Hidden Bolt Stem

Hey guys,
Today I was mucking about with a bike, and it’s got a shimano 600AX hidden bolt stem. I tried to get down to the hex bolt to loosen the stem out of the steerer tube, but couldn’t get an allan key in the right size to go in. Is there a special size allan key for this job, or am I doing it wrong?

From memory, should be a 6mm allen key - so either the bolt head is stripped or you’re doing it wrong. :wink:

Eeek, I am certain I tried to use a 6mm. Now I am hoping that I did it wrong. Trying to get this out without the bolt sounds bad

Are you using a T-handle allen key? Maybe spray some WD40/RP7 down there.

I hope I don’t need to say this, but, lefty-loosey. :slight_smile:

Mine is a little hard to get enough leverage, I put a spanner around the end of a long 6mm. Don’t fuck it up, or you’ll have to butcher one of the nicest pieces of cycling engineering to get it off :frowning:

Lefty Loosey was definitely employed haha, I wasn’t using a T handle, just a long L shaped one. I might go shine a torch down it and see how it looks.

i fucked mine over tightening it. be very careful!!!

are you sure the allen key was engaging? they’re super deep and i couldn’t find an allen key at home or work that was long enuff.

I thought I was getting deep enough to engage, but you could be right, might take it in somewhere and see if they’ve got one long enough, it sure is really deep

yeah it’s definitely 6mm, and you’ll need a long one. T-handle would be best, but I only had an L shape one that was long enough, and used multi-grips on the short bit to get extra leverage. Having a ball-ended allen key helps a lot too.

I did have one that seemed to seize up and took an almighty effort to loosen, and fucked those little grub screws in the process.

Where you at? I have a long 6mm allen key that suits my AX stem you can use if you are in M’burn…

This is what I had to do on one ugly stem. But I only knew to do it because I emailed NikCee with a picture and he told me to use the ball ended bit and use my risers on the end for leverage. What a guy.

This is how I tightened mine.

Unfortunately I’m in brisbane, took it to GEAR tomorrow and my heart sunk when a long 6mm Allan key wasn’t grabbing at all :frowning:


Unfortunately I’m in brisbane, took it to GEAR tomorrow and my heart sunk when a long 6mm Allan key wasn’t grabbing at all :([/QUOTE]

I’m sure you can salvage the stem - at worst just drill the bolt out and replace it.*

p.s. 600ax has no grub screws… that’s the DA model and they do seize up really bad. The wedge design is much better.

*EDIT… I didn’t remember the bolt being so intricate… perhaps not so easy to replace:

that does not really look like it would be particularly common. I wonder if I could find some kind of allen bolt that would sit flat on the top, while still reaching through the entire stem and then use the expander, that way the bolt would still be inside, just not so deep inside the stem.

^^^ do you have that in a larger graphic???

I have the DA 7400 as above and it’s seized! The expander may be stripped as a result! would love to salvage!!!

Ah yes, right you are.

some damaged ones come up on the bay, I reckon that would be your best bet.