Honda CX 500 Forum banner
1 - 20 of 35 Posts

·
Registered
2005 BMW R1200GS, 2003 Yamaha V-Star 1100, 2000 DRZ400, 1986 Honda Z50R, 1978 CX500
Joined
·
19 Posts
Discussion Starter · #1 · (Edited)
Tire Wheel Fuel tank Automotive fuel system Vehicle



Hello! This is my very first post here, hailing from Boise, Idaho. My name is Alex, I'm an engineer who runs a firearms manufacturing business. I have always been a fan of everything on two wheels. I find motorcycles are like puppies. I want to adopt every single one of them.

This is my first attempt at a build like this. I'm sure I will have a lot of questions. I jumped into this rather quickly. My most recent project was a refresh/rebuild of my DRZ400. You can see the progress of that build here.


Before that my son and I restored/refreshed a PW80.


Soon after a friend took note and showed up at my shop with a Yamaha XS850. He wanted to do a cross between a bobber and a cafe racer, but as time goes on the bike keeps sitting and I'm having doubts if we will ever actually get to it. It's a neat project, but I think I want to go a bit "deeper" into something than he does so I decided it was maybe time to get something for myself.

Wheel Tire Land vehicle Fuel tank Automotive fuel system


I have always been a fan of the CX500. I remember the first time I really looked at one. Pretty sure it was in stock form, but the transverse (is that the right word?) V-twin really spoke to me. I also really like how self contained the engine is. The engine doesn't rely on the frame to do a lot of things, if that makes any sense. Anyways, I knew if I did one of these it would be a CX500, not realizing that there is actually a huge following for them.

As it just so happens there is one on Facebook Market Place. Here is the ad:

Font Screenshot Multimedia Electronic device Software


I showed up on my V-Star along with another buddy and took a look.
Tire Fuel tank Wheel Plant Vehicle


Wheel Tire Vehicle Motor vehicle Automotive tire

Tire Wheel Land vehicle Plant Vehicle


Tire Wheel Plant Bicycle tire Automotive tire



Plant Motor vehicle Automotive tire Automotive lighting Tire


I offered him $1000, and he said no, let's do $900. And here we are.

Plant Blue Tree Automotive tire Road surface



Tire Wheel Fuel tank Automotive fuel system Vehicle


Anyways, Cheers, and here's to a new adventure.
 

·
Premium Member
1978 CX500 "The Grub", 1983 GL650I "Nimbus"
Joined
·
12,263 Posts
Welcome aboard.
That monoshock conversion may or may not have been done safely. I'd take a close look at it.
 
  • Like
Reactions: crane550

·
Registered
2005 BMW R1200GS, 2003 Yamaha V-Star 1100, 2000 DRZ400, 1986 Honda Z50R, 1978 CX500
Joined
·
19 Posts
Discussion Starter · #3 ·
Welcome aboard.
That monoshock conversion may or may not have been done safely. I'd take a close look at it.
Was just about to ask about this. I see there are several ways to do it. Anything in particular I should look out for?
 

·
Premium Member
1978 CX500 "The Grub", 1983 GL650I "Nimbus"
Joined
·
12,263 Posts
The swing arm wasn't designed to take a load where the new shock mount is attached. That surface should be reinforced. No one knows what the real loads will be, so over build it.
Also, I think the new shock mount is excessively long. I'd make that as short as possible to minimize the lever applying twisting moment to that attachment.
 
  • Like
Reactions: crane550

·
Registered
2005 BMW R1200GS, 2003 Yamaha V-Star 1100, 2000 DRZ400, 1986 Honda Z50R, 1978 CX500
Joined
·
19 Posts
Discussion Starter · #5 ·
Now comes the hard part, which is deciding which direction I would like to go. Obviously it's already headed in more of a scrambler direction. I tend to like this, and might just keep with it. It will probably have some pretty strong cafe racer aspects to it however. I have looked at a lot of builds in the last few days, and have found some that I really like. Basically I might steal little ideas for each and try to make this build my own. Imitation is the best form of flattery, 'amaright?

I'm sure just about everyone has seen this build before, but I really do like how clean it is. I like the rear disc conversion, and how the front forks really pop. I also like the painted engine with the heat fins grinded down to be shiny. The way the rear fender extends on this one is pretty sweet as well, tho I would make it match the tank. Very curious about what seat they used, or if it was a custom job. And this is probably my favorite exhaust I have seen, although not really a scrambler type. Hence, I might be going a hybrid.

Tire Wheel Fuel tank Automotive fuel system Vehicle


I like how the frame and coolant tube are a bright color on this build. Of course I am already thinking about color palettes at this point (how could I not) but that's getting a bit ahead of myself. It's an idea to be thinking about going forward.

Tire Wheel Land vehicle Fuel tank Vehicle


This is another build that has caught my eye. I like the color scheme on it. (Not the palette, but the scheme). I could also see myself doing the rear fender/seat along these lines as well.
Tire Wheel Vehicle Fuel tank Sky


More to come.

Lastly (for now) there is this one. I actually personally know the gentleman who did this build. I like how the engine and tank match up, although I probably won't replicate this. But it is a fun build I thought was worth showing. The more I think about it the more I think I need to go with some sort of aftermarket shocks for the front.

Tire Wheel Land vehicle Fuel tank Vehicle


I see there are two different frame types here. The first is different than the next three. Any insight on this? Clearly I'm stuck with the first design.
 

·
Registered
2005 BMW R1200GS, 2003 Yamaha V-Star 1100, 2000 DRZ400, 1986 Honda Z50R, 1978 CX500
Joined
·
19 Posts
Discussion Starter · #6 ·
The swing arm wasn't designed to take a load where the new shock mount is attached. That surface should be reinforced. No one knows what the real loads will be, so over build it.
Also, I think the new shock mount is excessively long. I'd make that as short as possible to minimize the lever applying twisting moment to that attachment.
Looking at this with my engineer brain I see your point and was thinking those things as well. The plate it mounts to is pretty thick, and the mount widens towards the bottom which will help with spreading out the load. I would be much more concerned with how removing the dual shocks which attach near the tire center line forces those members to become a cantilever beam than the point load there the shock mount is welded. Looking through other builds I don't see a lot of people addressing that or having issues with it. Since the shock is in compression I'm more at ease with it. The point at the top where the shock mounts to the frame is more of a concern for me.

Thanks for pointing this out. I will give it a more critical look over.
 

·
Registered
1982 cx500tc turbo
Joined
·
166 Posts
Hi
Welcome to the board
Have a look at BJ from brick house build YouTube channel
He has done one and it's done right His work is beautiful
I just picked up a 1981 GL500 and that's my plan to do a cafe bike out of that one
It has a pro link mono shock all ready and that makes it easy to do and a better ride

The cafe bike has to wait
Have to finish the CX500TC Patina Resurrection project first

TLD 🇨🇦 🇩🇰
 

·
Registered
2005 BMW R1200GS, 2003 Yamaha V-Star 1100, 2000 DRZ400, 1986 Honda Z50R, 1978 CX500
Joined
·
19 Posts
Discussion Starter · #8 ·
Have a look at BJ from brick house build YouTube channel
He has done one and it's done right His work is beautiful
Just starting the intro video, but it looks like there will be some fantastic info on this one. Thanks for the recommend.

I am considering purchasing a complete front end off of a Buell X1 Lightening, year 2000. The guy who sold me the project has a line on a complete bike. He wants the engine. For $500 I can have the ENTIRE front end. I just might do it. Thoughts on using Buell shocks, rotors, calipers, controls, etc? I think in 2000 Buells hand controls would pretty much be standard wiring. Of course I will need to cut connectors, but I'm thinking I might be able to get a lot of what I need for $500. Worst case I can part out the stuff and get my money back.

I don't know the the parts are metric or not. It would but me having SAE parts on this bike.
 

·
Registered
1982 Honda GL500 2002 BMW R1150R
Joined
·
37 Posts
I'll have my garage cleared out for work as soon as I get the roofing and remodel project finished. The bike is crusty but has only 5K miles on the engine and was free. I've ran the engine, sounds like new amazingly enough. Still in the process of imagining what I want the bike to look like so here I am in this thread looking at all the builds. Meanwhile I finally fixed my BMW R110R's fuel injection system and it's totally smoothed out the cruise so I'm loving the f-ck out of that right now.
 

·
Registered
2005 BMW R1200GS, 2003 Yamaha V-Star 1100, 2000 DRZ400, 1986 Honda Z50R, 1978 CX500
Joined
·
19 Posts
Discussion Starter · #13 ·
This may be a silly question- but how tall do these bikes naturally sit? I'm a bit under 5'8" with short stubby legs. I would like to be mostly flat footed on this build. I'm musing some ideas and just want to get a general understanding of the natural ergonomics of the bike.

Been sitting here on the computer tonight planning the future, and I think it's starting to come together, at least in my brain.

Current thought pattern:

1. Engine needs to be level from the get-go. This probably means I need to do the front forks first, so I can get the bike level with the front tire. I'm currently seeking the donor forks, but I have a couple of requirements. First- I want to use the stock wheels. I like them. I like how they are modular, and like the aesthetic of them. So even tho I'm wanting new forks and dual disc's up front I'm gunna have to find a way. This is a solvable problem, and I found this video very helpful in understanding this step.


2. I agree that the monoshock needs to be redone. In fact, I will probably replace the shock as well. If someone can recommend a good one I'm all ears. As for the frame-I have plans. First, I need to say something- I can't weld worth a crap. I have friends who can do a bit better. I can make two pieces of metal stick together and be semi-straight. I am, however, a decent machinist. As it so happens I have a firearms manufacturing company, and the a vertical mill that is mine-all-mine. Maybe this will be a hint at the direction I'm thinking.

3. Here is where my shortness comes in to play. I'm thinking I will want to tilt the tank forward by raising it in the rear considerably. Since this has already been messed with on this particular bike, I'm not sure what my starting baseline is here. If I raise the tank the seat needs to come up higher as well. This actually works to an advantage for my frame plans, but I want to make sure I don't build this too tall. I'm wondering how much an extra inch to inch and a half will make a difference.

I'm very concerned with getting the line of the seat and tank straight as an arrow, with the angle sloping down towards the front.

Tire Wheel Fuel tank Vehicle Motorcycle



4. Seat. I have ideas. Hopefully they are good ones. Will worry about this when the time comes.

5. Talk to be about electrical. I plan to make my harness completely from scratch, but need to know what's best to toss and buy aftermarket and whats best to keep. This world is new to me, so any good tips on where to start looking?

Fun fun!
 

·
Super Moderator
Joined
·
5,800 Posts
In your imagineering pay some attention to driveshaft angle. The U-joint will wear faster if the angle gets too large.
See posts in this thread low rider for example.
 
  • Like
Reactions: crane550

·
Registered
2005 BMW R1200GS, 2003 Yamaha V-Star 1100, 2000 DRZ400, 1986 Honda Z50R, 1978 CX500
Joined
·
19 Posts
Discussion Starter · #16 ·
In your imagineering pay some attention to driveshaft angle. The U-joint will wear faster if the angle gets too large.
See posts in this thread low rider for example.
Yes, indeed. I will be adding a bit, but probably not much. Remember, the same effect can be achieved by lowering the front. I'm not looking for a big angle on that swing arm.

In the picture you can see that the rake of the engine (yellow) and the rake of the tank/seat (red) are just about parallel. I think I want to shoot for this, or perhaps even add a bit of downward rake for aggressiveness.

Note that the picture (brilliantly edited by me in MS Paint) indicates that the picture is slightly rotated counter clockwise, as evidenced by the purple line sloping upwards. Green is to approximate the wheelbase line, and from the looks of it, since it's parallel to the purple line I think the bike in this picture has the same sized front and rear tire. As for my wheels, I have a 19 on the front and 18 in the rear. What I don't know is what my diameter with the tire itself is. I need to check that.

Tire Wheel Fuel tank Vehicle Motorcycle


Ideally what I think I will be shooting for is green and yellow parallel. Then I check to see where blue/green is and make sure it's an appropriate angle. Once this is set, red will be parallel or better yet raked slightly down for a more aggressive look, permitting this doesn't mean too much seat height.

I put this image into a bit more sophisticated image editor and made the purple line horizontal. The dotted lines are also perfectly horizontal.

Wheel Tire Fuel tank Motorcycle Automotive tire
 

·
Premium Member
1978 CX500 "The Grub", 1983 GL650I "Nimbus"
Joined
·
12,263 Posts
Once this is set, red will be parallel or better yet raked slightly down for a more aggressive look,...
Remember, fuel will flow to the lowest point in the tank. If you pitch the tank forward, the petcock will be at the high end.
Of course, if you're only building this to be looked at, that won't matter.
 

·
Registered
2005 BMW R1200GS, 2003 Yamaha V-Star 1100, 2000 DRZ400, 1986 Honda Z50R, 1978 CX500
Joined
·
19 Posts
Discussion Starter · #18 ·
Remember, fuel will flow to the lowest point in the tank. If you pitch the tank forward, the petcock will be at the high end.
Of course, if you're only building this to be looked at, that won't matter.
Good point. Hopefully the extreme acceleration forward will overcome the slight downward slope, pushing the gas to the rear. Plus I typically wheelie just about everywhere I go! Haha!

I don't build anything just to be looked at. In fact, I have a personal distaste for things that are solely decorative. I love where form meets function. I work on motorcycles so I can ride them. Each bike I have has is ridden differently, and I thoroughly enjoy each one in it's own way. Some are comfortable. Some are exciting. Some just sound and feel fun.

At this point I haven't done a single modification to this bike. But boy it looks good.

The grinder is coming out soon. Stay tuned.

Wheel Tire Land vehicle Fuel tank Automotive fuel system
 
1 - 20 of 35 Posts
Top