final gearing

[Mark Olson]

.....When on level ground I see 5k rpm for 80mph.

....and on hills? 

Noel

Don't know , too busy having fun .

[Arnie]

Opinion?  You want Opinions ?  OK, here's mine :-)

Assuming you are still running the OEM 150/80x16 rear wheel, a 17/43 isn't necessary, but it should be fun around town.  You'll give up some fuel economy and maybe have a few un-intended wheelies, but it will do no harm (other than maybe a ticket or two for those wheelies)
On a longish trip, the bike will seem busy all the time.
Your choice.
Or, get a proper "hooligan" bike

[Cash Dereszynski]

Thnx to all.

Regards

Cash

[IceFJ]

I´d like to add one thing that has not been addressed in this thread
In order to extend the life time of the chain it is preferred to use one sprocket with an even number of teeth against an odd number sprocket,
-just to throw in one more factor for you to think about 

[ribbert]

I´d like to add one thing that has not been addressed in this thread
In order to extend the life time of the chain it is preferred to use one sprocket with an even number of teeth against an odd number sprocket,
-just to throw in one more factor for you to think about 

That's the theory and why I run 18/41. I have always run odd sprockets for this reason but whether it actually makes a real world difference, cant  say.

Noel

[FJ1100mjk]

I´d like to add one thing that has not been addressed in this thread
In order to extend the life time of the chain it is preferred to use one sprocket with an even number of teeth against an odd number sprocket,
-just to throw in one more factor for you to think about 

I'm sorry, but I can't seem to grasp this. From your comment, a 19 tooth sprocket would wear a chain out faster than an 18 tooth sprocket. I don't get how just an odd number plays into this.

I can reason how a 17 tooth sprocket would wear faster than an 18 tooth sprocket, due to its smaller pitch diameter. Hence, more rotations over a given time, with the chain riding along with it. But I just don't know how a sprocket that has an odd number of teeth, and its tooth count being greater than the even count below it, would wear itself and the chain out faster.

I guess I require some enlightenment on the above.

Thanks.

[FJ1100mjk]

FJ gearing article. More food for thought...

http://www.fjcatalogue.com/f/FJ_gearing_sheet.pdf

[FJmonkey]

I´d like to add one thing that has not been addressed in this thread
In order to extend the life time of the chain it is preferred to use one sprocket with an even number of teeth against an odd number sprocket,
-just to throw in one more factor for you to think about 

The odd/even number of teeth has no affect on life of the chain. The two sprockets are only connected via the chain, otherwise independent of each other. However, bending a chain over smaller diameter sprockets can reduce the life, the chain links have to rotate more to turn around the smaller sprocket. But I don't think the difference of a 17T vs. an 18T will be worth the argument. Wives tales BS. Nothing personal, my background is mechanical engineering. 

[FJ_Hooligan]

The even/odd sprockets is a wear pattern thing.  The old bevel drive cams used even/odd gear sets to make sure the gears always meshed differently.  If it was an even/even gear set, the gear teeth would always mesh in the same pattern.  The even/odd ratio changes the gear teeth meshing on every rotation.  The theory was to prevent a potential fatigue failure from a constant wear pattern.

Same with even/even sprockets.  The sprockets will have a fixed engagement pattern on the chain.  Even/odd sprockets would have a random meshing pattern on the chain.  Whether it really makes a difference is anyone's guess.

Edit:  This technique is also employed on ring and pinion gear sets.  A quick check of common differential ring and pinion ratios shows them to be either even/odd or odd/odd, no even/even applications.

[rlucas]

Doesn't that all depend on whether you have an odd or even number of links in the chain? What if there's a half-link? 

[FJmonkey]

Edit:  This technique is also employed on ring and pinion gear sets.  A quick check of common differential ring and pinion ratios shows them to be either even/odd or odd/odd, no even/even applications.

I can see the ring and pinion as the teeth have direct contact with each other. I just don't see how two sprockets connected with a chain of 100+ links can have that much repeat contact with the same tooth and link. But since I really don't care or need to prove a point and I really don't want to figure out the math on this, I will leave at that. Besides, I am likely to have way more fun starting another oil or tire thread.... 

[wildfire]

So anyways which oil is better and why?.. just kidding

[FJ_Hooligan]

But since I really don't care or need to prove a point and I really don't want to figure out the math on this, I will leave at that.

Not defending the practice, just attempting to show where the "logic" comes from.

For the record, I'm running an 18/40 sprocket combo.

[rlucas]

For the record, I'm running an 18/40 sprocket combo.

Risk-taker.

[FJmonkey]

18/38 on my FJ