I need the stiffest shocks avalibale for a cb360

xb33bsa said:
i am not going to debate you, it's a waste of time
you clearly do not know wtf you are doing and have proven it
good luck with your project
Click to expand...

If he moves the swingarm shock mounts forward, the frame will raise up from the wheel, and he'll get closer to the original geometry of the bike.

That said, that thing looks like it would be a complete ball smasher. I'm all for a unique bike - and let's not pretend like everything each one of us does is a purely performance mod - but man, I just don't see how you wouldn't be hanging on by your hands, your nuts, and the hope that you don't fall back off that seat and lose both.

Tank looks pretty damn cool tho
 
Rich Ard said:
That said, that thing looks like it would be a complete ball smasher. I'm all for a unique bike - and let's not pretend like everything each one of us does is a purely performance mod - but man, I just don't see how you wouldn't be hanging on by your hands, your nuts, and the hope that you don't fall back off that seat and lose both.

Tank looks pretty damn cool tho
Click to expand...

Haha can't argue with that man. While garage racing my ass stays in place pretty well. Throw a fender on and I won't have to worry about loosing the goods. I know it's not going to be comfortable. I'm not building this to eat up miles on just something fun to tinker with and rip around town from time to time.
 
xb33bsa said:
yes but the rear wheel travel is increased even more, c'mon you know that
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Moving my lower mounts forward 3in will give me a bit over 4in of travel between the tire and frame. It will also improve the shock angle effectively stiffening up the suspension compared to where it's at now. Show me the equation that says the increase in rear wheel travel from moving the mounts will be enough to overcome the stiffer shock and increased distance.
 
xb33bsa said:
yes but the rear wheel travel is increased even more, c'mon you know that
Click to expand...

Indeed - but with a stiff enough shock you can lean the gods of tire clearance in your favor.

Still not clear on the reason behind making a nutcracker, but you've seen what I ride around on, so I don't have a pony in this show.
 
nateridesbikes said:
Moving my lower mounts forward 3in will give me a bit over 4in of travel between the tire and frame. It will also improve the shock angle effectively stiffening up the suspension compared to where it's at now. Show me the equation that says the increase in rear wheel travel from moving the mounts will be enough to overcome the stiffer shock and increased distance.
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no it will require even stiffer springs and increase the travel of the rear wheel even more
just remove the srings from whatever shock you are going to use and have it bottomed out to determine clearance at full bump.it will save you a lot of trouble
 
OP - if you're going to do this, why not just hard tail it?
 
nutcracker.jpg


I don't mind the lines of this bike but it really looks like it needs to be a hard tail with a springer seat. Just my opinion. Interested to see where this goes.
 
I've gotten basically all of my shock info from off road forums because those fellas seem to deal with shock angles a hell of a lot more than bike builder. Here's a chart that says the greater the angle the less effective the shock becomes. Would this not pertain to a swing arm as well? If I'm wrong tell me why instead of firing shots at me.

Source: Chassis Engineering by Herb Adams pg: 36

Shock mounted at 0 degrees: 100% effective (this is when the shock is completely vertical)

Shock mounted at 10 degrees: 98% effective (mostly vertical)

Shock mounted at 30 degrees: 86% effective

Shock mounted at 45 degrees: 70% effective

there is also this this calculator that shows as shock angle increases a higher spring rate is needed.

http://www.proshocks.com/calcs/anglefirst.htm
 
xb33bsa said:
yes but the rear wheel travel is increased even more, c'mon you know that
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No, sorry, but you are wrong. Increasing the angle of the shocks makes the swingarm travel farther. Also requires a stiffer spring. Laying the shock down was one of the first experiments for getting longer suspension travel on dirt bikes around 1970.

Moving the lower shock mount forward would solve the OP's problem. I would move the tire farther away from the frame, shorten the swingarm travel, and make the shocks stiffer.
 
AlphaDogChoppers said:
No, sorry, but you are wrong. Increasing the angle of the shocks makes the swingarm travel farther. Also requires a stiffer spring. Laying the shock down was one of the first experiments for getting longer suspension travel on dirt bikes around 1970.

Moving the lower shock mount forward would solve the OP's problem. I would move the tire farther away from the frame, shorten the swingarm travel, and make the shocks stiffer.
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moving the shocks forward on the swingarm increases travel as well
it is simple geometry and yes i was there and racing in 1974
laying the shocks down was the easiest way to get some more travel but as our lust for travel increased we needed to move them forward on the swingarm
 
http://www.dotheton.com/forum/index.php?topic=26839.msg596989#msg596989

:)

Told ya, haha :)

Strut it, seriously.

As far as issues with leverage and such, yes, the shock is most effective at a right angle to the swingarm. The more of an angle from the swingarm you get, the less the shock has to compress for the same travel of the swingarm.
 
An addenda to what I said...

Moving the lower shock mount forward, further from the axle, does indeed make the swingarm have more leverage against the shock. Moving the top mount of the shock back would have the opposite effect.

There are two effects here in the shock geometry, and you are only thinking about one of them. One is that as the lower shock mount is moved forward of the axle, the swingarm has more leverage and travel in increased. The other is shock angle. As shock angle is changed toward being perpendicular to the ground, wheel travel is decreased.

The problem that was introduced here is that the swingarm was lengthened, which in turn changed the shock angle. This made the shock effectively softer as well as increasing wheel travel.
 
xb33bsa said:
moving the shocks forward on the swingarm increases travel as well
Click to expand...

You are right. Your earlier statement was disregarding the effect of shock angle, while I was disregarding the effect of the shock mount being further forward from the axle. I had to give it a few minutes thought to consider both of those effects, which would largely cancel each other out if the lower mount was moved forward.
 
AlphaDogChoppers said:
An addenda to what I said...

Moving the lower shock mount forward, further from the axle, does indeed make the swingarm have more leverage against the shock. Moving the top mount of the shock back would have the opposite effect.

There are two effects here in the shock geometry, and you are only thinking about one of them. One is that as the lower shock mount is moved forward of the axle, the swingarm has more leverage and travel in increased. The other is shock angle. As shock angle is changed toward being perpendicular to the ground, wheel travel is decreased.

The problem that was introduced here is that the swingarm was lengthened, which in turn changed the shock angle. This made the shock effectively softer as well as increasing wheel travel.
Click to expand...

I wasn't thinking about only one, I was relaying only one. of course moving the lower mount forward would increase the leverage. Simple physics.

The closer the two points of the shock mounts to the rotational point of the swingarm, the higher the leverage (the less force it takes to compress it, in laymans terms), and the closer to 90 degrees the shock is to the swingarm, the further it has to compress for the same amount of swingarm travel (more force to travel the same distance, in laymans terms.)

There's both :)

Moving the lower forward will increase leverage (which reduces the amount of force required to swing) but increases the amount of compression of the shock required to move the swingarm. So who knows whether it will be 'stiffer'? We don't know how soft those shocks are.

Anyway, either way, they will change the angle of swingarm to frame with that length of shock, which I think will ruin his aesthetic endeavour here.

Which is why he should just strut it.

/edit: well shit, you changed wha tyou said, and it wasn't to me anyway... want me to delete this?
 
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