toppy said:
Obviously the cost of producing a crank to the original manufacturer's design and drawings as AN do with other components is more than likely not a cost effective solution. Given the tooling needed for casting and forging which has almost certainly been lost over time plus the specialist machining and other processes involved. AN also are on record as say if possible they will use modern methods or materials to improve a standard component and given the high cost an probability of low numbers to be sold let alone the warranty issue if an incorrectly assembled or manufactured (bearing radius, stress raiser on internal drillings etc) they have surely taken and most sensible approach. In making the decision to buy such an expensive item form such a reputable supplier instead of getting a secondhand item or other suppliers of cheaper products you would think that there would be more information about it on the website. From what i have seen (i may that missed it) there are little or no details on wether it will perform just as the standard item or have a marked effect in any way on the engine performance and driveablity characteristics. As Dances says there is more to it than just total static weight an you would think AN would be trying to promote the thing given its much cheaper an not to difficult to obtain a usable secondhand item for road use if not racing.
I hope you will forgive me when I say that the main error in your thinking is to assume that AN had any hand in development of the crank they are now selling, which they have come by after a deal with Mick Hemmings, indeed it seems that comments already here suggest they have never used one.
As we know and as noted already, the item was developed by Mick for a specific project. I suspect that AN would not be marketing this crank at all without that deal. To sell it with the caveats they have made seems reasonable, 'if you put this in a road bike you will be on your own in terms of suitability' (i.e. it may not provide the preferred riding characteristics of a Commando road bike). I would think that reliability and suitability for a race motor (should you like a lightweight crank) are not in doubt, this is Mick Hemmings and Peter Williams, a skilled manufacturer and AN we are talking about, not a disreputable backstreet operator.
The loss of NRE as a source of cranks for road use or those who prefer heavier race cranks is very sad. I beleive there is an opening for a reputable manufacturer to step in to provide an alterative to a 40 plus year old production item.
Personally I would have thought it viable for AN to pursue a replacement for the standard road bike crank, but clearly they have not launched a product so they are unlikely to agree with me, why should they? Perhaps the range of options already on the market (and subsequently reduced market potential) has been a hindrance, that may have now changed.
If they did choose to develop one surely the choice of one or three piece would be based purely on development and production costs.
There is also a small market for race cranks, of whatever weight. For many applications Steve Maney's product is a viable choice for a high performance engine and indeed many use it, it is available in a range of strokes. It suits me personally, but may not suit everyone!
Dave Nourish sold his cranks cheaper than Steve Maney, I would suggest that his development costs were long recovered and his production costs probably minimal, so don't assume that even a copy made in reasonable volume would come to market at the same price.
My assumption on production costs is based on the fact that a few years ago (less than 5) I met a guy who told me he used to go to Dave's on a Friday, after his week of nightshifts in aerospace, to machine cranks for Dave!
(I have several parts made by this guy, now also retired, on my race bike, he also told me that Dave wasn't best pleased one week when instead of making two 90s and a 360, he made two 360s and a 90!)