One key release on Shimano 600 cranks
 

I have a bike with self extracting cranks (Shimano 600 EX), which I've never worked with before, so have two questions:

1.
Is this retaining ring damaged? Should it be replaced?

2.
There isn't a retaining ring on the non-drive side of the bike (like that when I got it). Should there be? Or is the retaining ring swapped between the two cranks during removal?

1. Yes it's damaged. It shouldn't be cracked and the spanner holes are distorted. It's been abused as has the crank bolt.

2. Yes there should be an extractor ring on each crankarms so the one on the non-drive side is missing. Also, the crank bolt on the NDS has been replaced with a hex head bolt which is not part of the autoextractor mechanism.

I hope you didn't pay much for this crank. You can either find two replacement extractor rings and two compatible replacement crank bolts or replace both the surviving extractor ring and bolt with a new standard crank bolt and covers for both sides. A standard crank puller should be able to remove the crank arms in the future if you don't replace the autoextractor rings and bolts.

+1 on the suggestion to replace the cracked ring with a dust cap and use a conventional extractor for any future service. Andy

Toronto Cycles has inexpensive self extracting sets.

Take a good look at the threads on the left arm - the picture makes it look like they aren't there anymore.

I switched my Shimano self extracting bolts for something like these. https://www.ebay.com/itm/Sugino-8-mm...cAAOSwHMJYOVmt Still uses an allen wrench, looks decent and cheap. Never liked the self extracting collars as they didn't hold up to using much force. Best to just use a proper crank arm extractor tool as HillRider mentioned.

That's an attractive crank, like the pebbled accents!

The self-extractors can work well, but that particular size doesn't jive with aluminum collars, as they were produced.

If you have to have than, White Industries makes self-extracting bolts for square taper cranks out of stainless (the bolt) and bronze (the extracting collar).

One must wonder why the ring is cracked, as its good quality steel being screwed into ally crank arm ? to my mind the 1st thing to go would be the ally threads, see the enlargement it has several cracks, one wonders if someone has tried to undo the Allen bolt without taking out the ring ?

Undoing the allen bolt without taking out the ring is how self-extracting crank bolts work. The bolt head has a flange like the brim of a hat, that's almost the same diameter as the retaining ring, so when one backs out the crank bolt, the bolt pushes the crank arm off of the BB taper.

Either the crank got loose, and the ring was the only thing holding it on, and failed do to loading, or, more likely, the crank arm is really, really stuck on the BB, and the ring cracked during a removal attempt.

as someone who has had the self-extracting ring strip out the crank remove the ring, and throw it away ..

the more current bolts offer an 8mm hex socket,* include the function of the flat washer behind the bolt on the left
and a ring that covers the extractor thread from dirt, etc. and look nice..

https://www.universalcycles.com/imag...dium/16127.jpg

there are a few pedals also using an 8mm 'allen' wrench, so getting a long one helps both..


As to your "should" I suspect you did not buy it new,

the past owner may have dumped the other self-extracting ring, for the same cracking..





;)


...

Accepted however whenever I've taken these 600 cranks off or similar I undo the ring remove the Allen bolt, screw in the extractor tool, then screw through it & jack it off, I Don't rely on the ring.

.
...it honestly looks to me like someone tried to pull the crank arms, didn't have any luck, and sold the bicycle as a result.
+1 on the suggestion sto simply abandon the self extractors, and return to conventional bolts and caps, if there's enough thread remaining to remove both arms.

Embrittlement from bad plating, perhaps?

There is no reason to conclude that all self extracting systems are problematic just because this early verision cracked. Current system use a thin formed piece that likely flexes instead of cracking like the solid (cast?) steel version in this late '70s crank. Campy used their own version for many years as well. They are fine for occasional crank removal.

They also look nice.



Just like using an extractor tool, it is important to make sure that the collar is tight in its threads and there is grease between it and the bolt shoulder. I like to use some blue loctite on the threads to make sure they stay tight so you don't have to stick a pin spanner in it every time you want to use the extractor feature.

I didn’t pay much for the bike, it was an Estate Sale find and based on the amount of dust on it, it has been unused for a long time.

Thanks for the advice, much appreciated. I’ll need to decide on what to do. I like the idea of self-extracting cranks, but am perfectly ok with a more traditional system.

Thanks for the link, I’ll look into those - they look nice.

No, I the cranks came on the bike and I didn’t buy them new. That would make sense that the ring was dumped due to cracking.

There are at least several mfrs of these including Shimano so shop around although the Suginos are fine enough quality to use and probably least expensive. Double check for proper length and bolt diameter.

You did not buy the bike Brand New From the Dealer is what I was surmising....

The right doesn't have a self-extracting bolt. A 15mm socket will fit on that bolt and a conventional extractor tool will remove the arm. I would remove the ring and allen bolt on the right side and use the tool to remove the crank.
I have self extracting bolts on my bike and they work fine.

TA Auto-Extractors

I bought a set of those and the hex bolt stripped. I think this is partly due to the hex being 6mm instead of the more common and robust 8mm.

My road bike has Shimano self-extractors which have worked well many times over the last 17 years.

I got titanium crank-fixing bolts with self-extractors from Toronto Cycles for my Tern folder. I also replaced the SS chainring hardware with Ti equivalents. There's less corrosion, the Ti parts look nice and I saved about a half a gram!
The image of the chainring and crank is split horizontally, with the top half showing SS hardware and the bottom Ti. In the other images, the SS parts are on the left and Ti on the right.
Steve

That's a good question.

The obvious thing to try first is a pin spanner, after a liberal dose of WD40 or something.

I'd get someone to help by simultaneously tapping on each part of the ring with a punch. If that doesn't work, well... A painstaking hour or two with a Dremel?

I guess ideally, there'd be a tool to fit that you could pop into a rattle gun, but you'd have to make it.

retaining ring pliers might get enough bite in that.

Thanks - I found the Park Tool SPA-2 that looks like it will work.