Apex clutch on Sidewinder

[Fast]

Many of our customers have changed over to the Apex style (previous Yamaha) and are extremely happy with no issues. Everything from the sidewinder clutch will go in to the previous style clutch....only thing you have to do is add 3-4 grams of weight to your setup when changing over.

Where are they adding the weight? to the tip

 

[Crossfire12]

THUNDER PRODUCTS SAID The Apex clutch will still have harmonics noise -as it is the crank snub shaft...not so much the clutch. But the Apex style clutch has the extra set screws to lock the roller pins from moving and wearing.

WHY do you say it’s crank snub shaft? I have AC with same motor snub and mine never rattles. Can you explain? Being your a clutching Vendor?[/QUOTE]

 

[Thunder Products]

Sidewinders have the set screws too

For the weight pins, not the roller pins. The Apex clutch has set screws

Where are they adding the weight to the tip

Mainly on the tip

THUNDER PRODUCTS SAID The Apex clutch will still have harmonics noise -as it is the crank snub shaft...not so much the clutch. But the Apex style clutch has the extra set screws to lock the roller pins from moving and wearing.

WHY do you say it’s crank snub shaft? I have AC with same motor snub and mine never rattles. Can you explain? Being your a clutching Vendor?

[/QUOTE]

Even with the clutch off, there is still the "harmonics" noise that comes from the snub shaft.... this is the noise I am talking about. Some engines have more noise than others.
This harmonics noise gets louder with the bell effect from the primary sheaves.

 

[Fast]

Where are they adding the weight to the tip

Are all the apex clutches the same from 2006 to 2018 reason i ask is my 2006 gt had room for .060" of overdrive bringing it to 1:1, without machining the face and split collar the belt was over 1" from the top of the primary i cant see how it would work on the sidewinder

 

[Fast]

I know, thats it and what I recall seeing as well, but how is it happening with same angles, same belt and same dia it shifts to on the primary? Doesn't add up. Only way to get more OD is shift belt up the primary higher or further into the secondary, or use a wider belt. How does that happen with same angles, same belt and belt rides to the same dia on the primaries?

A wider belt by .020" in same length will provide a 2% higher OD as shown by Racepac computer jackshaft and engine speed.

Typically as had been said, is best speed is had staying out of OD. Well unless your drag racing and run em right outta gear thru OD and picking revs before the finish line. Most all trail sleds are geared to stay out of OD, but with the power of the turbos its easy to slip the belt in the primary down low on the holeshot with high gearing and good traction, high gearing is harder on belts also so what do you do? Find a clutch setup to bite the belt harder!

You can machine .060" off the split collar in the primary and anther .060" off the back of the helix this will give you significant overdrive on the apex clutch but the sidewinder clutch is maxed out the belt on my srx is dam near the top stock no more room left

 

[sideshowBob]

You can machine .060" off the split collar in the primary and anther .060" off the back of the helix this will give you significant overdrive on the apex clutch but the sidewinder clutch is maxed out the belt on my srx is dam near the top stock no more room left

Machining the Apex clutch for overdrive brings up the issue of increased jackshaft and resulting belt rotational speeds.

IMO:

Remember an Apex primary clutch and jackshaft, at a 1:1 shift ratio, is only spinning at @ 8600 RPM at 10,600 engine RPM so overdriving it at 10% is less then 9500 rpm jackshaft speed [still WAY to fast]
With a Winder engine that is already spinning at 8800 - 9000 rpm, anything above a 1:1 clutch ratio will have a detrimental affect on belt longevity. A 10% overdrive on a Winder results in potential Jackshaft speeds @ 9700 - 9900 RPM ! There is no belt that is going to take the resultant heat and flexing fatigue ,from high rotational speeds, overdrive creates on a Winder, at least not for any distance.

JM.02c

 

[Fast]

Machining the Apex clutch for overdrive brings up the issue of increased jackshaft and resulting belt rotational speeds.

IMO:

Remember an Apex primary clutch and jackshaft, at a 1:1 shift ratio, is only spinning at @ 8600 RPM at 10,600 engine RPM so overdriving it at 10% is less then 9500 rpm jackshaft speed [still WAY to fast]
With a Winder engine that is already spinning at 8800 - 9000 rpm, anything above a 1:1 clutch ratio will have a detrimental affect on belt longevity. A 10% overdrive on a Winder results in potential Jackshaft speeds @ 9700 - 9900 RPM ! There is no belt that is going to take the resultant heat and flexing fatigue ,from high rotational speeds, overdrive creates on a Winder, at least not for any distance.

JM.02c

Thats interesting, the 2006 apex was so detuned the clutches weren't close to 1:1 ratio right from yamaha so we were able to machine, im not sure if the newer apex clutches are different you would have to mock it up with the springs off, it's funny the old 2 stroke srx's would run 9500rpm all day with no belt issues

 

[74Nitro]

Thats interesting, the 2006 apex was so detuned the clutches weren't close to 1:1 ratio right from yamaha so we were able to machine, im not sure if the newer apex clutches are different you would have to mock it up with the springs off, it's funny the old 2 stroke srx's would run 9500rpm all day with no belt issues

They(SRX 700) spun 8500-8700
In addition, they were barely half the power these tuned Winders are putting out.

 

[Fast]

They spun 8500-8700
In addition, they were barely half the power these tuned Winders are putting out.

Dissagree

 

[Fast]

They spun 8500-8700
In addition, they were barely half the power these tuned Winders are putting out.

My apex ran 10400rpm at the motor and 8000rpm at the clutch after machining .060" (1:1)

 

[74Nitro]

My apex ran 10400rpm at the motor and 8000rpm at the clutch after machining .060" (1:1)

I was referring to the SRX 700

 

[Thunder Products]

I was referring to the SRX 700

Tested an SRX 700 clutch on a 270 SW and the only issue was getting certain weights to swing in the spider , because the SRX spider or 2 stroke clutch does not have the windows in the spider.

In my opinion, if the heavier 4 stroke weights would clear the spider, this clutch to me is just as strong as the Apex style clutch. This is because the parts from an Apex clutch will interchange with an SRX clutch.

 

[74Nitro]

Tested an SRX 700 clutch on a 270 SW and the only issue was getting certain weights to swing in the spider , because the SRX spider or 2 stroke clutch does not have the windows in the spider.

In my opinion, if the heavier 4 stroke weights would clear the spider, this clutch to me is just as strong as the Apex style clutch. This is because the parts from an Apex clutch will interchange with an SRX clutch.

View attachment 148484 View attachment 148485

Hi TP, I was just responding to Fast when he stated that SRX's turned 9500, which isn't true.

As far as comparing the clutch, it should be noted also that the four strokes were much thicker in key areas of the sliding sheave compared to the SRX clutch.

 

[PowderFalcon]

Hi TP, I was just responding to Fast when he stated that SRX's turned 9500, which isn't true.

As far as comparing the clutch, it should be noted also that the four strokes were much thicker in key areas of the sliding sheave compared to the SRX clutch.

Another good reason to try an apex (or viper) primary clutch (thickness)... flying weights like shrapnel doesn't sound appealing!!

 

[74Nitro]

Another good reason to try an apex (or viper) primary clutch (thickness)... flying weights like shrapnel doesn't sound appealing!!

The old SRX 700