's Forum Archives - Components

Archive Home >> Components(1 2 3 4 5 6 7 8 9 10 )

Self extracting crank bolts & Expanding Stem Plug(7 posts)

Self extracting crank bolts & Expanding Stem PlugCharlie The Fred
Jul 11, 2001 8:17 AM
Yet more silly fred questions!

I'm guessing from the name that self extracting crank bolts pull the crank off the BB when you unscrew them, so is this true and are they worth getting a set to replace normal crank bolts? And do they work with Ultegra splined BB and cranks?

I'm not 100% sure of the name of the this gadget but it's something like an expanding plug that replaces the star flanged nut in a headset. I know that they are reusable, unlike a star flanged nut, but are they as good for holding and adjusting a headset?
re: Self extracting crank bolts & Expanding Stem Plugdug
Jul 11, 2001 8:23 AM
1. yes thats what they do
2. worth getting = up to you
3. yes - they work with Ultegra
4. yes - as long as you get one made of metal. Don't get a 'plastic' one.
Cautionmnky grz
Jul 11, 2001 10:16 AM
Ultegra splined cranksets come standard with the self extracting crank bolts. Pay close attention when installing a crank with this feature. It is pretty easy to have the splines NOT in alignment, engage the bolts and subsequently strip the mating splines from the alloy crank arm. Seen it happen, so I usually advise people to remove the bolts prior to installation until they get used to the feel/appearence.
I agree - CautionMike Prince
Jul 12, 2001 9:18 AM
I will agree on being cautious. I put some X-Lite self-extract bolts (105 9-spd) on one of my bikes. Why I don't know, I guess I thought it would be easier to remove the crank or it made it look better. Anyway, installed exactly to directions and the first time I went to remove the crank to replace the BB the cap assembly deformed and ripped out some of the threads on my crank. Luckily there are enough left to use a regular crank remover in the future.

I have Dura-Ace on my new bike and I think I'll remove the bolts and use an extractor when I need to remove the crank. To me the appeal of the self-extacting bolt isn't worth the potential damage to one of the most expensive components on my bike. When thinking how often I actually remove the crank (at most 1-2 times/year) it really isn't inconvenient to use the right tools and have some peace of mind.
Save your moneySpoke Wrench
Jul 11, 2001 11:41 AM
How often do you remove your cranks or replace your fork?

I can see a purpose for the self extracting cranks if you disassemble and ship your bike around a lot, but even then a separate crank extractor is not a big deal to carry. A couple of years ago, Santana Tandems recalled the self extracting rings on all of their Ultegra equipped bikes and replaced them with plain (non-self-extracting) parts.

The star fangled nut in your fork can be used until you get a new fork. The purpose it serves is to set the pre-load on your headset bearings only until you clamp the stem into place to hold the adjustment.
re: Self extracting crank bolts & Expanding Stem Plugjim Hubbard
Jul 12, 2001 12:33 PM
Self extracting crank bolt are the worst idea that I have come across because of the force needed to get a crank off they have more of a tendency to rip the threads out of the cranks. And I can testify that this is heart breaking if it is dura-ace. Get rid of them and use normal bolts. As for the expanding plug these are normal used instead of a star nut with carbon forks. The best design I have seen is by frm. It uses to diffent size threading systems one to expand the plug in the steerer tube and the other for adjustment.
re: Self extracting crank bolts & Expanding Stem Pluggrzy mnky
Jul 13, 2001 2:26 PM
With the splined crank/BB design it doesn't take nearly as much as a square taper. It's cake really - and I use a torque wrench at the maximum spec when I install.