shimano fc-c103 bike arm crank

[deathtokoalas]

that said, the age of the existing system makes it unlikely to be able to fix as it is and the deduction that the whole thing will need to be replaced is likely correct.

 

[T4tomo]

i am sure that there has to be a lock ring because the connection is threaded. the gap is normal on many different spindle types, but the existence of a threaded surface gives it away - something is supposed to be there, and has apparently rusted away or been otherwise ridden down and fallen off.

OK one last try....

there is no lockring meant to go on this thread. that is the equivalent of this bit:

some of them have a finished edge, some just have extra threaded length, but it is supposed to look like that.

it may be slack if the whole BB unit is shifting within the shell, but the crank is firmly attached to the bb axle.

you need to remove the crank (presumably with a crank extractor, but the info pictures given aren't conclusive) and then tighten it with the correct splined tool.

a bit of politeness costs nothing.

 

[deathtokoalas]

the axle-pedal (or spindle-pedal) system is really solidly together, too. i can pull the system through the hole in the frame back and forth, to an extent; it's blocked by the chain wheel and the actual pedal. when i get the pedal off, i should be able to pull the spindle out altogether from the driver side. the thing that's loose is the connection to the frame.

 

[T4tomo]

you don't need to remove the pedal to remove the crank arm, but you do need to remove the crank arm to sort out the Bottom bracket, which sound like its not just loose, but completely farked, in which case you'll need a new bottom bracket. i think your are confusing "pedal" with "crank"

loads of video's on you tube.

search crankset removal, BB removal, throw in square taper until you find one that looks like what you have

if you dont have the tools, may be quicker and easier taking it to your local bike shop.

 

[deathtokoalas]

OK one last try....
View attachment 669432

there is no lockring meant to go on this thread. that is the equivalent of this bit:
View attachment 669433
some of them have a finished edge, some just have extra threaded length, but it is supposed to look like that.

it may be slack if the whole BB unit is shifting within the shell, but the crank is firmly attached to the bb axle.

you need to remove the crank (presumably with a crank extractor, but the info pictures given aren't conclusive) and then tighten it with the correct splined tool.

a bit of politeness costs nothing.

well, i have to take it apart, regardless, but it looks to me like even the bracket in your picture has a cap that is missing in my picture.

i don't expect i'll be able to tighten this simply by screwing it back together because it's not going to connect back to the frame snugly. call it a lock ring or something else but that cap has fallen off.

 

[deathtokoalas]

you don't need to remove the pedal to remove the crank arm, but you do need to remove the crank arm to sort out the Bottom bracket, which sound like its not just loose, but completely farked, in which case you'll need a new bottom bracket. i think your are confusing "pedal" with "crank"

loads of video's on you tube.

search crankset removal, BB removal, throw in square taper until you find one that looks like what you have

if you dont have the tools, may be quicker and easier taking it to your local bike shop.

yes, i apologize, i meant spindle-arm system, not spindle-pedal system.

 

[T4tomo]

but it looks to me like even the bracket in your picture has a cap that is missing in my picture.

so lets pretend there was a cap / lockring /cover screwed on there which has fallen off - why isn't it still attached, as it would still be a ring shaped thing surrounding a solid axle?? Unless the bike belonged to Paul Daniels.....

 

[Ian H]

So it seems that you need to get the cranks off to remove the bottom-bracket assembly. A Bayliss-Wiley set-up would suggest steel cranks with cotter pins, however your photo appears to show an alloy crank. Specifically, a "Bayliss-Wiley Unit" is rare and highly unlikely to be fitted to an Italian frame.
A photo showing the cranks would be helpful.

 

[Ajax Bay]

the bolt connects the [crank] to the axle, it doesn't connect it the frame. it is the lock ring that connects the axle to the frame and prevents it from moving. the axle and the pedals are now locked together as one system, but that system is disconnected from the frame. that is why the crank arm is loose and the bolt is not.
i was able to answer my question via my own research.
these posters are not well informed.

There is no lock ring. You have a cartridge BB - see the image @T4tomo shared. Whatever answer you think you've got is not. Take care with ill-informed assertions: we have tried to help.

for the benefit of any other readers, note that the following video explains the system quite well, and goes through the locking process as well:

Nope. That is a cup and cone loose (ball) bearings BB you have shared. That does indeed need a lockring. Yours doesn't.

i may have been imprecise in my description. i do not have the square taper you're suggesting and i should have looked it up before agreeing with you. the type of bottom bracket here is called a Bayliss Wiley Unit Bottom Bracket.

You do have the BB and crank that 'we' are suggesting: stop arguing!

i asked the forum because i didn't know. i have a reputation for being snarky, but this was an honest question,. . . i was looking for an experienced poster to quickly look at the bracket and say "yup, that's a ..."

i am sure that there has to be a lock ring because the connection is threaded. the gap is normal on many different spindle types, but the existence of a threaded surface gives it away - something is supposed to be there, and has apparently rusted away or been otherwise ridden down and fallen off.

i believe this type of bottom bracket went out of style in the 60s, but the bicycle might have been built from spare parts in the 70s or 80s. i don't know.

You got what you were looking for (an experienced poster). Your "I am sure" is a testament to your self-confidence, albeit misplaced in bike mechanism matters. Cup and cone BBs are still 'in style': I serviced one a few weeks ago. But the cartridge ones, like the one you've got, are an 'easier' solution and widely used for all square taper cranksets.

the axle-pedal (or spindle-pedal) system is really solidly together, too. i can pull the system through the hole in the frame back and forth, to an extent; it's blocked by the chain wheel and the actual pedal. when i get the pedal off, i should be able to pull the spindle out altogether from the driver side. the thing that's loose is the connection to the frame.

At last we might see the way ahead after you shared this symptom "i can pull the system through the hole in the frame back and forth". And the exposed threads in OP image gave a hint. I surmise your LH 'cup' on the cartridge BB is loose. You need to remove the crank bolt, extract the crank (using a crank puller tool) see my first post (#4)!!, and then you'll have access to the BB. I expect you'll be able to waggle the spindle end. You'll need a 20-spline tool to tighten it. Would be worth removing (only that end), cleaning, and applying some threadlocker (new ones come with that on already) and screw back in 40Nm. Refit the crank. And ride on. I am elaborating on what @T4tomo has already advised. This may be all that's 'wrong'.

well, i have to take it apart, regardless, but it looks to me like even the bracket in your picture has a cap that is missing in my picture.
i don't expect i'll be able to tighten this simply by screwing it back together because it's not going to connect back to the frame snugly. call it a lock ring or something else but that cap has fallen off.

You do seem to have trouble believing others. There is nothing missing. You will be able to "tighten this simply by screwing it back [in] because it's not going to connect back to the frame snugly".

 

[deathtokoalas]

so lets pretend there was a cap / lockring /cover screwed on there which has fallen off - why isn't it still attached, as it would still be a ring shaped thing surrounding a solid axle?? Unless the bike belonged to Paul Daniels.....

it has fallen off due to some combination of wear and erosion. that is the problem. it's a moving part on a very old bicycle. it's an entirely reasonable analysis.

 

[deathtokoalas]

There is no lock ring. You have a cartridge BB - see the image @T4tomo shared. Whatever answer you think you've got is not. Take care with ill-informed assertions: we have tried to help.

Nope. That is a cup and cone loose (ball) bearings BB you have shared. That does indeed need a lockring. Yours doesn't.

You do have the BB and crank that 'we' are suggesting: stop arguing!

You got what you were looking for (an experienced poster). Your "I am sure" is a testament to your self-confidence, albeit misplaced in bike mechanism matters. Cup and cone BBs are still 'in style': I serviced one a few weeks ago. But the cartridge ones, like the one you've got, are an 'easier' solution and widely used for all square taper cranksets.

At last we might see the way ahead after you shared this symptom "i can pull the system through the hole in the frame back and forth". And the exposed threads in OP image gave a hint. I surmise your LH 'cup' on the cartridge BB is loose. You need to remove the crank bolt, extract the crank (using a crank puller tool) see my first post (#4)!!, and then you'll have access to the BB. I expect you'll be able to waggle the spindle end. You'll need a 20-spline tool to tighten it. Would be worth removing (only that end), cleaning, and applying some threadlocker (new ones come with that on already) and screw back in 40Nm. Refit the crank. And ride on. I am elaborating on what @T4tomo has already advised. This may be all that's 'wrong'.

You do seem to have trouble believing others. There is nothing missing. You will be able to "tighten this simply by screwing it back [in] because it's not going to connect back to the frame snugly".piece to replace

i was not looking for advice as to how to fix the bicycle, i understood that i had to take the bicycle apart. i needed an analysis as to how the system in place actually worked, because i did not know which part was broken and consequently did not know which piece needed to be replaced.

the picture you keep posting does not resemble the system in my bicycle. the bolt is the inverse of the typical system with a hex key - i had to purchase a 14 mm wratchet set and utilize various tactics to unscrew it because it simply wasn't loose. once i got it out, i realized it was not stripped. the remaining hole is hexagonal.

the system is a slightly updated bayless system from the 60s or 70s. it is simply too old of a bicycle to have the modern bracket system you are insisting it has and does not have.

 

[T4tomo]

excellent now you have worked out the issue, I look forward to some photos of the dismantled system.

it will provide useful resource for subsequent cycle chat users.

 

[deathtokoalas]

the bracket has a "diamond" shape. cotterless may indeed be the correct description.

 

[deathtokoalas]

excellent now you have worked out the issue, I look forward to some photos of the dismantled system.

it will provide useful resource for subsequent cycle chat users.

i am going to have to purchase a crank puller and i am going to have to research the correct type.

 

[deathtokoalas]

it may be more correct to call it a washer than a lock ring but i am certain that a screw of some sort has eroded due to wear and fallen off. yes, the whole thing now needs to be replaced. i may end up purchasing a square taper.