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Old 12-28-2011, 04:52 AM   #104
ontic OP
Joined: Jul 2008
Location: Melbourne
Oddometer: 1,070
It's been a while...

lets see,
the motobins order has all arrived.
Lots of goodies there that I won't go into yet but the most important thing for now was the siebenrock single seat- I've been waiting on this so that I finish all the subframe and luggage frame fabrication...

This will be a long and rambling couple of posts- Fair warning

Honestly, I would have preferred the black, but motobins don't carrry the black, so hopefully this colour warms on me.
very nice seat, kinda firm but the foam feels like good quality and combined with a sheepskin it is going to be very comfortable... we all know the seats but heres the seat before I.... molested it.

with my big tank the seat would not fit all that well- so as wrong as it felt I opened it up and removed some foam from the front- luckily not too much had to be removed so that the cover would require altering.

Next was to figure out how I was going to mount it and secure it without the stock G/SPD luggage rack- ie, by making my own luggage rack (of sorts) that also had some other features. Not having seen how the stock G/SPD luggage rack solves the mounting/locking and weight supporting issue I just set out to 'engineer' my own solution.

A complication of my life at the moment (that I won't go into) is that this bike may be required to be used for two-up touring if I go OS late next year- maybe, maybe not- but at the least if it wasn't going to be used two-up all the time I would want the capability to double people on occasion- but I am not a fan of the stock double seat and am simply not comfortable without my single seat (I've got a single seat on the 90/6 too).
So, along with my single seat, I wanted to have the capacity to use and easily remove a rear single pillion seat.

Sounds easy huh?

Now, lets fast forward through 2 full days of shed tinkering, with lots of metal cutting, sparks flying and argon flowing...
First go around I made some beautiful forward brackets on the seat frame but drilled them a tad wrong so that the seat was a litte off centre and I just couldn't accept it- so late at night I tried re-drilling the holes and of course I moved the holes the wrong way... the seat was now more off centre and now my brackets were screwed. Next day I had to cut them off and start again...
Anyway, that is all an excuse for why it looks a bit messy up the front there.
We'll just call those extra holes drainage holes OK

I need to explain a few things I guess. I tend to make things more complicated than they need to be... we'll call that 'feature rich'.
There are two parts to the frame- the main seat frame and the rear pillion single seat frame- this rear seat frame bolts into the main seat frame by some captured and welded in nuts and that front 'tongue' on the seat base keeps the rear seat under the front seat...

Oh yeah, I cut up the stock double seat to make the rear pillion single seat.
Now, it became apparant that this main seat frame was contacting a crossmember on the motorbike frame and was now load bearing. This was Ok for me, but I didn't want it riding metal on metal- so that is what those black things on the front are for. I'd already gotten furiously annoyed at the rubber bumper things on the bottom of the seat that keep falling out of the seat pan- so I wanted to make something a bit different.
I captured some more nuts in the front tube and bushed some allen head bolts with some renewable rubber bushes... fuel line of course.
What this means is that with weight on it the seat now rests evenly on these fuel line rubber bushes and the stock seat pan rubber pads (and now these stock rubber pads don't keep falling out.)

Now I hope that all looked nice and easy.... cause it wasn't!
So much fiddling and thinking and testing. But, it works. The seat locking mechanism snaps in and yet is bearing no load whatsoever. To remove the rear pillion seat requires unscrewing two allen head bolts. Simple.
The indicator crossmember is now also partially load bearing (only significantly with a pillion- so later on I've reinforced that crossmember.

The rear seat aint all that comfortable right now, but I will build up the foam a fair bit higher and a little longer at the back and it should be OK. (no big buts please)
I suppose I will match the profile to the front seat- probably just cover it in black.

next post coming up,
1974 R90/6
1981 R80G/S
1994 XLR250R

ontic screwed with this post 12-28-2011 at 05:38 AM
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