what is the difference between a 8mm and 10mm hex key?

[Soup890]

I'm going to try and replace my bottom bracket for the first time but first I need to buy some tools. Any advice would be welcome I have a specialized sirrus sport 2014 if there is anything to watch out for please let me know?

 

[Spinney]

2 mm


(sorry, but someone had to say it!)

 

[glasgowcyclist]

Well that's got me stumped.

GC

 

[Panter]

Assuming it's a serious question, it does just refer to the width of the bolt. So a 10mm hex really is 2mm wider than an 8mm.
A local hardware store should have a selection of hex keys for a reasonable sum, I personally prefer those that either fold out of a tool (as long as its good quality) or come in a case so that they can all be returned to their rightful places when finished with otherwise I instantly lose them!
Do you not have a bike multi-tool type thing with hex keys on?

EDIT: Also have a search on Youtube, there are loads of really good tutorials out there for replacing/servicing BB's

 

[deptfordmarmoset]

This could end badly, I fear.

 

[subaqua]

yup just the size of the across flats on the hex.

there are a few workarounds and have been used succesfully on disassembling and reassembly of large water valves

 

[ianrauk]

If you are changing a BB, why do you need a hex key?
What BB is it?

 

[Panter]

If you are changing a BB, why do you need a hex key?
What BB is it?

My hardtail requires a hex key to remove the cranks. (Hope BB, think it replaced a Shimano Hollowtech?)

 

[ianrauk]

My hardtail requires a hex key to remove the cranks. (Hope BB, think it replaced a Shimano Hollowtech?)

But not an 8 or 10mm. They are far too big for the 2 crank bolts

 

[Panter]

But not an 8 or 10mm. They are far too big for the 2 crank bolts

Yes, sorry, that's a fair size isn't it. Can't remember what mine are but must only be 5mm tops, something like that.

 

[jack smith]

My cranks take 10mm allen bolts

 

[PeteXXX]

Size isn't important.. So I've been told.
If you have a set of them, just select the one you need.

 

[jack smith]

Heres a google image basically you tap the driveside through the bb and then tighten the non driveside with a 10mm allenkey i think all fsa cranks are like that

 

[mcshroom]

I have 8mm bolts in all my cranks I think. Standard for crank bolts on cartridge bottom brackets.

 

[jack smith]

Would help if i upload the image...