81 CB900c project in Virginia Beach

81 CB900c project in Virginia Beach

Hello all,
I’m new to the site but not to fabrication. Thought I would share what I have been working on, it is an 81 CB900C. I do understand that it’s a heavier bike and harder to modify. I have had the bike for some time and I wanted to do something different so I got inspiration from the café world. This is what I started with.



This is the rolling frame with the seat pan I made.



Here are a couple of pics that show the steps and the current condition of the seat pan. In the one pic you can see the side plates that I had not make yet in the above pic.



Side plate



Current condition



Here is a shot of the frame waiting for the motor to come back from the shop. I’m getting new rings and the head redone. After reading the post about CV Carbs and air filters I will be using the stock air box without the chrome side plates.



I hope to have the motor back by mid-December so the week I have off between Christmas and New Years I can dedicate to reassembly as much as I can. I hope you appreciate my work.

Looking good, did you get anywhere with your friend's 'mystery' Yamaha?

Thank you and no I have not got back with him. It was such an odd description I wanted to look into it.
I would like to get the bike some day but I have 2 apart in my garage all ready. My wife would kill me if I brought another one home. So it may need to sit in his garage for a while longer.

I fully understand the 'wife' issue! I have 2 in the garage at the moment and she has threatened any more and it will be them or her.........oh, the temptation!!  

morning, looking good so far.

i'm with Paul on the wife issue too.

that said, i'm selling one of the car projects in the drive to get her back on side.

it seems bikes hidden in a garage don't bother her as much as cars she has to walk past everyday. 

I understand the car thing too. I have a car project that I put on hold to start working on this one. I would rather work in the garage in the cold months. I always have several projects working at the same time, drives her crazy.

While I’m waiting for the motor to get done I have finished the fiber glassing on the seat pan. This was my first attend at making anything this size and looking back I would have done it differently. When I started the seat pan I had a basic idea what I wanted but you know how it goes you change your mind about this it changes that. Needless to say I have reworked it several times. So now I have the final fit and finish then it should be ready for paint, I hope.



Here are some of the smaller pieces that are ready for paint. I will see how well the chrome pieces buff up. If they look good I will leave them, if not they will get painted as well. I’m using black handlebars and mirrors that leaves the fenders. I think the back will clean up nice. The front will clean up as well but I’m not sure I’ll use the stock fender or even have a front fender.
Gauges



Indicators



More to follow.

Well the holiday is behind me and I got some free time. I got the motor back from the shop before Christmas and I got a chance to get it in the frame today. It was the only thing I had to have a second pair of hands for. Below is a pic. I hope to get the final drive, rear tire, and front end on tomorrow. Then I can mess with my Xmas gifts. Set of black clubmen bars, new head light bracket, and tail light.




More to come

Will I got some time and now I have a rolling frame. Once I put the pieces and parts together it’s starting to look like a bike again. Next I need to give the carbs a good cleaning and get them ready to go back on. I plan on doing something different with the front fender, ether a smaller one or just a strap.

Well this is what I looks like now.




More to come

I went through the front end and started reassembly everything this weekend and also starting to put the Xmas presents to use. The new head light bracket allowed me to lower the head light on the tubes. Then I plan on lowering the gauges 3” to fill in the space. I was not going to use turn signals at first then thought to avoid any legal issue I put them back on. Conveniently the new bracket already had holes to mount the new front signals. The new tail light is an all in one so I don’t need to mount anything else on the back. Now that all the major piece are in place I can run the wiring harness.  

Here’s a quick pic of the front.




more to follow

I said before I needed to lower the gauges and this is how it went. I stated with the stock bracket that looked look this




Then I made it look like  this with a grinder and a welder





These are some test fit pics of the work over this weekend










It starting to look like something. At least to me.




More to come

Looking good!

I finally got back in the gauge to sort out the wiring harness. After moving things around to get the clearances I wanted and keeping the parts to avoid legal problems I was able to reuse the stock harness without needing to shorten or lengthen anything. I did need to rewrap a good bit of the harness because things weren’t in the same place and you are only going to bend it so much. The new tail light is an all in one with turn signals so it has a 5 wires the same as stock, now I don’t need to worry about mounting anything else on the back of the bike. I don’t have any pics this time because no matter how much time you put into wiring when you stand back and look it still looks the same. Now I need it to warm up enough to do bodywork and paint.

Well I got a chance to work on the carbs today. There wasn’t anything wrong that a good cleaning didn’t take care of. I did need to cut off one screw that did not want to come out then I stripped out the Philips head. I used a dermal with a cutting wheel and took the head off.








Tomorrow I hope to get the exhaust on. More to come.

Well the weather eased up and I got a chance to put the exhaust on the bike and I can say that it was the single largest pain in the ass of the project so far. A second set of hands would have probably help but I got it on any. I get to work on the breaks next.  Then I need the weather to heat up so I can do body work and paint.





More to come

Well I finally found some time between bad weather, work, and family to get a little done work on the bike. It warmed up enough to do a little painting so I did the small pieces that I had ready and the air box.










I needed the air box so I could mount the carbs that I had to do twice. I found out that I needed to connect the throttle and choke cables before the carbs are mounted or you can’t get to them.

Something good to remember for next time.





I got the front brakes sorted out but I still have the bake to work on and the seat pan is in the finale steps before paint. The tank still needs prepped for paint and some other odds and ends need to be addressed but I can see light at the end of the tunnel.

The end is near.

More to come

yeh looking good mate you've made a good job of the single seat aswell   i'll be doing a similar thing with a fiberglass single seat too but never done it before, did you make a mould first and just lay it over the top ? you also said you'd do it differently next time . any tips for when I get that far (when I get that far !  )

Well first I used the bike it’s self as the template. I put the parts on that the seat pan would touch,. Then I covered the area with blue painters tape. I fabricated the mounting points out of some stainless steel that I had. I covered everything with aluminum tape then with turtle wax as a release agent.






I put a layer fiberglass down first so the bottom of the seat pan would be sealed. I then put all the parts in place and fiberglassed over then. And continued until I had everything covered how I liked it.




Because I used a Sharpie before I put the fiber on when the fiberglass set up the line transferred to the fiberglass so I had my shape.

What I would do different is remember less is more. What I mean is when I started I used large pieces of cloth and I mixed large amounts of resin thinking I could cover a large area quickly. Well that turned into a race with time. The large pieces of cloth made it tough to keep it were I wanted it and the resin was setting up faster than I could use it. I would use larger pieces of fiber if the area is flat or close to it and small pieces around compound shapes. 2 ounces of resin seems to be the best amount to work with. I thought if I used small pieces I would see where the edges are but that was not correct. I got some plastic cups and a lot of cheap paint brushes because I used 1 brush per batch. I found where 2 ounces came up to in the cup so I could get the same amount every time.

I hope this answers your question and let me know if you have any more.

Let me clarify one thing. When I said I first used large pieces of cloth, it was one piece that went from the front to the back trying to go around all the shapes of the seat pan at one time. I would not do that again.

cheers :)helpful info for sure and will revisit this post when I do mine. 'the race against time' sounds like a panic for you and fun for the spectators   

va-bch-chop wrote:

Let me clarify one thing. When I said I first used large pieces of cloth, it was one piece that went from the front to the back trying to go around all the shapes of the seat pan at one time. I would not do that again.

Yep, if you're using chopped strand mat rather than the woven stuff it has this horrible tendency to 'un-peel' and form air pockets when you're not looking! I would strongly advocate anyone trying to fabricate with glassfibre to follow va-bch-chop's advice and use small pieces for complex angles, I use light woven mat which can be cut to shape then finish with a couple of layers of tissue, unless of course you're working with a mould, then it's coloured resin in first followed by well soaked tissue and then the heavy mat to give it substance.

Well the weekend was nice and I got a chance to do some body work. I have the seat pan ready for the final sanding of the primer then I can put some color on it. I was well on the way with the tank until it slipped and created more body work. I was trying to decide to use the Honda emblems or shave them off, I’m saving them off now. I hammered everything down as much as I could then I used some fiberglass filings that I saved from making the seat pan and the tail light housing with some reason to fill in and build up. Once it sets up I will sand it down and use body filler to make it smooth.
More to come.

I recovered from my mishap with the tank and I am almost ready for color. I didn’t take a picture of the dent because when it happened I started fixing it immediately, but here is one after the repair.





Here are a couple of pic of the tank and the seat pan that need final sanding and then paint.








My progress has been hampered this last week with my wife wanted to redo the bedroom. You know it’s spring and that when my wife likes to decorate. It’s always a challenge to balance garage time and honey do time.


More to come

done a good job of the repair there matey

Had a nice weekend so I tried to get some painting done and like other parts of this build we had a learning curve.  First I built a better stand for the tank to sit on and then I made a paint booth with a halogen work light. Trying to keep the elements out as best I could and the light keeps it nice and warm. The reason I needed to build this is I’m making the wife happy by redoing part of the house and I have had contractors at my house for a week and they took over part of the garage for materials. Like I said all to make the wife happy.





I made a mistake and had to sand down the first attempt on the tank.





But I got a decent coat on the tank on the second attempt. There is a spot on the back of the tank that I need to fix but I’m going to put blue over it anyway. I plan on having the blue on the flat sides of the tank as well as a little on the top.






The seat pan came out ok I didn’t need to start over like I did on the tank but there are some runs I need to fix. I’m letting everything get nice and dry then I will fix the bad spots on both peace’s then put a second coat on and if everything goes well I can put some clear on seat pan and the blue on the tank.





Well at least I can see light ate the end of the tunnel and hopefully I will be done soon.


More to come.