SP PD-8 disc dyno hub

[SimonCelsa]

I just noticed this thread. As pure coincidence I used one of my fair weather bikes today, fitted with a SP PV-8 dynohub, for the first time since last June (the weather hasn't been that bad it's just that I've been mostly using my fixed gear machine).

Absolutely faultless dynamo and hub performance, smooth, silent and brilliant illumination (compared with my bottle & cheap Decathlon dyno light). Storage in a weatherproof shed which, although not damp, can sometimes be a little moist.

I usually apply a liberal spray of GT85 to all rotating elements plus frame tubes (easier to say the whole bike!) if not planning on using the bike for a while.

I hope you get yours sorted but think you've just been a little unlucky. Watch where you spray the water next time How come the postage was so excessive, £18!!!, was that special delivery both ways?

[Vantage]

A chap on YouTube did a video showing how he replaced the bearings on his PD-8. Maybe in time I'll take a crack at it, but not until I've the new hub built up and running in a wheel.
I believe the tolerances on SP's hubs would put NASA to shame.

I don't accept that the damage to the hub was in any way my fault. It's a part on a bike, a contraption that is well known for spending a great deal of its time outside in rainy conditions. A scrub with a sponge and bucket of water is something that shouldn't cause issues, yet did.
The hub itself has been brilliant up till that point. Products occasionally develop faults and I've no problem with that.
My issue was the companies response that cleaning the thing (something the rest of us consider taking care of it) is somehow mishandling or using it improperly.
That's like building a boat and claiming it's unsuitable for using in water.

[Vantage]

The quote from Royal Mail was iirc insured for £100 and signed for one way. I wasn't keen on it disappearing into thin air which has happened before.
Spa are knocking them out for £74 but other shops are asking near £90+. Understandably, Spas stock seems to be drying up.
The new hubs been ordered.

[slowster]

I would suspect water ingress as a result of the hub moving from a warm environment to a cold one, with the resulting pressure differential inside the hub sucking water past the seals into the bearings.

Current Son hubs have a small bladder inside the hub open to the outside via a breather hole in the axle: the bladder expands and contracts to equalise pressure inside and outside the hub.

[Vantage]

I would suspect water ingress as a result of the hub moving from a warm environment to a cold one, with the resulting pressure differential inside the hub sucking water past the seals into the bearings.

Current Son hubs have a small bladder inside the hub open to the outside via a breather hole in the axle: the bladder expands and contracts to equalise pressure inside and outside the hub.

Aaaaaah! My science is very rusty, would that apply if the bike went from cold outside to warm inside as in this case?
I read something about a pressure relief system in SON hubs but never had the foggiest what it was. Thanks for explaining

[PH]

I don't accept that the damage to the hub was in any way my fault.

In that case I really don't understand why you're not pursuing the warranty claim.
That the retailer who hasn't answered your email is the one selling a bit cheaper, probably isn't unrelated, judge for yourself, but I don't think they've served you well. You'll have spent nearly SON prices and still have a SP!
The manufacturer can tell you whatever they like, you're not their customer, they have no contract with you. They are well aware of the number of bearing failures, that's why they've been offering out of warranty replacements for £25. They are rumoured to have improved the sealing, whether that's correct or applies to Spa's stock I don't know. Those they made for some third parties always had better seals, Supernova used to highlight this.
Neither do I understand your reluctance to post, you've rejected the idea on the basis the dearest over the counter option, I've already pointed you towards a cheaper (insured) service, there's plenty of others. Of course insuring it for £100 will cost a bit more, but at the moment it isn't worth £100!
Whatever, it's your money. I've no problem spending my own, I just like better value from it, replacing a hub that's under warranty, because it's developed a common fault, just looks so wasteful.

[PH]

Absolutely faultless dynamo and hub performance, smooth, silent and brilliant illumination

That's also the experience with mine. If every one failed they'd have soon gone out of business. But you don't have to look very far to discover that they are prone to bearing failures due to inadequate sealing.

[NUKe]

Do they fix them or just run an at cost swap out service ?

[PH]

Do they fix them or just run an at cost swap out service ?

Those I know, or know of, who've had replacements have received reconditioned hubs, so repaired, but not the same hub. The turn around seems quick and some have been a long time out of warranty, so better than nothing, though you still have to rebuild the wheel.
I haven't seen any documentation which would oblige them to offer this out of warranty, it seems like goodwill, which in itself is some sort of acknowledgment that there's an issue.

[Vantage]

I don't accept that the damage to the hub was in any way my fault.

In that case I really don't understand why you're not pursuing the warranty claim.
That the retailer who hasn't answered your email is the one selling a bit cheaper, probably isn't unrelated, judge for yourself, but I don't think they've served you well. You'll have spent nearly SON prices and still have a SP!
The manufacturer can tell you whatever they like, you're not their customer, they have no contract with you. They are well aware of the number of bearing failures, that's why they've been offering out of warranty replacements for £25. They are rumoured to have improved the sealing, whether that's correct or applies to Spa's stock I don't know. Those they made for some third parties always had better seals, Supernova used to highlight this.
Neither do I understand your reluctance to post, you've rejected the idea on the basis the dearest over the counter option, I've already pointed you towards a cheaper (insured) service, there's plenty of others. Of course insuring it for £100 will cost a bit more, but at the moment it isn't worth £100!
Whatever, it's your money. I've no problem spending my own, I just like better value from it, replacing a hub that's under warranty, because it's developed a common fault, just looks so wasteful.

All valid points.
I've emailed the manufacturer again asking them to explain how washing it invalidates the warranty. I've not bothered asking spa again as the new hub has already been ordered. Add to that, I'm awkward. Stupidly so at times. Once I've decided to do something I tend to see it through regardless of how reckless it is.
On the other hand, if the old hub is content to grind along I'll use it to build a second set of wheels primarily for offloading.


Nuke as far as I can tell from their email, it's a bearing replacement service including a check on the hubs internals. Other than that I'm clueless.

[slowster]

would that apply if the bike went from cold outside to warm inside as in this case?

My science is likewise rusty, but I don't think so. Brucey mentions a couple of scenarios in this thread on Shimano dynamo hubs: taking a bike from warm indoors out into cold rain, and high humidity followed by a drop in temperature causing condensation inside the hub.

Another scenario which I suspect might also cause it, would be if very warm/hot water were used to clean the bike at the end of a ride, and enough of it were poured onto the hub shell to raise its temperature and cause the air inside to expand. In that event residual water around the seal edges would probably inevitably be drawn into the hub as it cooled.

Spraying a water dispersant, like GT85, at the seals after washing might help to prevent it happening, but given that the most important reason for washing a bike in winter is to remove road salt that would cause rusting, as opposed to actually cleaning the bike, I would have thought that a sluice or hose down with cold water might be sufficient (and quicker).

[Vantage]

SP have emailed back. They've apologized for assuming I pressure/jet washed the hub and said that the hub is covered under warranty. They want the same £25 upfront which they'll refund after checking and repairing the hub.

Pfft.

[Jdsk]

Well done. That's a straight answer.

I'd accept that and get it fixed.

Jonathan

[markjohnobrien]

Yes, good result.

[Brucey]

I would suspect water ingress as a result of the hub moving from a warm environment to a cold one, with the resulting pressure differential inside the hub sucking water past the seals into the bearings.

Current Son hubs have a small bladder inside the hub open to the outside via a breather hole in the axle: the bladder expands and contracts to equalise pressure inside and outside the hub.

there is such a device but it isn't a bladder; it is a long coil of plastic tubing. The idea is that moist air doesn't make it into the hub proper. I don't think it is perfect but it is certainly better than nothing. Much older SON hubs just had a drilling in the axle, no coiled tube attached to it. Either sort can be caused not to work if you use too much grease on the qr skewer. If you send your old hub back to Schmidt they can convert it to the newer system.

cheers