Shorter Stem affect steering?

BlueNGT
BlueNGT Posts: 119
edited June 2008 in Road beginners
I'm just having a bike I've just bought (2nd hand) serviced before I ride it as I want to be sure its up to scratch and not going to fall apart beneath me :?

I'm 6ft tall and the bike is a 'Large' Giant Compact. The Giant website says its the correct size for me and the frame size horizontal from headset to seatpost is the same as my Mountain Bike. However just sitting on the bike I feel the Bars are a little too far forward for me, although I havent ridden it yet and I hadnt fitted the pedals. So when I put the Bike in for service I asked them to put a shorter stem on it - currently a 120 and was going to fit a 100 or possibly shorter. The technician from the shop phoned yesterday just to ask a couple of things and in the conversation mentioned a shorter stem may affect the steering.

So my question is what affect could a shorter stem have?

Thanks in advance

Comments

  • It is quite a bit jump. I made a the same switch when I was messing around with different components for a flat bar roadie I was building. But it made the steering feel far too twitchy for me so I swapped back. So... a couple of things:

    1) Have you tried 'flipping' your original stem? Most can be fitted at either an upwards or downwards angle. This can make quite a big difference to the feeling of 'stretch' to the bars.

    2) What about fitting some spacers underneath the stem to raise the handlebars even further. Again this can make a big difference to comfort, but without affecting the steering in the same way as a 20mm shorter stem.

    3) Get the LBS to swap the stems over when you are there to get a sense of what each feels like (and get them to pop a 110mm on too to see if that's better). Even better, do a quick test ride with the new configuration. Swapping the stems around is literally a 3 minute job so this is not something they should object to.

    Finally, you might just want to try riding 'stretched' for a few days and see how you get on. Roadies are different in their geometry than MTBs and can take some getting used to.
  • vs4b
    vs4b Posts: 257
    I know what you mean.

    I have a giant scr in large, i'm 6'2" and i think its a but big for me. I was thinking of getting a shorter and adjustabel stem but before i did i flipped the stem to see. It made a big difference and made it much more comfy. I still feel a bit stretched but not so much as before
  • BlueNGT
    BlueNGT Posts: 119
    When its ready I'll try it out at the shop before bringing it home. They said I can give it a try with a shorter Stem whilst I am there too.

    So flipping the Stem raises the bars slightly?

    I know the Roadies are different to MTB as the MTB is much more upright even though I have Bar ends fitted to get lower down when on the Road.
  • Swannie
    Swannie Posts: 107
    I'm probably going to be going with a shorter stem for my 2nd hand road bike.

    The height isn't a problem. In fact, I'd prefer a little lower... but distance is a problem for me.

    Try the stems, see how it goes. The fact that you get to trial one without shelling out the cash is so useful. If the LBS's stems weren't so expensive compared to what I want to pay, I'd try and do the same!
  • simonjohn
    simonjohn Posts: 4
    I put a very short stem on my XL Giant. 50mm, maybe less, from a downhill mtb. Steering was fine, bike was comfortable.
  • i have a 60mm stem on my road bike and it is twitchyer but its not too bad.

    i think you notice is most when you take one hand off the bars.

    id much rather have a bit of twitch and comfort then a back injury.
    :D
  • dennisn
    dennisn Posts: 10,601
    Although not really a major concern with most cyclist's, stem length affects your out
    of the saddle climbing performance. If the stem is too long your body will be too far forward when out of the saddle in relation to the pedals and you won't be able to use
    your weight to full effect while pedaling. Same thing only opposite with too short a stem.
    But time out of saddle while climbing is not something you will be spending lots of time doing, so go for a stem length that gives you a reasonable comfort factor.

    Dennis Noward
  • BlueNGT
    BlueNGT Posts: 119
    i have a 60mm stem on my road bike and it is twitchyer but its not too bad.

    i think you notice is most when you take one hand off the bars.

    id much rather have a bit of twitch and comfort then a back injury.
    :D

    I agree I'd rather have a comfortable bike than one I cant ride because it destroys my, already knackered, back!!

    Can the twitchy steering be reduced by some wider bars? (not sure what width is on it at the moment)
  • no i think its all down to stem length not handlebar width, wider bars may just slow you down. :?:

    if your top tube and stem are too long anyway then a shorter stem shouldnt affect the out of seat climbing, it may just have a more twitch.

    on the plus side a shorter stem will save you a few grams in weight! 8)
  • Jez mon
    Jez mon Posts: 3,809
    edited June 2008
    IME narrow handlebars made my bike feel twitchy for a few miles, which IMO seems to be logical

    However, narrow handlebars will slow you down abit.
    You live and learn. At any rate, you live
  • BlueNGT
    BlueNGT Posts: 119
    Looks like the best thing to do is try it as is and then adjust to my preference, not what the LBS thinks is best!
  • simon_e
    simon_e Posts: 1,706
    SCR's large is about right for 6'.

    If you've only ridden MTBs or flat-bar bikes for a while the slightly more stretched-out (aerodynamic) position typical of bikes with drop bars might take a bit of getting used to. I suggest you don't do anything radical before you ride it.

    Also check the seat position. If it's too far back it can exacerbate this problem. Sounds like you need someone with a bit of knowledge to help you set it up properly.
    Aspire not to have more, but to be more.
  • tatanab
    tatanab Posts: 1,283
    BlueNGT wrote:
    The technician from the shop phoned yesterday just to ask a couple of things and in the conversation mentioned a shorter stem may affect the steering.

    As may a longer stem. Ask him what length the frame is designed for,what is the optimum length, and you will get no reply. There is none.

    I use stems in the range 9 to 13 cm according to the top tube length and what the bike is being used for. Most are 9 or 10 cm. Yes there is a difference - particularly when getting off the touring bike with a 9cm stem and getting on the track bike with a 10 cm stem But how much of that is due to the difference in the forks and angles and not the stem at all?

    I have seen posts here virtually saying that if you use a different length than the one supplied you will ruin the bike. So what happens for those of us who don't buy stock bikes but build our own? The truth is that we are blessed with a magical computer between our ears and we adapt to the slight differences in steering within a few yards.

    Go for whatever is most comfortable for you.