Sprocket Gearing

[79josh81]

To be honest, I'm going to run the fucker with just the key in the shaft first. If it shears it shears and the sprockets will just free-spin on the shaft and I'll figure out how to get it home. If it doesn't shear, I'll pull it apart and take a look at the keys when I get back to see if there's any obvious damage to them that would lead me to believe they'll fail. Then I'll worry about whether I'm welding something or whether I'm rethinking an entirely new setup.

 

[650Skull]

That would work if the 2 jack shaft sprockets aren't connected...............Have you thought about getting another key-way made up so there will be a least 2....even 3

There is no way out of having to spend some money making up something like this.........think 2M alluded to that

 

[79josh81]

Yeah another keyway machined in the shaft and sprockets would be an option. There's a lot of options so I'm probably just going to go from easiest to hardest and see what works.

 

[79josh81]

I’m just curious for future reference, but if I were to get a 6 splined shaft and two 6 spline sprockets, how do you keep them from moving axially down the shaft? With collars? And what size 6 spline shaft would fit the xs650 front sprocket?

 

[TwoManyXS1Bs]

Y'know, the XS650 countershaft sure looks like the inboard splines match the sprocket splines. I bet someone close to you has one...

 

[650Skull]

Get a old gearbox shaft and mount that using the splines for the 17 tooth sprocket t.

The gear shaft can be bearing mounted, as it is in the gear box, attached to your frame inside a purpose built cover........Yours to design.

I see some potential problems with this idea but they can be surmounted with a bit of thought.............

.............Post #25

Y'know, the XS650 countershaft sure looks like the inboard splines match the sprocket splines. I bet someone close to you has one...

View attachment 134819

 

[79josh81]

Yeah I’m just curious about the shaft diameter to get a longer one and the how to keep the sprockets from moving axially if I go that route.

 

[TwoManyXS1Bs]

Not all sprockets are clamped with a nut.

 

[79josh81]

Not all sprockets are clamped with a nut.

View attachment 134856

Yeah but there’s obviously a plate behind that sprocket that it bolts to I’m assuming. I’m wondering how I’d take like a raw 10” shaft with 6 splines that run the whole length and secure the sprockets so there’s no axial movement.

 

[79josh81]

.............Post #25

Maybe I’m not understanding by what you’re saying in post 25 as to how you fix the sprockets on the shaft so they don’t move axially?

 

[TwoManyXS1Bs]

Yeah but there’s obviously a plate behind that sprocket that it bolts to I’m assuming...

Nope, just that one visible plate.



You groove the shaft where you want to...

 

[TwoManyXS1Bs]

The XS650 front sprocket is a unique item.
May want a more popular type, like Honda...

 

[79josh81]

I’m not understanding visually how that plate keeps the sprocket from sliding back and forth...

 

[79josh81]

Oh do you actually notch the splines of the shaft so you can rotate the splines on the plate into the notches you made?

 

[TwoManyXS1Bs]

You slides the sprocket on, just past the groove.
Then you slides the retainer on, atop the groove.
Rotate it 1/2 spline.
Insert bolts...



Google "Honda front sprocket".

 

[79josh81]

You slides the sprocket on, just past the groove.
Then you slides the retainer on.
Rotate it 1/2 spline.
Insert bolts...

View attachment 134860

Ok now I get it. I’ve never worked with sprockets like that before so I had no clue. Thanks for that. That definitely opens some options for me now that I understand that.

 

[TwoManyXS1Bs]

Atta boy!

Now time fer the thinkin' juice...

 

[79josh81]

Lol

 

[shawnkva]

Check these guys out. I've used them in the past, you can choose the spline you want. You can send in a sprocket and they will broach the matching spline to it. Or they can provide a matching sleeve that you can then weld to your sprocket bore.

https://www.grobinc.com

 

[79josh81]

Just an update...

I ended up building the jackshaft with a 1” keyed shaft just like I had originally planned on. I ended up just keying the sprockets in with a piece of “1 ID tube in between them as a spacer to get the correct sprocket spacing. I then used collars on the outsides of the two sprockets to keep them from moving axially along the shaft and to take the stress off of the sprocket set screws. Concentric locking collars also secure the shaft within the pillow blocks. I’ve had this bike out a bunch of times now and have beat the shit out of it with fast clutching and hard riding and the keys in the keyway have held up great. It’s a smooth rider and I’m still trying to figure out why because usually things don’t happen like that for me.