I may be being stupid but taking the seat off the subframe seems like it should be easy but is far from it.
The seat pins locate fine in the frame lugs and slide out easy enough, but the hooks won't easily slide out from around the frame tubes and I've chewed up the paintwork trying. I did eventually get the seat off (and back on) but it seemed to involve far more wriggling, strange angles and sliding back and forth to achieve. Not sure I could do it on demand...
Am I missing a trick here or is something amiss - when latched shut, the seat is not aligned, is something bent out of shape?
Yes it's fiddly, there is a knack and the correct sequence. Practice makes....
Beware the front edge scratching the right side of the tank.
Ade B wrote:the hooks won't easily slide out from around the frame tubes and I've chewed up the paintwork trying. I did eventually get the seat off (and back on) but it seemed to involve far more wriggling, strange angles and sliding back and forth to achieve. Not sure I could do it on demand
Stand seat lock side.
Open the seat. Left hand under the right front corner, right hand anywhere to the right that's comfortable.
Slide the seat off the pins.
Rotate the seat a tad to enable you to move it forward taking care with your left hand.
When adequate clearance allows, move the front half of the seat towards you so the hook passes the frame.
Once that's done, tilt the front higher a bit more and rotate the seat so the rear hook passes the frame.
Sounds harder than it is...but it's a very step by step description. Takes 5 seconds in practice.
Thanks Steve. The hooks on yours are different to on mine (which according to some paperwork I have is an Oct'77 build). Mine are flat painted brackets - will take a pic when I'm back with the bike...
Any thoughts on the seat and rear light cluster misalignment? Is this unusual?
The frame and engine numbers match on this bike, so it's not a complete mongrel, I know the RS fairing and bars were swapped by the vendor for the S kit.. the clocks have some road rash painted out, I've a hunch the bike has led an interesting life...
Ade B wrote: ↑Sat Jul 19, 2025 5:29 am
Thanks Steve. The hooks on yours are different to on mine d'oh!(which according to some paperwork I have is an Oct'77 build). Mine are flat painted brackets - will take a pic when I'm back with the bike...
Any thoughts on the seat and rear light cluster misalignment? Is this unusual? Mine is also a tad "tweaked". I can't see it when I'm riding so not too fussed.
The frame and engine numbers match on this bike, so it's not a complete mongrel, I know the RS fairing and bars were swapped by the vendor for the S kit.. the clocks have some road rash painted out, I've a hunch the bike has led an interesting life...
Yeah I think we worked that out I have seen what looks like a flat metal version but memory tells me they worked pretty much the same. Memory might not be as good as it once might've been so ...grain of salt.
In an effort to understand the difference I had a look at the fiche.
They list and picture the same hinges for bikes from /5 to RT. I know that's not right as a mates /5 isn't the same...
Cross referencing to the 75/5 pn 52 53 1 236 351 is the rear hinge and has the same picture as above.
pn 52 53 1 230 314 is the front hinge and is also the same as above.
So, if they're different through the models from /5 to RT, does this mean that
1. the fiche is missing something or
2. they'll retrofit all
Is it one of those anomalies we seem to come across occasionally in the fiche
SteveD wrote: ↑Mon Jul 21, 2025 1:44 amYeah I think we worked that out I have seen what looks like a flat metal version but memory tells me they worked pretty much the same. Memory might not be as good as it once might've been so ...grain of salt.
In an effort to understand the difference I had a look at the fiche.
They list and picture the same hinges for bikes from /5 to RT. I know that's not right as a mates /5 isn't the same...
OK, I've added a few images of seat hinges below...
As a general rule, the hinge arrangement was common for all models of the same year... even when the seats were different. Bear in that BMW often changed the physical appearance of parts without changing the functionality...
1969 - 1980 (I think) - The hinges were as shown on the fiche. There may have been a version made out of flat plate by BMW but they appear functionally the same. The image is of my R60/6 which has plate hinges... but I can't be sure of they are OEM as the seat itself is aftermarket... The hinges are fixed with screws (confirmed form parts fiche).
20250721_160811.jpg (308.98 KiB) Viewed 28786 times
1981 (I think)-1984 - Hinges are plate and fixed to the seat pan by rivets. The first image is a dual seat, the second from a 3/4 seat both on a '1981 RS. FWIW, the same hinges listed against the earlier models are shown as replacement parts for these years as well... so presumably you have to drill out the rivets and re-drill for bolts.
20250721_160907.jpg (370.63 KiB) Viewed 28786 times
20250721_161345.jpg (432.41 KiB) Viewed 28784 times
1985 - 1995 - Seat and Hinges are quite different. Made of plate and held to the seat pan with hex bolts.
(I can only attach 3 images to a post... will post the fourth image of a post '85 machine as a reply to this post)
Hope that helps
Rob
Last edited by Rob Frankham on Mon Jul 21, 2025 12:02 pm, edited 1 time in total.
Thanks all.
To rule out a thought...the pins on the frame that the hinges slide onto on my post 9/80 RS both face rearwards. The seat slides to the rear off those pins, then is manipulated off the frame, up and off the bike.
My question...Is there any model where the pins face each other? eg the rear pin faces forward?
Dunno why they'd do that as it'd be a right pita.
I have seen what looks like a flat metal version but memory tells me they worked pretty much the same. Memory might not be as good as it once might've been so ...grain of salt. 
or 
