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Old 08-08-2011, 02:35 AM   #9 (permalink)
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Ryland - Problems? lol - too many lil ones to regal ya with. No worries however, they're mostly fabrication & learning curve related, I joined this fine forum mostly to peruse other's projects & experience - I posted here to get w/e feedback folks felt like sharing and to offer a sample of mine insanities... I'm not sure there is help for that

You have brought up some good critical feedback & I thank you for it! They're concerns I hope won't be too dire but only time will tell I s'pose. First, although it may look "road worthy" it is not nearly as close to completion as it may appear. I'm at the "pesky details" stage, which is ofc the most time consuming for the least profound changes - given that and the season, I've decided to take my time and attend to such during the fall & winter - it's relatively complex electrical harness would be an example as I hope to "marry" the two motors (charging & accessories) as well as full lighting - and I've not even picked out what lights I'll be using, let alone figured out how & where to mount them heh

The cassette/freewheel & potential pawl failure is another valid observation, the concern compounded by it's intrinsic nature to my electric hub, fortunately it's one I'm somewhat prepared for... There's been extensive testing of 49-66cc two stroke engines (aprox 2hp) being routed through a bicycle's power train via jack shaft & interestingly pawl/freewheel failure seems to only occur with those that have chosen to run older, used internally shifted hubs. New, quality hubs don't seem to have this issue - the '43 Rollfast pictured above has a lil over four thousand miles on it's jack shaft through a (modern) Sturmey Archer x-rd3 (3sp drum brake hub). Cassette users have reported no freewheel failures that I've seen - but some distortion of the sprocket's teeth (twisting, sometimes referred to as looking like a turbine) - but those individuals have always admitted to some abuse, as in "speed shifting" (leaving it at wide open throttle while shifting).

Admittedly, those low cost, piston ported two strokes don't have squat for torque compared to their four stroke brethren so there is some cause for concern. Backup plans include ridding myself of the rear disk brake and using it's six hole mount for a sprocket (retaining the electric hub) or worse case, ridding myself of the electric hub & batteries and using a jack shafted Nuvinci CVP from Fallbrook Technologies - which has been shown to be able to handle up to about 9hp before failure (using Morini Franco two strokes).

Insofar as the "power pulse" issue, that's been the subject of much debate. A number of folks have suggested that the momentary peak torque load of a human actually exceeds that of the motors typically used to power a bicycle and that it's actually the sustained "high speed" engagement that appears to cause some premature wear, when in actuality it isn't premature - the miles accumulate much faster at a constant 25-30mph than the typical & variable 5-15 while pedaling.

As I lack access to a dyno small enough to be accurate & both sides of the disagreement seem perfectly rational, I've chosen to shrug it off and go with what I've experienced... and that's most quality bicycle hubs are capable of transferring up to roughly 4hp (conservative) from an internal combustion engine w/o undue failure (electrics w/the "instant torque" may fare differently)... I s'pose I'll find out lol

As for the quality of the Lifan, I chose it over other Chinese variants of the Honda CRF50 as it's a true "clone" and not merely a copy, as in all Honda parts are fully interchangeable. I knew it might be a compromise in quality when I purchased it, yet it was one I was willing to make as this ...erm... "vehicle" is a prototype to say the least heh. When I received the Lifan I was pleasantly surprised to find that in actuality it's castings are gorgeous, the milling of machined parts done w/precision and even it's fasteners seem of equal quality to it's Honda equivalent... but again it's a case of "we'll see" heh - should the taddy itself prove a success but the Lifan problematic, I'll happily replace it w/a real Honda

Last edited by BarelyAWake; 08-08-2011 at 02:46 AM..
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