Stem bolt tightness

Ferrals

Now I know theoretically I should use a torque wrench and appropriate setting, but I don't have one. So can some give me guidance on how tight the bolts on the stem bar clamp should be as I'm fitting a new bar later. I'm assuming so long as the bar doesn't move, just finger tight, but not to the extent the Allen key flexes, is good? Or do I really need to buy a torque wrench (stem and bar both alu) - seems overkill.

Also is threadlock necessary?

nicklouse

you don't need a torque wrench.

as tight as needed so there is no movement. and do them evenly.

no thread lock is needed.

Ferrals

Nice one, thanks Nick

.blitz

As an approximation 5 Nm is tight using the short end of the hex key

Ferrals

Using the short end to hold or insert?

WindyG

Hold the short end, it stops you from using too much leverage on the allen key.

cooldad

You need to do it by feel, not rely on hope for the best. You might be a mighty muscle man for all we know.

Herdwick

5Nm is the same as applying 41,6 N or 4.2kg on a 12cm long hex key,

if that makes sense

stubs

If you crack a new stem and try to warranty it the first thing they will ask you is did you use a torque wrench.

cooldad

Crack a stem? You guys are animals.

stubs

cooldad wrote:

Crack a stem? You guys are animals.

Seen 2 cracked stems in the last few years. One was a Richey WCS carbon on a Trek roadie and cost a mint to replace because the lad who fitted it didnt use a Torque wrench. Doesnt mean it cracked because he didnt use one but its how they get out of warranty because it says use one in the instructions.

cooldad

Friend snapped a bolt last week, using a torque wrench. Even said it felt wrong but blindly carried on.

I'll carry on relying on feel.

The Rookie

If he snapped a bolt that's screwed into aluminium then
1/ The bolt was defective
2/ By the time it felt wrong the bolt was no good anyway, only saving grace if he'd stopped earlier would be that it may have been easier to get out!

I have a torque wrench for my sons carbon frame (seatpost clamp), when I bought it in the shop I went to check it on a display bike, the owner asked me not to as it was a carbon frame, he was a bit stumped when I asked him was it the frame that was particularly weak or the torque wrench I was waiting to buy that was likely to be defective.....

njee20

The preset torque keys are nice for things like stems, Bontrager and Ritchey do them. I'd far sooner develop a sensible feel with hand tools, using a long torque wrench, invariably not calibrated or treated particularly carefully is a great way to break things. Saw it regularly at the LBS. A torque wrench doesn't necessarily over ride being a ham fisted oaf!

rockmonkeysc

stubs wrote:

If you crack a new stem and try to warranty it the first thing they will ask you is did you use a torque wrench.

Any half sensible person will lie and say yes

batmo

I use a torque wrench not because I need to, but because I wanted to own a torque wrench because it is a Lovely Thing.

Angus Young

Batmo wrote:

I use a torque wrench not because I need to, but because I wanted to own a torque wrench because it is a Lovely Thing.

I bought two because of this. It was a way of guaranteeing my Man Card for the next six months.