Let's talk rear suspension theory.

[noiseguy]

I don't use that pipe anymore, my scorpion revs much higher.

Off-topic. Do you run your drag motors without fan?

[Trafficjamz]

I don't use that pipe anymore, my scorpion revs much higher.

Off-topic. Do you run your drag motors without fan?

No fan
No fan shroud

fans put extra drag on the engine.

Temps are closely watched

[Trafficjamz]

here is my 5 inch street stretch. It is very comfy to ride and stops the engine from bucking upwards.

I had to cut the seat bucket a little bit for this setup.

[Majourlittle]

here is my 5 inch street stretch. It is very comfy to ride and stops the engine from bucking upwards.

What kid of issues did you have with it bucking upwards? Adding the stock spring that close to the frame must put quite a push down on the swingarm? What kid of movement do you see in that area now?

There is nothing wrong with how honda designed the motor mount setup. I roadraced with it the way it is up to 85mph with no issues. Plus if you knew more than the honda engineers, you wouldnt be on here posting.

Wow, you fail to grasp what engineers do in regards to design. Generally something that goes 30mph isn't designed for 85mph. Mass production design usually has the two words "Cheap" and "Easy" governing their existence.

I never said that it was wrong, but that it can be improved. I am trying to improve and increase my understanding of the two link suspension. Are engineers banned from the internet?

I though that this was what this site was for. Asking questions and dissecting topics betters all. If you understand why there is a two link suspension, and every other two wheel device I have seen or owned doesn't have this setup, the be my guest and fill us in.

[bakaracer]

If honda wanted to do cheap and easy they would have made a nondamping motor mount . These are well over engineered pieces of machines. If they couldnt handle 85+mph type of riding, they would have broke along time ago and guys wouldnt race them. Again nothing wrong with how its engineered. The dual bushing mount setup is for damping. On a motorcycle the use larger bushings and you have more frame to dampen vibration vs these small bikes. These single 2 stroke engines give off a lot of vibration. Gets worst going bbk

[bakaracer]

If you want better suspension, get afteraftermarket shocks. The stock ones suck

[Trafficjamz]

What kind of issues did you have with it bucking upwards? Adding the stock spring that close to the frame must put quite a push down on the swingarm? What kind of movement do you see in that area now?

When the mount gets extended past stock length, the mount becomes less stable.

spring does not press down, it holds it in place. A honda shock was used to cut down vibrations.

I see very little movement in that area now. Cause that area ain't supposed to move.

[Trafficjamz]

If you want better suspension, get afteraftermarket shocks. The stock ones suck

The extended motor mount does not handle better. It does help to not wheelie.

[Majourlittle]

Well I went and tested a few theories that I had on the suspension.

I extended my motor mount by 3 inches from where I had it. I don't know where this if from stock, since the bike is a swap in the first place.


Anyway, I took it around the block and noticed the climb that TJ was talking about, and that I had theorized would happen as the swingarm buckled under the torque put out from the engine. I noticed that there was some lag in the throttle, but less wheelie action as before. The carb did come fairly close to the frame, and therefore needs to be corrected.

So I went back to my thoughts again on making a double bolt swingarm where the rear support is still rubber isolated, and where the center-stand use to be would be where there was another rubber isolated bolt securing the back part of the swing arm. Since I don't want to do anything permanent, I went ahead and took a c-clamp and pinned the swingarm down to the frame so that it couldn't move and went around the block.

I noticed that the throttle response came back better than ever and the wheelie action came back. While cruising, the vibration was no worse than stock, but at idle condition while moving, it was noticeable and annoying. Once stopped, it was Harley-Bad.

So to have the best of both worlds, I need to allow the mount to vibrate at idle and clamp down under throttle. I believe that this is what Honda has done with the tounge on the larger bikes in the frame tube. The SB did not come with that, so I will have to re create it.

[Majourlittle]

Well, I decided to take my lesson learned and combine it into an engine mount design that would absorb vibration under no-load, and tighten up under load. I came up with a rubber isolated bar with a tension spring holding it in place. It worked perfectly and held the swingarm down while absorbing the vibrations at idle. I think that I will revise and implement.