I purchased a 50cm CX style bike from an online retailer. After assembling the bike and filling the tires, I found only had around 1" of stand over in bike shorts. Since I will be commuting on the bike and using it for transportation around town, my preference would be for something with greater clearance over the top tube for the following reasons:

  1. Saftey - being able to dismount quickly in an emergency situation
  2. Clothing choice - I won't be wearing bike shorts when commuting or riding around town
  3. Cyclocross - I do plan on riding the bike off-road, so more clearance would be better on uneven ground.

Now to my question: I emailed the retailer asking for assistance selecting a smaller size, but they "strongly recommend" sticking with the 50cm frame stating it would be "perfect" and that the top tube length is more important than stand over height.

What is the thinking behind this advice?

  • 1
    1" is okay, for me, I fell of my bike twice because of black ice and top tube isn't really an issue, moreover, If you fall, the bike will be leaning right or left, so probably you still can stand on your own feet. – azer89 Mar 11 '15 at 12:13
  • 1
    One thing to consider is that the reach can be changed using a shorter or longer stem. the stand over height cannot be changed. How much difference is there in stand over height and top tube length of the smaller frame size? Some bikes only come in 3 sizes, and there's quite a gap between them. You might have to get a ridiculously long stem for smaller size to fit. Other bikes have 5 or 6 different sizes in the same range with very little difference between 2 consecutive sizes. – Kibbee Mar 11 '15 at 12:41
  • 1
    sheldonbrown.com/frame-sizing.html is a good read on this. – Batman Mar 11 '15 at 12:52
  • 2
    I think 1 inch standover is a bit small even for road bikes. However, this was from an online retailer -- theres a chance they're just saying this to avoid the restocking hassle. – Batman Mar 11 '15 at 19:28
  • 1
    @Batman It is a CX not road. I own 3 CX that all fit me and have less than 1" stand over each. Check the start line on a CX race will see that kind stand of over. It is stiff and you want a big triangle for shoulder carry. There is also a chance they are telling the truth. – paparazzo Mar 11 '15 at 19:52

Why should you prioritize top tube length over stand over?
Because top tube length affects fit and stand over does not affect fit.
When you are riding the bike stand over does not affect fit.

My CX only has 1" of stand over.
A big triangle is good for stiffness and shoulder carry.
A tall top tube means faster transition to shoulder carry.

I don't get your reasons

  1. 1" versus 4" should not affect your ability to dismount quickly.
    You ride on the seat - not the top tube.
    In a controlled dismount the bike is stopped - 1" is a quick and safe stand over dismount.
    If you have to bail because a truck pulled in front of you then lay the bike down - don't stand up.
  2. So your clothes touch the tube? What is the harm?
  3. How is more clearance better on uneven ground?
    When you stop then don't stop over a hole.
    If you fall on the top tube an extra inch of clearance is not going to save you as your feet are not going to be under and you are going to be moving.
    Even with 2" of clearance falling on the top tube should always be your last choice.
|improve this answer|||||

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.