I will be calling the dealership today and find out what's what.
Dan,
If you look at the bevel box below and squint your eyes...what do you see? Slightly resembles a GL1800 final drive?
At a quick glance and considering the center-line of the GL input shaft...after removal of the brake rotor and caliper bracket, it would provide ample room for a sprocket adapter off the FD...can't be any worse than having a loaded rear wheel hanging off of it.
I have thought about trying to morph a GL1800 swing-arm and final drive into the M3W but then you have drive shaft offset issues to deal with. With an adapter bracket, input flange and a flange to hold the sprocket, why couldn't a GL1800 final drive be substituted as a bevel box?
All this time, I wanted the full swing-arm to run a GL1800 wheel (with run-flat car tire) while eliminating the OEM bevel box and just over looked using it as a bevel box. Couldn't see the forest for all the trees.
The GL1800 FD is robust enough to deliver power to the rear wheel while dealing with the stressed loads of a 900+ lb. bike flying through the sweepers at 90+ mph (with two gravitationally challenged people on board)and towing a trailer. I see no problem it supporting the torque loads of a drive belt.
The gear ratio for the OEM bevel box is 2.0:1...the gear ratio for the GL1800 is 2.75:1 (33/12). The new swing-arm/final drive (trike pull-off) in the pic was less than $100 and are easily sourced. As you know, the GL1800 FD has a proven track record of high mileage service even when neglected. My buddies and I usually change them out at 150K miles just for general principle and considering how cheap they are but many I know of have seen upwards of 300k miles without a failure. It would require some final drive sprockets to bring the rpm's back in line but not the end of the world to have a reliable box that is quite. The GL1800 has two over-driven gears (4th is .843 & 5th is .686)...best I can gather on the Mazda 5-speed box, OD is in a range of .83 to .85.
I know it seems overly complicated but a current bevel box replacement is taking a failed product out only to put one identical to the one that failed back in. And a quite bevel box with 10K miles on it might not be so quite or reliable with 50K miles on it.
Food for thought...especially if you're considering building your own version of a M3W.
Z
