Press Collar Material

[VOH]

I need to press a new timing gear on to the crank for a dirt bike. what thickness of material do i need to safely press it back on? I expect something like EMT might have too thin of wall. Will a piece of Black pipe be enough? the original gear come off without any heat, so I don't think the fit it too tight.

(This isn't my actual crank, just one I found online for reference. Mine is in WAY better shape)

 

[GeoBruin]

Black pipe is a pretty good idea. Cheap, pretty thick wall, and available in a variety of sizes. In fact, you might get away with a piece of pvc depending on how much force it takes.

 

[cvairwerks]

Throw the crank in the freezer for an hour or so and the gear in the toaster oven for about the same time. No press needed.

 

[whateg01]

If you can't find something that is a close fit to the shaft, you can use something like a bearing or some thick washers and then press on those with the pipe or whatever you have to take up the height.

 

[VOH]

Throw the crank in the freezer for an hour or so and the gear in the toaster oven for about the same time. No press needed.

I had intended on heat and cold, but didn't anticipate it would be enough alone. Thank you.

-VOH

 

[cvairwerks]

I had intended on heat and cold, but didn't anticipate it would be enough alone. Thank you.

-VOH

It may or may not be enough, depending on how tight the interference fitting is. You can measure the od on the crank and the id on the gear and see.

 

[BillK]

Black pipe should work fine. If it is a timing gear it is probably keyed and not a lot of press fit. I have done plenty of those types of things and have never wasted my time heating them up.

If you are doing it in a press be careful how you support the crankshaft as you can bend it. Support it on the counterweight if possible.