1982 gs 650 gl /1980 850 G front end swap?

[orangechicken007]

my current daily driver is the 82 650gl with the single disk brake. I would like to upgrade to dual disk front end and I have an 80 850 g parts bike with the dual disks in good condition. I am wondering if I can swap the whole front end? I know the tubes are different 35 for the 650 and 37 for the 850 but according to some things I have seen online the steering stem bearing size is the same http://www.dotheton.com/forum/index.php?topic=20951.0
. Can anyone confirm this and if so has this swap ever been attempted? I know it will change the handling of the bike but im going to be riding in basically a straight line on I27 here in west Texas, no corners here So I would really appreciate the braking power.
Thanks for you time

[mnferwerda]

I know this has been done with a '83 GR650 (a 2 cylinder 650), and the owner was happy with the swap and said it was straightforward. You'll need to swap the front brake master cylinder too.

[Steve]

As long as you swap the WHOLE front end, it should be OK.

Basically, you will need to remove the master cylinder from the current handlbar, remove the nut on the upper triple clamp, slide the steering stem down the neck and put the 'new' stuff back in.

You will need to replace:
- forks
- fender
- triples
- master cylinder

Your headlight ears will need to have the rubber donuts swapped, unless you swap out the entire ears, but then you will need to change your headlight bucket, too.

The 650 and 850 use the same axle, so there are no issues with bearings, there, but if the 850 is older than '82, your wheel pattern will be different, so just use the wheel from your 650. There is a panel on the right side that covers the holes that hold the second disk.

.