1-2 auto transmission???

I am sure this is a dumb question and can be answered by plummen, timebomb, racer54, and many others. I have seen many transmissions for sale described as a 1-2 automatic transmission for dragbikes. Could someone define what exactly makes it different than the stock 5 speed. I kinda assumed it means that it automatically shifts from first to second:ohmy: . But how does it do this. Is it streetable?

They are called automatics, but they are really "overriding" trannys.

Modifications are made to the gear dogs and shift drums that allows the trans to be shifted into a higher gear while still in the lower gear.

In the case of a 1-2 auto, or the more popular 123 auto, the bike would leave in first gear, then when the air shifter button is pressed, it goes into second while still in first. This causes the trans to push itself out of first.

The advantage is there is no power interruption to the rear tire. Pro stock bikes run full 5 speed autos ( we sell them ). A 123 auto can cut two tenths of the quarter mile ET.

These trannys can not be used on the street because, due to the design, you can not back off of the throttle until you are in a non-auto gear. If you do, it will damage the trans, bending shift forks, etc.

Jay

yeah what he said!:laugh: thats some high dollar racing