Front sprockets

[Charles S Otwell]

I have a question, first how many sizes of front sprockets are offered for the Magna. I'm asking because most of my riding is in and around town and even tho I still enjoy an occasional romp I rarely cruise over 80 mph. The older I get the less I like launching from every stoplight and I catch myself getting lazy on my take offs.  I know that changing to a smaller sprocket will help this, but on the top end how much will I be raising my rpms at 70 or 80. I know it depends on how much I change the ratio, but again, I have no idea what size sprockets are offered. Anyone know what's available?? thanks

[Greg Cothern]

If memory serves me there is one less tooth and one more tooth option.  They seem to raise the RPM's at normal highway speed about 500 rpm.

[TLRam1]

I thought I had something that might be of help.....maybe not here but someone who wants to play with this.

I have not had a reason so not used it yet.

Gearing Commander

Motorcycle gearing/rpm/sprocket/speed/chain calculator


http://www.xs4all.nl/~ator0437/gc/

[TLRam1]

Here's another I have not used yet. Someone might want to play around with it some if the need arises.


Horsepower Calculator

Estimate Your Horsepower!

http://www.speedworldmotorplex.com/calc.htm

[Magnum Magna]

My main ride is around town, but if I start taking long trips I was going to increase the size for milage.  

For how much acceleration the Magna has it will not bother me to reduce it a little to increase the MPG.

[Greg Cothern]

He has a 107 gallon tank on that thing and he is worried about an extra 2 or 3 miles!    LoL

[Magnum Magna]

Very funny.  Believe me (My wife does not believe me).  More miles in the saddle is not what I would be after. I will have saddle sores as is.  I would do it for economy.  The reason I got back on a bike to start with was economical reasons.  I am still trying to keep that goal with a little fun also.

[Charles S Otwell]

I may not even need a smaller sprocket I may just need some carb work.(hint,hint) It's not really a problem riding solo but two up I feel like I'm having to rev it up and slip the clutch too much just to roll off from an intersection smoothly. Guess I need to go ride Bob's new bike just to make sure that it's not just me. . Is anyone running the smaller sprocket?

[rjb/AKA Bob Barram]

I have found when you ride the Magna like it was built to ride you do not get good gas mileage.......
Bob

[Magnum Magna]

I have found when you ride the Magna like it was built to ride you do not get good gas mileage.......
Bob

I was extremely lucky that the Magna fell in my lap.  I was not knowledgeable or time to do research to know the different bikes. I probably would not have bought a Magna.  I would have got one with better gas milage.  But extremely pleased that I got it.  If not only for the Moot club experience.   Long story short, at a red light someone asked to buy my truck. Sold my truck on Sunday and had to get a bike on Monday.

full story is at http://www.geocities.com/bible101a/magna750.html

[RedMagna]

I have found when you ride the Magna like it was built to ride you do not get good gas mileage.......
Bob

AMEN!

[Curtis_Valk]

Is anyone running the smaller sprocket?

I didn't but I definately considered it because of the way I used my Magna.  I planned on going to the extreme and replace the stock 16/40 front and rear sprockets with 15/42 for good launches at the red lights.  The Magna does take some practice and finesse to get under way smoothly.

Even with the stock sprockets I would sometimes fail to get the tire to hook up properly, but I still wanted to gear down so the bike would be in the power rpm's quicker.  With the stock sprockets I was almost all the way across the intersection before the "real" power came on unless I revved it mercilessly and slipped the clutch a lot.  However I didn't want to practice enough to get good at it and also didn't want to go through clutches frequently.  Len took the Magna off my hands before I spent any real money on it and I didn't get around to trying the different sprockets.

Curtis

P.S.  Also, I think the sprocket change would let you get into second at a lower speed and avoid some of the herky-jerkyness that happens in first gear at low speed if you are not perfect with the throttle.

[Magnum Magna]

I am far from a Magna expert but making the back sprocket bigger is the way I would go. That will be more expensive but in my mind safer.   It always makes me nervus making the small one smaller.    

[Curtis_Valk]

It's best to stay within one tooth (total for both sprockets) of stock so you can use the stock length chain and still have about the same amount of adjustment.

If you go down by one tooth on the front or up one on the back you're still within one tooth but you have not changed the ratio by very much (especially if you only change one on the rear).  If you increase the rear sprocket by two teeth you have made some perceptible difference, but now your chain adjusment will be all the way forward.  That is one reason I was going to go 15/42, as that combination is within one tooth of stock.

If you want to change only one sprocket, the front one is the way to go because one tooth difference has more effect and the front sprocket is way cheaper.

Curtis

[Charles S Otwell]

Thanks guys for all the input. I have a chain and sprocket replacement coming up, and I think I'm going to try changing the  ratio then. Like I said my main goal is smoother take offs when my wife is riding with me. I think Curtis described the problem with "herky jerky" . I can pull away smooth but if I have to back off a little because of traffic I have to clutch it and rev back up and slip the clutch to stop all the jerking. I think the lower gear ratio will help. First a tune up so I'll have a good baseline to compare to.