School me on swingarms!

[FireHead]

Not to jump in here on this post, but what size arm would i need for some 22" rippers and a 100hp motor in a stock frame?

What kind of riding are you going to do with that?

 

FYI: 100hp with Rippers in hard sand may net you a broken transmission.

 

With that said, +10" probably a good length to start with. You'll get some people to tell you to go longer......... Personally, I am a shorter swingarm guy. My red bike puts out 109hp at the PTO and it only has a +4" arm (I don't usually drag race it when a launch is required). :geek:

 

As a comparison point: My blue bike has a +10" arm and makes another 50hp at the PTO than yours does and I can launch it, but I think, as per recommended by Dave, I am going to need a wheelie bar for serious track work.

[FireHead]

if i am not mistaken the link is for travel and leverage on the rear shock. if you are just draggin it you shouldnt need that much rear travel. i am not sure if the stock shock will bolt up without the linkage. you may have to fab up a mount. and check to see if it will be to soft or stiff of a spring without the linkage.

You're not far off on the link theory of things................ leverage is the wrong word to use though. What the link is all about is changing the motion of the shock in comparison to suspension travel. By moving the shock in a different arc than the arm, you effectively put the shock travel into a more normalized stay that, by design, is spent in the median travel of the shock's piston.

 

Soimething to read about if you are so inclined is rocker arm or rising rate suspension in Formula 1, Baja racing, etc. There is alot of internesting stuff out there on the net for it. It's a fun thing to know some trivia about atleast. :thumbsup:

[BB3]

What kind of riding are you going to do with that?

 

FYI: 100hp with Rippers in hard sand may net you a broken transmission.

 

With that said, +10" probably a good length to start with. You'll get some people to tell you to go longer......... Personally, I am a shorter swingarm guy. My red bike puts out 109hp at the PTO and it only has a +4" arm (I don't usually drag race it when a launch is required). :geek:

 

As a comparison point: My blue bike has a +10" arm and makes another 50hp at the PTO than yours does and I can launch it, but I think, as per recommended by Dave, I am going to need a wheelie bar for serious track work.

 

Well this motor was in a Rigid frame and the whole bike didn't weight anything.

I plan to dune drag this bike and still take it to the track, i will be making a bar for it so i can run it hard @ the track and have no problems.

[shovelhead]

OK tell me this.. Let's say we have 2 fairly identical quads

 

 

Quad 1 is 100 hp with stock frame & 175 lb rider Drag race only in sand...

 

 

 

Quad 2 is 100 hp with stock frame & 250 lb rider on sand & dirt drag race only

 

 

 

** what swingarm lenghth would you seasoned guys & builders reccommend for these 2 racers and why ?

[SoCalinIt]

Well this motor was in a Rigid frame and the whole bike didn't weight anything.

I plan to dune drag this bike and still take it to the track, i will be making a bar for it so i can run it hard @ the track and have no problems.

 

I agree with Mark to an extent... I think people over do it a little, but if you are dead set on running rippers in a stock chassis, I think I'd start with a +12 over. I'm running a +10 up front +13 out back with my 14mm Cub with 12 paddle Haulers... I plan on doing some time and speed testing in Pismo, and Dumont in the next few months.

[shanYE west]

I was using a +12 arm with a stock chassis and 13pdl extremes. (4mil cub) Worked great on a fresh groomed track.. but after it got a lil tore up I needed a lil more traction.