yep. slow vs slow.
i call a diesel running at 4800 FAST. i call a car at 5200 near its redline usually.
i call a small 2 stroke at 4800 as barely breaking idle.
coming from a background of chainsaws running at 11000 rpm, and small nitro engines up at the 28000 rpm range.
not having a tacho, but having perfect pitch, i still reckon im doing around 7000 rpm... maths backs me up. 26" wheels, 36T rear, 60km/h...
and with no mods, thats as fast as a HT seems to go, because it makes no difference down a hill if i pull the clutch in or not! ie, unloaded, they still dont rev out
maybe 8000 max, unloaded, stock.
the occasional one does, but they usually have "clean" ports... but, take the chain and clutch off a chainsaw, put it in a heavy steel box and give it WOT... theyll get to around 15000 when things start breaking. even when the con rod is simply a stamped piece of alloy. listen to even a cheapo ryobi brushcutter rev out compared to a HT...
im not saying a HT is anywhere near capable of doing that! i wouldnt ever aim for more than 9G.
i did say a bronze bush is silly
but for maximum load bearing, bushes still reign supreme!
the argument i raise. any ball only has point contact. any roller only has line contact. a very thin, narrow line.
all engineering texts mention that only ONE roller EVER takes the full load. except in the case of taper roller bearings that are preloaded.
some scans...(not sure if i can get the resolution up...soz) since 1953, nothing has changed in regards to bearings, exception being, possibly, ceramic bearings. also mentions "in the early days, all bearings were of the "full type", still used for SLOW speed, HEAVILY LOADED areas..."
now, a bush...well, a bush when it fails, doesnt fill the case up with shards of hardened steel. the arc of contact is almost half of the shaft diameter. sure, the friction is higher at high speeds, but the load rating is much higher.
but, i still think its silly
stick with the cage bearings. they were developed for a reason.
oh! last thought! if you want to go with the press crank and replace rod and bearings alone....you will ALSO require a new CRANK PIN, as if its seized up, that will be damaged. badly.