Advice on comparing stem angle before purchase...

chrb8
chrb8 Posts: 38
edited February 2012 in Road buying advice
Hi,
I am thinking of replacing my stem, but do not want to affect my position on the bike in doing so because I am very happy with how it is currently. So I am trying to compare whether the stem I am looking at buying is sufficiently similar to my current one in terms of angle... but looking online there seems to be different ways of quoting the measurements etc. and it's a bit confusing.

Currently I have a FSA OS-150 XTC and I am looking at replacing it with a Deda Zero 100 Servizio Corse White Stem.

Can anyone give me any advice as to how similar these would be in terms of the position they would give me on the bike. (assuming I buy the same stem length of course)

Comments

  • Wirral_paul
    Wirral_paul Posts: 2,476
    The FSA should be a +/- 6 degree stem. So long as the Deda is the same then it should be putting your bars in exactly the same place so long as you buy the same length. If you're unsure of yours then measure centre to centre. They come at 10mm intervals so should be easy enough
  • have a look at this

    http://alex.phred.org/stemchart/Default.aspx

    you can input different stem lengths and angles and see what the difference is.
  • Bobbinogs
    Bobbinogs Posts: 4,841
    That's a great link, thanks ynyswen24
  • neeb
    neeb Posts: 4,471
    chrb8 wrote:
    Hi,
    but looking online there seems to be different ways of quoting the measurements etc. and it's a bit confusing.

    The biggest confusion probably comes from some manufacturers quoting the angle away from 90 degrees, and others subtracting this same figure from 90 degrees. So an 8 degree stem is exactly the same thing as an 82 degree stem, a 17 degree stem is the same as a 73 degree stem, etc.

    Your headtube angle is around 73 degrees to begin with, so if you use a completely straight stem (0 degrees) it will slope upwards from the horizontal at 17 degrees when fitted.

    If you use an 8 degree stem, it will slope upwards at 9 degrees (17 - 8 ) if mounted in the normal downwards position, and 25 degrees (17 + 8 ) if "flipped".

    If you want your stem to be completely horizontal when fitted, you need to use a 17 degree stem mounted downwards (assuming a 73 degree headtube angle).
  • rc856
    rc856 Posts: 1,144
    Bobbinogs wrote:
    That's a great link, thanks ynyswen24

    +1 answers my own question ....asked when I hadn't seen this!
  • rc856
    rc856 Posts: 1,144
    From the explanation by neeb and the link provided above, would the differences between the following two stems be quite a lot? I'm guessing at 14deg??

    My current stem which I use flipped

    Spesh

    Thinking of changing to this

    Ritchey

    Wiggle is the only site to mention the 84deg option though?

    Thanks :?
  • neeb
    neeb Posts: 4,471
    That specialized stem appears to be adjustable (which is unusual) and also available in two angles (or rather angle ranges).

    Which one do you have (12 or 17 degree?) and how have you got it set? It looks like the "12 degree" one actually can be set at 8 degrees at its lowest. The Richey is 6 degrees, so is going to be lower (if it's flipped as you say) in any case.

    If you had the 12 degree specialized set at 8 degrees, the Richey would be 2 degrees lower.

    At the other extreme, If you had the 17 degree specialized set at 21 degrees, the Richey would be 15 degrees lower.

    I'm assuming that by flipped you mean angling more upwards than it would be if it was the other way around.
  • rc856
    rc856 Posts: 1,144
    TBH, I don't understand the adjustable angles bit.
    Mine looks like it can go on one way or the other!

    Can't remember what one I got, it was just fitted during a bike fit :? Great help!



    Cheers
  • neeb
    neeb Posts: 4,471
    It's a bit difficult to tell just be looking at it..

    That's a VERY short stem though. What length is it, 60mm?? The stem is so short that I doubt the angle will make a massive difference to the height of the bars. But in any case, the Richey will be lower.
  • rc856
    rc856 Posts: 1,144
    Ok mate, cheers. Guess it can always be returned.
    The stem is actually 75mm.
    Checked my winter bike which has a 'flatter' ITM but the actual headtube is about 5mm higher.

    Yes, I could just get the same ITM stem but fancied something 'nicer' for my best bike.