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I recently got a new hybrid bike for commuting and recreation. I like it but the riding position is a little bit too aggressive. This is fine for the short term but I am thinking of customizing it so that the riding position is more upright.

I will probably replace the handlebar but I also learned you can replace the stem with another one that has a rise. I also know that you can add spacers to the steering tube and move the stem up. However the stem is already near the top with only one spacer above it. For now, let's assume that I only want to replace the stem.

I found this stem which has a 30 degree rise. However, it also has a length of 70mm (the shortest one available), whereas my current stem is shorter (calculated as 55mm) but has no rise. I think the added rise will get me into an upright position but it seems to me that the extra length will mean the handlebar is further away and negate the rise.

How can I know if this new stem will give me a more upright position? How can I find this out in general? I feel like the answer might be to use some trigonometry but I was pretty bad in that subject.

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  • Why not add spacers to your stem? Search "bike headset spacers" Aug 16, 2023 at 21:07
  • @spikey_richie Yes I was thinking of that too. However the stem is already near the top and only one spacer is above the stem. If I get a stem with a rise, and decide later that I prefer the aggressive position, I can just move the stem down, so it's more flexible. I'm probably going to move the stem up and get the new stem. Aug 16, 2023 at 21:09
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    Something like this calculator will help. reverse-components.com/en/content/stem-calculator
    – mattnz
    Aug 17, 2023 at 0:37
  • Cardboard can also be a big beneffit here, allowing you to "mock up" and imagine where the bars will end up.
    – Criggie
    Aug 17, 2023 at 1:18
  • An alternative option can be bar-ends with an horizontal part (Ergon GP5 - not an endorsement, but an easy find). Not ideal in all circumstances (the brakes and shifters can only be in one place), and the look might not be for everyone, but having multiple hand and back positions can be appreciable.
    – Rеnаud
    Aug 17, 2023 at 21:37

4 Answers 4

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You can use this comparison tool or draw the two stems on square paper

http://www.yojimg.net/bike/web_tools/stem.php

70mm at a steep rise is probably similar in reach to 50 without the rise.

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  • But the 70mm with a rise will increase the "stack" (I'm a noob and not sure if that is the correct word) and therefore also contribute to a more upright position, right? Aug 19, 2023 at 3:35
  • @CaveJohnson That's right! Sorry if it's not clear
    – Noise
    Aug 19, 2023 at 8:12
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One trick is to buy an angle-adjustable stem, and change that til you're comfortable. Then take measurements and buy a fixed stem that matches.

The adjustable ones are not recommended for long-term usage because they risk loosening in use.

enter image description here

The angle-and-length adjustable stems cost tenfold more, unaffordably so.

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    This sounds good but I'm a bit put off with the idea of buying something that I will only use one time. Also I want to make sure that specific lengths will work for me but as you said the length adjustable ones are more expensive. I do like the cardboard idea that you mentioned in a comment. Aug 19, 2023 at 3:32
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    @CaveJohnson fair point - If you use cardboard roll and make a mockup, and use your imagination while sitting on the bike, that can work too. Come bike shops have loaner libraries of adjustable things; mine will rent you an adjustable stem or special crank length adjusters or even saddles and on return will give you 99% of the rental back. Just, don't ride for real with a cardboard+tape stem :)))
    – Criggie
    Aug 19, 2023 at 7:27
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I found this stem which has a 30 degree rise. However, it also has a length of 70mm (the shortest one available), whereas my current stem is shorter (calculated as 55mm) but has no rise. I think the added rise will get me into an upright position but it seems to me that the extra length will mean the handlebar is further away and negate the rise.

The angle will negate most of the difference.

55mm without rise means 55mm horizontally.

70mm with 30 degree rise means

70*cos(30*pi/180) = 60.622

...so your 70mm stem with 30 degree rise has about 60mm horizontal distance. That's only 5mm more than the 55mm stem. I'd say this stem is about correct, it will give you

70*sin(30*pi/180) = 35

...35mm higher handlebars without affecting the handlebar-to-saddle distance much.

Usually stems are sold in 10mm increments, so 5mm is half of that. About nothing.

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    Remember the headtube will already be at 73 degrees or so, making the effective reach even less
    – Noise
    Aug 18, 2023 at 9:01
  • Thanks for the calculation Aug 19, 2023 at 3:26
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You need to know the stack height of both stems to make this determination. If you want to know the actual change in position you also need to know the head tube angle. At that point you have everything; if you want to avoid computing anything personally, just do it on graph paper with a ruler and protractor, or any free 2d CAD software.

Generally speaking if you have a 55mm or similarly short stem (near-zero extension) and it's already at the top of the steerer (no more spacers can go below it), the only ways of getting higher without also getting longer are a steerer extender, a bar with more rise, or changing the fork (the last being impractical in most situations).

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  • "You need to know the stack height of both stems to make this determination. If you want to know the actual change in position you also need to know the head tube angle." The second thing is what I was after. What would I need to know the stack height for and how would I determine that? Aug 19, 2023 at 3:28
  • @CaveJohnson The stack height is the vertical height of the part that clamps over the steerer, and there is some variance in it among different stems. Typically the "extension tube" will be centered on the "stack tube." If you had one stem where the stack is 35mm and the other is 45mm, for example, then all else equal (say they're both as high on the steerer as possible), you'll typically have a higher position out of the 35mm. It's not a huge difference, but your question deals with some pretty small positional differences so it is relevant. Aug 19, 2023 at 4:07
  • Some stems will list the stack dimension in the product info (although the term is not universal so you'll need to look out for it going by other names). Other than that you would need it in hand to measure it. Aug 19, 2023 at 4:08

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