Jim's Speed Twin Build

fredintoon said:
I presume the monoshock is for the sidecar suspension.
Click to expand...
I've had this geometric thought rattlin' round my head for the better part of a year now. Knew what I wanted... just never drew it out. Low and behold, about 10 min. after I ordered the shock, Mailman put up a thread 'bout this concept BMW. And there it is.... that's the thought been floatin' 'tween my ears all this time....

bmw.jpg


With the big massive side tins off the Speed Twin, you'll never see it
fredintoon said:
I got photos of an XS650 sidecar subframe if you need them.
Click to expand...

Cool. I'll take ya up on that.
 
You'll probably need a lighter spring. Being off a bike with a rising rate linkage it'll be on the stiff side with no linkage.

I've got an r6 rear shock on mine, with the linkage, and even with the preload down it could use maybe a 1 step lighter spring.
 
Ratranger said:
You'll probably need a lighter spring. Being off a bike with a rising rate linkage it'll be on the stiff side with no linkage.

I've got an r6 rear shock on mine, with the linkage, and even with the preload down it could use maybe a 1 step lighter spring.
Click to expand...
Thanks for the info. Are springs redilly available?
 
Oh yeah, racetech and many others will have what you need. Or you can go to about any companies coilover springs and look at stuff with a 2.5" ID and about 7-7.5" length. Eibach and others make tons of springs in that size range.
 
Jim,

Here are some sidecar build links..............
On an XS650
https://advrider.com/f/threads/run-what-you-brung-hack-build.980501/

Gordon Scotts XS650 Sidecar build thread from 650 rider...........Lot of different input but worth wading through
http://www.650rider.com/index.php?name=Forums&file=viewtopic&t=7925&postdays=0&postorder=asc&start=0
His condensed Sidecar 101 thread on here..........pics are missing, they are in the previous thread.............
http://www.xs650.com/threads/sidecar-101.5298/


650 rider site thread......This thread goes into Gordons Exhausts and what he does with a couple of Dyno graphs comparing his Standard set up 77D and a from a set of his pipes........not so much sidecar and at worse you may wast some time or for the better may just pick up a header/Exhaust idea
http://650rider.com/index.php?name=...0&postorder=asc&highlight=gordonscott&start=0

From thexscafe A Velorex on an SR500
https://thexscafedotcom.wordpress.com/2012/09/23/xs650-sr500-velorex-sidecar/
 
Yes! Looking forward to this kind of build...have been wanting to do something along these lines for a while, just don't have the budget or room to do it. Glad we get to come along for the "ride".
 
Swing arm.
OK, so... this is the first "softail monoshock" I've ever done... so I'm kinda winging it here.. :rolleyes:
Tacked the rear hoop back in place so I could hang the shocks back on and reinstalled the swing arm.

IMG_20190529_193423.jpg


Used some 4130 scrap to tack the rear axle plates to the jig.....

IMG_20190529_202036.jpg


... and cut the swing arm off...

IMG_20190529_203925.jpg


IMG_20190529_204015.jpg


Now the axle plates are correctly positioned to keep the same frame geometry as it started with. This means I'll have to build the swing arm "in place," but the more I think about it, I think this is the best way to go. I won't have to make any fixtures and jigs to build the swing arm, the frame itself will act as the fixture. Now I just have to wait for the monoshock to show up.
 

Attachments

  • IMG_20190529_204015.jpg
    IMG_20190529_204015.jpg
    205.2 KB · Views: 221
Last edited:
Monoshock finally showed up. Apparently it got sent here by way of Timbuktu. :rolleyes: Don't think it'll mount the way I wanted... but I have a pretty good plan B. Playin' around with it gave me some incentive to get back to it, so I spent a little time de-tabbing and cleaning up the tubes on the back of the frame. Look at all them tabs layin' on the floor :rolleyes:

detab1.jpg


detab2.jpg


detab3.jpg
 
Rasputin said:
Following this build.
A Triumph sprung hub would look nice.
Click to expand...

Hi Rasputin,
it'd only look nice hung up in a disaster museum.
A bike with one steered like a drunken pig and it killed a guy that took one apart without using the factory dismantling jig.
 
Swingarm Cont...
Ever have one of those days?
So... I cut the swingarm tubes where I (thought I) wanted. and removed the factory brace....

swingarm brace rem.jpg


I'm using the original pivot tube because it's actually a pretty hefty tube that's already machined for the bushings. No need to reinvent the wheel here....
Set the tube in place and I just didn't like where it was goin'.... didn't get a pic. Reorganized my thoughts and came up with a plan B. Except now the tubes I cut off are about 3" too short. Crap. I have an extra swingarm, but I kinda have plans for that. So.... found some 3/16" wall tubing the right size, cut some rosette plugs and extended 'em back out a about 3". Cleaned up one of the joints and noticed a fair bit of undercutting at the edge of the weld. Well hell... shoulda upped the wire feed a little... but that's strike 2 for the day. I'll probably just use the tig and fill 'em in.. but it's out of gas... yeah, let's just call it a day Jim. Piddled around a little cleaning up some more of the de-tabbed areas.
So yeah.... a few steps forward... a few back... just one of those days I guess :whistle:

lengthen.jpg
 

Similar threads

toglhot
Yamaha frame building.
Replies
2
Views
284
Max Midnight
Max Midnight
Hamon2
Building an XS.. that isn’t a 650
Replies
13
Views
743
Hamon2
Hamon2
DB90
1981 Chopper Build
Replies
2
Views
341
DB90
DB90
JBMatthews82
Ignition trouble when hot?
Replies
7
Views
492
JBMatthews82
JBMatthews82
JBMatthews82
Ignition trouble?
Replies
1
Views
340
Raymond
Raymond
Back
Top