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-   -   Messing with a 1 - piece crankset - is it worth it? (http://www.bikeforums.net/bicycle-mechanics/933346-messing-1-piece-crankset-worth.html)

himespau 02-08-14 06:59 AM

Messing with a 1 - piece crankset - is it worth it?
 
I'm cheap (and don't have a ton of disposable income). Just thought I'd get that out of the way right to start.

My daughter (3 years old tomorrow) has outgrown her tricycle and I thought it was time to get her onto a two-wheel form of transportation. After looking into a lot of the pros and cons, it looked like starting her off on a balance bike rather than going with the training wheels thing. I thought it seemed kind of silly to buy a balance bike (good ones aren't cheap) and then 6 months or so later buy a pedal bike in the same size, so I found a good deal on a used Giant Pudd'n that seemed the right size for her, so I figured I'd take the pedals (and maybe crankset) off for her to use as a balance bike and then put them back on when she got used to balancing on the bike.

Turns out the bike has a 1 piece crankset like a really low end box store BSO, and I've never tried to mess with one before. Are they a pain to take off/put back on/get adjusted so that I'd be better off just pulling the pedals (and maybe zip-tying one crank arm to the frame) and calling it a day, or is pulling it and then putting it back on later not that big of a deal?

Thanks so much for your help.

Retro Grouch 02-08-14 07:04 AM

I think that if you just take off the pedals she'll be good.

rhenning 02-08-14 07:38 AM

Actually the one piece BB are very easy to take apart with a large cresent wrench and a small cresent wrench or 15 mm for the pedals. No special tools required. Roger

Murray Missile 02-08-14 07:48 AM

Like 'rhenning' said, piece of cake.

himespau 02-08-14 09:26 AM

Ok, figured it'd be easy to get them off. I was more wondering if it's hard to get them back on/adjusted properly. My only experience with non cartridge BBs were the two I pulled and replaced (or will replace) with cartridges. I've messed with some cup and cone wheels (cleaning, repacking, adjusting) and headsets, and it seems cleaner/safer to pull the crank and chain too, but I've had several people tell me that I should just pull the pedals and call it a day, so I didn't know what went into it. I have a pedal wrench, so doing the pedals will be easy (assuming it takes a normal sized pedal wrench).

LesterOfPuppets 02-08-14 09:43 AM

It's really easy. Remember to knock the cups out of the frame too, just so they don't fall out on their own while she's out and about.

Reinstall Is easy. Put in drive side cup, slide drive side bearing onto crank and pack that side, put nds cup in frame, pack it, add bearing, then adjust cone a hair loose. Add keyed washer, install and tighten locknut. May have to loosen locknut and readjust cone a time or two.

himespau 02-08-14 09:45 AM

Hmmm, sounds doable. Might even do that before her birthday tomorrow and give it as a b-day gift, though with as much snow as we have it won't be usable for a while, so I might just wait.

LesterOfPuppets 02-08-14 09:47 AM

NDS cone and locknut are reverse thread, btw.

okane 02-08-14 09:58 AM

as usual, sheldon tells all http://sheldonbrown.com/opc.html

Andrew R Stewart 02-08-14 10:05 AM

The most common mistake in reassembling these cranks/BB is to reverse the ball retainers so the ring is rubbing on the cup, and not the balls contacting the cup. Use a lot of grease, so much some oozes out. Andy.

Amesja 02-08-14 10:08 AM

Simple to do. If it is a caged bearing then save them for re-install but if not just throw them away and go to your local bike shop and get some new 1/4" bearing balls. They cost $.05 each so it isn't worth capturing and cleaning them all. Odds are you are going to lose one anyhow unless there is enough grease in there to keep them from falling out and bouncing all over the place. If you REALLY don't want to have to go to the LBS and buy more bearings then disassemble over a plastic garbage can lid or something similar as they will bounce and roll 5-10 feet away when they fall out and you'll never find all of them.

Like it was said, try and pop the races out of the shell if they are loose, but if they are really in there really hard I wouldn't bother. A screwdriver tap from the far side will usually get them out without much trouble. If they resist your efforts then they aren't going to fall out on their own.

I would not just pull the pedals off. That's going to HURT when they get whacked with little ankles and lower calves. Pain is the biggest de-motivator for any activity. If it hurts then kids aren't going to want to keep trying to learn. If it is fun, then they will take to it naturally.

Follow the Sheldon Brown link that was posted above and pulling the OPC is piece of cake.

dsbrantjr 02-08-14 10:20 AM

Unless the chain has a master link you will need a chain tool to remove it from the frame. I'd recommend a master link for when you re-install it.

himespau 02-08-14 11:46 AM

Quote:

Originally Posted by dsbrantjr (Post 16478436)
Unless the chain has a master link you will need a chain tool to remove it from the frame. I'd recommend a master link for when you re-install it.

Yeah, that was the plan. Figure out the chain width and then go to the bike shop and see about a master link. Originally, I'd been thinking about just getting a whole new chain, but when the bike arrived, the current one looks in pretty good shape.

himespau 02-08-14 11:46 AM

Quote:

Originally Posted by okane (Post 16478389)
as usual, sheldon tells all http://sheldonbrown.com/opc.html

Of course, how could I forget about Sheldon?

Andrew R Stewart 02-08-14 03:30 PM

[QUOTE=Amesja;16478408]Simple to do. If it is a caged bearing then save them for re-install but if not just throw them away and go to your local bike shop and get some new 1/4" bearing balls. They cost $.05 each so it isn't worth capturing and cleaning them all. Odds are you are going to lose one anyhow unless there is enough grease in there to keep them from falling out and bouncing all over the place. If you REALLY don't want to have to go to the LBS and buy more bearings then disassemble over a plastic garbage can lid or something similar as they will bounce and roll 5-10 feet away when they fall out and you'll never find all of them.

Like it was said, try and pop the races out of the shell if they are loose, but if they are really in there really hard I wouldn't bother. A screwdriver tap from the far side will usually get them out without much trouble. If they resist your efforts then they aren't going to fall out on their own.

I would not just pull the pedals off. That's going to HURT when they get whacked with little ankles and lower calves. Pain is the biggest de-motivator for any activity. If it hurts then kids aren't going to want to keep trying to learn. If it is fun, then they will take to it naturally.

Follow the Sheldon Brown link that was posted above and pulling the OPC is piece of cake.[/QUOTE

I thought that the question was about 1pc cranks/BBs. They take 5/16" balls, not 1/4". Also some bearing geometries don't work with non caged/retainered balls. The balls float off location. Andy.

Murray Missile 02-08-14 05:32 PM

Unless they're sloppy loose and you can pull them out with your fingers I'd leave the bearing cups in place, if you're concerned about them falling out throw a couple heavy duty zip ties through the bottom bracket to hold them in place. When pulling bearing cones I due it directly over an old tin tray with a large magnet on the bottom. If any ball bearings fall out they'll be drawn to the magnet under the pan, I use it when reinstalling them also, I always drop at least one.

Amesja 02-08-14 05:38 PM

Magnets and bearings should never cross paths.

FastJake 02-08-14 06:03 PM

+1 One piece cranks are crude but very easy to disassemble. Keep the bearing cages, this is one of the few bicycle applications where you definitely want to use them.

I probably wouldn't bother buying a master link unless you really want to. Chain is probably 1/8" and in any case certainly isn't Hyperglide so it should be able to be safely re-attached by pushing the pin through.

himespau 02-08-14 06:24 PM

Quote:

Originally Posted by Amesja (Post 16479407)
Magnets and bearings should never cross paths.

Why not? That's how I kept track of them all when cleaning/repacking my hubs?

Amesja 02-08-14 06:47 PM

Once magnatized the bearings will attract filings and instead of the metal slag and detritus from the bearings being pushed out of the tracks it will be drawn back in.

Just about every real mechanical institute teaches not to magnetize bearings.

himespau 02-08-14 09:01 PM

Huh, good to know. Hopefully, that won't cause problems with my hubs.

As far as the crank in this case, came apart easy as pie.

zacster 02-08-14 09:41 PM

And I went through Ashtabula today...

Turtle Speed 02-10-14 09:01 PM

Quote:

Originally Posted by Amesja (Post 16479550)
Once magnatized the bearings will attract filings and instead of the metal slag and detritus from the bearings being pushed out of the tracks it will be drawn back in.

OK, but how easy is it really to magnetize a bearing surface? It's not like touching a magnet to metal for 5 seconds will do it, will it? Even Park Tool recommends suggests using a pencil magnet to remove balls in their hub overhaul tutorial.

FastJake 02-10-14 09:11 PM

Quote:

Originally Posted by Turtle Speed (Post 16485305)
OK, but how easy is it really to magnetize a bearing surface? It's not like touching a magnet to metal for 5 seconds will do it, will it? Even Park Tool recommends suggests using a pencil magnet to remove balls in their hub overhaul tutorial.

Depends how strong the magnet is. A brown fridge magnet is unlikely to do anything. But if you've ever messed around with those super strong neodymium magnets, those will definitely leave steel magnetized. You only have to touch it once. The amount of time is irrelevant.

Turtle Speed 02-10-14 10:50 PM

Quote:

Originally Posted by FastJake (Post 16485331)
Depends how strong the magnet is. A brown fridge magnet is unlikely to do anything. But if you've ever messed around with those super strong neodymium magnets, those will definitely leave steel magnetized. You only have to touch it once. The amount of time is irrelevant.

That makes sense. But I guess my question is, is it OK to use a pencil magnet with an old steel hub? Any scientists or people with experience know?


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