the other wheel and use a cheaper wired unit as [MENTION=38165]HillRider[/MENTION] suggested. Just enjoy the ride and don't worry too much about your metrics. We frequently get caught up with our devices and being connected that sometimes it is nice to just ride to ride. You will still get a work out and still get some training in and plenty of pros trained without any power meters and gotten great results (Eddy Merckx had 525 really great results over his career on a steel bike with downtube friction shifters and non-aero brake levers)

Have fun at your ride on Sunday. I am hoping my ride won't be rainy because a lot of folks are going to it from all over.

Yeah, good point. I was thinking that, too, but was willing to take the chance. But, as it turns out, it would've been a major hassle to get the wheel and the bearings to the mechanic on Friday--and I have the same situation here: rain in the forecast for tomorrow, so that puts the kibosh on my ride, anyway. The good news is that it gives me more time to solve this persnickety problem ... I'm looking at buying the bearings myself. A DIY youtube video on the G3 hub mentioned a Canadian website where he got his. (There were no videos for my particular model of PowerTap, unfortunately.) I'm looking for four 6901 RS bearings, according to the Saris owner's manual.

• Is there no difference in quality between ball bearings? Are they basically just a commodity?

If that's the case, then I'll just go with the most convenient vendor. On the other hand, Chain Reaction Cycles is selling four for only $12 (USD) plus $6 shipping, and they are 'Brand-X' brand, for whatever that's worth. I don't know how long it'll take to get them, but I'm willing to wait a few extra days if the quality is better.

It might be best if you wait to pull the bearings so you can see if there are any special markings on them denoting a fitting class. Different bearing classes have more or less internal clearance depending on application. And I wouldn't buy any $2.99 bearings. Something from a name brand would be safer, although more money.

NSK and SKF are respected, high quality bearings. You're overhauling a $400 hub...no need to skimp.

'k. Thanks, guys, for the input. Btw, your commentary and this subject are apparently of interest to a lot of people. 267 pages views of this thread already...

I'll do some more investigation... Not that it's all that important, but anybody know of a way to access the QBP catalog? Harris Cyclery used to have a way of getting at it but the link is dead, now. That's always a useful thing to have...

A little rain didn't stop our big ride, plenty of people showed up and road though parts did get flooded which was less fun but it was a good time. Sad your ride got cancelled but I can understand the weather was crap.

As far as bearing 6901 are not too difficult to find, though I do prefer quality bearings from the likes of Enduro, Phil Wood or if I needed to spend a lot CeramicSpeed. However generally when looking for a replacement bearing I go Enduro because most of the time that is the bearing in my component anyway and I like to support U.S. manufacturing when I can. Your local shop can order them through QBP and they have several selections of of 6901s from Enduro and others. The reason I prefer higher quality bearings is I don't like to replace things often, I would rather spend a little more in the first place and get something of quality that will last then replace a lot. With sealed bearings you are still dealing with grades of balls but also the quality of grease and seals and the prices even for say Enduro Zerø ceramic bearings aren't super expensive. Granted I probably wouldn't go ceramic for my purposes but someone like you might be more interested in that?

Good luck with the rebuild, give them time to do it and you will be happy with nice new bearings and smooth spinning wheel.

As far as access to QBP you will need to work at a shop or within the industry to do that. But you can visit BTI's website and see what they have available minus price. You can also do the same for Merry Sales Co. and Euro-Asia Imports again minus pricing. QBP did used to do a consumer catalog at the shops and I think shops can still order one for $50 but with computers being more prevalent and the ease of use of their site most shops aren't doing that these days.

Lots of folks have run into this issue with powertap overhalls. My hub was out of warranty anyway, so there was no risk of voiding it by trying to do the service myself. It is a bit more hassle (and risk) than normal rear hub bearing replacement, and the process is different between their different hubs. Mine was a G3, and the axle needed to be removed from the opposite side of the hub shell than the older unit in the youtube video I found, so whoever does the job needs to be careful and not force anything. Try to use the bearing press to push out the old bearings instead of tapping it out with a mallot.

Because of the extra steps and risk, I would strongly recommend ordering up some SKF (from a legit source, not counterfeit junk from ebay) or NSK or similar. My G3 hub came with Enduro bearings and needed service after only 2-3 years, where a friend's earlier model powertap that came with high quality Japanese bearings lasted 5-6 years, so there is definitely a difference. Enduro is not on the same level as genuine skf etc.. Next time this hub needs service you'll wish that you had put in quality stuff the fist time. Stay away from "brand X" no matter the claims. There is a reason that they are cheaper.

Both my own G3 as well as my friend's older model p-tap hubs have been fine since my service...and best of all, if something goes wrong, you can still spend the 180 for an overhaul with Saris to repair/recalibrate etc..

Best of luck. You can do the repair 'right' without sending it back in and paying the overhaul fee.

-Jeremy

I was thinking the exact same thing. What's the point of trying to save a few bucks now?

So again, not all bearings (of the same size) are the same. There are different classes of fit so do some research and order the right parts. Look for some denotation on the race such as C3 or similar.

This is true, but as far as I'm aware, only Mavic actually tells you what they spec.

Thanks to everyone who posted. Sunday night, after a lot of web surfing, I put in an order for Enduro 6901 Abec-5. Per veganbikes' comments, QBP's catalogue is no longer available to retail customers, and I visited the websites of BTI, Merry Sales Co. and Euro-Asia Imports, just to see what the options were, going through an LBS. BTI was the only one of the three that had extensive choices of Enduro bearings, but they only had Abec-3, did not have Abec-5. They had Phil Wood too. Merry Sales had very limited choices. Euro-Asia Imports had Phil Wood but not 6901 (which is the type I need), didn't have Enduro at all. I purchased the Enduro Abec-5s from Universal Cycles, four for $47 shipped. They shipped them Monday, due to arrive today.

I will be curious to see what was originally installed in my Pro+ hub. I put 20,500 miles on it which, apparently, is a lot better than some have gotten out of their PowerTap hubs. It might be because I am fairly light (150 lbs), don't ride in the wet, and only raced for one and a half seasons.

UPDATE, 12/21: I got the bearings. On the exterior of the races, they are marked "61901 SRS ABEC5 CN". 61901 and 6901 are the same. I don't know what 'CN' means. The key thing is that there are indeed two levels of workmanship offered by Enduro: The Abec-3 bearings are cheaper, about $5 each plus shipping. These Abec-5s are $10 each plus shipping.

Ha! Saris--or the bike shop that sold me the wheel--had a joke at my expense. Even though the hub cap said Pro+, and I got the right bearings for that model, they were the wrong bearings. The mechanic had to get a new set, which were for SL+ and SLC+ hubs: 3 x 6902RU (TSC Raptor), $5 each, and 1 x 6802 LLB ceramic (Enduro), $30. That was an annoyance too, that the mechanic threw those bearings in there without checking with me first, but he also trued the wheel for free, saying it was dangerously de-tensioned, so I guess I can't complain. (The worn bearings were 'EZO' brand.) $80 total before tax plus $15 to return the wrong bearings. That's $85 cheaper than mailing it to Wisconsin, with only a 5 hour wait instead of weeks...

The axle feels pretty tight, doesn't spin freely, but I assume that tightness is normal?

Over 400 page views of this thread. I guess there are plenty of people out there who might benefit from all this info...

I've ridden the wheel for two long work-outs since I got it back from the mechanic, and it works great! I didn't even have to do a manual zero of the power meter. Apparently, all it takes to overhaul the hub is to have an experienced mechanic--or even an experienced amateur--do the work. So, I have no idea why Saris insists on having customers send their wheels to Wisconsin--unless it's just to make more money...

Hi: I saw your post when I was searching for information on changing the bearings on the older PowerTap hubs (the ones with the cone bearing on one side). It is one of the few posts that I've seen that refers to these older hubs, and if you have the time, I was wondering if you would be able to tell me:
1) What the replacement bearing sizes are
2) If you have any tips/advice (or documentation) on the best way to take these apart and re-assemble them
Also, do you know if the freehubs on these are standard Shimano/SRAM or are they a PowerTap special?

I know it's been a while since you made the original post, and I hope you don't mind me responding to it. If you'd rather not clutter up the thread, please feel free to DM me.

Many thanks,

Nick

Hi Nick, I'm afraid that was almost 7 years ago: I don't even remember replacing the bearings, let alone what type or size they were! But, as you can see from here above, I had a local bike store (LBS) do the work, and I had gotten the wrong ones anyway, thanks to Saris (or previous owner?) mislabeling the hub. I kept no notes, other than what's in this thread.

Hi: Many thanks for replying to my post. Going back through the thread, I can see that you posted a lot of detail on the bearing types back then that I will follow up on. Just wanted to check one thing with you though: Is the model of hub that you had serviced the same one that davidad posted on (and that I have)? i.e. with a cap and cone bearing on one side or is it one of the later ones that had all sealed-unit bearings?

Thanks again and best regards,

Nick

Judging by what I said here above, my hub is either the SL+ or the SLC+. (It is NOT the Pro+, as I discovered--the end cap was somehow mislabeled.)

Maybe send Davidad a DM and see if you get a reply, if you need more precision?