1981 CB650C Cafe Racer Project

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VII
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Re: 1981 CB650C Cafe Racer Project

Postby VII » Mon Apr 16, 2012 1:43 am

Figured I should post a little update. It has been slow going with this project as I have had a handful of other bikes come and go since I started with this one.

Still never had the tire mounted or painted the rear wheel but I did finish my initial polishing of the rim. Tire to finally go on by the end of this week.

Couple other things messed with:

-exhaust painted satin black, baffles removed
-exhaust hangers currently being polished
-exhaust wrapped
-cbr900rr brake master
-black aluminum/rubber grips
-new push/pull throttle (no more right hand controls)
-new smaller left side controls (horn push is now engine start)
-removed turn singal wiring from harness
-Rear loop cut from a KZ650 and almost ready to be welded to the rear of my frame
-Painted rear shock cover oil rubbed bronze
-Front fender cut (I won't be using my pedestrian slicer)


I'll get some picks up within a week or so when I finally get the exhaust back on and the rear wheel done. Once the rear wheel goes on I'll be able to figure out how I will attach my rear hugger to the swingarm.

VII
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Re: 1981 CB650C Cafe Racer Project

Postby VII » Mon Apr 16, 2012 10:04 pm

A few pics:

My "workshop" is a little messy at the moment. Just enough room to pull one of our cars in. The other half of the garage has a couple other bikes, one of my cars and other junk.
Image


Here you can see the new top tubes. Used 7/8 piping with a tube cut down to fit perfectly inside both tubes to strengthen everything up. It all still needs to be welded and some final grinding/prep done.
Image


Here's the seat pan that will be under the fiberglass seat and spot welded to the frame tubes. The wiring will run through the hole at the front.
Image


Seat pan, with the modified rear fender cut to meet the seat pan. Also shown is the KZ frame loop almost ready to be welded to the rear of the frame.
Image

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Volker_P
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Re: 1981 CB650C Cafe Racer Project

Postby Volker_P » Tue Apr 17, 2012 1:12 am

Quite much effort for a minor frame modification.
Of course it means a change of the lines, however with regard to the reduced diameter of the intermediate tubes, will it be visible at all?
Or just done for yourself to know it's there?
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

VII
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Re: 1981 CB650C Cafe Racer Project

Postby VII » Tue Apr 17, 2012 5:04 pm

Volker_P wrote:Quite much effort for a minor frame modification.
Of course it means a change of the lines, however with regard to the reduced diameter of the intermediate tubes, will it be visible at all?
Or just done for yourself to know it's there?


I agree it's a lot of work; more than I was hoping. I've seen several 650 cafes with the angled rear tubes and it just looks awful. There are so many bikes out there claiming to be cafe racers with just clubmans and a cheap fiberglass seat; a real build requires effort. I'm not saying I'll acheive the best possible outcome but I'm doing my best.

As far as the tubing goes; it's the same size. I thought it was 7/8" but I guess it's 1". Once it's all welded together and smoothed out, you shouldn't be able to tell the frame was modified (hopefully).

cb650
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Re: 1981 CB650C Cafe Racer Project

Postby cb650 » Tue Apr 17, 2012 10:10 pm

You should have started with a 79 frame.
Did you clean the tank out?!?!?!?!

VII
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Re: 1981 CB650C Cafe Racer Project

Postby VII » Tue Apr 17, 2012 10:17 pm

cb650 wrote:You should have started with a 79 frame.


We already went over this; read the apprpriate post.

cb650
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Re: 1981 CB650C Cafe Racer Project

Postby cb650 » Tue Apr 17, 2012 10:23 pm

OK I just seconded the first post . :lol:
Did you clean the tank out?!?!?!?!

VII
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Re: 1981 CB650C Cafe Racer Project

Postby VII » Tue Apr 17, 2012 10:34 pm

I suspect those that respond with similar comments are not resourceful enough to build a bike correctly. Cutting, bending, a little lathe work, welding, etc would be enough to prevent some from such a task but then again, it is those same people that do not build noteworthy bikes.

cb650
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Re: 1981 CB650C Cafe Racer Project

Postby cb650 » Wed Apr 18, 2012 12:46 am

Wow another touchy one. I'll leave the building to those of you with superior knowledge. This will be my last comment goodbye
Did you clean the tank out?!?!?!?!

VII
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Re: 1981 CB650C Cafe Racer Project

Postby VII » Wed Apr 18, 2012 1:37 am

cb650 wrote:Wow another touchy one. I'll leave the building to those of you with superior knowledge. This will be my last comment goodbye


Your comment of "you should have started with a 79 frame" when it has obviously already been stated demonstrates that you have nothing constructive to say. This is the bike I have and I can easily modify it to work as shown. Your statement is irrelevant and ignorant. If, in the future, you have an appropriate comment to post, I fully encourage you to do so. For now, I have no issues with you finding something else to occupy your time. :wink:

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Volker_P
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Re: 1981 CB650C Cafe Racer Project

Postby Volker_P » Wed Apr 18, 2012 2:07 am

VII wrote:As far as the tubing goes; it's the same size. I thought it was 7/8" but I guess it's 1". Once it's all welded together and smoothed out, you shouldn't be able to tell the frame was modified (hopefully).

All right, a straight frame line there is something more or less expected for a cafe bike. :wink:
You may smoothen possible welding traces with solder in a final step. This should help to get invisible seams.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

VII
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Re: 1981 CB650C Cafe Racer Project

Postby VII » Thu Apr 19, 2012 12:03 am

Volker_P wrote:You may smoothen possible welding traces with solder in a final step. This should help to get invisible seams.


I had not heard of the solder idea; very interesting. I'll have to give it a shot.

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Volker_P
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Re: 1981 CB650C Cafe Racer Project

Postby Volker_P » Thu Apr 19, 2012 12:57 am

Typically used in carriage repair for historic cars and maybe already a bit anachronistic.
Sorry, I only found a German link: http://www.auto-portal.org/verzinnen.html
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

VII
Posts: 44
Joined: Tue Oct 18, 2011 4:47 pm

Re: 1981 CB650C Cafe Racer Project

Postby VII » Mon Apr 23, 2012 10:14 pm

I was productive today.

-Mounted and balanced the new spitfire tire on the rear wheel.
-Welded the new top tubes
-Filled in the holes in the frame where the old tubes mounted
-attached the rear kz hoop

Still lots of grinding and such to do but for my first time welding, it came out ok.
Image

Rear hoop fits pretty well so far.
Image

New tire on wheel. In this and the other pictures you can see the rough fitment of the rear hugger.
Image

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Volker_P
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Re: 1981 CB650C Cafe Racer Project

Postby Volker_P » Tue Apr 24, 2012 2:01 am

Good progress.
Looks all right as it is now, but if you would insert the rear axle, the wheel will get a good part higher. Might come close to the rear frame, at least with the weak stock shocks.
If you plan no modifications here (I would consider to lift the rear a bit not only for that), better check out before you try it out unintentionally on a bump on the road.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum


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