HELP! Pedal crank replacement (issues with 1 piece to 3 piece)

R

robbdaman

New Member
So I am attempting to swap my motor to a new bike as the old one's frame is coming apart. In doing so I need to swap out the 1 piece for a 3 piece crank and have run into a bit of a snag with it not being the right size. The 3 piece I have is this one from Bicycle-Engines.com 1pc to 3pc Wide Crank Conversion Kit [4S-CDS-1to3WCconv] - $18.99 Yet the bracket on the new frame is the same size as the housing for it. Here are some pics to illustrate.

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I wonder if Biknut's post here would help or could be adapted to what I already have? My bracket looks very similar to what he has in this pic:
biknut-albums-biknut-repair-album-picture460-biknutproductions2736.jpg
 
It's a little hard to tell but it looks like your races are pressed into the frame. On my bike the BB was threaded and the race screwed in.
 
The silver rings, i think there called races,well you can take a hammer and screw driver and tap them out, then you can slide the black ones in and put everything together.
 
Yeah I think they are stamped. I tried hammering them out and didn't get anywhere. Meaning unless I can find some way to connect a 3 piece through it as is my only likely option for using that frame may be to bore out those races completely. :( Ugh what a headache.
 
Or you can get a wide 1piece kit, or peddals with short crank arms off a kids bmx or excercise bike.

maybe u just need a bigger hammer! or Power saw...
 
I'm putting my 4-stroke over to a Cranbrook from a Jaguar. Having replaced the 1-piece to 3-piece wide crank before...I am having a bear of a time getting the inner ring with 2 notches off on the left side of the bike.

Am placing a screwdriver on the left hand side and hitting the screwdriver down to turn the nut counter-clockwise. Not sure if I'm turning it the right direction or not...but seems like it's going nowhere.

From there...will be taking the 3-piece crank off the Jaguar to put on the Cranbrook with the 1-piece going onto Jaguar.

Anything you can suggest would be greatly appreciated.
 
It looks like it's pressed in. You should be able to knock it out. For some reason they always seem to put the BB races in tight. You'll need a big drift, and a big hammer to go with it.

I think you probably know you stick the drift in from the other side and beat the race on the opposite side out.


robbdaman said:
P6070002.jpg
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Well you guys were right, lots of hammering like I'm Thor, a few bruises and destroying a good screwdriver and they finally popped free. Its insane how tightly they get those things in. Hopefully the rest of this swap won't require so much work.
 
phoobarnvaz said:
I'm putting my 4-stroke over to a Cranbrook from a Jaguar. Having replaced the 1-piece to 3-piece wide crank before...I am having a bear of a time getting the inner ring with 2 notches off on the left side of the bike.

Am placing a screwdriver on the left hand side and hitting the screwdriver down to turn the nut counter-clockwise. Not sure if I'm turning it the right direction or not...but seems like it's going nowhere.

From there...will be taking the 3-piece crank off the Jaguar to put on the Cranbrook with the 1-piece going onto Jaguar.

Anything you can suggest would be greatly appreciated.
Click to expand...

To disassemble a one-piece crank, start by removing the left pedal (turn it clockwise to unscrew it--everything on the left side of a one-piece crank is left (reverse) threaded.) Then remove the locknut on the left side bottom bracket (clockwise to remove), lift of the keyed washer, and unscrew the left cone (clockwise to remove.) The left cone usually has grooves that allow you to turn it with a flat-bladed screwdriver. Pull out the ball retainer, then you will be able to withdraw the whole crank assembly from the right side of the bottom bracket. Pull the crank partway out of the bottom bracket, then reach in and remove the right side bearing retainer. If you try to pull the corners of the one-piece crank through without removing both retainers from their cups first, you may damage the retainers.
 
Rob, When you go to drive the the new pieces in (if you haven't all ready) you have probably notice three bolt hole in each one. After you get one in make sure you get the holes lined up befor you drive the other side home. If the bolts that come with it are long enough and then tap it lightly to get it started. I just took some wire about the same size and stuck it thru each hole and the drove it in. Good luck. Dan
 
biknut said:
It looks like it's pressed in. You should be able to knock it out. For some reason they always seem to put the BB races in tight. You'll need a big drift, and a big hammer to go with it.

I think you probably know you stick the drift in from the other side and beat the race on the opposite side out.
Click to expand...

Finally got the whole assembly out on Monday after figuring the correct way to turn this POS. Took me/my roommate another day for him to hammer enough to get the bike crank side out with 5 minutes of hitting it with the hammer/screwdriver...after I hammered like crazy for 2 hours the day before. He got the race out by tapping on it fast. When it came out...almost made me a eunuch...but I was happy to get it out. Will be putting in the 3 piece crank tomorrow after finishing up the 3 yards I have to mow.
 
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