CNW e start conversion, sprag failures

I did a little research online and it seems to say that sprag grease should not have EP additives as below.

"You should never use an Extreme Pressure (EP) rated grease in a sprag clutch. EP additives contain slippery,
anti-friction compounds (such as sulfur-phosphorus or graphite) that prevent the sprags from gripping properly.
This leads to clutch slipping, over-speeding, and premature failure"

Then I looked for non EP greases for sprag bearings and the below came up. The Kubler is expensive. I don't know why the
Mobilux EP is on the list as it is EP.

I then found a non EP grease called Mobil Polyrex EM that is non EP and under $20 for a large grease gun type tube.
Love to get your thoughts because the next time I pull out the sprag, I could regrease it.

Dennis

  • Klüber Isoflex LDS 18 Special A: The industry gold standard. It is a dynamically light, synthetic grease approved by major manufacturers (like GMN and Onyx Racing). [1, 4]
  • Klüber Asonic GHY 72 & Synth HB72-102: Excellent synthetic options for high-temperature and extreme-duty overrunning/backstopping clutches. [1]
  • Mobilux EP 2 / Lith SHC-100: A widely used lithium-based multipurpose grease; perfect for standard industrial and automotive sprags. [1, 2]
  • Shell Aeroshell No. 7 & 16: Trusted by heavy-duty industrial sprag manufacturers like Marland and Formsprag. [1, 2]
  • Yamalube Ultramatic Grease: Widely used in ATV/motorcycle one-way starter and centrifugal clutches.
  • Silicone Greases: Often recommended in vintage motorcycle and specific powersport manuals. [1]
 
DennisMo said:
I did a little research online and it seems to say that sprag grease should not have EP additives as below.

"You should never use an Extreme Pressure (EP) rated grease in a sprag clutch. EP additives contain slippery,
anti-friction compounds (such as sulfur-phosphorus or graphite) that prevent the sprags from gripping properly.
This leads to clutch slipping, over-speeding, and premature failure"

Then I looked for non EP greases for sprag bearings and the below came up. The Kubler is expensive. I don't know why the
Mobilux EP is on the list as it is EP.

I then found a non EP grease called Mobil Polyrex EM that is non EP and under $20 for a large grease gun type tube.
Love to get your thoughts because the next time I pull out the sprag, I could regrease it.

Dennis

  • Klüber Isoflex LDS 18 Special A: The industry gold standard. It is a dynamically light, synthetic grease approved by major manufacturers (like GMN and Onyx Racing). [1, 4]
  • Klüber Asonic GHY 72 & Synth HB72-102: Excellent synthetic options for high-temperature and extreme-duty overrunning/backstopping clutches. [1]
  • Mobilux EP 2 / Lith SHC-100: A widely used lithium-based multipurpose grease; perfect for standard industrial and automotive sprags. [1, 2]
  • Shell Aeroshell No. 7 & 16: Trusted by heavy-duty industrial sprag manufacturers like Marland and Formsprag. [1, 2]
  • Yamalube Ultramatic Grease: Widely used in ATV/motorcycle one-way starter and centrifugal clutches.
  • Silicone Greases: Often recommended in vintage motorcycle and specific powersport manuals. [1]
Click to expand...
Still not sure I would lube a sprag except in a dry primary, but I bet this stuff would work great in the speedo gearbox. That Mobilux is available in the US too.
Thanks for posting that.
 
MexicoMike said:
I have no experience with the CNW E-start though quality-wise, based on all my experience with CNW, I have always assumed it was more robust than the Alton. However, even if the CNW E-start had been available at the time I probably would have still selected the Alton because it allows the retention of the OEM Ham Can air filter assembly which was very important to me. It is also less "visible."
Click to expand...
We conducted a survey re: e-start options for Commandos https://www.accessnorton.com/NortonCommando/best-e-start-for-pre-mkiii-is.38239/

Also on fecebook, with similar results... https://www.facebook.com/groups/103...cIjpcImF1dGhvcl9tZVwiLFwiYXJnc1wiOlwiXCJ9In0=

I don't recall a single occurrence of a disgruntled Alton owner tossing his unit and installing a CNW replacement.

(FWIW)
 
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DennisMo said:
I am curious why you would not lube a sprag except in a dry primary?
Dennis
Click to expand...
Because I greased my MKIII sprag once and it would not hook up, and after talking to Jim Comstock about it once, he agreed it should not be greased. But I used high pressure bearing grease which was probably a GL4 or maybe GL5. Stock MKIII primary has enough oil fling to keep that sprag wet. Dry primary may need something to prevent rust so perhaps a little lube might help, especially since there appears to be something specific available.

The way I see it is the "hook-up" is accomplished by the dog bone "roller" being cocked between the inner and outer race when the starter button is pushed. The more bite there is, the better it holds, grease may prevent a good solid lock-up between the two surfaces. Once the button is released the "dog bones" lay back down so there is no contact between the races. Give it a try, there is nothing that can't be reversed if the grease doesn't work.
 
The replacement Matt sent to me about 6 or 7 years ago was Renold REGP4127 Sprag Cage Elemt Spec.

Also had 10016575 on the box but that might be a distributor stock number.
 

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johnm said:
The replacement Matt sent to me about 6 or 7 years ago was Renold REGP4127 Sprag Cage Elemt Spec.

Also had 10016575 on the box but that might be a distributor stock number.
Click to expand...
Tried both those numbers on the Renolds site without success (0 results)
 
robs ss said:
Tried both those numbers on the Renolds site without success (0 results)
Click to expand...
I last tried in 2020 and got this reply. Maybe it's been deleted.

Added later. Finding it on UK sites and on special order in NZ. The website has nil search function so I had to go through the product list.
 

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Deets55 said:
Because I greased my MKIII sprag once and it would not hook up, and after talking to Jim Comstock about it once, he agreed it should not be greased. But I used high pressure bearing grease which was probably a GL4 or maybe GL5. Stock MKIII primary has enough oil fling to keep that sprag wet. Dry primary may need something to prevent rust so perhaps a little lube might help, especially since there appears to be something specific available.

The way I see it is the "hook-up" is accomplished by the dog bone "roller" being cocked between the inner and outer race when the starter button is pushed. The more bite there is, the better it holds, grease may prevent a good solid lock-up between the two surfaces. Once the button is released the "dog bones" lay back down so there is no contact between the races. Give it a try, there is nothing that can't be reversed if the grease doesn't work.
Click to expand...
Thanks for sharing why. I just looked at the tub of grease I last put into the sprag and it is a Lucas red tacky grease that I like and always have on hand.
Of course it says EP on it so I will get a non EP and regrets next time.

Now there is one thing in your reply that I do not agree with. You say that once the starter button is released, the sprag dog bones no longer contact the race so there is no contact. I could be wrong, but on my Alton sprag, the dog bones are always in light contact so that when starter button pushed, there can be a little friction that causes the dogs to cock up and lock.
To me, this constant contact is why some lubrication is needed.
By the way, I once asked Google if dry-lube is ok for Sprags and it said No.
Dennis
 
Now there is one thing in your reply that I do not agree with. You say that once the starter button is released, the sprag dog bones no longer contact the race so there is no contact. I could be wrong, but on my Alton sprag, the dog bones are always in light contact so that when starter button pushed, there can be a little friction that causes the dogs to cock up and lock.
To me, this constant contact is why some lubrication is needed.

Indeed this could be possible, I can't say one way or the other on that. I'm approaching 50k on my motor and just replaced the original sprag and associated parts last summer. No lube or grease just Rotella T-6 15-40 in the primary. It started to occasionally slip, so I am guessing the wear could have been on the engaging face of the dog bone, no way I could accurately measure that. I believe the problem was in the driven ID face of the outer gear, I used an internal micrometer and could not get a consistent reading. There was no noticeable rubbing or wear marks on the back side of the dog bone pins that I noticed.
BTW, there is slight spring pressure in that sprag to cause those bones to lie down.
What ever you decide, good luck.
Pete
 
Deets55 said:
Now there is one thing in your reply that I do not agree with. You say that once the starter button is released, the sprag dog bones no longer contact the race so there is no contact. I could be wrong, but on my Alton sprag, the dog bones are always in light contact so that when starter button pushed, there can be a little friction that causes the dogs to cock up and lock.
To me, this constant contact is why some lubrication is needed.

Indeed this could be possible, I can't say one way or the other on that. I'm approaching 50k on my motor and just replaced the original sprag and associated parts last summer. No lube or grease just Rotella T-6 15-40 in the primary. It started to occasionally slip, so I am guessing the wear could have been on the engaging face of the dog bone, no way I could accurately measure that. I believe the problem was in the driven ID face of the outer gear, I used an internal micrometer and could not get a consistent reading. There was no noticeable rubbing or wear marks on the back side of the dog bone pins that I noticed.
BTW, there is slight spring pressure in that sprag to cause those bones to lie down.
What ever you decide, good luck.
Pete
Click to expand...
The roller cams in the sprag in the Alton e start kit are held in light contact (via an oil seal type spring) with the hub that carries the starter sprocket when the engine is stopped. Upon starting, the sprag revolves with the crankshaft and the roller cams are thrown clear of the starter chain hub so no contact between the roller cams(or dog bones) when the engine is running. When the engine stops, the spring then pulls the cams into contact with the hub ready for the next start. The dog bone type of sprag works the same way, dog bones thrown clear when engine running and when the engine stops the thin wriggly spring (between the double cage) pushes the dogbones into contact with the drive gear ready for the next start.
This does not happen with the cnw kit, the dogbones are constantly held in contact with the engine pulley hub.
 
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