schnurrp

I have crank dust caps on a recently acquired bike that I can't see how to remove. They are part of a Shimano golden arrow crank set and they appear to have a hex fitting in the middle but 5mm is too small and 5.5mm is too large. Do these require a special tool?

I had a nice photo ready to attach but I haven't reached the 10 post level. Sorry.

schnurrp

Kontact 

I don't believe that is the original cover. That crank had 6mm self extracting bolts.

I would try imperial size allens or torx to get it out. It is low torque. Don't put it back in - something is rounded out with it.

schnurrp

Okay. The few that I saw for sale on ebay showed the "hex" hole going all the way through the cap which I think would defeat the purpose of having a cap. All appear to have been distorted a bit by a tool or is not an actual "hex".

Thanks.

easyupbug 

Looks like my caps but with some damage. I would also give it some penetrant spray, PB B'laster or the like, at that age things can start coorsion/binding and cause a hex to round out.

Kontact 

The cap is there mainly to protect the crank thread and keep debris out of the area around the bolt that the socket goes into. Most threaded caps have holes that go all the way through.

If you can't get it off with other size hex tools (it is clearly hex in your picture), carefully slot it with a dremel cutting tool and use a large screw driver or coin to turn it out.

Mr. 66

Your 5mm is the correct allen, try some PB blaster, and/or some heat, that should help your allen key.

Iride01 

For self extracting crank arms, the hole is necessary because you have to be able to access the bolt that holds the crank arm on. The bolt head pushes on the "cover" as you unscrew it and pushes the arm off the spindle.

The socket for the bolt is a smaller size hex than the hex in the cover.

I'm not going to guess though what that is you have. But if there is a small hex socket visible inside that hole, it may well be self extracting. Though someone has already questioned if that is the correct cover for that. So even if it was, it may not be any longer or vice versa.

Kontact 

There are many pictures online of the 600ex self extracting bolts, and this is not it. Someone replaced those with a normal 14mm bolt and put an aftermarket cap on that was probably 5mm, but is now rounded out.

These caps are often made of soft cast aluminum or even chromed zinc, so they aren't built for much torque and get rounded out easily.

Iride01 

I didn't doubt you at all. There wasn't any need for you to explain it to me.

But I guess it does start as a jumping point for you to give further info to all. I only characterized it as "cast doubt" because I didn't have any proof at the moment, nor did I want to look for proof.

Kontact 

I was trying to clarify if my previous reference to self extractors was causing some confusion. I didn't intend to make things confusing, just trying to point out that the cap in the OP was not factory.

3alarmer 

.
...when the hex in those gets rounded out like that (not uncommon), the simplest method of extraction is to drill a couple of small holes in the cap, and employ and adjustable pin spanner. But these caps have a long history of getting corroded in place, when not initially inserted using some sort of grease or anti-seize compound on the threads. So if that's the case, this sounds a lot easier to do, than it often is in practice. What usually helps (a lot), is a couple of heating and cooling cycles, using a Mapp gas torch and Freeze Off.

It's one of the reasons I've gradually tried to replace mine with the crank bolts that are all one piece, and have a socketed head.

3alarmer 

...you want to drill your holes to end up with something resembling this.

schnurrp

Thanks.

The 5mm hex in mine do not go all the way through. They have a bottom. I guess I will try the two drilled holes solution to start with.

In case you're wondering the bike is a mid-80s Ross Signature 292s I bought on Craigslist for $100. I intend to upgrade it a bit and use it on the many miles of paved greenways here in Raleigh, NC and surrounding. It came with 700x23s but I had no problem installing a front wheel off another bike 700x33. I think there may even be enough room for a 35 so light gravel may not be out of the questions. The Shimano golden arrow brakes will work with the larger tires if you give up quick release.

3alarmer 

,,,the best penetrating oil is a 50/50 mixture of ATF/acetone. I mix it in a small used Tri-flow bottle, with one of those applicator straws. Apply to the threaded interface between crank and cap, and let it wick in. Otherwise, the heating/cooling thing usually works OK before you try to extract it with the pin spanner.

dedhed

Those are the correct covers for the OP's FC-S105 crank. It did not use self extractors

https://manualzz.com/doc/53869411/sh...-exploded-view

Kontact 

Good catch. I thought those were 600.

SJX426 

@3alarmer - I am soaking a post with that mixture. It has been sitting for a couple of months. Does the acetone evaporate out of the mixture over time?

3alarmer 

...it's acetone. Depending on exposure to the air, it evaporates out pretty rapidly. The main reason it's in there is to thin out the ATF, so it wicks into the thread spaces better (or in your case, the space between the post and frame). The heating with a torch thing helps a great deal, and the expansion and contraction from that probably does a better job of breaking any corrosive bonding. In your case, if you are worried about frame paint. apply your heating to the exposed parts of the post. The acetone portion will flare off, so reapply before you start twiting and turning to extract.

The real value of the stuff seems to be that it penetrates well, due to the acetone, and it reduces friction at the interface, due to the space age additives in the ATF.

SJX426 

@3alarmer Thanks for the explanation of the mechanics! I have not tried the application of heat due to the rubber stopper at the open end of the post. The paint looks really bad so I may just apply there too after refreshing again. Refreshed a couple of weeks ago with no change in removal resistance.
PXL_20221115_180109829 on Flickr

Some would say, "why bother." Well, it is a challenge, and I don't like to loose! The head of the post has been removed with most of the post still intact.

I have non period parts for it so i was thinking it would be a good beater bike as is with some upgraded (newer 70's like parts).

3alarmer 

.
...what happens when an alloy post gets galvanically corroded in a steal seat tube, is that the aluminum oxide junk kind of fills any space between the two. So if there's a long length of post in there (which sometimes, sadly, there is), you can't get good penetration of anything. My own preference is to try Ammonia in there first, then go with heating and cooling cycles, to provide some shock to interface with the expansion and contraction. I don't usually go with the ATF/ acetone stuff until I'm ready to put the end of the post in the bench vise, prior to twisting the frame off the post. If you've already had the ATF in there that long, don't bother with the ammonia. The oil will probably prevent it penetrating very far. Don't twist the frame without putting a hub or axle spacer in the rear dropouts, and it's easier to handle if you pull the fork.

It's also easier if you can get another person to help. One person does the twisting, and the other person pulls on the frame to try and make it move off the post, while you are twisting.

They usually come out eventually...maybe 90% of them or a little better. With the torch heating and cooling, I think maybe 100%, IME.

schnurrp

I used the two hole method and it worked very easily. Caps were not tight or stuck, to my surprise, just lacking a way to provide force. Five mm hex hole on the caps does go all the way through. I don't see what they do.

The rest came off without a hitch. The Cup-and-cone bb is shot. I may keep it and use loose balls and grease or I may replace it. Removing the dust caps was the most difficult part of the job.

3alarmer 

...they mostly are there to protect the threading in the crank arms, so you can easily insert the puller and tighten it in place.
A lot of people run without them. Or you can replace with the one piece crank bolt version that is available, which also protects the threads..

dedhed

personally, I'd throw a cartridge in it and be good other than needing another tool to install it

schnurrp

That makes sense 3alarmer. When I removed the first one the crank bolt was rusty but it came out with no problem and yes the threads used by the crank puller were in good condition.

And, yes, I have a cartridge on another bike that will work so I'll probably do that.