Author Topic: Bitsa Project  (Read 946 times)

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: Bitsa Project
« Reply #30 on: May 05, 2018, 08:49:10 PM »
The reason I mention it is the bike in my avatar pic (Yamaha he whispers) does the same , it even gets in down my neck, its 'orrible. I'm slowly moulding a new rear seat unit to stop it.
What was that Tom, didn't quite hear, was it YAMAHA :o
Im a Nurse, trust me, this won't hurt.....much !!!

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Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: Bitsa Project
« Reply #31 on: May 27, 2018, 02:12:03 PM »
Millie is all run in now, other than 1 tappet doing a Michael Flattery impression of River Dance, no other issues to report. Therefore, oil and filter change, check and adjust tappets and a general check over of nuts / bolts etc, that's all that needs doing. This is such a brilliant bike to ride, probably the best old Honda I have ever ridden actually, great fun.
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
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Offline Underdog1

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Re: Bitsa Project
« Reply #32 on: May 28, 2018, 05:42:58 PM »
Looking good!

What foam was used for the seat? And how is the seat cover fixed to the pan? Need to sort mine I’ve been threatening to finish for the last millennium

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: Bitsa Project
« Reply #33 on: May 28, 2018, 07:57:21 PM »
I used re constituted foam, 1" thick and stuck 2 together with HD spray glue. Easy to cut to shape and sculpt with an electric carving knife. After I made the vinyl cover, I stretched it over the metal base Trig made for me and pulled the cover really tight and held it in place with that silver carpet tape. We then used this metal upholstery strip but cut the spikes off and drilled through the holes in the metal strip and the metal pan and held the strips in place with pop rivetts.
I'm just about to make another seat for another project bike so I will take some pics of the underneath so you can see what it looks like.
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Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Underdog1

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Re: Bitsa Project
« Reply #34 on: May 28, 2018, 08:56:09 PM »
I used re constituted foam, 1" thick and stuck 2 together with HD spray glue. Easy to cut to shape and sculpt with an electric carving knife. After I made the vinyl cover, I stretched it over the metal base Trig made for me and pulled the cover really tight and held it in place with that silver carpet tape. We then used this metal upholstery strip but cut the spikes off and drilled through the holes in the metal strip and the metal pan and held the strips in place with pop rivetts.
I'm just about to make another seat for another project bike so I will take some pics of the underneath so you can see what it looks like.
(Attachment Link)

(Attachment Link)

Nice that’s a massive help!

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: Bitsa Project
« Reply #35 on: June 28, 2018, 04:30:49 PM »
Photos for Phil (Underdog1) of how I made the seat.

The base is 3mm steel, powder coated, with air holed drilled and bolts welded on. Bent to shape at the end to same profile as upswept hoop on bike. A trim of plastic stuck around the edge to stop it cutting into the vinyl covering.

Stuck 2 pieces if 1" foam together with spray glue, drew around the metal base and roughly cut foam to shape with bread knife and then did fine trimming with electric carving knife. Covered foam in a heavy cotton as not sure if foam would hold together after quite a bit of use.

Temporarily stuck foam to seat pan with tape and then made the cover out of vinyl. Heavy duty non stretch for the top and lighter weight with some stretch for the sides.

Put cover on and pulled it as tight as I could, making sure all the seams on the cover were in the right places,and stuck down with tape to hold in place.

Used this metal upholsters fixing strip, which comes with spikes attached but cut and ground the spikes off. Drilled down through the holes in the strip, the vinyl and the steel pan and pop riveted the strip in place, making sure the vinyl was still stretched. Remove tape and cut off excess vinyl.

The last pic shows it in situ but not with the nuts done up yet in the underside if the fixing plate. This is on a work in progress bitsa CB750.

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« Last Edit: June 28, 2018, 04:42:55 PM by Nurse Julie »
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
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Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: Bitsa Project
« Reply #36 on: June 28, 2018, 04:33:22 PM »
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Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Underdog1

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Re: Bitsa Project
« Reply #37 on: June 28, 2018, 06:09:50 PM »
Photos for Phil (Underdog1) of how I made the seat
Nice one Julie! Had my seatpan powder coated recently, I’ve welded nuts on the seatpan rather than bolts but looks similar. Good to see how you fastened then cover down as that was what I was still trying to figure out :)

I’ve not drilled any large diameter holes in the bottom for air, going to try without at first as I think there might be enough air gaps between the rivers etc. Can always add at a later date with my bench drill if it doesn’t ‘reinflate’ very well
« Last Edit: June 28, 2018, 06:13:17 PM by Underdog1 »

Offline Nurse Julie

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Re: Bitsa Project
« Reply #38 on: June 28, 2018, 06:16:52 PM »
With both this seat and mine it was the only way we could think of attaching the seat to the flat cross bar thingy. Doing it this way just means we can put wing nuts and washers on from underneath, which we thought was less fiddly than trying to get a bolt up through a blind hole. The front of our seat pans lock in under where the tank mounting rubber goes so doesn't need any other fixings there. Your way will work just as well I'm sure.
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Tomb

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Re: Bitsa Project
« Reply #39 on: July 11, 2018, 01:58:48 PM »
Nice work on the seat.

I've been doing seats for years and found an angle grinder with worn out flap wheel very useful for shaping (very gently), more rounded edges can be achieved. Also for smoothing out the dimple effect of the reconstituted foam being visible through the cover I use upholsterers wadding (click) before the vinyl cover.
There are usually 3 different grades of density of the reconstituted foam, I use the middle one.

And Julie SHHHH! I don't want everyone knowing I ride a Yamaha
Tom
'73 CB550 with CB500 engine café racer
'62 CB77 Sprinter
'70 CD175
'78 CB550 with sidecar
'80 Z50R
And a load of old Yamaha 1100's