60 tooth sprocket on CBR

[sharukh]

we were advised not to use a 60 tooth sprocket on a CBR 600 F4i, because it might cause the clutch to wear out.

what do most teams use? why might the clutch wear out?

[drivetrainUW-Platt]

????????

The only reason I would think it would affect the clucth is if you have too much torque because of the high gear.

You mean a 60 tooth on your differential I am sure.....what tooth count would you run on the engine output?

[Pete M]

Yeah, i doubt you'll have any problems. Assuming you're NA, your engine won't be able to produce enough torque to slip the clutch no matter what you do with your final drive ratio.

[sharukh]

yes, the differential sprocket is 60 teeth, engine sprocket is 16 teeth.


Yeah, i doubt you'll have any problems. Assuming you're NA, your engine won't be able to produce enough torque to slip the clutch no matter what you do with your final drive ratio.
- what is NA, but yes we definitely wont have a lot of torque, coz of restrictor, losses, etc.

thanks guys, please let me know if u have anything more to add

[cmeissen]

NA - Naturally aspirated meaning no turbo or super charger. Most teams run smaller sprockets on the engine like 11 or 12 tooth so that they can reduce the size of the rear sprocket. You might want to look into that option, but if not the 60 tooth should be fine.

[Pete M]

60/16 = 3.75, which is actually quite a small final reduction in SAE terms. When we were NA, we were usually around 4 i believe. But it depends on what gears you plan to use (mainly whether you consider 1st or 2nd your lowest gear).

But as chris pointed out, most teams do that by dropping the front sprocket size significantly. We've run with a 12 tooth one for years without any problems.

[drivetrainUW-Platt]

16-60 are big gears. Packaging will be a lot nicer with like a 12/13 engine and a 45 tooth rear.

[DustinJones]

I believe we ran an 11/44 setup this past year on our Honda RR, and had no problems with it. I think the gears from either from Thrust or Rebel.

[Brett Neale]

We run an 11 on the front, with a ratio of about 4 or so. Running 16-60 would be fine. The 11 is great for packaging the chain drive, we have a center distance of around 210mm with an idler sprocket tensioner...

[abhishek502]

Originally posted by Brett Neale:
We run an 11 on the front, with a ratio of about 4 or so. Running 16-60 would be fine. The 11 is great for packaging the chain drive, we have a center distance of around 210mm with an idler sprocket tensioner...

hello,
what about the chordal action if a use less no. of teeth(as you told 11) and will it be strong enough to handle so much high chain tension forces????

[Boffin]

Originally posted by Pete M:
60/16 = 3.75, which is actually quite a small final reduction in SAE terms. So I don't know what to class our 43/15 = 2.87 that we ran with the cbr. That said we were making butt loads of torque though and could easily burn all of 1st from a standstill.

The concern with wearing the clutch out would probably be due to the longer that you "theoretically" have to slip the clutch to launch the car effectively.
I would not be concerned about it at this stage. Perhaps monitor it and measure plate thickness when it’s easy to do so.

[Owen Thomas]

5 year old thread...

Abhi,

The short answer is "Yes, probably". There are some calculations you can do to check that the teeth do not yield (see Shigley's Mechanical Engineering Design or equivalent text) provided you know your material, torque at the crank and final drive arrangement. From my experience, it is very unlikely that you will shear teeth right off of a sprocket with any conventional FSAE drivetrain, however a high final drive ratio or otherwise poor design may cause increased wear.