apbenton

I'm currently sprucing up an old bike I've had in the garage for a while. I thought it would be a good way to practice and improve my bike mechanic skills. The crank arms seem to wobble quite a bit and from a bit of research this seems to point to bottom bracket problems. I'm currently trying to remove the crankarms & bottom bracket but I'm not sure what tools I need. Would anybody be able to help and provide advice? I've attached photos to show the bike in question.

Thanks in advance!

cyccommute 

You need a crank arm puller to remove the arm. For your bottom bracket, you need a thin wrench (32mm?) and a hook spanner to adjust the bearing cup. That can actually be done with the crank arm still in place. Go over to Park Tools and look at bicycle repair help/bottom brackets to see how it is done.

JanMM

If your crank arms wobble, that could be either a problem with the crankarm/crank axle interface or with the bottom bracket itself. Either way, taking it all apart is a good plan and referring to Park Tools repair help is a great first step.

fietsbob

once again, you have to choose , buy all the BB tools to remove the cranks And BB cups ..

Or have a bike shop do the work and not have to buy all the tools . ..

OR seek out a Cooperative Bike repair, join it, and be able to share the tools owned by the CoOp, as a collective resource..

wrk101

+1 In general, tools do not pay for themselves until the third repair or so. And there are a lot of different styles of cranks and bottom brackets, so one set does not work on every bike. Going a co-op is a great way around the tool cost problem.

Retro Grouch 

If the problem is in the crankarms, they will wobble independently. If the problem is in the bottom bracket, the crankarms will wobble together.

A crankarm extractor is a semi-frequently needed tool and there really isn't an adequate work around for having one. If you're planning to work on bikes, put one on your shopping list.

That bottom bracket might be a different story. After removing both crankarms, take a hammer and an expendable screwdriver to undo that lockring. The right side will almost surely be a left hand thread. Then try to find a wrench to fit the bottom bracket itself. The right side is called the "fixed" cup for a reason. The trick is to keep the wrench engaged on such a narrow flat. It might help to use a semi-loose clamp to hold the wrench engaged.

Good luck.

Bill Kapaun

How'd you get the first arm off?
IF it came off by itself, your crank is the problem, not the BB unless it's also coincidentally bad.

fietsbob

as I see it in middle picture its still there , end on of a nut fixed solid axle BB, the serrated teeth of that nut
just barely marking the bottom of the crank arm extractor socket.
black painted arm. Nut may have fallen out for lack of tightening with a 14mm socket.

This appears to be a budget parts spec overall ..

ramzilla

Lay the bike on it's side between two saw horses. Spray some liquid wrench down in the hole where the 14mm bolt holds the crank arm. Use plenty of lubrication when you thread the crank arm extractor on & off. Threads down there are easily damaged. After you get the crank arms off you gotta figure out which way things thread. Here's a good guide: Tool Tips--Bottom Bracket Cups

fietsbob

You are thinking of a different BB axle, not seeing the one shown,


Have to have a Crank Extractor that fits Over the Stud End of that solid BB Spindle ... Fixing is not a bolt, but a Nut.

I have that sort of tool ..In that case Id take the extractor apart

screw the 1 piece into the arm solidly, then screw the handle, part 2, into the extractor, part 1.
a little grease on the extractor threads

Bill Kapaun

You're right.
It was so zoomed in, I lost perspective of what I was looking at.

fietsbob

End on it is an odd perspective..