allen key size for rotor bolts ?

[cyberknight]

Just tried to take the rotor off my fubared rear wheel and its an odd size bolt head , 3 mm too small. 4 mm too large ?? definitely allen key rather than torx .

 

[Alex321]

They vary, but most are either T25 Torx, or 4 or 5mm Allen key.

It is possible to get 3.5mm allen keys, so yours could be that.

 

[Big John]

Daft question but are you 100% sure it's not torx? My eyesight is pretty suspect these days, even with glasses, and I've been caught out before trying to put a hex key into a torx head. If it's a torx then, as stated above, it'll likely be a T25. We all have our likes and dislikes but I hate torx. They just don't seem as user friendly as hex.

 

[Sterlo]

For gawds sake, be careful you get the right size. I used a slightly too small allen key on the cover screw for the hydraulic oil top up on the brake lever, it's rounded the internal hex and I now have to get it off with a pair of pliers. Still trying to find a replacement.

 

[cyberknight]

Daft question but are you 100% sure it's not torx? My eyesight is pretty suspect these days, even with glasses, and I've been caught out before trying to put a hex key into a torx head. If it's a torx then, as stated above, it'll likely be a T25. We all have our likes and dislikes but I hate torx. They just don't seem as user friendly as hex.

definitely hex , i have some torx and none fit either.As for eyesight i need glasses too for close work

 

[cyberknight]

ahh
luck would have it found one that fits on my electric screwdriver, got them out very odd

 

[Ajax Bay]

odd size bolt head , 3 mm too small. 4 mm too large ?? definitely allen key rather than torx .

https://handtoolessentials.com/blog/tools/hex-key-conversions-allen-wrench/
9/64"

 

[wafter]

Seems a bit odd; perhaps a yank standard with a 1/8" / 3.18mm key..?