Please help with removal of Shimano Hollowtech 1 Arm Removal

[MichaelW2]

Shimano used 'Hollowtech' for their cranks too, as well as their Hollowtech II BB/crankset interface. Hence 'Hollowtech' is part of the crank logo (in OP image).
You're right: I'm confusing this with Octalink 1 and 2 in my comment above.
So what is Hollowtech 1?

HT 1 is Octalink. Some people report that hollow axle square taper spindles were also called Hollowtech.
Hollowtech cranks are full of air. Some are glued others welded shut.

 

[vale82]

Thanks everyone for the quick replies!! Your advise is very much appreciated!

 

[vale82]

Well - they are original Hollowtech I which is square taper BB, not Hollowtech II which had its own type of BB, but above is correct - you need a standard square taper crank extractor. plenty of YouTube vids to explain.

Thank you!

 

[vale82]

Hello,

I’d really appreciate some help please!!

I have a Specialized Rockhopper with the old Shimano Hollowtech arms.
I’d really like to remove these arms to put on my other Rockhopper but for the life of me I cannot see how this can be done!!
I’ve added some photo’s, please please can somebody help me!!
Thank you in advance!! View attachment 603927 View attachment 603928 View attachment 603929

Thanks everyone for your advise with this! Much appreciated

 

[rogerzilla]

Technically, Hollowtech refers to the hollow crank arms (they were forged over a steel mandrel which was removed, and the cranks then welded up). However, HT2 has come to refer to the Shimano external BB standard.

 

[PpPete]

Drifting OT but AFAIK the current generation of hollow cranks is limited to Ultegra R8000 series and up? And consist of two shells bonded together (not welded). There are cases of the adhesive bond failing, and if you are concerned about this then 105 (R7000) is for you. They are not hollow, just heavily machined on one side.

 

[MichaelW2]

Drifting OT but AFAIK the current generation of hollow cranks is limited to Ultegra R8000 series and up? And consist of two shells bonded together (not welded). There are cases of the adhesive bond failing, and if you are concerned about this then 105 (R7000) is for you. They are not hollow, just heavily machined on one side.

The hollow crank arm only is a lower end feature. Forged as a tube-like shape with end cap welded on then drilled and threaded for pedal.