Paul, cant find anybody on the NATS forum who has rebuilt NF5 ones, but check out http://rgracing.fr. they are making NX5 & NXA cranks, and are working on ND5 ones, I think they would be prepared to look at NF5 ones if there was enough interest. The NX5 & NXA cranks they have done, and tested certainly look the biz.
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