I was just wondering if you could press out the bronze bushing on the stock puch crank and press in a needle bearing. I know next to nothing about machining. I noticed a needle bearing on Quarterkick, but I guess the dimensions would have to match exactly for this to be within the realm of possibility, eh?
Im sure you could though you wouldnt want to really press it in. The one from QK is for the motobecane, and is a stock replacement.
The ID (inside diameter) of the bushing and the bearing are the same. The bearing has a larger OD (outside diameter). The stock crank dose not have enough meat to be opened up to accommodate the OD of the bearing. If you look at an aftermarket roller bearing crank you will see that the small end of the con-rod is larger.
That's what I needed to know. Just to make sure this is totally impossible, you couldn't weld on additional metal to the small end of the connecting rod, then grind it out to accept the larger needle bearing, could you? The thing that pops into my mind first would be that it might throw off things weight-wise, but again, I don't know jack shit about that. Can you tell that I can't afford a race crank? Fuck college.
cost of welding and machining would be close to the cost of performance crank. forget about it dude. really not worth it.
Pretty sure the large side of the crank rides on a bushing as well. granted I have never pulled a crank apart to know for sure.
Pony up the 80-100 and get a crank, or just run the stock one.
you can also press apart the crankshaft and put in a new con rod
the big end of the con rod has a roller bearing stock, they are relatively indestructable.
good to know about the big end. Only issue with going with a new roller con rod is they cost 30-40$ and if you take it to someone to unpress and repress the crank they will charge you 35+ for the service.
That's what I needed to know.
could u get a new connecting rod from http://www.hotrodsproducts.com/ ? I dont know the size of the rod you need but they have alot of em on there. You could maybe get a longer rod and use a cylinder spacer to increase your rod ratio for higher rpm. They dont seem to have a connecting rod longer than 88mm that will fit a puch e50 without changing the crank pin size and the piston pin size though. I have been looking. The puch con rod is already 90mm which makes an awesome rod ratio already. 2.09:1
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