SP PD-8X Dynamo Hub and K-Lite lights

When looking for a light to go with my dynamo hub the obvious choice was the K-lite, compact, light weight and the choice of riders in the Tour Divide. The only choice I had to make was the setup. I decided to go for the brightest 1000/600lm light with a Sineway USB charger for my Garmin 800 and iPhone. The hub was also a straight forward choice, SP do a number hubs but the PD-8X was the only one that had a 15mm thru axle. It also seems to come out on top in all the reviews.

The hub arrived first and I built it up using a Travers carbon 29+ rims which are tubeless compatible and a feathery 540g, which saved 500g over a Northpaw rim with innertube. I did what everyone does when they take a new hub out of the box, I tested the bearing for smoothness, smooth isn't the word these were positively notchy! so much so that I considered stopping the project there and then. I cant put these on my bike! I had read the reviews before I bought the hub but I wasn't expecting them to feel this rough. I had the hub and rim so went ahead and built it, they laced up just as any other hub, there is an arrow down the middle to show you the direction of rotation but as this was going on a mountain bike with disc brakes you can only put it in the dropouts one way.

Once built up, especially when you have mounted the tyre the notchiness all but disappears to such a degree that unless you were told or spotted the small plug you would never know it was a dynamo hub. In use on the trail, I couldn't feel any extra draggy, from the figures published on the SP site the drag ranges from 1-6 watts. The SP PD-8X was quite underwhelming, its just felt like any other hub! Which is praise in its self.

The K-Lite turned up a couple of days after the hub so the bike way ready and waiting. On opening the packet that the light came in I was presented with what seemed like a lot of cables, not to be put off I laid them out on the table and it soon became clear what everything did.

A cable plugs into the dynamo hub on the right fork leg and runs up to the switch on the top of the steerer above the stem, this switch swaps between the light and the Sineway USB Charger. Two cable run out of the switch, one to a battery with another switch on (this switch goes from High to off and Low for the light) the other cable diverts to the Sineway USB charger. I will use this to power my Garmin 800 and my iPhone.

I played around with the position of the light and decided to mount the head unit under the bar to keep it out of the way, this also allowed me to mount the battery to the face plate of the stem and run the cables under the Garmin. I have read a few reviews from recent BB200's and there is some bike carrying to be done and I wanted to limit the chance of pulling out a cable or knocking the light.

Like a big kid the first thing I did was pick the bike up by the bars and span the front wheel to see if I could get the light on, to my surprise it did! Not only that I can report its quite bright, I did it so you dont have to...! I then rode the bike around the corner, maybe 200m to take some pictures and this was enough to charge the battery. I was only there for a couple of minute but the light stayed on for the whole time.

Once I was happy that the system worked and I had everything zipped tied down in the right place I kitted up and headed out for a proper test. I have been using a Exposure Maxx D mk3 up until now so I am used to a reasonably bright focused light and wasn't expecting the K-Lite to come close. The climbs are defiantly a weak point for the K-Lite, on open fire roads it wasn't an issue but on more technical loose climbs I was finding the light of other riders were casting my shadow on the trail. This is obviously an issue with every dynamo system, there is only so much power generated by the hub for the light. This all changes when the speed picks up, normal cursing speed is enough to illuminate even the trickiest single track or downhill. The light is less focused than my Maxx D but gave a bright flood light. It was so bright that my Exposure Joystick on my helmet made no impression on the ground within the area illuminated by the K-Lite.

I still have a bit of tweaking to do with the setup. I am probably going to move the Sineway USB charger to the front of the frame bag for the BB200 to make it easier to swap between the iPhone and Garmin. I had a quick chat with Kerry from K-Lite and showed him the pictures of my set up to make sure I had everything correct and a strategy for the best way to charge my Garmin and iPhone on the BB200. With the switch directing the power to the light it pulls more power from the hub especially when traveling at higher speeds (compared to the off or Sineway position). This isn't really a concern for me as the high speed will probably be gravity assisted, so wont have a great impact on my legs. I had considered riding with the light on during the day to aid my visibility to car drivers, my thinking was the dynamo is running all the time I might as well use it. Now this is were my basic understanding of dynamo systems lets me down...as by having the light on it will use about 7 watts of power compared to 1 watt in the off position.

The other thing I discussed was the large size of the battery box, again my basic understanding of electrical systems let me down shamefully! The box isn't all battery but also holds capacitors. K-Lite uses high quality capacitors (unlike other brands) ideal to give extra peace of mind when you are in the middle of nowhere.