Replacing self extracting crank bolts

[Mrs Pingu]

Specifically on a TA Carmina crankset.
I can't find any useful information on the Specialites website. The Allen bolt is getting rounded on the RH crank so I'd like to replace it. I currently have the ones with the black dust cap. I can only find silver TA ones for sale.
1. Will the silver one be ok?
2. How the hell do I go about removing the old one and putting the new in?
3. What special tool do I need?

Thanks 👍

[tatanab]

Removal - any tool with a pair of small pins for ends, such as needle nose or round nose pliers, Circlip tool, or even a small pair of scissors may work.  Insert into the two holes and rotate anti-clockwise, just like undoing a normal screw.  This removes the coloured cover, then remove central crank securing bolt as normal.

Reverse procedure for fitting, although I guess the new one might come with instructions about applying grease and what to or not to.

I've been using "other brand" self extractors for 25 years, my logic being that it is one fewer tool (crank extractor) to carry when on tour.

[Mrs Pingu]

Does the bolt just fall out when you remove the dust cap?

[tatanab]

The "dust cap" is not a dust cap, it is the screw in feature that the central bolt works against to remove the crank i.e self extract.  Once that cap has been removed the central allen key bolt (which holds the crank onto the bottom bracket) can be removed in the usual manner.

A Youtube video shows it all.  It features an ISIS bottom bracket rather than a square taper but the principle is the same.  https://www.youtube.com/watch?v=mxAj-zbynPI&ab_channel=ParkTool

[Feanor]

 I replaced someones FSA self extracting crank bolts last week. Assuming its similar...

The 'dust cap' is an essential part of the self extracting system. The crank bolt shoves against the inside to push the crank off.

The crank bolt was a 10mm hex, normal thread, but a bit deeply set. Some hex keys are a tad short and only partially engage, which encourages rounding.  I got a long 10mm hex driver with 1/2 in square drive to use a long handle wrench to remove it.

If you then wish to remove the cap, you need a 2 pin tool or similar. It should not be super tight, but it might be a LH thread. The FSA one had markings that it was LH.
ETA: The reason it's a LH thread is so that as you unscrew the internal crank bolt, and it begins to bear up against the inside of the cap, the friction does not unscrew the cap at the same time!
ETA: This also means that once he cap is removed. a conventional crank puller CAN NOT be screwed in; the cap threads on the crank are LH, the crank puller is normal RH.  You will destroy the threads on the crank if you force it.

Also ETA: The reason I needed a big wrench to remove the crank bolt was that the owner had mis-interpreted the LH thread markings on the cap and thought they referred to the main crank bolt, so had been beasting with all her might in the wrong direction. She's quite strong, and the thing was now Bastard Tight!

Here are the tools I used:
https://www.amazon.co.uk/dp/B08SQ77GBJ
https://www.bikeparts.co.uk/products/park-tool-spa-6-adjustable-pin-spanner

[Mrs Pingu]

Alright, seems simple in theory (lol), though I don't have the benefit of handy arrows. Will buy the bolts and give it a whirl.

[robgul]

I replaced someones FSA self extracting crank bolts last week. Assuming its similar...

The 'dust cap' is an essential part of the self extracting system. The crank bolt shoves against the inside to push the crank off.

The crank bolt was a 10mm hex, normal thread, but a bit deeply set. Some hex keys are a tad short and only partially engage, which encourages rounding.  I got a long 10mm hex driver with 1/2 in square drive to use a long handle wrench to remove it.

If you then wish to remove the cap, you need a 2 pin tool or similar. It should not be super tight, but it might be a LH thread. The FSA one had markings thai it was LH.

Just to add - my preference when refitting self-extracting cranks is to remove the self-extracting retaining cap "a.k.a. dust cap!!" to fit the crank on the splines, then fit the bolt and torque it up before refitting the cap (either with a pin spanner or - carefully - with a punch and hammer to turn it.)  [New bolts will, of course, require removal of the cap]

[slope]

Just to add - my preference when refitting self-extracting cranks is to remove the self-extracting retaining cap "a.k.a. dust cap!!" to fit the crank on the splines, then fit the bolt and torque it up before refitting the cap (either with a pin spanner or - carefully - with a punch and hammer to turn it.)  [New bolts will, of course, require removal of the cap]

+1

[tatanab]

my preference when refitting self-extracting cranks is to remove the self-extracting retaining cap "a.k.a. dust cap!!" to fit the crank on the splines,

I note splines where perhaps the exact torque is required (I've never used such a bottom bracket so do not know).  All mine (5 machines and 25 years of self extracting) are square taper, so I have never removed the "dust cap" when refitting.  It is necessary to hold the crank in the right orientation versus the square taper because in my extractors the screw thread engages before the taper reaches the crank.  In the past, I recall reading of people who thought they could not torque a square taper appropriately using the allen key, and so would strip out the self extractor, fit the crank with the hex headed bolt, and only then reinstall the self extractor.

[Feanor]

I don't use a normal hand allen key for this; I use a hex key with a 1/2 inch square drive ( linked in my updated post ) which fully engages with the deep-set bolt and allows me to use a regular torque wrench.

[robgul]

I don't use a normal hand allen key for this; I use a hex key with a 1/2 inch square drive ( linked in my updated post ) which fully engages with the deep-set bolt and allows me to use a regular torque wrench.

Ditto - the Allen/hex & Torx sockets are some of my most used tools (one set from Park and the other from Herr Rose)

[Mrs Pingu]

I don't think deep set is an issue with my bolts, or the length of the Allen key, more that the socket (? the depression the key fits in) in the bolt itself is not very deep. At least I understand how the things work now, which explains the briefly loose followed by stiff again turning action.
Maybe it's time we bought a torque wrench though.

[Mrs Pingu]

That went ok. The original retaining caps were quite loose!
2023-07-30_11-36-41 by The Pingus, on Flickr

[Feanor]

Out of curiosity, was the cap LH thread or not?

[LittleWheelsandBig]

Early Campag C-Record used a LH extractor thread to keep the self-extractor caps (7mm Allen key required) in place. Campag made a LH extractor just for the track version which didn’t use the self-extractor bolts. I have a LH extractor, of course.

I don’t know of any other cranks and self-extractors with LH thread.

[Mrs Pingu]

Out of curiosity, was the cap LH thread or not?

Weirdly, no. Everything was lefty loosey righty tighty.

[Feanor]

Early Campag C-Record used a LH extractor thread to keep the self-extractor caps (7mm Allen key required) in place. Campag made a LH extractor just for the track version which didn’t use the self-extractor bolts. I have a LH extractor, of course.

I don’t know of any other cranks and self-extractors with LH thread.

See above.
The FSA one I replaced a short while ago had a LH thread on the cap, so that during extraction the main crank bolt (RH thread) does not begin to remove the cap via friction.

[LittleWheelsandBig]

I have stayed away from FSA cranks. LH extractor threads are the exception, not the rule.

[BFC]

Miche pistard 2.0/air are also a LH thread in the self extracting cap.

[LittleWheelsandBig]

So we are up to three examples of cranks with LH extractor threads out of hundreds of crank designs.

[Captain Nemo]

So we are up to three examples of cranks with LH extractor threads out of hundreds of crank designs.

I have just had reason to remove my 2007 Shimano XTR FC-M970 crank.

May I offer up this as a fourth left hander - and this one is not a captive self-extractor but requires its own dedicated tool (TL-FC35) with a M30 x 1 LH thread which did not come with the cranks. The tool was not cheap back in the day when the cranks were current (about £15 if my memory serves me well) and will now sting you over £40 for NOS and not much less for used examples on the bay of thieves.

https://www.youtube.com/watch?v=HI7h7ol0ClE

Removal from 3:12 onwards