Mr. Kidney

Give Trialshop.pl a look. Pro 2 hub axles and bolts seem like they were made to fit the piranha frames. Fit perfectly on the frames Ive seen.

Id recommend the KMC Z510HX 1/8" Chain if your looking for a new one. Ive ran mine for a good 5 months now and its only just begun to show signs of needing replacing. Make sure you buy a high quality chain tool to prevent any difficulties fitting the chain Fat Spanner do some petty decent tools