Magna Owners Of Texas

Please type in what year and sprocket size in the text as well.. and if you modified it from stock..

I just replaced my chain and sprockets.. I replaced the chain 35K miles ago, and did not replace the sprockets at that time...
I purchased what all the sources said was stock 40/16.
When I went to do the work, I realized that I had a 43 on the rear..
Now I had to replace the chain shortly after getting the bike, so I don't believe anyone changed out the sprocket before me...
So, it brings up the question.. Did the '94 come with a 43 and later models come with a 40??? Thus the survey..

all the gen 3 models came with a 40 tooth sprocket rear/16 tooth front. most people replace the 16 tooth to a 15 tooth (it's cheaper) but changing(increasing)  the rear sprocket by about 3 teeth has the same effect as going down one in the front. either one will raise your rmps on the highway, less fuel mileage,but more off the line/around town driving benefiits. some people change to the 17 tooth front to save gas and lower the rpms on the highway.

My '94 has the 40 on the rear, and I have a 15, 16, and 17 front so I can tailor it for specific rides. The only thing that seems to change with different sprockets is the acceleration. Mileage is relatively unaffected. The 15/40 combo is lots of fun, quicker than stink, but the 17/40 is much better for long trips. The engine is not so "busy" at freeway speeds.

Quote from: Magniac on February 25, 2009, 06:10:04 PM
My '94 has the 40 on the rear, and I have a 15, 16, and 17 front so I can tailor it for specific rides. The only thing that seems to change with different sprockets is the acceleration. Mileage is relatively unaffected. The 15/40 combo is lots of fun, quicker than stink, but the 17/40 is much better for long trips. The engine is not so "busy" at freeway speeds.

This is great info..
How much does the change in Front Sprockets change your Chain adjustment??
BTW.. Going from a 43 to a 40
Before 55MPH @ 4000RPM
Before 70MPH @ 5000RPM

Now 55MPH @ 3500 RPM
Now 70MPH @ 4600 RPM
Now 75MPH @ 5000 RPM

I'm sure my bike will not jump off the line like it used to.. This will give Dan a better advantage when we Race..  :lol:

At 5000 RPM's your bike is actually doing a true 70 MPH with the stock setup. If you are showing 75, your speedo is off as usual.

The size of the back tire will make a difference also.

With 17/40 gearing, and a 170/80 Metzeler on the back, mine indicates 80 mph at 5000 rpm. Don't know how accurate the speedo is. The first 3 gears at 10,000 rpm give 55, 85 and 115 mph indicated. Don't know about 4th or 5th, and don't really care. If you haven't made your point by 115, chances are it won't be made. ;^)

Quote from: Magniac on February 26, 2009, 02:14:38 AM
Don't know how accurate the speedo is.

This does not indicate others bikes accuracy but my GPS indicate at 60 MPH it is with in one mile a hour accuracy.

based on road side radar trailers, my speedo is accurate within 1 MPH at 35 MPH.. I can't see it being that far off at double that..
The car tire made almost know difference (maybe 100 RPM) and I would have expected that our of a new motorcycle tire..
No my wife's Sabre.. They are known for being 10 percent off

Quote from: Magnum Magna on February 26, 2009, 12:38:56 AM
The size of the back tire will make a difference also.

Yes, my mistake, that is with a stock tire.

The chain adjustment is easily made by the adjusters at the rear axle if you use a 15,16, or 17 tooth front sprocket. If you go smaller or larger you will need to add or subtract links of the chain.

QuoteI'm sure my bike will not jump off the line like it used to

My Magna ran great when I first got it, as long as I could get on it pretty hard taking off, but in traffic having to take off slow in an intersection or because of someone easing along in front of me I found it to be a real hassle. I had to keep the rpms up and slip the clutch, almost like I was taking off in second gear. It wasn't until I replaced the chain that I realized someone had change the front sprocket to a 17. I replaced it with the stock size sprocket and it made all the difference in the world. I could see no difference in gas milage and I do a lot more taking off than I do running top end. So don't throw away your stock sprockets until you've tried the new ones, just my opinion..

Quote from: Magniac on February 28, 2009, 01:40:06 AM
The chain adjustment is easily made by the adjusters at the rear axle if you use a 15,16, or 17 tooth front sprocket. If you go smaller or larger you will need to add or subtract links of the chain.

Magniac;
Thank you for your response.. Please help me to understand better..

So does this mean that you use clip type master links, and use more than one master link to change chain size to adjust to the sprockets?
Does this mean that you use clip type master links, but have 3 different length chains in your garage?

I can see how a larger/smaller sprocket on the back would cause the need for more/less links as there is a pretty significant change in sprocket diameter, but it would seem that the front sprocket size would not be so different in size as to need to add/remove links..

As long as you keep the 40 tooth rear sprocket, there's no need to break the chain. You can change the front by just loosening the tension, and then re-adjust after the change. I have used clip-style masterlinks in the past, but went back to the staked type which I'm using now.

Quote from: hootmon on February 25, 2009, 10:16:39 PM

Quote from: Magniac on February 25, 2009, 06:10:04 PM
My '94 has the 40 on the rear, and I have a 15, 16, and 17 front so I can tailor it for specific rides. The only thing that seems to change with different sprockets is the acceleration. Mileage is relatively unaffected. The 15/40 combo is lots of fun, quicker than stink, but the 17/40 is much better for long trips. The engine is not so "busy" at freeway speeds.

This is great info..
How much does the change in Front Sprockets change your Chain adjustment??
BTW.. Going from a 43 to a 40
Before 55MPH @ 4000RPM
Before 70MPH @ 5000RPM

Now 55MPH @ 3500 RPM
Now 70MPH @ 4600 RPM
Now 75MPH @ 5000 RPM

I'm sure my bike will not jump off the line like it used to.. This will give Dan a better advantage when we Race..  :lol:

Lol, I'm glad you're still up for the challenge!

This is why I keep my bike stock (no power upgrades) because I'm one of the few bikes on the roads these days at 700cc that gets 51 mpg!

I see a Used Yamaha VMAX in my future or possibly a V65 Magna/Sabre (so I can feel the awesome power of acceleration!).  We shall see when the money starts to rolling in!

I also see 70 mph at 5000 RPM.  Although DG contests that his bike shows a slightly different speed.  I checked mine with my friend's car driving next to me.