Shutter Precision hub bearing replacement
 

A brief backstory: I bought a Shutter Precision SV-8 hub in late 2015, and have enjoyed its light weight and low drag ever since. Though it's only rated at 2.4W when used on 26"/700C wheels, I was pleasantly surprised to find out that it could also power a tail light with ease. However, that low drag came at a cost and the hub began to rumble and ping the spokes after about 4300 miles of service. As you can see, it has also developed some bearing play, making it difficult to check the wheel trueness.


The hub is now well out of its 2-year warranty period and the cost of shipping it to Taiwan and back for service would represent at least half the cost of a new hub. Inspired by this YouTube video:
I decided to tackle the job myself. I figured that since the hub was out of service anyway, I wasn't out much if I broke it beyond repair.

Right away, I learned that there were differences between my rim-brake hub, and the disc brake hub in the video. Where his end caps threaded onto the axle, mine were a press-fit. So I started by pulling off the NDS end cap using this little bearing puller. (Pro-tip: file off any sharp edges first so you don't gouge up the aluminum.)

https://i.imgur.com/hwt5qGk.jpg?1
https://i.imgur.com/erwlIzo.jpg?2

Rather than completely disassembling the wheel, I wanted to see if I could leave one side laced up throughout the process. That could have some benefits for leverage if I needed to twist one half against the other. I left the tire on and inflated while doing this, the lower spoke tension allowing the nipples to turn with a bit less friction than if I had removed the tire first.

Another difference to the YouTube video: the two halves of my hub don't join with a twist-lock, they're more like a plastic Easter egg. So by adding a pull to the twist, the hub separated easily. That meant I'd have to be careful about aligning the spoke holes when reassembling the hub.

https://i.imgur.com/6V5cIqx.jpg?1
https://i.imgur.com/A0cEE72.jpg?1

I heard a "pop!" when pulling the DS end cap and briefly panicked that I had snapped something inside.

https://i.imgur.com/edNYe9k.jpg?1
https://i.imgur.com/uCJCwYc.jpg?1
https://i.imgur.com/ebl1pAp.jpg?2

You can see a bit of black rubbery goo in there, presumably to block water entry. I'd need to use something to fill those gaps back up later.

Here are the dyno guts out of the hub shell. How this thing works wasn't immediately clear, but that silvery disc in the center is the magnet. It is suspended between the two parts of the coil by the two halves of the hub shell with a total clearance of about 0.023". This is the "tolerances of less than a millimetre" that Shutter Precision says makes the hub not user serviceable. I love a challenge sometimes.

https://i.imgur.com/RKvOR1U.jpg?2

In this picture, I was also checking the continuity, fearing that I had broken the connection somewhere. Whew!

Here's what the bearings looked like under the seals. The NDS bearing had noticeable play, but the DS was merely grungy.

https://i.imgur.com/30vMt4L.jpg?2

As much fun as this has been so far, it's not something I want to repeat every few years. So I ordered a pair of these Enduro bearings with labyrinth seals from Nashbar. They felt smooth and solid in the hands, and oozed a tiny bit of grease onto my fingers, which I took as a good sign!

https://i.imgur.com/xHqy6Z3.jpg?2

Pressing in the bearings was nerve-wracking, as it's not something I have a lot of experience with. I used a board with a hole in it, a 10mm QR axle, some washers, and axle nuts to pull the bearings through. Chilling the bearings in the freezer for a few hours and applying a light coating of Tri-Flow to the bearing seats in the hub shell seemed to help.

https://i.imgur.com/VTzY8Wi.jpg?2
https://i.imgur.com/bx1dB2d.jpg?2

I don't have any pictures of reassembling the spacers and plug wiring for the DS, largely because I used dabs of rubber cement around the wires and needed to work quickly before it dried.

Pressing on the end caps was nerve-wracking as well. They were understandably a tight fit, and I struggled to keep everything aligned in the C clamp while applying force. Shutter Precision no doubt has nice jigs for doing this.

While doing this, I also needed to make sure that I pressed the hub shell far enough onto the axle so that it would hold the magnet in the right spot. Too far to either side, and the magnet would drag against the coil. So I made sure the magnet was stuck to the DS coil, and pressed until a "pop" indicated that I had pushed it just past center and made it jump to the other side. Releasing the pressure from the vise allowed the hub shell to move back slightly.

https://i.imgur.com/SevwyqS.jpg?2

At this point, I stuck on the NDS portion of the hub shell and squeezed around it with fingertips to make sure it was seated evenly. It's a close fit, but not a tight one. Good thing, because I needed to twist it slightly to make sure the spoke holes were staggered correctly.

Finally, I pressed on the NDS end cap. Because it's the longer one, it was easier to align before getting to the press-fit portion.

https://i.imgur.com/IWsjxrV.jpg?2

What a relief it was that when I turned the axle with my fingertips, the "notchy" dynohub feeling had returned, and there were no sounds of metal rubbing. I threw the partial wheel in the stand and hooked up my multimeter to check if it still made juice:


Whew! All that remained was to reinstall the NDS spokes and true the wheel. I couldn't resist trying a "trick" mod of using red aluminum nipples while I was at it. The spokes are long enough to extend past the screwdriver flats, so I'll see how they hold up. I've only used brass nipples up until now.


At this point, I think I'm done. It seems that Shutter Precision relied on the press-fit between the hub shells and the magnet disc to seal the hub at the joint, but since I've been in there I'm considering running a thin glue (or something) into the parting line for a little insurance.

Hope this was illuminating!

Thanks for posting. That looks a lot more forgiving of disassembly than the Shimano hubs. Some dielectric grease at the parting line would help with water and won't hurt anything.

Thank you VERY much for posting. The Youtube video and your description along with photos are VERY enlightening.

I own two SP PV-8 hubs, bought my first one (36H) in April 2013, at that time I could not find a seller in USA, bought it shipped from Taiwan. I bought it based on a couple write ups from Europe. The center band of the hub that is between the flanges where there is text and direction arrows is like your late 2015 version, this hub also is curved like yours, not flat. Bought my second one (32H) in March 2017, that one has a center band that is flat like the one in the older Youtube video that you cited.

After watching the video and looking at your photos, I looked at my two hubs. My first (2013) one has wrench flats on the ends like in the Youtube video. But my newer one (early 2017) is like your late 2015 version, no wrench flats, thus likely press fit.

Thus, they have made some changes on at least two occasions, one of those changes was before your hub was built, one was later, yours has the older curved center band and the later press fit ends.

Perhaps the flat band in the middle on the newer design coincides with the twist lock to connect the shell halves where the rounded band in the middle was part of the "easter egg" connection that you described? Or, maybe the twist lock is specific to the disc version, we might find out some day.

A translated version of this article is one of the reasons I decided to buy my first SP hub in 2013, this link also shows a partially disassembled one with the curved center band and threaded axle.
https://fahrradzukunft.de/14/neue-nabendynamos-im-test/

I have always been a bit nervous about non-user serviceable components. That is why on three of my bikes I use the Shimano rear XT steel axle cup and cone (with quarter inch ball bearings) hubs. Two of those three hubs are on touring bikes, the third used to also be on a touring bike. Thus have carried more than the average amount of weight.

I am a bit less nervous now about my decision to buy a couple SP hubs, but I still would rather not make the repair that you made, but I would feel better about trying it.

Wow!!
We have the same hubs on our touring bikes. And 2 years ago while riding across Canada my wife's started getting noisy and play started to develop. I emailed SP in Tiwain and they DHL a replacement to General Delivery in International Falls, Minnesota! I picked it up and a local bike shop let me use tools to rebuild the wheel!!

@Tourist in MSN, I have a hunch that the twist-lock assembly may be necessary for disc brake hubs, to keep braking forces from moving one half of the shell relative to the other. :)

Thanks Scott. My main gripe with SP was the short service intervals and necessary return to factory.

I've got over 7,000 miles on an SP dynohub with no problems so far (and I weigh about 210 pounds). As for the return to the factory, that's what I thought until I found the list of "SP Partners". There's one in California. :-)

Scott, this was an *outstanding* report! I have bookmarked it in case I decide to service my SP hubs when the time comes. About 8 years ago, before I got my first SP hub, I had a bearing failure in a Dahon "Joule" ("Joule 1"... subsequent Joule hubs for Dahon and, eventually, Tern, are made by SP!) dynohub at about the 2,000 mile mark. I was told the hub was not serviceable... not what I wanted to hear! Eventually, I figured out how to replace the bearings, which is just about the only part of a dynohub that can (or should) wear out. I documented the repair HERE. It appears that the service of the SP hub requires a bit more technical expertise than the Joule 1, so I'm glad to have your experience to temper my enthusiasm to service them myself! There's an SP service center in California, apparently (see above).
Best,
Steve

Thank you, Steve! Your report on Hubstripping helped inspire me to take the plunge, and I hoped that I could help add to the knowledge base whether I succeeded or failed. :thumb:

is it possible to upgrade the bearings?

That was my goal! Time will tell if the seals on these Enduro bearings do the job better than the originals.

It's very possible that I added a tiny bit of seal drag with these new bearings, but if they last longer it will have been worth it.

Considering how rare reports are of bearing failures on SP hubs, I suspect that they use pretty good bearings with low probability of failure. But all things mechanical, some failures will occur earlier than other failures.

I bought one of my SP hubs in late winter 2013, at that time I could not find a seller in USA so I had one shipped from Taiwan. That hub does not have a lot of distance on it, but it does have over two months of heavily loaded touring. And mountain biking on Maah Daah Hey Trail and White Rim Trail.

It's possible that I accelerated the failures on mine by commuting to work and then leaving my bike parked outside when it rained. The left side bearing was in worse shape, contributing most of the noise and play in that first video, and I always lean my bike to the right when locking it up...

I should make clear that I'm not upset about any of this. No bearing is perfect, and they have a rough life in service on bicycles. I'm glad that it's fixable. :)

The "SP Partner" that is listed for CA only sells the hubs. You are still required to send them to Taiwan for servicing as per a recent email. (I was looking for help repairing a damaged SV-8.) Here is the gist of the conversation:

"...Unfortunately, this will need to go to the Shutter Precision factory in order to be repaired.
Out of curiosity, how old is the hub and what model is it?
If the hub is less than 2 years old and you have proof of purchase, we at Cycle Monkey will support a warranty exchange.
If the hub is older than two years old or we don't have it in stock, you could send it directly to Taiwan for them to service. More information can be found here (SP Dynamo System).
Please let me know if you have any other questions."

I really wonder what the role of a "Partner" is if they only sell them, just like lots of others sell them without being a "Partner". Or maybe they are the distributor for USA, maybe other SP hub sellers in USA have to buy from the "Partner"?

I am pretty sure that the partners are just importers that resell the hubs.

Well, my bubble is burst! I might be repairing my own hubs after all. :(

They do service hubs, just not SP. I suspect that is at SP's request. From their website:

"Cycle Monkey has more than 15 years of experience servicing bicycle hubs and a diverse collection of specialized tools to do the job right. We have experience with hubs from Rohloff, Chris King, DT Swiss (Hugi), Shimano, Campagnolo, Mavic, Phil Wood, White Industries, American Classic, Industry Nine, Tune, Zipp, and many other brands. Our hub service includes:

• Comprehensive maintenance of the Rohloff SPEEDHUB
• Disassembly, cleaning, and inspection of the freehub mechanism
• Cleaning and regreasing of loose ball or rebuildable cartridge bearings
• Replacement of bearings and freehub body as necessary"

Yes, I got essentially the same information from them. Sad, but I wonder if the overhaul of such hubs can be profitable (as it must be for a business). It was pretty clear to me that the Joule hub I serviced was not worth being serviced by any shop... the hub itself only cost $50; it would be cheaper to simply replace it. The SP hubs are more expensive, and the economics of repair might be more favorable. I'll probably take a stab at repairing mine myself when the time comes. Thanks to Scott's impressive work, I believe it's possible.

Awesome post ThermionicScott!
 

Absolutely! Lots of replacements out there. But all bearings are not alike...

As far as bearing replacement goes, I'd look at Hambini on YouTube for suggestions. He evaluated all of the common replacement radial and angular contact sealed cartridge bearings on his site.
He concludes that ceramic bearings are not worth the money. And he finds SKF and NTN are the smoothest and the most durable. Others such as Enduro he wasn't too impressed with. I happened to be having a rear tandem hub serviced by a manufacturer and I happened to bring up bearings. "Why don't you use Enduro? They're local." The reply was something like, "Um we choose not to use that brand!" with a smirk on his face. He refused to go into detail but he made it pretty clear that they chose to not devalue their products by using Enduro bearings. Wow, that was kind of a surprise! But then Hambini said basically the same thing. So take that for what it's worth. Given the difficulty in servicing the SD hubs, I'd be sure to pick the highest quality replacement I could find.

I just took delivery of an SD-8 and was perusing the interwebs for service info. Thanks again for the great info, ThermionicScott!

Hi everyone, I'm trying to get the bearing replacement done too on my SP PD8 dynamo hub and have been looking everywhere for the specs (dimensions) of the bearings so I can buy them before dismantling my wheel. Does someone have this information? Thanks a lot for the help from previous posters on this thread!

I Used NTN and NSK from Japan, in my car and bike, but they are expensive here in sri lanka

If they're the same as my SV-8, they were 6000 2RS. I used these: https://www.nashbar.com/enduro-abi-6...00-2rs/p303076

In the time since my bearing replacement, I've learned a bit more about bearing offerings and kinda wished I had gone for the ABEC 5 version for better precision and seals. But these ones are holding up just fine for now, so I'm saving any serious regret for later. :thumb:

I'm glad this thread came back up. My Quixotic quest to convert another brand hub to the SoN connectorless system has a new potential victim.