First apologies for the delay in writing a review - I've been off the road due to a bout of flu. I've now managed two short rides this weekend and have set out initial thoughts below. I'll also add them to my bike and wheel blog, with pictures, at the weekend, as well as updating when I've done dome longer rides.
Ordering, delivery and first impressions
Simple and straightforward. I submitted an order on the website and the unit arrived in it's little box a couple of days later. My first impression was one of delighted surprise at how small it actually is and also how nice it looked in it's plain titanium case. Unassuming and very much form following function.
Fitting was very straightforward. I simply ensured that I had enough bare wire and twisted the ends together with my front light wires, and then pushed them through the Shutter Precision/Shimano lego block. A bit of insulation tape to help route the cable up the fork leg and then to hold the D1 to the front of the headtube on my GF Ti - nice matching colour, and practically not at all noticeable. Worth pointing out that the cable ties wouldn't have gone around the big head tube, but that was fine in my case. This bike is in working trim and insulation tape is 'de rigeur'.
For completeness, and because there are a lot of tests using the SP PV8, I fitted the D1 to my GF Ti with an SV9 dynamo hub, Schmidt Edelux 2 and B&M Secula Plus. The SV9 is a tiny hub that doesn't meet the German regs in a 700c wheel, but does in a 20 inch wheel. The Shutter Precision website helpfully suggests that, 'You can just pedal 1.7km/h faster...' I was particularly interested in whether there would be any surplus power available to charge with the lights on at the same time - possibly asking a bit much - as well as what charge rate can be delivered without lights.
The usb leadout from the D1 is then fed past the headtube and into a small Restrap frame bag that I use to hold electronics and bits. The bag has a dynamo cable port, so that bit was easy too and it should keep the socket dryish.
So far only two test rides. One very short and a slightly longer ride today.
Ride 1: I rode just over 6 miles around town with only the D1 in use, charging my work iphone 6. The D1 charged fast enough to add 10% to the charge position of the iphone, based on a battery monitor app. I was actually quite impressed by the speed of charge and only heard the phone 'bleep' to mark the end of charging when slowing right down.
Ride 2: I started this ride and did 15 miles at just over 15mph average with the lights on and the iphone charging. The charge status of the phone increased by only 2%, suggesting that the lights are power hungry enough that the dynamo cannot really supply sufficient power (or at least the voltage curve is such that...) to support significant charging at the same time. I then switch off the lights and rode the 7.5 miles home at a lower speed (into the wind) and found the iphone charge status had increased by 11%. Again, a very positive charge rate absent the lights.
I've ordered a usb charge meter so I can see what actual current is being put out by the D1 and will aim to use it on some longer rides. I've got a 3,000 and a 10,000 maH powerpack that I've allowed to discharge so I can test the D1 into those. The 10,000maH pack has pass through charging as well, so that will be a further test. Depending on the weather, some of this should happen in January - weather because the wind today interacted with the 30mm rims, 28mm tyres and guards on the GF Ti to make some gusts pretty terrifying, so the guards and big tyres are coming off.
I'm really pleased with the D1. It appears to work very well, and certainly much better than the usb-werk I had before. One positive is that I had no light cycling/flashing with the D1 today, it just didn't charge. The usb-werk and my (then) exposure revo were an unhappy combination with moments of unpredictable darkness. The charge rate appears useful and over a long ride I am comfortable that it would keep a powerbank charged, allowing continued used of phone and Garmin on tour for example. I suspect this is the main purpose and is one that I will likely adopt as well (look out for my trailer project...)
Andrew, thanks for the offer to test and review the unit. It seems to me to the most useful available at present and is also nicely and functionally put together. The accessories that you are developing with be really useful as well to those with more than one dynamo equipped bike and other wider needs. I hope the project goes well.