# Square Taper and self extracting bolts



## Topher (Jun 5, 2005)

Hi all,

I'm putting together a coupled travel bike, and was wondering if there was any reason why I shouldn't use self-extracting bolts on a Centaur square taper BB/Crank. I'd use the old Sugino bolts. 

Thanks for any help!

Chris


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## cs1 (Sep 16, 2003)

Can't see why not.


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## ericjacobsen3 (Apr 27, 2007)

In theory self extracting bolts should have reverse dustcap threads so that friction does not back out the outer portion of the self extracting bolts. C-record cranks had this reverse thread. Of course if the bolt gets buggered you will be hard pressed to find a reverse thread extractor -only Campy made them I think.

Practically speaking, possibly with the help of a bit of loctite a self extracting bolt with standard right hand threads should work fine. Way back Shimano had this on Dura Ace and 600 AX and EX cranks (only issue there was the 6mm allen fitting was undersized for the torque needed). 

I have never seen self extracting bolts sold separate from cranks. Do you have a link where they are sold?


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## zmudshark (Jan 28, 2007)

Used them for 25 years on a Dura Ace crankset that was not reverse threaded without issue.

They are available from many sources.
http://www.google.com/products?hl=e...esult_group&ct=title&resnum=1&ved=0CCoQrQQwAA


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## cyclust (Sep 8, 2004)

I'm assuming you want these so you can remove the cranks for traveling? If so, I wouldn't recomend it. Frequent removal of sqaure taper cranks will wear the seating surfaces on the crank, causing them to seat just slightly further on the spindle each time. You'd be better off with the newer style of external BB style cranks for frequent removal, or better yet, not removing them at all.


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## Topher (Jun 5, 2005)

Thanks for all the input - as cyclust suggested, I was thinking of using them for removal for traveling... I haven't practiced packing the bike yet (not built up yet), but it seemed like removing the crank would help. I will try to see if I can make it fit without removing them. 

thanks again,

Chris


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