takin' a break, boss
Joined: Jul 2005
Location: Elmore, VT
An Unholy Union: DR forks on a G/S
The original idea for this came from Crankshaft, who, a few years ago installed a cr250 front fork on an 81 g/s .
So his idea planted the seed, but I thought that the process was out of my league. I mean, I can change the oil and everything, but taking things apart to that degree was daunting. Some time goes by, and I end up meeting Aaron at his cold and rainy Ironhead Rallye, of which SethS and I were the only participants. At the fine meal afterwards, we got to talking about his g/s conversion, and how bad the forks and braking are on the stock g/s, and he just happened to have a DR650 front end in the barn in good shape. With a promise of assistance along the way, I decided to go for it. I thought it would be great to learn more about my motorcycle, about the art of modification, and hopefully make the bike more suited for a run on the TAT and Baja next summer.
I got the forks and triple tree from Crankshaft, the rotor and wheel from a bike salvage in Georgia (expensive but it great shape), and the caliper from ebay (10 bucks).
At first measurement, I realized that the forks were really long, like several inches long, but since the DR650 forks are designed to be shortened (along with the DR650 rear end), they make a good match for the modification. In no way was I interested in lengthening the rear swingarm. I didn’t want to permanently modify the bike, one reason why I have kept all the stock parts as well (basically an entire g/s front end from wheel to headlight assembly…and no…its not for sale).
First step was taking off the g/s forks. No big deal—Ive always had an easy time taking things apart. It’s the putting things back together where things can get tricky. After a call to Jesse at Keintech, I learned more about the DR forks, downloaded the manual, and got to work.
The DR forks are designed so that if you shift the position of a spacer from the top to the lower fork leg assembly you will shorten the fork length. Jesse thought that 2 inches wouldn’t be too big of a spacer, and recommended some 1 inch iron pipe, available from any hardware store (you could use PVC spacers, as many people do, but Jesse recommended against it, especially with a more durable, easily obtainable alternative). I borrowed a pipe cutter from work, smoothed off the edges on my yard sale (free) bench grinder (it is an old washing machine motor with no switch), and got my spacers.
The finished product:
The triple tree is too long, but before I dealt with that I wanted to make sure that the forks wouldn’t be so long as to mess with the geometry of the bike. I reassembled one of the forks without oil, put it in the triple tree, bumped it out an inch above the top plate, and measured. From the bottom plate on the g/s fork to the axle is 22.75 inches, and the length from the DR bottom plate to the axle is the same, within a few millimeters. The fork diameter will go from 36mm to 43mm.
One leg on for sizing:
So it looks like it will work. Prep stage is complete, now to sort out a spacer for the top of the steering tube to accommodate the extra stem length…the bearing fit…attaching the G/S headlight assembly…the front brake…
I’ll gladly listen to any words of wisdom as the project continues!
elmoreman screwed with this post 01-22-2008 at 12:52 PM