thompsonmx100
Over 1,000 Posts
Re: 79 CB750K "Off Track"
sounds like you need to build a scrambler or street tracker.
sounds like you need to build a scrambler or street tracker.
79 CB750K, RCB clone-ish build
- Thread starter Basement rat
- Start date
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"
Ive never herd of those terms before I came here. I still don't know what a scrambler is... I'm just building a bike that makes me go "Oh F* yea" You can see its nothing like I had envisioned it at the start but that's because I'm still learning so much about the style of these things. I'm a knewb when it comes to building these things but once I finally have my plan, its easy.
Im going to try these shocks off the bat. If I need stronger, I can upgrade easy. This bike was designed to be able to carry two passengers so lets see how it works, it will only ever be me in this configuration.
^^^ EDIT: Shit, gotta buy new ones... I need eye to eye, not the stock system...
Plan for tomorrow/ this weekend...
design mount, spacers/ bushings for shocks on upper attachment point
make template for gusset doubler
design bushings and spacers for shocks on swing arm
design swing arm caps for pivot
calculate wheel spacers
maybe chop the seat some more and work on in seat battery box
relocating the wiring.
This week after work try to get some time on the lathe to turn down everything I need,
The big picture:
Rotor- Drill, paint gold
Caliper- clean, paint gold, organic pads
Forks- new seals, palish?
Starter- figure out why it started to die on me
Seat- Finish
Welding- In one shot is possible
Paint- Refinish reworked areas, paint all non painted.
and much much more.
Rebuild in living room upstairs before moving outside ;D (womans not gonna like that)
Ive never herd of those terms before I came here. I still don't know what a scrambler is... I'm just building a bike that makes me go "Oh F* yea" You can see its nothing like I had envisioned it at the start but that's because I'm still learning so much about the style of these things. I'm a knewb when it comes to building these things but once I finally have my plan, its easy.
Im going to try these shocks off the bat. If I need stronger, I can upgrade easy. This bike was designed to be able to carry two passengers so lets see how it works, it will only ever be me in this configuration.
^^^ EDIT: Shit, gotta buy new ones... I need eye to eye, not the stock system...
Plan for tomorrow/ this weekend...
design mount, spacers/ bushings for shocks on upper attachment point
make template for gusset doubler
design bushings and spacers for shocks on swing arm
design swing arm caps for pivot
calculate wheel spacers
maybe chop the seat some more and work on in seat battery box
relocating the wiring.
This week after work try to get some time on the lathe to turn down everything I need,
The big picture:
Rotor- Drill, paint gold
Caliper- clean, paint gold, organic pads
Forks- new seals, palish?
Starter- figure out why it started to die on me
Seat- Finish
Welding- In one shot is possible
Paint- Refinish reworked areas, paint all non painted.
and much much more.
Rebuild in living room upstairs before moving outside ;D (womans not gonna like that)
VonYinzer
Over 10,000 Posts
Re: 79 CB750K "Off Track"
A scrambler was a bike made for street and trail. Before most manufacturers made dedicated off road only factory bikes they put higher bars, high mount pipes, and knobbier tires on their road bikes (as well as other small changes) to allow for more aggressive off road riding. Look up a CL350 and a CB350 and check out the difference.
A scrambler was a bike made for street and trail. Before most manufacturers made dedicated off road only factory bikes they put higher bars, high mount pipes, and knobbier tires on their road bikes (as well as other small changes) to allow for more aggressive off road riding. Look up a CL350 and a CB350 and check out the difference.
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"/ You told me so...
Did a shopping trip for some stuff I needed and some more research... OK, Ok, ok... talked to the local "Guru" and he explained it a little more with some examples he had around his shop.
You guys are steering me in the right direction. Thanks!
Mu dumb ass forgot to ask. Is there a wrong way to mount that shock? Upside down wise?
My Ghetto varsol tank...
I will have a work update tonight.
Did a shopping trip for some stuff I needed and some more research... OK, Ok, ok... talked to the local "Guru" and he explained it a little more with some examples he had around his shop.
You guys are steering me in the right direction. Thanks!
Mu dumb ass forgot to ask. Is there a wrong way to mount that shock? Upside down wise?
My Ghetto varsol tank...
I will have a work update tonight.
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"/ You told me so...
Nothin worth taking pictures of. Im tryin to lay off a little.
Removed rotor, attempted to map out holes... gave up and will let the guy whos gonna cut em do that. I just used black marker to mark how I wanted the pattern.
The dual rear suspension system is on the shelf while as you saw I have the mono shock. Gotta press a bushing out when I get to work to before I try anything else. (is there an up and down way to mount the shock or does it matter?)
Got my swing arm on properly, I bought a dremel and removed the less than .01" that was interfering. Now I gotta make some spacers for between the arm and the frame... Any problems with using shim stock?
Aligned my rear wheel for chain fitment reasons, One spacer is perfect and the other is too wide, need to remove about 1/4" from it. May make new aluminum ones with fins.. don't know... don't know if I care that much about them...
Tried my buffing wheel/ grinder out on my drive sprocket cover... Not bad... Just used a #2 polish on about 1/2 of the cover.
Got the caliper removed and taken apart. Started sanding to prep for gold paint.
Choped off a nice chunk of the back of the seat to prep for cutting a recess in my pan for my battery to sit between the frame rails... after doing that I found a cross member right under it... I may buy a battery like Traveler is looking at.
Nothin worth taking pictures of. Im tryin to lay off a little.
Removed rotor, attempted to map out holes... gave up and will let the guy whos gonna cut em do that. I just used black marker to mark how I wanted the pattern.
The dual rear suspension system is on the shelf while as you saw I have the mono shock. Gotta press a bushing out when I get to work to before I try anything else. (is there an up and down way to mount the shock or does it matter?)
Got my swing arm on properly, I bought a dremel and removed the less than .01" that was interfering. Now I gotta make some spacers for between the arm and the frame... Any problems with using shim stock?
Aligned my rear wheel for chain fitment reasons, One spacer is perfect and the other is too wide, need to remove about 1/4" from it. May make new aluminum ones with fins.. don't know... don't know if I care that much about them...
Tried my buffing wheel/ grinder out on my drive sprocket cover... Not bad... Just used a #2 polish on about 1/2 of the cover.
Got the caliper removed and taken apart. Started sanding to prep for gold paint.
Choped off a nice chunk of the back of the seat to prep for cutting a recess in my pan for my battery to sit between the frame rails... after doing that I found a cross member right under it... I may buy a battery like Traveler is looking at.
Big R
Heaven is so far away.
Re: 79 CB750K "Off Track"/ You told me so...
I looked all over for a pic of how my shock mounts on my suzuki and can't find a decent one. But you are going to want to mount the end with the hose up top. I don't think it matters in the long run but that's how mine is. Here is a pic of my swingarm (it's upside down on a table - notice how the mount would be hanging down when installed)
But it's all about how you mount it. What is that shock off of? I personally would try to replicate the mounts to the original if at all possible. Like the distance from the swingarm pivot and the original angle. Just my .02
I looked all over for a pic of how my shock mounts on my suzuki and can't find a decent one. But you are going to want to mount the end with the hose up top. I don't think it matters in the long run but that's how mine is. Here is a pic of my swingarm (it's upside down on a table - notice how the mount would be hanging down when installed)
But it's all about how you mount it. What is that shock off of? I personally would try to replicate the mounts to the original if at all possible. Like the distance from the swingarm pivot and the original angle. Just my .02
VonYinzer
Over 10,000 Posts
Re: 79 CB750K "Off Track"/ You told me so...
Ya man... Mounting a mono shock on a bike thats not originally made for it requires a ton of planning. Im sure its something you personally can do, but PLEASE make sure you do the research needed to set the shock up correctly! It could b e very unsafe otherwise...
Ya man... Mounting a mono shock on a bike thats not originally made for it requires a ton of planning. Im sure its something you personally can do, but PLEASE make sure you do the research needed to set the shock up correctly! It could b e very unsafe otherwise...
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"/ You told me so...
Thanks, however its in there, it will be in there good. Don't worry about bird shit welding.
How bad is this? I know the shock is off to the right. That will keep it out of the way of the air box with minimal "cutting to fit" while if it was centered (would have to take about .025" of the inside of the most inside of swing arm brackets (no big deal) to accommodate the shock and remove a hellova lotta air box.
Why don"t I remove the box and use pods? Tried pods last summer. No good for these bikes. They like there boxes allot better.
now, all that wiring is going under the tank in that nice new space I have with my supports.
If this wont work, who has any ideas that could do the trick? The only problem I see is if the shock is stiff enough with the adjuster.
I was even toying with the idea of using a pull shock system from a HD Soft tail under the frame.
Back to the basement...
Edit, Also bought a mini battery like Traveler. If you read this, thanks for posting about it!
Thanks, however its in there, it will be in there good. Don't worry about bird shit welding.
How bad is this? I know the shock is off to the right. That will keep it out of the way of the air box with minimal "cutting to fit" while if it was centered (would have to take about .025" of the inside of the most inside of swing arm brackets (no big deal) to accommodate the shock and remove a hellova lotta air box.
Why don"t I remove the box and use pods? Tried pods last summer. No good for these bikes. They like there boxes allot better.
now, all that wiring is going under the tank in that nice new space I have with my supports.
If this wont work, who has any ideas that could do the trick? The only problem I see is if the shock is stiff enough with the adjuster.
I was even toying with the idea of using a pull shock system from a HD Soft tail under the frame.
Back to the basement...
Edit, Also bought a mini battery like Traveler. If you read this, thanks for posting about it!
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"/ You told me so...
sonofabitch
I here by dedicate this thread in all its entirety of failures of mechanical design to those who ask "Why not" or "What would happen if?"
This is why and what happens if...
I placed a socket extender through the eye of the top of the shock and let it rest on the gusset of the frame. This is just me, no seat, no gas in the tank or anything.
May ALL of you learn through my examples that they may not be suffered in vane.
Sorry guys, I was one of those kids who when told not to touch the stove because it was hot, wondered how hot "hot" was and needed to find out.
Kanticoy sent me this a little while ago:
Newman:
I think I will source out those parts and just copy the rear suspension and go from there. Unless someone has a better idea.
sonofabitch
I here by dedicate this thread in all its entirety of failures of mechanical design to those who ask "Why not" or "What would happen if?"
This is why and what happens if...
I placed a socket extender through the eye of the top of the shock and let it rest on the gusset of the frame. This is just me, no seat, no gas in the tank or anything.
May ALL of you learn through my examples that they may not be suffered in vane.
Sorry guys, I was one of those kids who when told not to touch the stove because it was hot, wondered how hot "hot" was and needed to find out.
Kanticoy sent me this a little while ago:
Newman:
I think I will source out those parts and just copy the rear suspension and go from there. Unless someone has a better idea.
hedrives
Been Around the Block
Re: 79 CB750K "Off Track"/ You told me so...
Re: Your rear shock and spring.
I come from a long auto racing background and have some info you need to consider with your rear spring and shock setup.
You need to do a little math and figure out what spring rate you will need to run. How much SPRUNG Weight will be on the rear axle? Measure your swingarm length axle to pivot. The measure the pivot to shock swingarm mount length. That gives you a mechanical advantage ratio which will tell you the effective spring rate at rest.
You also need to see how much distance the the swingarm will move from full droop to full compression. This gives you the shock motion length. You need a shock that performs to this measurement. Don't forget to add in a bump stop on the shock shaft. All of this will also give you the length of spring you need.
So, figure up your measurments and get the right shock and spring to handle these forces. Otherwise you my find you bike unrideable.
BTW, I am building an 82 dohc cafe and have been following your progress. Good job, love your creativity, but don't cut corners on the shock spring setup.
brad
Re: Your rear shock and spring.
I come from a long auto racing background and have some info you need to consider with your rear spring and shock setup.
You need to do a little math and figure out what spring rate you will need to run. How much SPRUNG Weight will be on the rear axle? Measure your swingarm length axle to pivot. The measure the pivot to shock swingarm mount length. That gives you a mechanical advantage ratio which will tell you the effective spring rate at rest.
You also need to see how much distance the the swingarm will move from full droop to full compression. This gives you the shock motion length. You need a shock that performs to this measurement. Don't forget to add in a bump stop on the shock shaft. All of this will also give you the length of spring you need.
So, figure up your measurments and get the right shock and spring to handle these forces. Otherwise you my find you bike unrideable.
BTW, I am building an 82 dohc cafe and have been following your progress. Good job, love your creativity, but don't cut corners on the shock spring setup.
brad
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"/ You told me so...
Is it as simple as halfing the spring rate and doubling the shocks to run duals?
Do I need to weigh the bike at rear wheel and add my weight plus some for gas and other to get sprung weight?
this is gold, thanks.
Is it as simple as halfing the spring rate and doubling the shocks to run duals?
Do I need to weigh the bike at rear wheel and add my weight plus some for gas and other to get sprung weight?
this is gold, thanks.
hedrives
Been Around the Block
Re: 79 CB750K "Off Track"/ You told me so...
The simple way is to put scale under rear wheel, sit yourself on bike and get weight. That will be the sprung weight on the rear. (Before the techies chime in, this is the good old boy method.) BUT... But, you need to take OUT the rear spring and put a strut in at ride height to be close. You are trying to find out how much weight the rear holds up. The, the ratio and other stuff I suggested kick in.
And, yes, to run duals (don't know why you want that?) you basically split the amounts. For example, if the rear needs to hold up 250#, you can run two 125# springs. Where it gets hinky is suspension travel, shock length tell you how long a spring to get and don't forget to get bump stops to keep you shock from bottoming out.
Basement rat said:
The simple way is to put scale under rear wheel, sit yourself on bike and get weight. That will be the sprung weight on the rear. (Before the techies chime in, this is the good old boy method.) BUT... But, you need to take OUT the rear spring and put a strut in at ride height to be close. You are trying to find out how much weight the rear holds up. The, the ratio and other stuff I suggested kick in.
And, yes, to run duals (don't know why you want that?) you basically split the amounts. For example, if the rear needs to hold up 250#, you can run two 125# springs. Where it gets hinky is suspension travel, shock length tell you how long a spring to get and don't forget to get bump stops to keep you shock from bottoming out.
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"/ You told me so...
Thanks, I'm talking with aftershock suspension right now about what I need.
Along with the you told me so... Who would anyone recommend to modify my Dunstall to fit my bike?
I was messing around with MS paint last night, walked away for a wile, came back and went "Whats the problem?" after a moment I realized this is the lowered tank... I think I should go for it . I could have someone try to make this one fit, like tank for my frameor change direction again... I like this tank...
I think I'm going to talk to BCR and who else?
Thanks, I'm talking with aftershock suspension right now about what I need.
Along with the you told me so... Who would anyone recommend to modify my Dunstall to fit my bike?
I was messing around with MS paint last night, walked away for a wile, came back and went "Whats the problem?" after a moment I realized this is the lowered tank... I think I should go for it . I could have someone try to make this one fit, like tank for my frameor change direction again... I like this tank...
I think I'm going to talk to BCR and who else?
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"/ You told me so...
Emailed RocCity this morning.
Emailed RocCity this morning.
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"/ You told me so...
Ok, I have my swing arm just about mounted... I thought it was but now I have a problem. Mounted the way that I do, the swing arm is moving side to side measured at the very end by about 1/8". I made some spacers to fit between my swing arm and frame where the swing arm caps would go. They are about .05" each side. My plan was to use some hard core gasket sealer to seal the edges of the caps/ bushings to the . I figured this would work so long as I took a little time every year to re grease it. but this side to side movement is bothering me.
I cant be sure, is why I'm asking this. Will everything hold its self nice and snug in place with the shock/s mounted? (haven't 100% decided on 1 or 2 yet)
How bad is this?
Ok, I have my swing arm just about mounted... I thought it was but now I have a problem. Mounted the way that I do, the swing arm is moving side to side measured at the very end by about 1/8". I made some spacers to fit between my swing arm and frame where the swing arm caps would go. They are about .05" each side. My plan was to use some hard core gasket sealer to seal the edges of the caps/ bushings to the . I figured this would work so long as I took a little time every year to re grease it. but this side to side movement is bothering me.
I cant be sure, is why I'm asking this. Will everything hold its self nice and snug in place with the shock/s mounted? (haven't 100% decided on 1 or 2 yet)
How bad is this?
tWistedWheelz
BUILT NOT BOUGHT!
Re: 79 CB750K "Off Track"/ Swing arm issue...
I would say you have a problem, every swing arm I have ever worked on had ZERO side to side movement!
ZERO
I would say you have a problem, every swing arm I have ever worked on had ZERO side to side movement!
ZERO
Basement rat
Over 1,000 Posts
Re: 79 CB750K "Off Track"/ Swing arm issue...
I think right now what the problem is my CB750 axle OD is JUST a little smaller than my swing arm axle ID. I was thinking if this is the case I can get a new bolt to fit the swing arm axle and drill/ ream my frame mount to fit.
I just want to know what the norm is, sure this aint the norm thoe.
I think right now what the problem is my CB750 axle OD is JUST a little smaller than my swing arm axle ID. I was thinking if this is the case I can get a new bolt to fit the swing arm axle and drill/ ream my frame mount to fit.
I just want to know what the norm is, sure this aint the norm thoe.
