I've finally finished my latest modification, and I thought I'd share and post a couple of pics. This time round, I finished putting the front end from a 2007 GSX-R 1000 on my Thruxton. Apperance-wise, she's exactly what I was hoping for - a more aggressive, meaner looking Thruxton with USD forks and twin brake discs. And after surviving my first shakedown ride around the block, I'm also really happy with the handling. Here are some pics:
(that digital gauge is temporary, and it's all cracked and stuff because I spilled petrol on it. I'll be swapping it out for an analog gauge sometime soon).
This mod replaces the SV650 front end that I had on prior to this, and I have to say that the GSX-R front end was actually easier to do than the SV650. Surprisingly easy in fact, and I'll write a bit about how it was done for anyone who might be interested in doing the same.
Overall, I wouldn't mind if the GSX-R forks were a bit longer as the front is a little bit low, but this is something I'll compensate a little bit for with some shorter-than-stock rear shocks later in the year (I'm aiming for a slightly slammed look so I don't mind giving up a bit of steering geometry), and I've traded upright ergonomics for a more hunched over, racer's crouch. But the upside of that is I had an absolute blast on my shakedown ride, and I was still taking it very easy. When I'm confident the front isn't going to fall apart and I've scrubbed-in the new front tyre, I think my bike is going to be a ton of fun to ride.
I'll describe what was required to make this work, for those who are interested. The lower steering bearing is identical between the Thruxton and the GSX-R, so all that is required is a custom upper steering bearing, which you can get from here
(The SV650 guys who upgrade to GSX-R front ends also need the same size bearing).
The GSX-R steering stem is just the right size, so no need to press it out and swap it with the Thruxton's. The GSX-R's steering stops are too wide, so you'll need to drill and tap a couple of holes to put in some bolts to act as new steering stops. And here's where the GSX-R front end swap is easier than the SV650 - you don't need to grind off the old steering stops on the GSX-R lower yoke whereas you do if you go for a SV650 front end swap. So, with just a custom steering bearing and two bolts, the whole GSX-R steering assembly will slide right into the Thruxton's steering tube.
Because I had a 2009 model Thruxton, all my switchgear was for a 1" bar, which meant a lot of rewiring to get the 7/8" switchgear connected. I think the earlier, clip on Thruxtons all used 7/8" clip ons, so if you have one of those you can use your existing switchgear to make life much easier.
I couldn't really come up with a good idea for mounting the headlights, so I reused the stock Thruxton's and made some ghetto brackets out of hose clamps:
Not the greatest, but for 4 x $1.50, they're not too bad.
The indicators (not stock, but some aftermarket ones I had spare) I mounted on a bracket screwed into the GSX-R's lower steering yoke, where the steering damper usually goes. Again, not the greatest, but they work fine.
The bar end mirrors are held in place by a tightening/expanding screw thing inside the 'bars. I used a stock SV650 clutch perch and lever and Brembo radial master cylinder (one of the best upgrades I've done). I also had to get new brake hoses.
My throttle cables are a bit too long, so I've had to rotate them in such a way to take up the slack. Really, the thing to do would be to snip the nipples off, shorten and resolder them. But you can make the stock throttle cables work if you're creative with the routing.
I think that's about it. Hopefully some of that will be useful to anyone else contemplating something like this.