Raleigh dynohubs

[ChrisEyles]

Having a few problems with the Raleigh dynohub on a wheel I recently acquired for an on-going restoration, and wondered if any fellow enthusiasts here might be able to help me out.

I started by seeing if the headlamp that came with the hub would produce any light when connected up.... and so far no joy - but I'm definitely not ruling out user error yet. Are there any points to be aware of (e.g. do the red/black wires need to be connected to the correct terminals), or should it just be a case of connect-and-go?

I'd also like to switch the bulb over to a more functional LED, and add an appropriate rear light at a later stage. If anyone's able to offer some properly idiot-proof advice on how to go about this, I'd be much obliged. My friend did draw me a circuit diagram when I asked him, but I can only hope he was massively over-complicating things (he is in the middle of a PhD in electronic engineering, and given his personality this seems quite likely), since I didn't understand a word!

Secondly the bearings feel extremely "coggy", even when I back the LHS cone all the way off. Is this just the normal resistance of the magnet in the dynohub, or does is mean the RHS bearings have somehow bound together or some other problem with the hub?

Thanks for the help! Still got quite a lot of cleaning up etc to do, but looking forward very much to finally putting the bike in question together, even more so now I've got the dynamo hub front wheel and 3-speed SA hub rear

 

[mjr]

I'd also like to switch the bulb over to a more functional LED

http://www.reflectalite.com/LEDpage.html and yes some lights need the red/black wires the right way round (based on my more modern lights with black/white wires) and I think magnets mean dynamo hubs always feel a bit notchy but I can't really help with the rest of it, sorry

 

[ChrisEyles]

Thanks for the link, looks great. If it's literally just a case of swapping out the regular bulb for an LED bulb, that's a big plus - I'm still recovering from the last time I tried to repair something with a soldering iron!

I'll have another look at the hub and try out all the possible wire/terminal combos, and hopefully there will be light at the end of the tunnel (haha). Also very pleased to hear the notchiness is expected on a dynohub. It's a lot stronger than I'd have expected, but (thinking aloud) maybe a good strong magnet was necessary to provide sufficient light from a tiny little incandescent bulb.

 

[lukAs98]

The magnets in the hub may need to be re-magnetised

 

[tyred]

It will never spin as freely as a hub without a dyno. There will always be some drag but you won't notice when you are riding.

The + and - is usually marked on the hub but it shouldn't make any difference unless the lights are earthed to the frame - the hub itself is completely isolated but problems can arise if the headlamp and tail lamp are earthed and you mix the connections up and short it out inadvertently. It sounds though as if you are only using headlamp. Old wires can break internally. I'd get a little speaker wire or similar and run it directly from the hub to the lamp (is there a switch in the lamp - are the contacts clean?

I would check all these things with my multimeter but if you don't have one, go to the poundshop and buy one of the big old 6V torch batteries with spring contacts on top. Remove the wires from the hub and connect them to the battery and see if the light works. If so, there is something wrong with the hub (or it's connectors).

If not, remove the bulb and connect directly to the battery (just touch one contact of the blob of solder on the base of the bulb and the other to the threaded part on the side of the bulb). If the bulb doesn't light, you need a new one (0.25A x 6V MES). If the bulb lights, then you have a connection issue, check all wires again, clean switch and bulb contacts (don't use coarse sandpaper) and a little spray of WD40 on them all and see if it helps. If you have the genuine metal Sturmey-Archer lamp, I've found that the spring contact which touches the base of the bulb doesn't always spring into place as it should and requires a strategic bend with narrow nosed pliers.

I'd be surprised if there is anything wrong with the hub unless someone has dismantled it and removed the armature from the magnet. One thing to bare in mind is they don't put out much power below about 8 - 10 mph.

If you have the later square beige coloured plastic lamp with the capless bulb, you will struggle to find anything to replace the bulb with as it's an unusual design (in 6v, you will find 12v versions for things like VW number plate lights). SJS had original bulbs in stock at one point, don't know if they still do.

 

[midlife]

Blimey that post took me back 40 years trying to sort out dynohubs . The guy who taught me, "Bunny" Adams told me to always assume in the first instance that the hub was working as they were pretty bulletproof

Shaun

 

[midlife]

Blimey that post took me back 40 years trying to sort out dynohubs . The guy who taught me, "Bunny" Adams told me to always assume in the first instance that the hub was working as they were pretty bulletproof

Shaun

 

[ChrisEyles]

Thanks @tyred, that gives me plenty to look at. It is one of the old SA metal headlamps so I'll check the spring under the bulb. Broken cables and dodgy contacts are also a possibility, I'll see if I can borrow a multimeter to check the lamp out. I'll also try giving the wheel a bit of a meatier spin too, since I doubt I was up to 10mph on my last test run.

Should be a fun Saturday afternoon!

 

[KoffMixtures]

Hi, Guy's.
Appreciate this is an old thread, but it seems this is a suitable option to ask a question.
I'm in the process of stripping my '78 'Shopper' to give it a deep service.

The Dynohub equipped versions have a distinctive rear light assembly with a lovely red lens which has to be removed to access the bulb and somehow detach the wiring.

My problem....how to remove the lens?
It appears it needs twisting (anti-clockwise?) to release it. Mine only moves a minimal amount.
As this cycle is in exceptional condition, I'm hoping to not damage such fittings.
Would someone please reassure me on how to proceed?

 

[EltonFrog]

Its been a while, but if I recall correctly, when you have twisted it that small amount it pulls off. I'll go and have a look at mine a bit later and check and report back.

 

[EltonFrog]

Well, this is awkward. I can't get mine off either! I'm pretty sure I did it a few years ago, I can twist it, but cant get the lens off.

 

[KoffMixtures]

Well, this is awkward. I can't get mine off either! I'm pretty sure I did it a few years ago, I can twist it, but cant get the lens off.

A fine pickle to be in!

 

[KoffMixtures]

Hi, 'EF'.

Finally got the lens off...a good squirt of WD40.
It twists about 90degrees to the left and pops off.
Bulb is plastic and pulls out of two connectors.

Problem now is how to remove the reflector....!!!!

This has to be solved so I can remove the back mudguard.
Though the innards of the lamp are now exposed, in reality I'm no further forward.
A frustrating state of affairs.

 

[EltonFrog]

Hi, 'EF'.

Finally got the lens off...a good squirt of WD40.
It twists about 90degrees to the left and pops off.
Bulb is plastic and pulls out of two connectors.

Problem now is how to remove the reflector....!!!!

This has to be solved so I can remove the back mudguard.
Though the innards of the lamp are now exposed, in reality I'm no further forward.
A frustrating state of affairs.

Fab!

 

[KoffMixtures]

Yes.....but....that was half the problem.

It is clear (makes sense) the 2 brass contact fittings were crimped onto the wires after original assembly.
That makes them an 'interference' fit through both the reflector and the lamp housing.
It's a hell of a faff, but after much cussing, they came out.
Not looking forward to re-fitting them, but at least I can now remove the mudguard.