[merkit the grof]

QUOTE (Doug @ 1 Sep 2012, 09:22) <{POST_SNAPBACK}>

QUOTE (Coopdevil @ 3 Sep 2012, 08:26) <{POST_SNAPBACK}>The next logical step in this kind of component lightening must be to introduce plastic wheels and save weight by not using a metal grub-screw but instead knurling the ends of the axle...

That rings a bell!!

Plastic pinions, knurled axles, plastic wheels, perhaps Hornby had it right all these years ago.
For me plastic pinions bring back warm memories of hours spent replacing the split ones in old Scalex cars.

QUOTE (rick1776 @ 3 Sep 2012, 23:38) <{POST_SNAPBACK}>The reduction in inertia by going to a hollow rear axle which is 1g lighter that a standard axle is the same as removing 0.003g from the weight of a tyre fitted to that same axle system. You would probably lose that much rubber form the tyre after a couple of laps.

I am with rick1776 on that one.
We all agree it makes a difference, but it's all relative, and I think that in most cases, the contents of your stomach will have a greater impact on your lap times than fitting a plastic pinion.
And it is rather disingenuous to suggest otherwise (especially if the testing was as unscientific as described).
Manufacturers must think we are totally gullible. (It would interesting to hear what actual lap time reduction is being claimed for these wonder pinions, I mean a 1g reduction, its bound to make a difference)

Joel

PS: Then again....

 

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QUOTE (rick1776 @ 5 Sep 2012, 00:12) <{POST_SNAPBACK}>Set up a drag run. Measure the elasped time with a brass pinion. Replace the brass with a plastic pinion. But make sure to add the weight difference so that the car's overall weight does not change. Repeat the drag race run. Now you will be testing the effect of any reduction in inertia. Do the run 10 times and take the average. Repeat with the plastic pinion. I suspect that the variation between any two runs will probably be greater than any "measurable" gain. Once again happy to be proven wrong, but pleased show me the data.

I would want to see a double blind test, to remove any trace of subjective judgment on the part of the driver.
I think in some respect we are both missing the point, the idea is to get the customer to think it makes a difference, the actual difference is less important.

QUOTE (stoner @ 5 Sep 2012, 07:34) <{POST_SNAPBACK}>we,re really arguing about top racers in world finals. if it gives you 1inch more per lap its a better product. john

John, no we are not, we are talking about cheap plastic pinions used to run at home or at club level.
If the gain is 1mm per lap, then you have wasted your money, and as rick1776 and I have hinted, there are many many other factors (including some unexpected ones) which will make a more noticeable difference and cost nothing.
In any case what works at top level does not always transfer lower down (like a shopping trolley with F1 tyres for example).
For me the irony of these transmission "improvements", is that most of these cars still rely on the motor shaft rubbing on the side of the contrate to locate the rear axle.

Joel

 

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QUOTE (Screwneck @ 5 Sep 2012, 19:52) <{POST_SNAPBACK}>It's also interesting to see people rejecting plastic gears based on experience from years ago.
I know, shocking isn't it!
But I had to go back a long way to find a pinion as poorly designed as the ones shown here.

QUOTE (Screwneck @ 5 Sep 2012, 19:52) <{POST_SNAPBACK}>I've never had to replace a plastic or nylon pinion in 6 years apart from the useless new grey Fly ones, and that wasn't because they are plastic but because they are badly designed.
I am glad you agree with me, nothing wrong at all with a properly designed plastic pinion (within reason), I too have had good experience with Ninco, Fly (in the early Vipers), and Scalex plastic pinions.
But they all share one thing in common: A reinforcing ring at one end to stop them splitting. I am much less convinced by what I am seeing here.

Joel

 

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But you certainly wouldn't buy another from the same bakery, or in this case of the same design.

The difference is that Ninco and the others have designed a pinion which they know will be reliable, surely they would have used the same plastic as MBslot and saved themselves the bother?

I am not at all convinced that those pininos are not just bog standard stuff available form many factories in China (in fact, I have found similar ones myself).

Joel

PS: And we have not discussed the price yet (the Chinese pricing is rather interesting).
PPS: The French would much rather buy a bas*ard than a baguette any day (Anglo French joke about bread)