Dual-Disc Conversion on an "L" Model

[Mike_H]

Ok, So I just happened to end up with an "extra" brake caliper (thanks pasturized ) and started thinking about what I was gonna do with it. I mean the one on my 650 is still in good shape, but it seems a waste to let the other caliper in equally good shape sit on the shelf...

I'll put a dual disc set-up on my bike. Has anyone tried this? For the record, the bike is an 82 GS650GL. Is it as simple as finding another lower fork unit with caliper ears and another disc? Thanks.

mike

[duaneage]

You might be able to rebuild your forks with 650G lowers, I don't know if it has been done before.

Your forks are longer and the frame is different so you would have a hard time swapping forks from a G.

you'll need a dual disk master cylinder, the lines, a wheel, the L and R disks, and a L and R caliper. You also have to swap the tire over.

I have everything you need to do this if your still willing to try, PM me and we can work out something.

[Mike_H]

I gotta look in my service manual. I sure would like to have dual disc up front. The bike stops Waaaaayyyy slow right now. It got better with new pads, and I still need stainless lines, but boy, dual discs.... I can't believe noone has done it yet...I'll have to document my findings. Thanks

[Mike_H]

Its a Sign!

Well, It must be meant to be. I was just checking my fleabay account, and a whole bunch of stuff popped up that I hadn't seen before. Low and behold, a complete 650 G being parted out. The guy only want like a total of 30 bucks (by bids) for the whole front end, minus triple tree. Looks like this project may be a go. I'll keep you all posted.

[Nerobro]

For all intents and purposes, it has been done ;-) I did a dual disk conversion on my GS550E. With GS650 forks.

And I intentionally used a single disk master cylinder for incresed braking pressure.

[humhead]

Most, if not all L model bikes have leading axle forks. Make sure you get fork lowers that are leading axle & dual disc capable. Switching to Standard style forks will change your steering geometry.

Terry

[pasteurized]

:-)

Hope it works out for you Mike... let us know how it works out!

[Mike_H]

Well, I have most of the components. Wheel, Discs, Lines, Master Cylinder...Only thing I need are some fork lowers. Looks like a 1100 has an offset axle, just like a "L" model. Not sure if the diameters and lengths are the same though. Gotta get up to the storage location, and take some measurements. I will definately be seeting up a website to document the trials here. thanks for all the help.

[Mike_H]

Ok, so I found some forks from a 750 that look pretty good. They have a trailing axle, and dual disc mounts. Only problem is I don't know if they are the right size. Can someone with a 750 (don't know if its a G, GL E, etc) measure their forks for me? I would need Diameter of upper tube, overall length, length of the lowers, amount of "step" in the fork (where does the axle pass through in relation to the bottom), and finally, the distance along the fork from the center of the steering tube to the ground, and the vertical distance from the center of the steering tube to the ground (this will let me trig out the fork angle). THANKS!!!!

PS. this is the auction...take a look see

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4597497887&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

[duaneage]

The 750 had 37 mm diameter tubes, yours are probably 35. keep looking

[SqDancerLynn1]

The two valve 750's HAVE 35mm forks I believe the later ones do too.
The 850 & up have 37 mm. The GK has an odd 39? mm.

[duaneage]

You need to ask potential sellers about the length of the forks, preferably installed on a bike (although that is kinda tough in most cases) and also measure the distances from the axle to the top of the fork, the axle hole diameter, the clamp distance (how much the fork grabs the axle by), determine if they are air forks and if a crossover tube is needed or included.

The triple tree on your bike places the forks at a different position relative to the head tube than a gs650g. You might need a 650G triple tree or even another model to make it work. If you go into the 750 or other sizes it may get even more interesting.

I would STRONGLY suggest that you ask other members for measurements of their front ends to try and narrow down what may work before buying some parts. I have a complete GS650G front end both installed on my bike and in parts. PM me if you are interested in measurements.