1973 R75/5, LWB, seat question

[kantuckid]

On my (basket case project) bike I just finished assy. of the seat. I had the "J" hook hinge parts,new rubber bumpers,nice original cover & trim,numberplate repainted black, have new grab rail, redid the pan & foam was nice but lack the rest that "attaches" seat to the frame , which I see on my parts bike, but not such nice shape it appears with out tearing into them. Also, I have a lock cylinder on the parts bike(no key) and a nice lock housing from the good bike but no cylinder. Is it really worth the $ to replace the lock is one question. The other is that in looking @ the fiche on Max's,Hucky's & Motobins, none show the parts that fasten to the "J" hooks & "keep" the seat on the frame? Is it just that they are nla & also not purposeful? Does the seat just sit there OK on the frame/bumper pads? THANKS!
BTW, if you redo one of these seats the1/2"x 4-40 SS panhead screws,washers-flat & lock,nuts in the Lowe's drawer work great in the narrow aluminum trim for install.

[oldroadie]

On my /5 the two seat hinges, J hooks as you call them attach to the seat pan with 6 countersunk Allen head bolts. The hinges go on opposite each other attaching to the pins on the underside of the subframe rail, trapping the seat on the subframe and the locking pin holds the seat to the frame. Is this what you're asking?

[rufusswan]

Mine had no attachments to the frame except the piece that goes down into the lock on the left side. It stays on the frame really solid, believe it or not.

[merge87]

I haven't done it yet, but I'm going to try the lift off seat mod found here

http://w6rec.com/duane/bmw/seatmod/index.htm

Others have said it works well.

[disston]

You don't need a lock on the seat. It will work just as a button. The seat covers the tool box and battery. That lock isn't protecting much and anymore these days nobody knows how to open the seat anyway, I think.

The J hinge hooks are attached to the frame at pins welded to the rear frame. These pins get broken and they may be missing. Somebody makes a part to fix the pins which it sounds like you may need. I forget who this is. We will find it, or them, or somebody will mention this again later.

With the J hooks, or at least one attached at front. The seat will stay in place if the post engages. Then to open use button. But when opened lift off the seat instead of standing on side. Much like rufusswan said earlier and this is how mine currently works. Every couple of years I play with all the parts and try to make it, maybe, more secure. But it is fine just the way it is I think.

[kantuckid]

Originally Posted by oldroadie

On my /5 the two seat hinges, J hooks as you call them attach to the seat pan with 6 countersunk Allen head bolts. The hinges go on opposite each other attaching to the pins on the underside of the subframe rail, trapping the seat on the subframe and the locking pin holds the seat to the frame. Is this what you're asking?

DUHHHHHH! THANKS! I was looking too hard at my parts bike & not at the projects frame! The project frame is very nice ,was a good running 51k commuter bike that a 2nd owner took apart then sold to me much later . The pins are there & fine to use with the hinges which I have mounted on the good seat. My seat has a like new pan now and the post & rubber bumper are present too & I also got a set of new smaller bumpers with the nos parts boxes and the bike. My guess is the 1st owner lost the key & removed the lock cylinder from the project bike.
The parts bike has no pins on the frame and yet there were these mystery parts that held it from being lifted off the frame.It's sitting in the dark so I was trying to see down in a dark area. After reading the links & further inspection, I see that it is a jury rigged something bolted to the hinges that prevents removal.
On a similar subject, I have a decent tool box but no rubber lid to cover it. Anyone seen/have a way around the $40-50 for a crappy used one? I'm trying to think of a way to come up with a replacement solution???

[oldroadie]

You're all set with the seat. You'll have to bolt the rear hinge on after it slips over the hinge pin, thus trapping the seat on the frame. I don't have a lock, either, but the spring loaded catch does a fine job without it.

[disston]

Originally Posted by kantuckid

On a similar subject, I have a decent tool box but no rubber lid to cover it. Anyone seen/have a way around the $40-50 for a crappy used one? I'm trying to think of a way to come up with a replacement solution???

You don't need a cover. /6 doesn't have a cover. BMW eliminated the cover. Cover the tool box with a plastic shower cap?

[kantuckid]

Like Albert says...

[helion42]

/5s for sure and I think /6's only have the rubber gasket, not a full cover, between the seat and box -- part # 52 53 1 230 398, (~$11)

[kantuckid]

I have a roll of adhesive neoprene foam-is like 3/16"th x 1 1/4", with peel off backing that I was thinking of for the edge on my tool box but haven't tested to see what the "touch thickness" needs to be for sealing against the seat pan??? I see no reason to buy the $11 version(I see those listed several places), as there are lots of other choices for a foam edge.

[rufusswan]

Mine was so damned ratty I exacto'ed it off years ago. No harm, no foul.

[helion42]

Originally Posted by kantuckid

I have a roll of adhesive neoprene foam-is like 3/16"th x 1 1/4", with peel off backing that I was thinking of for the edge on my tool box but haven't tested to see what the "touch thickness" needs to be for sealing against the seat pan??? I see no reason to buy the $11 version(I see those listed several places), as there are lots of other choices for a foam edge.

Definitely, I's mostly just putting the part out there for info's sake. You could easily use $free.99 weatherstripping or whatnot, even bed foam and black tape. The OE gasket appears to have something like ~6mm of pretty soft compression between the seat pan and the tray, is that what you meant by touch thickness? It's just enough to hold the tray firmly down so it doesn't rattle, and possibly keeps out some water.

[Hawk Medicine]

IINM (And I may be!) those tool bob lids are still available but check Max or one of the other suppliers to be sure.

The last rubber lid I bought, I found on Ebay. They last a decade or two and then the bubber splits and they need to be replaced but theyre the best way to keep you tools safe and dry unless you pack them in a plastic bag.

The rubber gaskets work but I like the lids.

[kantuckid]

I remember something like $44 for a new lid. The few that come onto ebay are hardened rubber with torn edges & not worthy of my money. Seems a ziplock would be more logical?