I dont get why companies make a -1 swingarm. Why would you want a shorter swingarm. I dont see the advantage. Also why do some swingarms have linkages on them. for examle the trx450r. isnt just a direct mount to the swingarm with the shock lighter?

 

the -1 swing arm is for tt, much better handling, especially on an early trx250r. They later came from the factory with a -1 swing arm. The linkage is used because its very difficult to balance shock angle and mounting location. If you have the shock mounted too far back on the swing arm, the shock will have extreme force on it because it is at a very hard angle. If you mount it too far up the swing arm, you will have a weak swing arm because of the leverage of the rear portion to the shock mount. Linkage is a way of having a far rearward mounting position, but keeping the shock closer to an upright angle so that it provides the best suspension possible.

 

ThreeWRacer,

Linkage also adds to your suspension travel without going to a longer shock and having an outrageous ride height in the process.

-1 swingarms are also used by some woods riders..for the same reason they are popular with TT racers.

 

Many banshee owners puchase a shortened swimgarm to get more traction.

 

i can see it would be a harsh ride with the shock way back on the swing arm because it doesnt have as much leverage on the shock. But couldnt you just lean the shock in more. Thats what idid eith my 250 sx and it gave 8 inches of travel versus 4.7"

 

Usually the -1 swingarms are for 86/87 250Rs. The 88/89 models had a -1 shorter swingarm which made them better for mx because it puts more weight over the rear tires for better traction.

 

You guys my be right, but if you check out a bike with linkage I think you'll find it is set up so the shock does not have to compress or decompress very much. Meaning that a very short shock can provide 8" or more of travel. Old Husky dirt bikes had as much as 12" of travel while having the shocks mounted at the very rear of the swingarm. They also had shocks that were nearly 18" long. Now days a typ. motorcross bike has around the same travel while useing linkage and a 8" long shock. The linkage just changes the amount the shock has to move up and down.
Shorting the swingarm puts more of the machines weight on the rear tires. But it also will take some of the weight off the front. All this means is more traction, quicker turning ect...

 

On a side note, honda didn't just shorten the swingarm on the 88/89 models, they also shortened the dog bone and used a new, shorter rear shock to compensate for the leverage difference. This resulted in the same travel with -1 in lengnth. They also used a-arms that were +1 so overall the wheelbase stayed the same.

 

I remembered my father had an 86 and 87 R, then an 88. He always said that the short swinger helped him out in the handling dept.

 

i didnt thnk an 1 inch would make a diff