bike fit on a road bike

My lower back bends a lot and the weight goes to my arm. What is the problem?

  • 1
    Your arms are too stiff. Jul 6, 2022 at 12:26
  • 1
    Can't tell from the photo, but you might check saddle tilt. If my saddle is sloped downwards towards the handlebars, I'll find myself sliding forward, which I have to resist with my arms. That can be tiring on the arms. My saddles are usually level so I don't slide around. Increasing core strength, flexibility, and triceps strength can help if the bike fit is good otherwise.
    – Evan
    Jul 6, 2022 at 17:03
  • Can you try riding without the backpack for a bit? That may be contributing, though it doesn't look heavy.
    – Criggie
    Jul 6, 2022 at 19:42

1 Answer 1


We discussed your position a little in Bicycles Chat. It's possible your frame is one size too small - but we could see a number of possible adjustments that might help.

It looks like your saddle is set too far back and too low. I would start by moving the saddle 5-10mm forward and 10-20mm up.

It also looks like you are pedalling with your toes on the pedal rather than the ball of your foot - this may be (or not) a subconscious compensation for your saddle being so far back.

Making this adjustment may result in needing a longer stem - but try it for a while first and see if you feel cramped.

There are also a couple of factors that are not necessarily related to bike fit.

The rounding of the lower back and 'collapsing' onto the arms can be related to poor core strength. A stronger core and better posture will take weight off the arms.

Finally, your arms are very straight with elbows locked - this doesn't allow your arms to work as shock absorbers and transmits every bump up to your upper arms and shoulders. Keeping a bend in your elbows helps reduce this type of fatigue/soreness (although places more demands on the core muscles).

  • 2
    And flip the stem to raise the bars some - especially if the saddle is moved a bit higher. That might be all that's needed. IMO a longer stem is likely to make the stiff-armed reaching for the bars worse. Jul 6, 2022 at 13:48

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