I have a Sportcraft TX4.9 and it speeds up and slows down while in use. It seems to be worse when not holding the grips.

greg, January 2007

One thing I was not aware of is that many treadmills require that the treadmill belt / deck need to be lubricated regularly. Your manual should tell you if your treadmill requires that the treadmill belt be lubricated.

Not all treadmills require lubrication, and a specific lubricant will be required depending on the manufacturer.

Here is an article that discusses it:
http://editorials.arrivenet.com/health/article.php/7719.html

Good Luck

joe, January 2007

I have the same problem with my ProForm 990. I suspect it's a loose belt (the pad you stand on). Holding the grips takes just enough pressure off the belt that it "catches" better and runs at the speed that the computer wants it to. When it slips the computer gets mixed readings and constantly tries to adjust the speed to compensate. Adjusting the belt tension can be a pain but you probably have instructions that came with the machine. Follow them closely but before you start get a good feeling for how tight the belt is now (lift it at the center and see how high it goes) and where the adjustment screws are set. It's very easy to get into the process and loose track of just how much adjustment you've made. Good luck.

Steve, January 2007