Hi All Since I am having my rear fender eliminated, I wanna try raising the rear of the bike. Has anybody ever tried doing this? Looking at the rear suspension there is a "dog bone" that attaches to the swing arm. I think shortening it will raise the rear by 1-2inches. See picture below: But I am afraid it will scrap the collector box in the process.




The "dog bone" is the piece that has a hole in the middle. Guess the hole is to adjust the rebound. I am going to fabricatea shorter 'dogbone'out of reinforced steel. I am also wondering about the issue of performance.

 

Such amod is very common on Blackbirds, next to mandatory. By putting a 6 mm thick shim on top of the rear shock upper u-clamp, the rear is raised about 30 mm at the wheel axis. This makes the bike much more willing to turn and keep the line thru curves. I've done it on my Bird and it is a great mod without reported cons on the Blackbird. The nature of the mod will reduce the high-speed stability of the bike to some degree. Nothing that can ever benoticed on a Bird, and the Hurricanes basic stability is also very fine so it might justwork fine. What I would do if I was to be the first trying such a mod, would be to rise the bike in small increments, not a full inch directly. And then go up like 5 mm'sper adjustment andwatch up very carefullyfor any signs of stability problem. Things can happen very fast if the front loses the grip in a high speed bump, and if the bike is changed too much so it doesn't stabilize itself it cancause a high speed tank slapper whichis extremly dangerous.

 

Thanks R1000

All you need is to add a shim? that is easier that i thought. However, I may have thought of this process before - but can't exactly picture how you can add shim to a U-shapped clamped. It would move it sideways and not up and down? The exhaust collector box is in the way at the bottom, will it be hit? Ok besides cosmetic improvements you will notice that the bird will want to turn more on curves...ok will try it.

cheers

 

The blackbirds are easy to shim because of their different top shock mounting that uses a bolt. Unfortunately it isn't that easy for the Hurricane

 

hey R1000

Where shall I add the shim? A. or B.? Thanks

 

Trips is right, the top jointof rear shockaredifferent on Hurricanes and Birds. Perhaps youcan use the idea from the Bird, buy modifying the schock-to-frame-joint? You can see the solution for Birds below.

[IMG]local://upfiles/4562/0629F1E631254B6CBF575DC6EA4B6A4D.jpg[/IMG]

 

I have shortened the "dog bone" to raise my Hurricane. I just drilled an extra hole. Whenever I want I can go back to stock in no time. It was no problem and it handels much better. The back end became a bit stiffer because of the more upright shock position. That was good since the 1987 is a bit soft on the back.
Be careful with the shortening though. If it is to short the spring will hook up in the front end of the swing arm when damping. At least in the 1987-1988 model. The stock exhaust will not fit since the swingarm becomes in a lower down position. Also the chain has to be a little looser when ajusted in "idle" position because the movement will increase distance from the front sprocket.

Good luck

 

Can you show us a pic?

 

OK.
I have made a new hole about 20 mm from the original. That did about 100 mm at the back if I remember correctly.
And, NO, it will not be to weak. There is just drag and pull force on that thing to keep everything in position. If I was to move it back permanently to the stock setting I would eliminate the hole to get it stronger.




[IMG]local://upfiles/15598/DDC9F1FED15A48A4A19FC258851C8E17.jpg[/IMG]

 

Is the bike still stable? 100 mm up rear is extremely much and will cause a major change to the bikes geometry and handling. I guess the bike turns quickly now as an Aprilia 250 CC [sm=smiley36.gif], but the risk for high speed wobble, especially at corner exits or road bumps must be rather high [sm=smiley5.gif]. The Hurricane has a conservative chassi stock though, so raising the rear to some extent must be beneficial.