450 K0 Black Bomber Seat Troubles

Troy

Troy

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Location
Canmore, Alberta, Canada
My bike arrived to me without a seat or any seat hardware.

In the last few weeks I have received a new seat Texavina. While I'm not an expert with upholstery, to my eye it looks fantastic and I'm very impressed.

I also purchased a seat hinge set from David Silver Spares https://www.davidsilverspares.com/CB450K0-SUPER-SPORT-1965---1968/part_298864/
Curiously the hinges are all marked CMSNL
IMG_1758.jpg
Anyhow, there seems to be a discrepancy with between the frame and the new hinges. The distance between the center of the hinge pin and the center of the frame tube is about 33 mm, while the distance between the same 2 point of the hinges themselves are about 25 mm. This means the left hand hinges aren't able to sit squarely on the frame tube when the seat is lowered the the right hand hinges are way off as well. Does anybody have any experience with this scenario? It would be great if someone had original hinges or Clauss Studios hinges that they would be willing to measure up for me please!!! I will be contacting DSS but would like to have as much information at hand before I do. Could I force a fit somehow? Perhaps but that doesn't seem like a good answer to the problem. The pictures below show how the hinge won't sit squarely on the frame when connected to the pin.
IMG_1756.jpg IMG_1755.jpg

Thanks
 
Last edited by a moderator:
jensen said:
Hi,

I have Claus Studio hinges, I can make pictures if you like. What specific area are you interested in ?
Click to expand...

Thanks Jensen. Left hand hinges, looking for the distance between the centre of the hinge pin and the centre of the frame. It doesn't need to be highly accurate but in my extimation a value of approximately 33 mm would allow the seat to align properly. You can see the values of mine are approximately 22mm and 25 mm +/- but the distance between those 2 points on my frame is approximately 33mm.

Bedankt
Troy

IMG_1763.jpgIMG_1762.jpg
 
I pictured them mounted on my bike :

0d820b40-5ff0-42f6-9ba5-d9616beaee63.jpg

Mounted seat hinge

7261fba4-a11e-4a31-849b-508c1110d363.jpg

seat hinge measurement

cbea3628-4221-4527-902e-c1ca0cadb1a6.jpg

situation in almost closed position

16466867-5f63-4a97-b716-99cf44aa4ec3.jpg

Centre to centre measurement
 
I also have a few original seat hinges, but have the same dimensions as the Claus Studio ones, just 1 or 2 mm off. In the beginning the rubber hinges had to set, not a perfect fit.
 
jensen said:
I also have a few original seat hinges, but have the same dimensions as the Claus Studio ones, just 1 or 2 mm off. In the beginning the rubber hinges had to set, not a perfect fit.
Click to expand...

Thanks Jensen. I think mine are a little different to yours. I will reach out to DSS and see how they respond.

I don't expect a perfect fit and I know that there will be a settling in but I don't think these will cut it.
 
The hinges I bought from CMSNL are the same as everyone else's - about 25mm from the centerline of the hinge pin to the centerline of the frame tube. Maybe on your bike someone welded on different hinge pins years ago to accommodate some alternate seat? Just a guess.
 
wentwest said:
The hinges I bought from CMSNL are the same as everyone else's - about 25mm from the centerline of the hinge pin to the centerline of the frame tube. Maybe on your bike someone welded on different hinge pins years ago to accommodate some alternate seat? Just a guess.
Click to expand...


Thanks Bob & Jensen, I knew something was/is off, but not sure if it was the seat pan, the hinge or the frame. I was sure hoping it wasn't the frame as that's a much more difficult thing to fix at this point. Looks like that is the likely problem. On my frame it seems more like 32-33 mm from centerline of the hinge pin to centerline of the frame tube. If it was in the same range as yours I would have no problem. Curses.

I guess I will now need to find someone to weld a new pin onto my beautifully powder coated frame. That makes me sad.
 
Are you sure ? In the beginning the fit of those parts where not good either, I had difficulties to close the seat with the knob, much force needed. I still need a lot of down force on the seat to lock it with the knob. I can measure the distance between pin en frame it you want, to see if yours needs to be corrected or not ?
 
jensen said:
Are you sure ? In the beginning the fit of those parts where not good either, I had difficulties to close the seat with the knob, much force needed. I still need a lot of down force on the seat to lock it with the knob. I can measure the distance between pin en frame it you want, to see if yours needs to be corrected or not ?
Click to expand...

No, I'm not sure and I would be grateful. The welds on the pins don't look like they were done by hillbillies in the barn, they look pretty nice. (Nothing against hillibillies in barns, in fact that accurately describes much of my family)

I'm going to be pondering this for a while before I do anything drastic.
 
So Troy is saying ~32mm from centerline of peg to centerline of frame tube. That is what mine is. I also have the Clauss Studios hinges. Which fit about like jensons pictures.

I don’t actually have a seat. But it take a little downward force to fully seat the hinge on the frame. Nothing too excessive. I could do it with my fingers.


‘69 CB350
‘68 CB450K0
 
One more thought. The two hinges are different, so maybe you have them switched? The two on the right side are the same, but the two on the left are different.
 
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