Removing Shimano Hollowtech I Cranks
 

I have a a Gary Fisher 2006 Hoo Koo e Koo with what I think is Shimano Hollowtech I (one) crankset.
(Not Shimano Hollowtech II).

All the online instructions I have found point to that being a 8mm wrench for the crank bolt to be removed.

But when i put my Park Tool 8mm P-Handle hex wrench in, the whole length of the wrench goes straight through the bottom bracket.

Does anyone know how to remove it?

What is inside there, looks like the crank bolt or something is 10mm hex. But not sure.

Does anyone know how to remove this, like is it a 10mm crank bolt instead of 8mm?

2 pictures I wanted to attach. But I am new to this forum and it won't let me.

It says "Hollowtech" on the crank arms.. And also "Mega 9". And also "Shimano Drivetrain".

The bike is 9x3 speed.
Thanks

Some where 10 mm. What ever size it is find a good fitting hex key and just turn it the proper direction. Been a while since I did that, but I think counter-clockwise on the left and clockwise on the right to loosen. Someone else will be fast to correct me if I'm wrong!.

I'm pretty sure that is a self extracting crank arm. What's the exact model/part number? That'll probably be on the inboard side around the hole for the pedal.

Here are your pic's.....

https://cimg4.ibsrv.net/gimg/bikefor...d5f9753b0.jpeg
https://cimg3.ibsrv.net/gimg/bikefor...0c42405bf.jpeg

https://www.bikeforums.net/g/picture/33025983

The opposite site of the crank to where the pedal sticks out..think it has wrriten:

Shimano FC-M510 MALAYSIA VIA BK 175

So Black 175mm

Do you have these instructions? They say 8mm too. But still Shimano used both sizes for the bolts at various times. Maybe yours isn't the original bolts or it's a version that wasn't out at the time of this document's publishing.

https://si.shimano.com/en/pdfs/si/F7...000-00-ENG.pdf

more documents that might be helpful are here.... https://si.shimano.com/en/manual/sea..._model=fc-m510

Your version seems to be more similar to the FC-M540 with the 10mm style bolt. Bolt should be counter-clockwise to remove, on both sides. Cover should come out with the bolt, revealing standard crank extraction treads. Probably a Octalink V2 hollow spindle BB.

https://cimg4.ibsrv.net/gimg/bikefor...bd29b5ee83.jpg

You need a crank puller designed for the large hollow spindle, or use an adapter on a standard puller (see the center circled adapter, sometimes referred as a 'top hat) to 'cover' open spindle.

https://cimg5.ibsrv.net/gimg/bikefor...aad7822c0e.jpg

It's been awhile since I took one apart with that style bolt, if I recall it's just a normal bolt. The bolt is hollow, so the allen wrench will go all the way through if you let it. Pretty sure it's not self extracting and that cap stays on the bolt.

You can see the odd dust cap here: https://si.shimano.com/en/pdfs/ev/FC...-M540-2401.pdf

Different model number there, but same generation cranks.

Just the bolt: https://rmcbikes.com/en/shimano-octa...-bolt-682.html

Edit: Oops, already posted. I'll leave the link up anyway.

In a pinch I’ve used a stack of dimes as an “adaptor” for my standard crank puller with success.

Wow, classy - I'd use a penny. :-)

Had I known when I bought a crank puller for my old square taper BB back in the day that Octalink would come along and need a different puller, I would have bought one of these that can do both. CWP-7 Compact Crank Puller | Park Tool Simple, bullet proof and cheap.

You can get a little magnetic cap to adapt a square-taper puller to a splined crank.

Thanks. I've ordered a 10mm park tool hex tool, so waiting for that to unscrew the crank bolt. Hopefully that should work.

Also already ordered and waiting for a CWP-7. Which should be Octalink V1 compatible.

Watch out for the crank bolt washer. It likes to stay in the crank, and then get stuck on the crank extractor.