CBX Frame material

Land_Shark · Post by **Land_Shark** » Mon Mar 17, 2003 4:02 pm

Can anyone tell me specifically what the '79 frame is made of? I remember reading somewhere it was more than simply a steel frame.

EMS · Post by **EMS** » Mon Mar 17, 2003 9:15 pm

The frame is/was a diamond-type, tubular chrome-molybdenium steel frame with the engine as a structural member. Chrome-moly steel frames are nothing special, though. It is also sometimes referred to as "mild steel"

John S. (5594) · Post by **John S. (5594)** » Mon Mar 17, 2003 11:47 pm

I believe that EMS is correct on the CBX frame tubing material - I recall reading that Honda used chrome moly (4130 CroMo). The primary advantage that CroMo tubing offers over mild steel is strength. In example - a motorcycle frame made of mild steel would weigh ~40% more than one of equal strength made with CroMo (which would have a thinner tubing wall thickness).

The one comparative disadvantage of CroMo tubing is the welding requirement. Inert gas welding (TIG or MIG) is generally needed for CroMo frames. The welded frames (while still in the assembly fixture or "jig") were sometimes moved into an oven to "normalize" the material and to prevent brittleness in or adjacent to the welds. Without this process - the grain formations from welding could allow the frame to break.

I have seen mechanics use a gas tourch to accomplish this process after repairing a CroMo frame. But if extensive repair is required in an area such as a steering head - a fixture of some sort might be required to retain dimensional integrity.

Not a metallurgist or welder myself - these are just my observations from years past watching tuners repair tweaked CroMo motocross and dirt track frames - some of them mine :)

All the best,

John
San Jose, California

Guest · Post by **Guest** » Mon Mar 17, 2003 11:53 pm

So it's safe to say it can easily be polished?

John S. (5594) · Post by **John S. (5594)** » Tue Mar 18, 2003 12:10 am

Polishing alone should be no problem. Untreated - the polished frame will rust though - you may consider a clear coat of some type to prevent this (a bit more expensive - nickle plating looks sharp on some of the dirt track frames I have seen).

If the frame does need to be repaired/ welded - I would recommend taking it to someone experienced with chrome moly motorcycle frames.

Cheers,

John

EMS · Post by **EMS** » Tue Mar 18, 2003 8:11 am

Yes, it can be polished. Although you may not get the chrome-like luster you would achieve with stainless steel. And then there is, like John says, the corrosion problem. Also, polishing a small diameter tube frame is quite an effort. Have you considered powder coating it ? Maybe in a different color than black?

Land_Shark · Post by **Land_Shark** » Tue Mar 18, 2003 2:37 pm

Actually powder-coating was my first choice - until I saw one of the moto-martins with the chrome frame. I'm considering all three and will probably clear-coat over whatever I decide to do.
Thanks for the input

Jeff Bennetts · Post by **Jeff Bennetts** » Wed Mar 19, 2003 8:22 am

Land_Shark wrote:Actually powder-coating was my first choice - until I saw one of the moto-martins with the chrome frame. I'm considering all three and will probably clear-coat over whatever I decide to do.
Thanks for the input

How about HPC, they have the polished Alum finish and it is chemical resistent and can bare temps to 600 deg.

I'm working with a rep from HPC as speak to try and get a discount for all ICOA members,but it may take another month or so to finalize and I'm not making any promises just yet.

http://www.hpcoatings.com/

Jeff Bennetts ICOA #1111

The International CBX Owners Association

CBX Frame material

CBX Frame material

CBX Frame

Chrome Moly Frame Tubing

to Polish?

Polishing the frame

Frame Polish

coatings