HELP

Will a 91 - 99 750 or 900 ss swing arm fit on a 1987 F1 motor? These cases are 155mm at the swing arm pivot. I have a 5" wheel, so the tire shouldn't be a problem but the hub is 210 mm wide, almost 25 mm larger than the inside swingarm distance. If not, what else will?

Thanks,


Gene Danyo

Hi Gene,

The 750 supersport swingarm will latch onto the cases without any problems, however because of the of the rear facing exhaust that exits through the swingarm the shock mount is pushed back. This means that you will need a longer shock - one from a supersport will do the trick.

Mike,

Thanks for the info. It's good to know that it can be done. On the other hand, I just had the original shock rebuilt! I'm looking at a couple of options vs the rear wheel fit so I'm sure I'll be back begging help soon.


Thanks,


Gene

Gene. Only a 1989-1900 750 Sport, or a VERY EARLY 750 SS (perhaps 1991-1992, and now scarce) swingarm will fit the F1 case, but you will need the 1-inch or so longer shock. Or, the Verlicchi aluminum swingarm designed for the F1 will work as a "bolt-on". They all have the 27mm swingarm pin. After 1992 the 20mm pin became common on the 750 models as, I believe, was always used on the 900 case; both are rather wide near the lower frame/footpeg area.

Nice F3s there Mike.

I have thought about biting the bullet and looking for a Verlicchi swing arm, if one can be found from a reliable source.
I want to use it with a specific wheel - fits (91-99 ss, 851/888sp) and I need to be concerned about fitting a disc and caliper,etc. without too much grief. I guess it's the next thing to look into.


Gene

Hi Gene,
If you fit a Sport swing arm you may not need a whole new shock to get the 1" longer length. Check with your shock manufacturer (or others) to see if they offer a different length rod end to change the overall length of your shock. Or check the thread size and shop at somewhere like McMaster-Carr for one that way. When I had to switch to a Sport swing arm for my Harris, I was able to purchase a 1" longer rod end from Penske.
Bill

Bill,

I'll look into extending the shock. It's a Fox unit I had rebuilt recently and I would like to use it if I could. Finding a 750 sport or ss swing arm looks like it might take a while. I wrote to Metamachex to see if they could make something I could use. The ss design is from the same period as the F1 so I'm hoping I won't have a problem running the bike in vintage classes. Thanks for the info.


Gene

You can get re-production swingarms from Two Wheel Classics.

http://www.twowheelclassics.co.uk/catal ... ngarm.html

When it comes to the 750 F1 or any other bike for that matter you can make quite a few parts quite easily using home CNC equipment and maybe soon 3D printing. But, it is always the part you desperately need and can't get hold of that can't be made at home.

My bad...

The 750 swingarm fitted to the 400 below has a smaller diameter spindle and is about a half an inch too wide at the crankcase - so some modification is required.

I will post some photos of different swingarms tomorrow that demonstrate the relative differences between them.