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Dalton's new Quick Adjust Cam Arms.


Wow, these look impressive! Which ones should I order? I'm running a nytro at 18lbs of boost for approx 280hp max.................unless I ad some nos! lol
 
Ken Climb you wont have to weight as heavy as a super tip to get the same results and these weights are awsome they will make a normal guy into a clutching expert just because you will adjust until you hit the sweet sppot it takes seconds to move mass around.
 
Which weight to use depends of course on a lot of variables. Some people like to tune with different rate primary springs,..some like different helixes,...some run low gearing,...and some prefer those big stiff yamaha primary springs for their application.

...changing any of the hp ratings,along with any of the above variables will mean a different total flyweight mass.
 
shift characteristics

How do these weights shift compared to the supertip style profile??? similarities, differences??? how does the different profile affect the shift curve/rpm? Boosted apex 14-18 lbs.
 
All weights,including our own earlier DPY style that have a "polaris..ish" type of curvature...similar to 8DN-20 and such are going to act different.(most aftermarket)

Like I mentioned earlier,we still have some shops that prefer these style weights,especially for short drags,etc.,as usually with a very agressive curve,it requires less weight in total to acheave the similar amount of shift force. The real agressive curves using light weight spool up quickly and make quicker power.

When the 03 RX came along,you may have noticed that yamaha did not continue to use the 8BU's,8DN's,etc at 48-50 grams like they did on a similarly powered srx....it was different.
...when the first RX's came out,,...everybodys first instinct was to get the big club 70g flat curve weights out and get in some 8BU's that they had successfully used in SRX's.

Most were quick to realize that this stuff didn't harness the torque very well,and huge issues of low speed belt slip ensued...so people went to a bit less agressive polaris type curve weights that were more useable in lighter increments than the stock early flat rx-1 weights. ....and many had much better drag racing results and that was important to many.

..BUT ,the lighter required mass still meant some low speed belt burn here and there in certain situations.,etc...a comprimise that was fine with many as they did get results they wanted for certain applications.(thus came along the well known use of GOING to SMALLER ROLLERS,etc)...as they were trying to get more "untucked mass" at the point of belt contact.
....which was a big part of the reason Yamaha went to that big long FLAT curvature in the first place(THEY OVERDID IT IN MY OPinion). By using that flat curve and the resulting necessary big GRAMS thyat went along with it,they got better low speed belt grip.
..I know this because I was THERE in Sumit Lake, Alaska on the same week as the japanese and US Yamaha people in November of 02' ..and we were both there to do testing with 4 stroke yamahas....and Sumit lake only has one gas station/hotel /restaurant ...and it is all in one small building,lol.

To make it easy to explain,I guess we feel that the curvature we use on our DPYR rivet adjustable series(and the new DTYA adjustable ones) is the favorite,as it allows more "untucked mass" at belt contact,and a still somewwhat more agressive curvature than a stock weight,...but improved performance and acceleration characteristics over a stock curvature,..but with less of the negative effects (backshifting,belt grip,..the often NEED for TIP weight TOO LiGHT for top speed)of a weight with too much curve for typical 4 stroke trail application.

As you can see,I'm only generalizing,as this is clutching we are talking here....and no one's opinion rules,..it is clutching...and people do clutching for a reason,..because nobody sees the ultimate set up to be the same thing. That is why there are so many variables,so many opinions,and it often establishes long heated debates....it is clutching and people have different priorities.

For instance,...the helixes we supply to so many Yamaha dealers vary in angles WIDELY...and they are ALL for Apex models ! ...THERE IS NO most common..there is not. It is all over the place. That is beacause any time you change one peice of the puzzle(intended use,track size,studded?,preferred spring rates,gearing,type of favorite flyweight!, etc,etc,etc) ...the helix changes to get the proper balance.

This DPYR curve has been a favorite of us and our customers,and it is the one used on the new DTYA Quick adjust cam arms to make it even more flexible.
 

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I grabbed this post from another thread I was in for additional info.
HAMMER said:
Clutching -- Where do I start?

Correct Air Fuel Ratios are a must before you can begin clutching.

Focus on the primary and getting your engine rpm right. Your combination of clutching should take you right to PEAK HP and create continuous acceleration from bottom to top. In the primary (drive) you'll increase or decrease the weight and or profile of the flyweights to achieve this. Lighter weights reduce "grip" or "squeeze" and raise the rpm. Heavier weights increase the "grip" or "squeeze" lowering rpm. Heel = bottom end, Middle = Mid-range, and Tip = top end. Make sure you're using the same profile of weight when you make changes or you'll end up chasing your tail. High profile weights apply force quicker and flat profile weights apply force slower. Large rollers tuck the weight into the weight pocket and decrease the weights leverage or initial force. Small rollers untuck the weights and increase the weights leverage or initial force. You want just enough "grip" or "squeeze" on the belt that it doesn't slip.

Once you have your rpm where you want it your next job is to get the combination to shift the way you want it to. That's the job of the secondary. The combination of spring and helix is what determines your rate of shift either up or back. The secondary spring directly equates to side-force or "grip" or "squeeze" on the belt. The idea is that the more side-force you have on the belt the less efficient it is because of belt drag. You want just enough "grip" or "squeeze" on the belt that it doesn't slip. Too much pre-load, side-force, and the clutch will back-shift too fast, put you in too low of a ratio, and overrev when you stab the throttle out of a corner. All rpm and no GO !!! Too little and it won't back-shift fast enough, it will react sluggishly, or bog out of the corner, or lose rpm while trying to maintain high speeds. For the climbers you'll lose rpm while climbing. If your shift rate is where you want it DO NOT use the secondary to adjust engine rpm. I've seen a lot people use an increase in the pre-load, side-force, of their secondary to bring up their engine rpm, myself included. You are shooting yourself in the foot !!!! Once you go past the balance point it will decrease the efficiency of transmission of power to the track while adversely affecting the ability of the secondary to keep the shift curve flat. Lastly, I'm a believer in running the lowest gearing possible and still make the mph you're looking for. Gearing is a great way to increase out of the hole acceleration (torque multiplier). Its less work for the clutches, engine, and they will both run cooler.

Common Pit-Falls: Clutches MUST be clean. Clutches MUST have the correct side-clearence, deflection, offset, and center-to-center. Bushings MUST be serviceable. Springs MUST be within tolerence. Belt MUST be cleaned before break-in and within tolerance after. If all of these conditions are met see below.

Only change ONE thing at a time. Take good notes, like snow condition, temp, elevation, terrain, what you changed, and the effect it had. The primary (drive) and the secondary (driven) will directly effect each other. Try not to over compensate one to "fix" the other, it's a BALANCE you're looking for.

Note:
What works for boondocking/hillclimbing will not work for drag racing and what works for drag racing will not work for boondocking/hillclimbing.

Under target rpm.
1. Too heavy primary (drive) weights.
2. Too low finish rate (drive) spring.
3. Too steep secondary (driven) helix angle.
4. Too low tension in secondary (driven) clutch.
5. Too tall gearing.

Over target rpm.
1. Too light primary (drive) weights.
2. Too high finish rate (drive) spring.
3. Too high tension in secondary (driven) clutch.
4. Too shallow secondary (driven) helix angle.
5. Too low gearing.
Click to expand...
 
Dtya-2 i have a set coming in the mail will let you guys know what i think!! Any one what some H.H. with tons of tunning washers and stuff??

THANK YOU Skydog
 
WOW they look killer!! What great service i got from them UNREAL!!

Thank you Skydog P.S. Now let the #*$&@ kicking start!! :) :)
 
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