Topic: sprockets and gearing

[736cc]

I have a Morris mag w/ a unique 630 chain and sprocket sprocket carrier and its time for new sprockets & chain (530). Any comments re: aluminum vs steel and gearing? 48T rear is standard on a K1, and (correct me if I'm wrong) 17T front. Anybody play w/ gearing? My Yosh motor is pretty modified and very healthy. I was thinking of taller gearing, maybe drop a couple teeth in rear (46T) and go w/ 17T front.

[LoopsAndLogic]

From what I've read, steel sprockets come stock on bikes and are very strong and last for a very long time. The performance minded rider usually swaps these out for hard anodized aluminum sprockets. By switching to a hard anodized aluminum sprocket, the un-sprung weight of the rear end is significantly reduced as well as the rotating weight that the engine drives. A quality aluminum sprocket will have no safety risks associated with their use, but will wear out far quicker than their steel counterparts.

 If your overall goal of your motorcycle is to ride it hard for a long time, put minimal money into it, and have it work reasonably well, then a steel sprocket should be your choice. If maximum performance of the suspension and acceleration is more important than shorter part life, then the lighter aluminum sprocket should be your choice

 Hope this helps! But as far as the sprocket ratio's go, I've always left my bikes stock, cause the makers already experimented with the overall best ratio.

 Just my .2 euro's

 And switching from a 630 chain to a 520....... Best choice anybody could make.

  Cheers

  LL

[nteek754]

Hey there 736, I in the past 32 years have played with  the gearing. and I like the stock 18 48. Ive done one down on the front but it is just too much into the powerband yup its great if you want to be racing 1/8th mile, or light to light in town , but  I like your idea of going a bit taller where as you say your modified a bit . I run a 1973 750 K with a 1970 836 power plant and run the stock as mentioned . I think  If your use to 17 48 you will like 18 48 good luck have fun Craig in Maine. 

[736cc]

What does 18/48 tach at 60 mph?
What does 17/48 tach at 60 mph?
What does 18/46 tach at 60 mph?

My Yosh K1 had a 630 chain & sprockets ( 15/40) and I'm switching to 530 using totally different # of teeth.

Early CB750's tach around 4100-4200 w/ 17/45 and 4.00x18 tire.

My rear 16" wheel and fairly new 130/90-16 Dunlop GT501` is exactly 25" diameter; anybody have an 18" wheel w/ a new tire to measure and compare?

[nteek754]

736 Hey there I forgot to mention I run a  16 inch rear 130 90 and I found the tach to be  just about 4100 at 60 mph   and as for the 630 stuff they had to change the number of teeth cause of them being so much bigger but  I think they ended up with about the same gear ratio.  providing you had the stock numbers.   hope this helps  Craig in Maine.

[upperlake04]

What does 18/48 tach at 60 mph?
What does 17/48 tach at 60 mph?
What does 18/46 tach at 60 mph?

http://www.xs4all.nl/~ator0437/gc/
http://www.dropbears.com/u/utilities/gearing.htm
http://www.dansmc.com/mc_software1.htm

[andy750]

"What does 18/48 tach at 60 mph?"

4000rpm on a stock CB750K4 (stock rear wheel, 110/90/18)

Havent got used to the 17/48 to know for sure....

cheers
Andy