If one or both rear wheels on your Knee Scooter have developed a substantial wobble, you probably have a bent rear axle. This can be a common problem on the older models of Roscoe Knee Scooter (ROS-KSB). If the axle is bent, it is imperative that you discontinue use until the axle has been replaced as extended use with a bent axle will cause the bearings in the frame to fail and could result in injury or reinjury. Recovering on one foot for 4 to 6 weeks is bad enough, no point in extending the recovery period unnecessarily.
How To Remove The Roscoe Knee Scooter Axle
To remove the rear axle of a Roscoe knee scooter, you will require a 17mm wrench, a hammer, and a hairdryer (optional). You should always start on the right side by the brake hub. Start by removing the acorn nut, followed by the silver spindle that locks the wheel to the axle. After the spindle, there should be 2 or 3 small standoff washers, remove these followed by the wheel its self. After the wheel removes the lock washer, then the flat washer. The final two parts on this site that need to be removed are the brake drum itself and a hexagonal washer.
With the right side taken care of let’s switch to the left side. Again remove the acorn nut, spindle, spacer washers, wheel, and the lock washer that sits between the wheel and the bearing in the scooter’s frame. With these removed, there should be nothing left on the axle its self.
To remove the axle push or pull it out the right side of the frame. You may need to use the hammer here to help remove the axle depending on how bent it is. Once you remove the axle its is recommended to change the axle bearings as well as they may have been damaged when the axle bent.
Removing Roscoe axle bearings.
Removing axle bearings can be tricky, especially if the bearing has catastrophically failed or “blown out.” But no need to worry we’ve done the hard work and figured out the easiest way to get them out. If your bearings are still intact simply use the longer side of the old axle slid through the frame from the opposite side to tap them out. However what if the bearing has failed and the outer raceway is stuck in the frame? The answer is simpler than you might think. Simply remove the bearing from the opposite side (it is very rare that both bearings will blow out) as previously stated. Then inserting the old (bad) axle from the opposite side of the destroyed bearing short end first. The hex nut welded to the axle is the perfect size to grab the outer race, and you can knock the race out with a little assistance from your hammer. You will find a small metal tube between the axle bearings. This is the bearing spacer; it keeps the bearings from pinching when the new axle is installed so don’t lose it.
Well, the hardest part is behind us! For how to install your new Roscoe Knee scooter click here for How to install a Roscoe Knee Scooter Axle