SP dynamo hub grumbly bearings - how long have they got left

[slarge]

So a week before the a Tuscany a Trail, my SP dynamo hub has developed grumbly bearings and a tiny amount of play (less than 1mm at the rim). The wheel spins fine, and the dynamo works fine, but do I risk the Tuscany Trail with it? How do these things normally fail?

I have a spare non dynamo wheel, which means I would take battery packs to keep the electrics going, just the dynamo would be more convenient. Do I risk it?

Cheers

[Bearbonesnorm]

I think you already know the answer Steve

[Chew]

I'd say either way its probably going to be in the back of your mind all of the time if you take it?

[slarge]

I think you already know the answer Steve

Thanks Stu, but in this moment of uncertainty I need some knowledgeable souls to tell me what to do.

[Zippy]

How difficult is it to actually swap them?

[Dave Barter]

Steve if wheel size is 650B you can have a lend of mine.

[ianfitz]

How difficult is it to actually swap them?

Not user serviceable. They apparently use a massive press due to the magnets.

Yeah bitch, magnets! (With apologies if you haven't seen breaking bad!)

[ianfitz]

I think you already know the answer Steve

Thanks Stu, but in this moment of uncertainty I need some knowledgeable souls to tell me what to do.

If they are grumbly and rumbley then they last a while, both in terms of producing power and actually turning!

If there is significant play when you push the wheel side to side then power generation will cease pretty soon in my experience (of three replacements...)

[slarge]

Cheers Dave for the offer, but they're 29 inch wheels.

I think I'll put the non dynamo hub on, and probably replace the SP with a Son hub at some point. Not been too impressed with the reliability of the SP hub, and it seems I am not the only one. And every time it fails it's a wheel rebuild - even for bearing replacement.

Thanks all, as Chew said, it will always be a niggling doubt, and I know where it will fail - just at the point where there are no bike shops and it's 10 past midnight.....

[ianfitz]

Cheers Dave for the offer, but they're 29 inch wheels.

I think I'll put the non dynamo hub on, and probably replace the SP with a Son hub at some point. Not been too impressed with the reliability of the SP hub, and it seems I am not the only one. And every time it fails it's a wheel rebuild - even for bearing replacement.

Thanks all, as Chew said, it will always be a niggling doubt, and I know where it will fail - just at the point where there are no bike shops and it's 10 past midnight.....

As I've posted several times before. Get your Dynamo wheel built by 18 bikes (or other really good LBS) they have liaised with Ison to get new hubs and never charged a penny beyond the initial purchase. They even got me a refund from Ison after the third one broke. Then rebuilt the wheel with the son hub I bought elsewhere (they couldn't get one) for free.

[Bearbonesnorm]

I'd say either way its probably going to be in the back of your mind all of the time if you take it?

That's really what I meant

[Trail-rat]

has anyone actually had a look ?

i mean just how big a press we talking ?

i appreciate its not in everyones garage but i have a 20t in the garage - and access to a monster 150ton at work......

just curious as i have 2 SP hubs that will likely need bearings in their future.

[ianfitz]

has anyone actually had a look ?

i mean just how big a press we talking ?

i appreciate its not in everyones garage but i have a 20t in the garage - and access to a monster 150ton at work......

just curious as i have 2 SP hubs that will likely need bearings in their future.

I guess not many will have that set up! I've no idea what's inside

[Dave Barter]

Cheers Dave for the offer, but they're 29 inch wheels.

I also have an SP on a 700c cyclocross rim if that helps?

[Trail-rat]

absolutely.

sounds like a project when the time comes although reading into it and looking at the hub and various drawings. - i suspect its made in two halfs then bonded together and the ring "clamped" round the middle.

Would be nice to fit proper bearings as the ones used are no namers with limited sealing. dunno about you guys but i could live with a little more drag in lieu of sealing or even ceramic hybrids.......

[Javi]

Hey Steve, same problem with the sp here. Twice has failed. First time it was replaced under warranty in record time but again failed and on the move is difficult to coordinate a proper rescue. Really fed up and next time I'll put a SON.
Had to buy an etrex and still learning how to use it. Not happy for last minute trouble for htr.

[slarge]

Javi, I've gone down the route of external battery packs for my edge800. I think 4 will keep me going (and it's the approach I used for my first HTR). Disappointed in the SP hub, but I have a scrap one from my first warranty replacement that I might cut up to have a look inside.

Good luck on the HTR !

[Trail-rat]

Slarge - if you do cut it up i would be interested in seeing photos to see if its something i can work with - and to save destroying mine which are still under warrenty.

[Zippy]

i mean just how big a press we talking ?

i appreciate its not in everyones garage but i have a 20t in the garage -

I'd be surprised if a bicycle hub bearings needed something bigger than this. I suspect I'll also have one of these in my arsenal in the not too distant future, so anyone local wants to use it, they'd be welcome

Slarge - if you do cut it up i would be interested in seeing photos to see if its something i can work with - and to save destroying mine which are still under warrenty.

This and some exploded diagrams should help a lot of people out I would have thought.

[Trail-rat]

"Alas, SP hub dynamos are not user serviceable and indeed we are aware of no hub dynamos that are based on manufacturer’s recommendations. Any attempt to service a SP hub dynamo will void its two-year warranty. We have received quite a number of requests from consumers on how they might service their hubs even accepting that attempting to do so would void their two-year warranty. They accept this risk thinking that this would save the need to disassemble and rebuild the wheel. Unfortunately, the design of SP hub dynamos like that of many other brands requires disassembly of the wheel for bearing replacement. Furthermore, the delicate generator mechanism housed within the hub body must be re-calibrated to tolerances of less than a millimetre each time bearings are replaced. Failure to carry out this operation properly (which is likely without expert knowledge, experience and tools), will generally result in catastrophic failure of the generator mechanism after a period of use. SP engineers have considered making their hubs user serviceable (with much prodding from IDC at the behest of our technically savvy testers). But the expertise and equipment required to carry out recalibration of the generator mechanism each time the bearings are replaced presents a technical hurdle that SP engineers, and indeed all other hub dynamo manufacturers we are aware of, have so far declined to attempt."

it seems its this recalibration of less than a mm is whats stopping you servicing them - ive worked to closer tollerances. So long as i understand what it is im tryign to achieve.....

[Zippy]

A dial gauge is hardly expensive

[johnnystorm]

Reading that quote and considering that one of my SP's will be over 2 years old when/if it does go I might as well just bin the wheel as the faff of disassembly, sending abroad, and reassembling into a potentially already battered wheel seems a bit pointless.

[ctznsmith]

Reading that quote and considering that one of my SP's will be over 2 years old when/if it does go I might as well just bin the wheel as the faff of disassembly, sending abroad, and reassembling into a potentially already battered wheel seems a bit pointless.

You only have to send it back to Ison and they send you another (not new) hub with new bearings. I think when I did it they sent me the hub with new bearings before I'd even returned the worn out one.

They also offer a service to rebuilld the wheel for you (at a cost obviously).

If you haven't dinged your rim so much it has flat spots/damaged bead hooks I don't see why you would chuck a perfectly serviceable rim?

[johnnystorm]

My new sp hub (250ish miles) is making a funny "cracking" noise every so often as the front wheel turns.
Need to buy some earplugs or just hum a bit louder perhaps...

[ctznsmith]

trust me that noise get worse and hub becomes noticeably stiffer to spin.