Oh, I thought you cut the cross brace off from between the top of the rear shocks and welded a hoop thingy on the rear part of the frame right next to the frames shock mounts.
Introduction - Cam'run_1776
Hello, all:
I am a Maryland resident currently working on building a cafe racer out of a 1982 CB750K and 1981 CB750C. This is my first build and I'm a new rider, so although I generally work through the process on my own, I'm hoping to use this site to avoid stylistic or mechanical oversights on account of inexperience. I bought the 1981 CB750C first, then bought the 1982 CB750K after realizing it was an easier starting point (confirming what I read on this site).
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I am a Maryland resident currently working on building a cafe racer out of a 1982 CB750K and 1981 CB750C. This is my first build and I'm a new rider, so although I generally work through the process on my own, I'm hoping to use this site to avoid stylistic or mechanical oversights on account of inexperience. I bought the 1981 CB750C first, then bought the 1982 CB750K after realizing it was an easier starting point (confirming what I read on this site).
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No, that cross bar thing was already cut off when I bought the bike. But that is more for securing the rear fender than anything else, anyways.Oh, I thought you cut the cross brace off from between the top of the rear shocks and welded a hoop thingy on the rear part of the frame right next to the frames shock mounts.
Oh is that right, I did not know that. Well it's a good thing that section of the frame does not require structural integrity.No, that cross bar thing was already cut off when I bought the bike. But that is more for securing the rear fender than anything else, anyways.
... have you ever ridden a heavy motorcycle hard enough to actually feel the frame flex? I have, it's scary.
No, that was structural. If it were just for attaching the fender it would have been flat narrow steel rather than the formed.No, that cross bar thing was already cut off when I bought the bike. But that is more for securing the rear fender than anything else, anyways.
That cross bar ties the two rear shock mounts together. Without it, the frame will go all trapezoid when turning
It seems too thin to do much structurally, but I may be wrong. I haven’t put much thought into it because by the time I bought the second bike and realized that was even there, I had already welded a thick steel L bar across in that area. Sounds like that is more important than I thought so I’ll look into it further and beef it up.No, that was structural. If it were just for attaching the fender it would have been flat narrow steel rather than the formed.
I did the test with the shocks from the 750k and found that the tire radius (of the 750k wheel with moderate tread wear) was 5/8” too much. In other words, the rear hoop would need to be moved 5/8 inches to prevent contact.It won't pass the ratchet strap test, you don't even need to try it.
Don't know what the cowl is, unless you're talking sleds but, carry on with your personal touching.
I measured the travel of the rear shocks at 3.5”, fully extended, but there is also a 1” rubber bumper (so 4.5” of travel w/o bumper). I got 15-7/8” from wheel center to rear hoop when shock is fully extended, and 12.5” when shock is completely depressed. Also, the spring rate of the shocks are on the second to lowest setting, with 3 stiffer alternatives available.
To keep the rear hoop, I thought of a few things (or combination things) that I could do: 1) replace 1” bumper w/ 2” bumber; 2) select a stiffer shock setting; 3) adjust the position of the rear hoop. What portion of the shock travel is actually used during normal driving conditions, and how bad of a situation am I in if the shocks bottom out? In other words, are these shocks designed to accommodate a wide range of riders and riding styles without adjustment, or is the owner expected to adjust the shock settings so that the full 3.5” of travel is used?
You are wrong, it is structural.
The tire bottoming out is the issue, not the shocks.
Making the spring stiffer doesn't increase the travel.
Your modification doesn't work. The tire will hit it and it doesn't give the shock mounts the rigidity they should have. You can do whatever you want, me I would cut it out and make something that works properly.
The tire bottoming out is the issue, not the shocks.
Making the spring stiffer doesn't increase the travel.
Your modification doesn't work. The tire will hit it and it doesn't give the shock mounts the rigidity they should have. You can do whatever you want, me I would cut it out and make something that works properly.
41 - 48 of 48 Posts
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