SCHMIDT'S ORIGINAL NABENDYNAMO

[collis53]

I have acquired a bike with a schmidt Dynamo. It looks relative new and gentley judders when you spin the wheel, but does not appear to output any power. I have done simular successfull checks with my union hub dynamo brought from SJC some time ago.
Is there any further checks I can do?
Or where can I send the dynomo for a check and service, I have tried a few local places but they have said  I need Specialist help.

Thanks

Steve

[PH]

It'll need to go back to Schmidt in Germany, email them for instructions;
http://www.nabendynamo.de/english/index.html

When I contacted them I had a stab at doing so in German, the reply has in English.  They'll have a look and tell you if a repair is viable.  Although well made they're a pretty simple bit of kit, there's not much that can go wrong, it's usually the bearings, though that wouldn't affect output.  I had a service and the bearings changed for around £40 inc post (around a year ago) they's also gave it a polish and it came back looking like new.
If it's the old model with a black band it'll need taking out of the wheel, with the modern version you have the choice of sending back the wheel or just the hub.

[freddered]

The juddering is the normal attraction of the magnets and disappears at cycling speeds, not to be confused with actual friction.

It's likely that someone has attempted a home repair and tried to rotate the axle and accidentally twisted the contacts.  This will simply snap the contact wires internally.

Send it to Schmidt, it's worth it as they are still, just about, the best ones still.

[collis53]

Thanks for the swift reply guys

[Dave Whittle Thorn Workshop]

Hi,  I used to be in charge of returning Schmidts for servicing to Germany here at SJS for about 5 years,

Practicaly everything under 4 years old was people turning the conectors being sheared by people trying to "adjust" or "get into" it something that just isn't possible this causes the cables to detach from the conectors or the armature. 

On older hubs no preasure compensation system was fitted this meant condensation could corrode the magnets causing the hub to seize or feel rough, Schmidt now fit all hubs and wheels returned for services with this system at no extra cost.

I saw two hubs in my whole time that actualy had bearings wear out, this is very rare, and never caused the hubs to cease output.

Dave Whittle

SJSC parts sales