I want to change the tires on my sport bike but I have a few questions since no one in my shop has done it for a motorcycle. I work in an automotive shop as a mechanic and I have access to tire changers, high speed balancers, wheel weights, lifts, bearing presses/pullers etc. I have experience working with cars but very little with motorcycles. Here are my questions.
After removing the wheels from the motorcycle, do I need to remove the bearing from the wheel to balance it? The balancer we have in our shop requires the wheel to be placed on a cylindrical shaft, about 1.5 inches in diameter, and a cone needs to be tightened onto the wheel to center it for balancing. I only plan to do a static balance, but from what I see it looks like the bearings need to be removed.
If I do remove the bearings will the balancing machine I plan to use damage the outer bearing race? The wheel bearings on my bike are a press fit where the outer bearing race is “locked” to the wheel and the inner bearing race is “locked” to the “axle shaft”.
When I do balance my wheels do the brake rotors need to be attached to the wheels? It seems like I should be balancing the wheel/brake disc system since that is what is going to be spinning at high speed. If that is the case then I can not use our balancer since there is no way to balance the front wheel with their dual disc brakes. On the other hand I have never needed to balance a brake rotor for a car and they are much more bulkier than the thinner than dinner plates discs on my bike.
If you have any tips for me I would really appreciate it. I really do not want to have to take it to a motorcycle shop if I can do it myself. Thanks so much.
Motorcycle tires are typically not dynamically balanced. They are statically balanced by supporting a axle shaft on low friction bearings. When it is far off, the wheel will rotate itself heavy side down. When you get close, you have to spin the wheel several times and note where it stops each time. The wheel bearings usually have too much drag for accurate balancing due to preload and thickish grease. Another balancing method hangs the wheel flat…faster, but very error prone IME.
Motorcycle wheel changers usually grab the rim around the outside with hooks, rather than through the center like an automotive machine. The forces are low enough that most shops use a manual machine rather than a powered one. Cotes (sp?) is one popular brand. Harbor freight makes a manual changer with motorcycle wheel adapter that you can get for around $50 on sale.
Google"DIY motorcycle wheel change" for tips on building simple bead breakers and balancing jigs for the home shop.
Thank you very much Kevbo you have been really informative.
Since your post I have located a stand online for static balancing. I was hoping to be able to use our balancer at work since it has the option to perform a static balance. Fortunately I will not have to buy the tire changer from Harbor Freight our machine can clamp from the inside of the wheel or the outside. I wasn’t worried about replacing the tire, only balancing it.
This just leaves the question on whether I should leave the brake discs on or off during the static balance.
You want to balance everthing that spins.
Typically, there is a white or yellow dot painted on the tire to indicate where the valve stem should line up.
Balance it with the disks installed. Not only is it “better” but also saves the work of R&R the disks.
I know you said you won’t be mounting tires, but others may search and find this thread:
Another feature of a motorcycle wheel machine is that it has an arm that goes over the top to support a vertical rod that you use as a fulcrum for the tire lever. This would go up through the middle of a car wheel, but it is not usually possible on motorcycle wheels.
That said, many, even most people don’t use those long tire machine levers, or need the overarm, as it is very easy to damage an alloy rim with them, or pinch a tube if you are using a tube… especially the cheap HF ones. Instead they use a several plain tire levers and pry the bead on and off without sliding the levers around the rim. Adds a few extra minutes but is much safer. Depending on the tire and rim, it is often possible to get the tire on without the levers at all. It is all about making use of the dropped center in the rim. I know one guy who mounts a lot of MC tires, and about 1/4-1/3 of the time he can literally throw the tire at the lubed rim and have the first bead end up on the rim.
Finally if you ask around, you may find a club that has the equipment available for members use. In the case of the local BMW club, it lives in the “tire thrower’s” garage. Many BMW riders put a lot of miles on their bikes and go through a lot of tires.
I am going to replace the tires. That is why I was asking about balancing. The machine at our shop can clamp from the inside or outside of the rim. We have a pneumatic bead breaker so I am not looking to pry it manually.
I am going to have to remove the discs because there is no way I am going to risk damaging the discs while replacing the tires. Besides I can’t mount the front wheel on the tire machine with both discs on.
Thank you Kevbo for letting me know that I should balance with the discs on. I can now attempt this task with confidence.