What clutch weights to use and why.......
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There is always the question of which weight should I use and why? The answer is simply use the weight which is designed for the type of terrain your riding and or racing in.
1.) A drag race weight: Will have a aggressive heel to middle area section, it will have a steep taper with hardly any tip weight, the reason is your concerned with the holeshot and max belt squeezing for a short distance, topend speed is not of importance, so tip weight is of no concern. This family of yamaha weights includes the 8bu-00, 8bu-10, 8ab, 8ca, 89a-10 weights
2.)trail riding weights: Will have a all around constant surve on the weight, balance weight from heel to the tip, this makes the weight act stable and smooth thru out the shift curve, a steady flow of force would be a easy way to describe it. These weights can accellerate nicely but not as aggressive as our first family of profiles, they keep a nice even curve, from start to finish they are all moderate. This includes the weights of the 8dn-10, 8dn-20, 8ek,8dg
3.) Top speed weights: These weights will have alot differnt profile as most of the mass will be out in the tip area of the weight, they will be most beneficial in a top speed situation and apply alot of force to the belt on topend, this in turns squeezes the belt more and yeilds faster top speeds. They will not have the holeshot take off of the drag race weights, but then again the drag race weights wont yield the same topend forces as these do either. This family of weights include the 8dn-00, 8cr, 8bu-10
There are alot more weights to choose from then just what I have listed and they all have strong and not so strong areas they perform in, its knowing which weight to select for the type of riding/racing your doing being the key element on how the sled will perform. Some weights you will note will almost do 2 things good but leave something else for improvement somewhere in the shift curve. Yamaha provides weight force charts with the profile of the weights pictured. I encourage anyone wanting to learn about how to pick a weight and why to get copies of these charts and sit down and look at them, its easy to make the correct choice viewing the charts.
There is a last part to this equation which can be used , thats the aftermarket clutch weights out there, heel clickers, super tips, heavy hitters, thundershift, etc. they are adjustable to fit many differnt situations, but the key is finding the one with the best shift curve and profile to match the type of riding/racing youll be doing. Its all a matter of using the correct spring rates, helix angles and seconday springs along with placement of the weight in the cam arm to get the optimum result.
There is only 1 way to get the optimum result, Test, Retest, and Test again. The key to get something from testing new set ups is to keep good notes.
1.)What rpm the sled engages at?, the rpm at which you shift it at?,
2.)The characteristics of the set up, the bad things, the good things
3.)The speeds or times your testing with, conditions have alot to do with results, try and keep the conditons with in reason, meaning your not going to get the same results on a warm 45 degree day with wet slushy snow versus a crisp 20 degree day with light powder snow on track or course. also keep the track length the same to the type of tuning your trying to get the best result for.
This all has to be written down along with exact tune up specs you have in . When you sit down and look at the notes it will become easy to pick out the good set ups over the bad and easy to think of new combinations to get a better result, this never ends!!!
Gearing will have a large effect on the amount of clutch weight you can run and the shift curve, this is kinda opening up a can of worms and I will add a post later on to help add gearing into the equation, just trying to keep it simple for now.
Just when you think it cant get any better, you try something as minor as a 10 degree drop in secondary spring tension and the sled jumps mph or drops E.T of the time.........now go out and Test and Have Fun!!!!!
__________________
It's just a little 700!
--------------------------------------------------------------------------------
There is always the question of which weight should I use and why? The answer is simply use the weight which is designed for the type of terrain your riding and or racing in.
1.) A drag race weight: Will have a aggressive heel to middle area section, it will have a steep taper with hardly any tip weight, the reason is your concerned with the holeshot and max belt squeezing for a short distance, topend speed is not of importance, so tip weight is of no concern. This family of yamaha weights includes the 8bu-00, 8bu-10, 8ab, 8ca, 89a-10 weights
2.)trail riding weights: Will have a all around constant surve on the weight, balance weight from heel to the tip, this makes the weight act stable and smooth thru out the shift curve, a steady flow of force would be a easy way to describe it. These weights can accellerate nicely but not as aggressive as our first family of profiles, they keep a nice even curve, from start to finish they are all moderate. This includes the weights of the 8dn-10, 8dn-20, 8ek,8dg
3.) Top speed weights: These weights will have alot differnt profile as most of the mass will be out in the tip area of the weight, they will be most beneficial in a top speed situation and apply alot of force to the belt on topend, this in turns squeezes the belt more and yeilds faster top speeds. They will not have the holeshot take off of the drag race weights, but then again the drag race weights wont yield the same topend forces as these do either. This family of weights include the 8dn-00, 8cr, 8bu-10
There are alot more weights to choose from then just what I have listed and they all have strong and not so strong areas they perform in, its knowing which weight to select for the type of riding/racing your doing being the key element on how the sled will perform. Some weights you will note will almost do 2 things good but leave something else for improvement somewhere in the shift curve. Yamaha provides weight force charts with the profile of the weights pictured. I encourage anyone wanting to learn about how to pick a weight and why to get copies of these charts and sit down and look at them, its easy to make the correct choice viewing the charts.
There is a last part to this equation which can be used , thats the aftermarket clutch weights out there, heel clickers, super tips, heavy hitters, thundershift, etc. they are adjustable to fit many differnt situations, but the key is finding the one with the best shift curve and profile to match the type of riding/racing youll be doing. Its all a matter of using the correct spring rates, helix angles and seconday springs along with placement of the weight in the cam arm to get the optimum result.
There is only 1 way to get the optimum result, Test, Retest, and Test again. The key to get something from testing new set ups is to keep good notes.
1.)What rpm the sled engages at?, the rpm at which you shift it at?,
2.)The characteristics of the set up, the bad things, the good things
3.)The speeds or times your testing with, conditions have alot to do with results, try and keep the conditons with in reason, meaning your not going to get the same results on a warm 45 degree day with wet slushy snow versus a crisp 20 degree day with light powder snow on track or course. also keep the track length the same to the type of tuning your trying to get the best result for.
This all has to be written down along with exact tune up specs you have in . When you sit down and look at the notes it will become easy to pick out the good set ups over the bad and easy to think of new combinations to get a better result, this never ends!!!
Gearing will have a large effect on the amount of clutch weight you can run and the shift curve, this is kinda opening up a can of worms and I will add a post later on to help add gearing into the equation, just trying to keep it simple for now.
Just when you think it cant get any better, you try something as minor as a 10 degree drop in secondary spring tension and the sled jumps mph or drops E.T of the time.........now go out and Test and Have Fun!!!!!
__________________
It's just a little 700!
thanks for that info as i am new to clutching but eager to learn more where might i find these charts that you speak of mr.v
bajardine
New member
MrViper, Do you know of a place to get the same information from the graphs but in a chart form? I'd like to be able to graph any combination of clutch weights against each other. Also, across the bottom of the graph, what is the range? The top right corner says @ 7500 RPM yet the scale across the bottom reads from 0 - 30. It says stroke in mm. What stroke is it refering to? Any help here?
Thanks,
Bruce
Thanks,
Bruce
ttt for tuner time
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