Author Topic: SON dynamo service  (Read 1300 times)

T42

  • Old fool in a hurry
SON dynamo service
« on: September 09, 2019, 08:54:10 am »
Chum of mine has a SON dyno wheel that grates when he rotates it.  He used it on PBP 2011 so it's at least 8 years old.

He's asking me if he should try to service the bearings himself. Sending it back to SON is likely to be a royal PITA and cost as much in the end as new kit.

What thinketh the panel?
I've dusted all those old bottles and set them up straight.

Re: SON dynamo service
« Reply #1 on: September 09, 2019, 09:31:12 am »
it is probably grot inside the generator that is making the noise, e.g. bits of rust between the stator and the magnets. The bearings could be fine.

You don't say what model of hub he has but there is one that is easy (ish) to service; the innards unscrew from the RH side. However all the other SON models are pigs to work on.

If you want a SON then a factory service will make the old hub like new and at that price it would be very cheap for a new SON hub. However you can buy an alternative ( cheaper, less good) hub for about the same money.

cheers

T42

  • Old fool in a hurry
Re: SON dynamo service
« Reply #2 on: September 09, 2019, 09:48:50 am »
Thanks, Brucey.  I don't know what model he has - come to that, I'd be hard put to remember which I have.

Anyway, I'll pass it on. Ta.
I've dusted all those old bottles and set them up straight.

Re: SON dynamo service
« Reply #3 on: September 09, 2019, 09:59:21 am »
It cost about £64 to have my old black-barrel one serviced and returned via SJS.  It now even has a breather hole inside the hollow axle.

T42

  • Old fool in a hurry
Re: SON dynamo service
« Reply #4 on: September 09, 2019, 10:31:54 am »
Just checked mine (model #K179) - still silent and developing 8.5v when I spin it by hand. 12 years old with 8 of service.

ETA Thanks, Ian H - duly passed on.
I've dusted all those old bottles and set them up straight.

pdm

  • Sheffield hills? Nah... Just potholes.
Re: SON dynamo service
« Reply #5 on: September 09, 2019, 12:18:10 pm »
IMHO, don't service it yourself. I have 3 SON 28s that have done many miles. about 3 years ago, one developed slight loosening/roughness of the bearings after 5 years of very heavy use - sent it off to SON and got it back as good as new free of charge! I would have gladly paid the £64 for the years and distance it had given me nonetheless...

Wowbagger

  • Dez's butler
    • Musings of a Gentleman Cyclist
Re: SON dynamo service
« Reply #6 on: October 10, 2019, 04:13:06 am »
Mine is 13 years old, has done almost 39000 miles and has had to put up with my great bulk, which has been in excess of 105 kg for all of that time, and 10kg more than that for most of it. I have been advised not to get it serviced until it shows signs of deterioration.
Eating's a serious business. Don't bollocks around wagging your tail.

rower40

  • Not my boat. Now sold.
Re: SON dynamo service
« Reply #7 on: October 10, 2019, 05:18:23 am »
Dearly beloved,

We are gathered together to give thanks for this wonderful item of engineering, which lighteth our way, yea verily, e'en when all batteries have shuffled off this mortal coil...
Be Naughty; save Santa a trip

Re: SON dynamo service
« Reply #8 on: October 10, 2019, 10:19:37 am »
Just checked mine (model #K179) - still silent and developing 8.5v when I spin it by hand. 12 years old with 8 of service.

IIRC ~K179 is the Stvzo approval number, rather than the model number per se.  The ~K number does vary with the model though, since each (electrically) different generator needs a separate approval.     Is yours a 28 Klassik?



If so this is one of the few that can be opened up without undue difficulty.  Using the appropriate tool all the gubbins unscrews from the RHS.

After a certain date all SON models have their 'pressure compensation system' which comprises a long coiled plastic vent tube connected to a drilling in the axle. The basic idea is that  water can't into the hub through the vent, even though the air volume in the hub is contracting and expanding with changes in temperature.  If you send an older SON in for a factory service (outside the five year(?) warranty period) they can upgrade the hub to the newer style vent.


cheers

Re: SON dynamo service
« Reply #9 on: October 10, 2019, 04:28:56 pm »
Chuck it and buy a Shimano one  :demon:
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Wowbagger

  • Dez's butler
    • Musings of a Gentleman Cyclist
Re: SON dynamo service
« Reply #10 on: October 10, 2019, 10:47:30 pm »
Dearly beloved,

We are gathered together to give thanks for this wonderful item of engineering, which lighteth our way, yea verily, e'en when all batteries have shuffled off this mortal coil...

The key question is - does a SON dynamo have an immortal coil?
Eating's a serious business. Don't bollocks around wagging your tail.

Re: SON dynamo service
« Reply #11 on: October 10, 2019, 11:23:17 pm »
Dearly beloved,

We are gathered together to give thanks for this wonderful item of engineering, which lighteth our way, yea verily, e'en when all batteries have shuffled off this mortal coil...
... In the name of going farther and of the SON and of the oily spirits...
L'enfer, c'est les autos.