There's a holder for each bulb which twist-locks into the flasher housing. Thought the task was simple, just install and connect, and ran into the first problem.

I didn't realise that the front bulb and holder on the Concours is not horizontal when installed in its reflector housing, it's aimed more like 20 deg upwards. With the incandescent bulbs, this is no problem, light is emitted in pretty well all directions. With LEDs, most of the illumination is along the bulb axis, so birds and low flying planes would see these new LED running lights/turn signals, but cars in front of the Concours wouldn't see much.

The solution was to break away the plastic housing around the LEDs, bend the LED array down 20 deg on its leads, and reinforce the new position with hot-melt glue. Installed, tested, now works like a charm. Placing and twisting the bulb holder into place is challenging for those large of hand. At least now they're slightly easier to insert without the plastic cowl on the bulb.

The front ones worked out so well, I installed a couple of 35-LED 1157s in the tail light. Each bulb has 19 LEDs on axis facing back, and 16 firing radially to bounce off the reflectors. Compared side by side with the incandescent, they seem fine.

Current draw is 25 ma plus 90 ma when braking, each bulb. $12.40 US a pair from eBay , including shipping.

Further Blinker Developments

(Feb. 2013)
Well, these LED blinkers have been in there for a while, and technology has marched on. Now there are Surface Mount Device LEDs which can be installed without modification because they are less directional (and cheap). So I bought a pair of 22 SMD Amber 1157s and plugged them into the front turn signal sockets. The blinker part would work, but not the running light. So I plugged them into the brake light sockets, and they worked like a charm. And I know there's nothing wrong with the front turn signal sockets, because the existing LEDs have been in there happily lighting up for a few years.

(Put new LEDs on shelf and scratched head for about year).

(Oct. 2013)
On a ratty Ottawa October day I thought I'd have another look. Tried a bunch of useless things and then stumbled to the fact that when I removed the back incandescent blinker bulb, the front running light would glow the way it is supposed to.  Here's why:

With the front LED 1157 installed, the running light current has a second path to ground out through the front bulb flasher contact and then through the rear (incandescent) blinkers. There's no such path with an incandescent front bulb. With the existing LED 1157s, this only reduced the brightness somewhat, with the new SMD 1157s, the LEDs didn't light at all. This means I've been riding 6 years or so with the front running lights dimmer than they could be and never knew. Even if the rear was an 1156 LED instead of incandescent 1156, it wouldn't have worked correctly; both front and back would have been dim running lights.

Solution - install 1N4005 diodes in the blinker leads:

I cut the Gray wire between the connector and the bulb socket, soldered in the diode and covered with heat shrink tubing, looks pro.

So back to the new SMD lights. Brightness is fine and they are less directional. Cooperate nicely with the incandescent 1156s in the rear. All for about $5.

Liked the front ones so much, I installed 22 SMD 1156s in the rear.