CNW e start conversion, sprag failures

robs ss said:

What were the symptoms? Was it off-and-on or a sudden complete failure?

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Yep. At first I whirs then catches almost instantly you’d hardly notice. Then I whirs and you need a second press. After that it fails to catch at all when cold but after a ride all good. Then, bollox!! Nada. Kickeroo time and for me with all that luggage that’s none too easy.

It occurred to me that Bill only had it fitted in 2021 (bike built in 2013) so it ain’t lasted long. Replacement is a doddle especially as I’m so effin practised at stripping the primary

Solution? Centre stand and loaded that’s a struggle too as I’m not exactly heavy

I’ve had a few minor issues along the way which I’ll detail in a write up but right now I’m on the ferry supping a cool drink

MexicoMike said:

I find this all very interesting and curious. BASED ON THIS THREAD the (sprag) issue with the CNW E-start is reasonably well known yet AFIAK, no one posted about it until this thread. Until now no one has ever (that I can find) said anything bad about the CNW E-start.

I have always believed that the CNW was a more robust unit than the Alton (even though I purchased the Alton), but this thread indicates that choosing between the two is more about appearance/price/which potential failure mode is more acceptable!

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I think that no one posted about the cnw sprags failures as they might have been under the impression that theirs was a unique failure and not a design fault.
It was only when I saw inside the CNW sprag assembly that the failure mode was built in. Couple that to possibly owners would have been reluctant to admit the sprag failures after they have spent £2500 plus buying the kit that has a built in fault.

So are there alternatives that should not fail?

It looks like the sprag in the CNW Mk3 uprate version is a Ringspann, with a different shape for the dog bones. Correct?
If so, is that same sprag used in the Mk2 conversion as well?