After various dynamo threads a couple of people messaged for instructions, do here's a build thread which might be useful. I've left off a wheel build as it's nothing different to a normal wheel, apart from the dynamo being directional in rotation, so needs the same level of attention as building a rear wheel. The bike is a 1980 Witcomb, refinished in early 2024 by GA Cycles in Southampton. Build thread: https://www.retrobike.co.uk/threads/1980-witcomb-restoration.477670/
My wheel uses a J-Tek dyno, which appears to be a rebadged SP PV-8. I bought it from SJS Cycles. It's able to take a radial lacing, and I found spokes on a special deal at the right length. Had they been available in 1x, 2x or 3x I would have used those lengths instead, it's not critical for the usage I imagined.
As I was intending for Audax / credit card touring, I wanted a rear rack, which makes rear light mounting much easier. I used the Supernova rear, which looks really neat, but doesn't include a reflector.
The rear cable is pre-wired, I ran it along the rack, secured by threading through doubled o-rings. I intended the same idea along the brake cable for the top tube by threading several rings along the outer. In the end the rings proved too small to thread the spade terminals through, but at least stop cable rub on the new paint. Spade terminals were soldered on and heatshrunk with insulation. Next time round I might use WAGO connectors.
The front lamp is also the junction box, having cable in from the dyno and also out (switched) to the rear. I used the B&M IQ-X. It needed some fiddling with spacers as the mount otherwise fouled the lower headset race. I also needed a thinner brake nut as I ran out of thread with the mudguard fixings.
All in all it works very well, I had superb amounts of light riding the Dunwich Dynamo in July, with no light range anxiety. The beam is very well shaped (low and wide) so doesn't dazzle and directs all the light where it's useful.
The only small snag is mixing lamp brands - the Supernova rear expects a standlight supply from the front, but that isn't available from the B&M, who locate it in each lamp. In due course I will switch to a B&M rear or make a little standlight supply.
My wheel uses a J-Tek dyno, which appears to be a rebadged SP PV-8. I bought it from SJS Cycles. It's able to take a radial lacing, and I found spokes on a special deal at the right length. Had they been available in 1x, 2x or 3x I would have used those lengths instead, it's not critical for the usage I imagined.
As I was intending for Audax / credit card touring, I wanted a rear rack, which makes rear light mounting much easier. I used the Supernova rear, which looks really neat, but doesn't include a reflector.
The rear cable is pre-wired, I ran it along the rack, secured by threading through doubled o-rings. I intended the same idea along the brake cable for the top tube by threading several rings along the outer. In the end the rings proved too small to thread the spade terminals through, but at least stop cable rub on the new paint. Spade terminals were soldered on and heatshrunk with insulation. Next time round I might use WAGO connectors.
The front lamp is also the junction box, having cable in from the dyno and also out (switched) to the rear. I used the B&M IQ-X. It needed some fiddling with spacers as the mount otherwise fouled the lower headset race. I also needed a thinner brake nut as I ran out of thread with the mudguard fixings.
All in all it works very well, I had superb amounts of light riding the Dunwich Dynamo in July, with no light range anxiety. The beam is very well shaped (low and wide) so doesn't dazzle and directs all the light where it's useful.
The only small snag is mixing lamp brands - the Supernova rear expects a standlight supply from the front, but that isn't available from the B&M, who locate it in each lamp. In due course I will switch to a B&M rear or make a little standlight supply.
