Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 08-07-06, 07:09 PM   #1
JRZRacing
Junior Member
Thread Starter
 
JRZRacing's Avatar
 
Join Date: Aug 2006
Bikes:
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Help with 3 piece crank

I've been making and modifying bikes for over 5 years now and I have recently come acrross some trouble. Since I've worked mostly with BMX in the past, I don't have too much experience with the 3 piece crank sets used on MTBs. Does anyone know an easy way to get the crank apart without scratching the parts?

Last edited by JRZRacing; 08-07-06 at 11:48 PM.
JRZRacing is offline   Reply With Quote
Old 08-07-06, 08:23 PM   #2
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Do you have a crank puller?



Scratch or no scratch, I'll be darned if you can figure out a way to remove a square taper crank without one Okay, maybe with a long crowbar hooked around the crank arm, and leveraged against the seat tube of the bike... but that probably wouldn't be too good for the frame .

You have to understand how a square taper crank is attached to the bottom bracket: the bottom bracket has a sloping square spindle onto which the crank is pressed using the crank bolts. Once you remove the crank bolts, the crank is still held into place by being compressed against the steel BB spindle. In order to remove the crank from the spindle, you must physically force them apart. That's what the crank puller is for. Sheldon Brown has a good page that explains how to remove crank arms: http://sheldonbrown.com/tooltips/cotterless.html

Last edited by moxfyre; 08-07-06 at 08:31 PM.
moxfyre is offline   Reply With Quote
Old 08-07-06, 08:42 PM   #3
JRZRacing
Junior Member
Thread Starter
 
JRZRacing's Avatar
 
Join Date: Aug 2006
Bikes:
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
thanks, but I am usually able to find a way to take things apart without the proper tools, for example I have taken off freewheels,and taken apart and put back together chains. And as I usually do, I have just found a way to take apart the crank on one of the bikes with one hit of a hammer, the other one is not as easy, but I'm sure I'll fugure it out too.
JRZRacing is offline   Reply With Quote
Old 08-07-06, 08:53 PM   #4
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by JRZRacing
thanks, but I am usually able to find a way to take things apart without the proper tools, for example I have taken off freewheels,and taken apart and put back together chains. And as I usually do, I have just found a way to take apart the crank on one of the bikes with one hit of a hammer, the other one is not as easy, but I'm sure I'll fugure it out too.
Um... sorry to say this, but that's just nuts! The proper tool costs about $8 and it'll take about 30 seconds to remove any square-taper crank with it.

By using a hammer, you risk bending the frame, crank, bottom bracket spindle, or bottom bracket shell, due to the extremely high force you'll need to separate the crank from the spindle. Furthermore, a hammer blow will result in a sudden very high lateral load on the bottom bracket bearings, which could cause other problems.

I believe your original question asked how to do this without scratching the bike? If you want to do it right, do it with the right tool

PS- I'm quite impressed that you managed to remove a freewheel without a freewheel tool. That's quite a feat, actually. Did either the freewheel or the hub survive the ordeal?
moxfyre is offline   Reply With Quote
Old 08-07-06, 09:14 PM   #5
JRZRacing
Junior Member
Thread Starter
 
JRZRacing's Avatar
 
Join Date: Aug 2006
Bikes:
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
My project is somewhat of a salvage project, some people are crazy with the things they throw out, I found a full suspension ccm in almost mint condition, except for the derailleur, which I simply replaced from another bike I found. Seeing as I have found over 20 bikes and have alot of spare parts, I don't consider hammering the crank "nuts" However if I had went out and bought a $600 bike I would be much more inclined to go and buy the proper tool.

And to your question, yes, in one case, both the freewheel and the hub were left in great condition, another time I was removing a broken freewheel, so all I was worried about was the hub, and it was undamaged, mind you these were off BMX bikes, not multi-geared bikes.
JRZRacing is offline   Reply With Quote
Old 08-07-06, 09:19 PM   #6
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by JRZRacing
My project is somewhat of a salvage project, some people are crazy with the things they throw out, I found a full suspension ccm in almost mint condition, except for the derailleur, which I simply replaced from another bike I found. Seeing as I have found over 20 bikes and have alot of spare parts, I don't consider hammering the crank "nuts" However if I had went out and bought a $600 bike I would be much more inclined to go and buy the proper tool.

And to your question, yes, in one case, both the freewheel and the hub were left in great condition, another time I was removing a broken freewheel, so all I was worried about was the hub, and it was undamaged, mind you these were off BMX bikes, not multi-geared bikes.
Gotcha. Well, sounds like you're rather twistedly ingenious

If you can remove a freewheel without a freewheel puller (even a single speed ferewheel), that's pretty darn good... maybe you *can* find a way to remove a crank without a crank puller.

However, it sounds like a huge pain in the butt, and as I've said there are quite a lot of parts you can damage. Once I managed to strip the threads on a crank set, and the resulting wrecked bike wasn't pretty. I used to be a "ghetto mechanic" like you, then I bought a very complete $100 bike toolkit and realized that having the right tools saved me a whole lot of time that I could spend doing more interesting things to my bike...

PS- What's a CCM?
moxfyre is offline   Reply With Quote
Old 08-07-06, 09:25 PM   #7
barba
Senior Member
 
barba's Avatar
 
Join Date: Nov 2005
Bikes:
Posts: 4,083
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Try at your own risk:

Remove the crank bolts and ride the bike carefully. The crank should loosen (just don't let it fall off!).

The tool is dirt cheap, though. If you are going to be doing much work on cranks, it is worth the investment. Alternately, I can't imagine a shop would charge more than a buck or two (if at all) if you asked to borrow the tool for a second.
barba is offline   Reply With Quote
Old 08-07-06, 09:31 PM   #8
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by barba
Try at your own risk:

Remove the crank bolts and ride the bike carefully. The crank should loosen (just don't let it fall off!).
That'll work... but you'll have to put a decent amount of stress on the crankarms, and in so doing, you'll probably round them off a bit, since the aluminum crank arms are softer than the steel BB spindle.
moxfyre is offline   Reply With Quote
Old 08-07-06, 09:33 PM   #9
barba
Senior Member
 
barba's Avatar
 
Join Date: Nov 2005
Bikes:
Posts: 4,083
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by moxfyre
That'll work... but you'll have to put a decent amount of stress on the crankarms, and in so doing, you'll probably round them off a bit, since the aluminum crank arms are softer than the steel BB spindle.
I agree, but I can't think of another way besides buying the tool. Everything else involved tools that are more expensive than a crank puller or would destroy the crank even more.
barba is offline   Reply With Quote
Old 08-07-06, 09:36 PM   #10
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by barba
I agree, but I can't think of another way besides buying the tool. Everything else involved tools that are more expensive than a crank puller or would destroy the crank even more.
Yeah, definitely... I think we can both agree that JRZRacer ought to buy the correct tool: $8 from Nashbar
moxfyre is offline   Reply With Quote
Old 08-07-06, 09:46 PM   #11
JRZRacing
Junior Member
Thread Starter
 
JRZRacing's Avatar
 
Join Date: Aug 2006
Bikes:
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Unfortunately what I am working with here is a stripped frame (beside the crank) so I can't ride it around.

"CCM" is the make of the bike, the model is "REVENGE". Personally I didn't like the colours, so I decided to strip it down, clean it up, and repaint it. I do street stunts, so I wanted it to look more serious for when I'm riding around.
JRZRacing is offline   Reply With Quote
Old 08-07-06, 09:52 PM   #12
barba
Senior Member
 
barba's Avatar
 
Join Date: Nov 2005
Bikes:
Posts: 4,083
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I am afraid it is a crank puller for you my friend. Seriously, a shop may loan you one for a minute if you ask nicely or have a resonable relationship with one. I wouldn't go for the hammer and a punch idea I know is floating around in your head. The aluminum won't hold up to much violence. As long as the threads of the crank are in decent condition, the puller will work.

Just out of curiosity, why do you need to pull it off? Is the bottom braket in decent shape?

Good luck with the project.
barba is offline   Reply With Quote
Old 08-07-06, 10:00 PM   #13
JRZRacing
Junior Member
Thread Starter
 
JRZRacing's Avatar
 
Join Date: Aug 2006
Bikes:
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I am pulling it off a "specialized hard rock" frame to put on the CCM bike. I didn't like the stock, plastic-coated steel crank, so I thought I would replace it with something a little more beefy, less weight, and better looking. The whole crank is in good shape.
JRZRacing is offline   Reply With Quote
Old 08-07-06, 10:07 PM   #14
barba
Senior Member
 
barba's Avatar
 
Join Date: Nov 2005
Bikes:
Posts: 4,083
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sounds like a fun project. I am a big fan of rehabbing other folks' cast offs. Getting the crank on the other bike is just a hex wrench job. The only other danger is that the BB spindles will be different lengths or standards. It ought to be close enough, though. If the BB on the Hard Rock is still smooth, you might consider taking it as well. You need a cheap tool and a big wrench.

This may be a long shot depending on where you are, but is there a bike co-op anywhere near you? They are great places to use specialized bike tools for free (plus they often have treasure troves of old parts laying around).
barba is offline   Reply With Quote
Old 08-07-06, 10:11 PM   #15
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by barba
Sounds like a fun project. I am a big fan of rehabbing other folks' cast offs. Getting the crank on the other bike is just a hex wrench job. The only other danger is that the BB spindles will be different lengths or standards. It ought to be close enough, though. If the BB on the Hard Rock is still smooth, you might consider taking it as well. You need a cheap tool and a big wrench.

This may be a long shot depending on where you are, but is there a bike co-op anywhere near you? They are great places to use specialized bike tools for free (plus they often have treasure troves of old parts laying around).
Or, if you're in college or grad school, your university may have a bike shop filled with tools that you can go use for free. Mine does (university of Maryland)
moxfyre is offline   Reply With Quote
Old 08-07-06, 10:22 PM   #16
JRZRacing
Junior Member
Thread Starter
 
JRZRacing's Avatar
 
Join Date: Aug 2006
Bikes:
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I've got a cyclepath and a re-my sport shop near me. BTW the spindles are different sizes, so I am replacing the entire crank system, worst thing that could happen is it won't fit, in which case I would put the origional crank back on. I have already managed to remove the crank off the CCM, it's the hard rock I'm having trouble with.
JRZRacing is offline   Reply With Quote
Old 08-07-06, 10:49 PM   #17
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by JRZRacing
I've got a cyclepath and a re-my sport shop near me. BTW the spindles are different sizes, so I am replacing the entire crank system, worst thing that could happen is it won't fit, in which case I would put the origional crank back on. I have already managed to remove the crank off the CCM, it's the hard rock I'm having trouble with.
I imagine the Hard Rock's crank is of a significantly better quality, and less prone to coming loose.

The appropriate tool for removing a cartridge BB is the $7 cartridge BB tool, which will work not just on square-taper cranks but most fancy splined cranks as well. If you try to remove the BB without the proper tools, you're going to have to jump through more shenanigans. Be aware of the fact that the LEFT side of the BB is threaded normally (righty tighty, lefty loosey), but the RIGHT side of the BB is reverse threaded (left tighty, righty loosey). Removing the BB without proper tools will be another difficult task, and if you do it by violent force you are likely to damage the very fine, fragile threads of the bottom bracket shell, the part of the frame that holds the bottom bracket. If you hose the BB shell, you've basically wrecked the frame (it'll cost a lot more than $8 to fix that).

You have been warned
moxfyre is offline   Reply With Quote
Old 08-07-06, 11:40 PM   #18
JRZRacing
Junior Member
Thread Starter
 
JRZRacing's Avatar
 
Join Date: Aug 2006
Bikes:
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Well, the hard rock can wait, the main reason I wanted to know how to get the crank apart was so I could paint my ccm's frame, and now that that crank is off, I can, besides, I'm still waiting for my street tires to come in, so I got time. I guess I'll just have to get that tool to get the hard rock's crank off.

BTW any suggestions for my handle bars? Not sure weather to go with straight or angled bars.

Last edited by JRZRacing; 08-08-06 at 12:51 AM.
JRZRacing is offline   Reply With Quote
Old 08-08-06, 02:01 PM   #19
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by JRZRacing
Well, the hard rock can wait, the main reason I wanted to know how to get the crank apart was so I could paint my ccm's frame, and now that that crank is off, I can, besides, I'm still waiting for my street tires to come in, so I got time. I guess I'll just have to get that tool to get the hard rock's crank off.
Glad to hear we've convinced you I think you'll be amazed what a difference the right tool makes. By the way, if you're gonna be working on a lot of different bike parts, I'd highly recommend getting a complete toolkit, such as this one which has every tool you're likely to need on any modern MTB, except for a cable cutter (the $99 version of the toolkit has that and probably somewhat better quality tools).

Quote:
BTW any suggestions for my handle bars? Not sure weather to go with straight or angled bars.
You're talking about MTB bars here? Whatever's more comfortable for you. I think that totally flat bars are really uncomfortable, I prefer the angled ones with a bit of rise to them.
moxfyre is offline   Reply With Quote
Old 08-08-06, 04:43 PM   #20
Wogster
Senior Member
 
Wogster's Avatar
 
Join Date: Jul 2006
Location: Toronto (again) Ontario, Canada
Bikes: Norco Bushpilot (out of commission), Raleigh Delta
Posts: 6,941
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by moxfyre
Gotcha. Well, sounds like you're rather twistedly ingenious

If you can remove a freewheel without a freewheel puller (even a single speed ferewheel), that's pretty darn good... maybe you *can* find a way to remove a crank without a crank puller.

However, it sounds like a huge pain in the butt, and as I've said there are quite a lot of parts you can damage. Once I managed to strip the threads on a crank set, and the resulting wrecked bike wasn't pretty. I used to be a "ghetto mechanic" like you, then I bought a very complete $100 bike toolkit and realized that having the right tools saved me a whole lot of time that I could spend doing more interesting things to my bike...

PS- What's a CCM?

CCM actually stands for Canadian Carriage Makers, which is where the company started out, they moved on to bicycles when the carriage market dried up, and you could buy cast iron pipe quite inexpensively.

Now you can still get their bicycles in Canada today, at such high quality bicycle retailers as Walmart , I doubt they have built a bicycle in Canada in years, prefering to buy from the lowest bidder in Asia.

These days CCM are best known for hockey gear.

As for tools, my preference is to buy them as I need them, I wanna remove a crank, I look in my toolbox, no crank puller, then I just go buy a crank puller. If the tool is expensive, and something you do fairly rarely, then I am likely to let the LBS do it.
Wogster is offline   Reply With Quote
Old 08-08-06, 04:48 PM   #21
JRZRacing
Junior Member
Thread Starter
 
JRZRacing's Avatar
 
Join Date: Aug 2006
Bikes:
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Actually, on the bike it says CCM Canada Cylye and Motor
JRZRacing is offline   Reply With Quote
Old 08-08-06, 04:57 PM   #22
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Wogsterca
As for tools, my preference is to buy them as I need them, I wanna remove a crank, I look in my toolbox, no crank puller, then I just go buy a crank puller. If the tool is expensive, and something you do fairly rarely, then I am likely to let the LBS do it.
It's a pretty good strategy, but you'll probably spend more in the end... I got into bike mechanics all at once, and bought a $100 toolkit from Performance. An excellent investment! The only tool I've had to add to it is an old-style BB lockring wrench.
moxfyre is offline   Reply With Quote
Old 08-08-06, 05:34 PM   #23
Noam Zane
Senior Member
 
Join Date: Oct 2005
Bikes:
Posts: 169
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
And you don't need to buy the proper size wrenches if you have a pair of pliers in your toolbox. Gah! I've seen plenty of examples of decent bikes essentially ruined by "mechanics" like this.
Noam Zane is offline   Reply With Quote
Old 08-08-06, 05:37 PM   #24
moxfyre
cyclist/gearhead/cycli...
 
moxfyre's Avatar
 
Join Date: Oct 2004
Location: DC / Maryland suburbs
Bikes: Homebuilt tourer/commuter, modified-beyond-recognition 1990 Trek 1100, reasonably stock 2002-ish Gary Fisher Hoo Koo E Koo
Posts: 4,166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Noam Zane
And you don't need to buy the proper size wrenches if you have a pair of pliers in your toolbox. Gah! I've seen plenty of examples of decent bikes essentially ruined by "mechanics" like this.
There's no better way to undertighten and strip a nut simultaneously, than with a pair of pliers.
moxfyre is offline   Reply With Quote
Old 08-08-06, 06:05 PM   #25
JRZRacing
Junior Member
Thread Starter
 
JRZRacing's Avatar
 
Join Date: Aug 2006
Bikes:
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Don't get me wrong, I have lots of good tools (metric and imperial wrenches, allen keys, screwdrivers, slip joint pliers, vise grips, socket sets and so on) I just don't have very many specialized tools for working on bikes.
JRZRacing is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 12:22 PM.