Stem size

[Frazer]

I have Giant SCR 2 with the standard stem it comes with, but i need to get a slightly shorter stem. How do I know the size of the current stem? Will a 1 1/8" stem fit?

Any help appreciated

 

[bonj2]

Most steerer tubes nowadays are 1 1/8", although some are 1".
Measure the length of your current stem from where the middle of the steerer tube would (is) be to where the middle of the bars would be (is).
I've got a stem that's 105mm if you want it let me know.

 

[gkerr4]

You also need to know the diameter of the bars you want to hold with it.

std is 26mm - oversise is 31.7mm

I am fairly sure that the SCR needs a 1 1/8th clamp for the fork steerer, but not sure about the bars - it will be written on them.

I think it comes with a 100mm stem as std too - so you need to look for an 80mm or something - it doesn't sound a lot, but makes a big difference!

 

[bonj2]

I thought standard was 25.4 oversize 31.8mm?

 

[Frazer]

i measured my stem last night...for some reason the Giant one it came with is 115mm...a bit too long for me, im going to go for a 80 or 90mm one instead now.

 

[slow down]

I thought standard was 25.4 oversize 31.8mm?

Depends on manufacturer - Deda is 31.7, but ITM (and most other) is 31.8 OS. I think Cinelli was 26.0 but again ITM is 25.4 (I think)

 

[woohoo]

Depends on manufacturer - Deda is 31.7, but ITM (and most other) is 31.8 OS. I think Cinelli was 26.0 but again ITM is 25.4 (I think)

They are the same size viz. 1.25 inches which equals 31.75mm. It is just that some manufacurers round down the quoted size to 31.7 and others round up to 31.8.

 

[slow down]

They are the same size viz. 1.25 inches which equals 31.75mm. It is just that some manufacurers round down the quoted size to 31.7 and others round up to 31.8.

I realise 0.1mm isn't going to be critical

 

[woohoo]

The handlebar clamp on my SCR2 is 1 inch i.e. 25.4mm.

 

[woohoo]

I realise 0.1mm isn't going to be critical

Agreed but you have to make sure that the weight weenies don't think they are getting an advantage by losing that 0.1mm.

 

[TheDoctor]

I thought standard was 25.4 oversize 31.8mm?

MTB standard is 25.4mm. Road is 26mm. Oversize for road and MTB is 37.7mm or 37.8mm - I forget which way round but they're close enough that it doesn't matter.

Having said that, I've used 25.4 mm bars in a road stem, and I'm currently using drop bars in a 25.4 mm stem, so it seems not to be as critical as all that.

 

[bonj2]

MTB standard is 25.4mm. Road is 26mm. Oversize for road and MTB is 37.7mm or 37.8mm - I forget which way round but they're close enough that it doesn't matter.

Having said that, I've used 25.4 mm bars in a road stem, and I'm currently using drop bars in a 25.4 mm stem, so it seems not to be as critical as all that.

yep. but you mean 31.7 and 31.8, not 37 ~ ...

 

[TheDoctor]

yep. but you mean 31.7 and 31.8, not 37 ~ ...

Indeed I do. Well spotted.