The Specs on the angular state a max RPM of 20K. If the pull and cable are adjusted properly, and the bearing and plate are not angled in any way, that shouldn't be a problem. My concern would be that any misalignment of the plate or bearing could push the bearings RPM near or up to the max. In general, mechanical designers then to spec components such that they are expected to see no more that 60-70 percent max load under peak performance. The angular is nowhere near that.

Like I said early on in the thread, it’s your call. This is just to educate you a little about Road Star’s clutch and your figures.

The clutch basket is driven by a 72 tooth primary gear off the crankshaft. The driven gear on the clutch basket assembly has 72 teeth. Even @ 5,000 RPM engine speed the clutch assembly, through the gear reduction, including the throwout bearing, is only turning around 3,200 RPM. I doubt if that bearing will ever see the 20K you quoted.

BikerRon wrote:
The Specs on the angular state a max RPM of 20K. If the pull and cable are adjusted properly, and the bearing and plate are not angled in any way, that shouldn't be a problem. My concern would be that any misalignment of the plate or bearing could push the bearings RPM near or up to the max. In general, mechanical designers then to spec components such that they are expected to see no more that 60-70 percent max load under peak performance. The angular is nowhere near that.

Like I said early on in the thread, it’s your call. This is just to educate you a little about Road Star’s clutch and your figures.

The clutch basket is driven by a 72 tooth primary gear off the crankshaft. The driven gear on the clutch basket assembly has 72 teeth. Even @ 5,000 RPM engine speed the clutch assembly, through the gear reduction, including the throwout bearing, is only turning around 3,200 RPM. I doubt if that bearing will ever see the 20K you quoted.

Thanks for the update. I was reluctant to post what I found simply because there was so much I didn't know on the subject. One of the things I love about the RSC is how much you can learn. The difficult part is separating fact from opinion. Thanks for the help on that.

G_Conway wrote:
BikerRon wrote:
The Specs on the angular state a max RPM of 20K. If the pull and cable are adjusted properly, and the bearing and plate are not angled in any way, that shouldn't be a problem. My concern would be that any misalignment of the plate or bearing could push the bearings RPM near or up to the max. In general, mechanical designers then to spec components such that they are expected to see no more that 60-70 percent max load under peak performance. The angular is nowhere near that.

Like I said early on in the thread, it’s your call. This is just to educate you a little about Road Star’s clutch and your figures.

The clutch basket is driven by a 72 tooth primary gear off the crankshaft. The driven gear on the clutch basket assembly has 72 teeth. Even @ 5,000 RPM engine speed the clutch assembly, through the gear reduction, including the throwout bearing, is only turning around 3,200 RPM. I doubt if that bearing will ever see the 20K you quoted.

Thanks for the update. I was reluctant to post what I found simply because there was so much I didn't know on the subject. One of the things I love about the RSC is how much you can learn. The difficult part is separating fact from opinion. Thanks for the help on that.

The math can be done with the manual specs given. The fastest the bearing will probably ever see would be on your way into 5th gear when your engine rpm is screaming at say 5,000. Considering primary gear reduction and the 5th gear ratio that's still just around 4300 rpm at the bearing. I agree I think you're well under 20k.

Huh? Since the clutch basket speed is entirely related to the engine speed through the primary gears the RPM ratio stays the same whether you’re in neutral or bumping the limiter in high gear. The transmission’s input shaft spins the same speed as the clutch, provided the clutch is engaged, no matter what gear is selected to turn the output shaft.

Now, take the bike up to top speed in high gear and pull in the clutch and drop the transmission all the way down to first, if it’s possible, and the bearing will see RPMs beyond comprehension.

That's right. So the rpm at the bearing is probably even lower than I stated. Thanks Ron!

So, based on that, assuming two crank rotations (4 stroke) per cyl fire, that should mean the bearing will see a max of 10K. So RPM should not be an issue.

The crank gear is a lot smaller than the clutch gear so the bearing won't experience anything near that speed. The primary reduction is listed as 1.532 so at 5,000 rpm's the clutch would be spinning at approximately 3,264 rpms.

texasscott1 wrote:
The crank gear is a lot smaller than the clutch gear so the bearing won't experience anything near that speed. The primary reduction is listed as 1.532 so at 5,000 rpm's the clutch would be spinning at approximately 3,264 rpms.

Thank you. Been trying to simplify this so it’s easy to understand.

Watch the video and imagine the smaller gear is the drive gear on the crankshaft and the larger gear on the right is the driven gear on the clutch. The larger gear turns slower in relation to the smaller gear, because of the gear reduction. Crankshaft RPM is all that counts when comparing two stroke or four stroke engine speeds.



Edit: my earlier post is in error. I need to do a better job of proof reading my shit and keep the distractions to a minimum.

“The clutch basket is driven by a 72 tooth primary gear off the crankshaft. The driven gear on the clutch basket assembly has 72 teeth.”

It should have stated, “The clutch basket is driven by a 47 tooth primary gear off the crankshaft. The driven gear on the clutch basket assembly has 72 teeth...”

Sorry for the confusion.

1.532 primary feduction is about a 35% reduction in engine rpm at the bearing.

If you still need more assurance why not just spend the $12 for the conical roller bearing already mentioned? You seem concerned enough to possibly justify the price tag.

That bearing design will handle anything the roadstar can throw at it.. and with your concerns why not.

Actually, all of this makes me more comfortable NOT changing the bearing. I'm not seeing a NEED to change it and the loss of Mfg warranty on the Barnett is worth more to me right now than any perceived benefit of the new bearing.