Stem size/angle advice please.- Mtbr.com
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  1. #1
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    Stem size/angle advice please.

    Hi everyone, I have recently, 11 weeks ago, had both knees replaced, Previously I was quite bow legged leaving but now am straight legged & have gained one inch (25 m.m.) in height. Consequently I have raised the saddle height by one inch but that has placed a lot of weight on my wrists & I'm looking for advice regarding the stem size & height I should be looking for to return me to the previous riding position. The bike is a Trek Marlin 5 29er & the relevant geometry details are

    Fork: SR Suntour XCE 28, coil spring, preload, G2 Geometry w/51 mm offset on 29ers, 100 mm travel (13.5: 80 mm travel)

    Stem: Bontrager alloy, 31.8 mm, 90 m.m. 7-degree, Blendr compatible,

    Head set1-1/8˝ threadless, semi-integrated, semi-cartridge bearings.

    I'd be most grateful for an answer or details of how to work out what I need.
    Many Thanks, Steve.

  2. #2
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    If you raised your saddle, 1) look at the saddle angle as angling the nose up ever so slightly will tilt your pelvis back to a neutral position if it isn't there already, and 2) you may need bars with a bit more rise to compensate for the increased saddle height, to bring the bar/saddle height ratio back to where it was.

    Is your stem angled up or down? Do your bars have any rise?

  3. #3
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    Since your seat tube is angled you are now sitting about 6-8 mm further back as well as about 25 mm higher than before. If you have the room I'd first adjust your seat position forward to compensate for the rearward shift.

    After that you'll want to get an additional inch of rise in your cockpit through a combination of stem and bar changes. If you want to get that much rise through stem alone you'd need to increase both stem length and rise angle by an amount that depends on your head tube angle. At a guess I'd say you'd want something around 100 mm length with 25 degree rise angle, but you may need to experiment a bit.
    Last edited by wayold; 3 Weeks Ago at 04:34 PM.

  4. #4
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    Quote Originally Posted by matt.s67 View Post
    If you raised your saddle, 1) look at the saddle angle as angling the nose up ever so slightly will tilt your pelvis back to a neutral position if it isn't there already, and 2) you may need bars with a bit more rise to compensate for the increased saddle height, to bring the bar/saddle height ratio back to where it was.

    Is your stem angled up or down? Do your bars have any rise?
    Thanks for your response Matt & to answer your query the stem is 6+, it is angled upwards. I'm going to move the saddle forward a little & angle it up as you suggest & see what difference that makes.
    Last edited by AusSteve; 3 Weeks Ago at 03:16 AM.

  5. #5
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    I think you need to get a shorter stem, probably with 7 angle and 50mm length, and a new handlebar with around 30mm rise. If you have spacers above your stem you may not need that much rise on the handlebar or the 7 angle on the stem.
    Check your LBS or your friends to see if they have stems and/or handlebars you can try before you buy new stuff without knowing for sure if it works for you.

  6. #6
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    Quote Originally Posted by Aglo View Post
    I think you need to get a shorter stem, probably with 7 angle and 50mm length, and a new handlebar with around 30mm rise. If you have spacers above your stem you may not need that much rise on the handlebar or the 7 angle on the stem.
    Check your LBS or your friends to see if they have stems and/or handlebars you can try before you buy new stuff without knowing for sure if it works for you.
    Thanks for your help Aglo, I have found Walter's Bicycle Stem Rise/Reach Calculator & believe if I use an 80m.m. stem with a +30 uprise stem it will lift the bars by 22 m.m. & bring the reach back by 27 m.m.

  7. #7
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    Do you have any spacers on top of your present stem? If so the easiest thing to try is moving your existing stem up so all the spacers are below it.

  8. #8
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    Quote Originally Posted by wayold View Post
    Do you have any spacers on top of your present stem? If so the easiest thing to try is moving your existing stem up so all the spacers are below it.
    Hi Wayold, thank you for your reply. I have 3 spacers on the top of the steerer tube Below the stem & no room for anymore at all.
    Cheers,

  9. #9
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    Check out this illustration of the DMR Defy stem...provides 15-20mm rise over a regular stem due to the low profile clamp...

    https://m.youtube.com/watch?v=9oxkX-PW0RA

  10. #10
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    Thanks for this Heist30.

  11. #11
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    Backswept bars is another option... Here is a review on a new bar available with 12 or 16 deg angle and up to 45mm rise...
    https://www.bikemag.com/gear/compone...30x-12-degree/

  12. #12
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    Quote Originally Posted by Heist30 View Post
    Backswept bars is another option... Here is a review on a new bar available with 12 or 16 deg angle and up to 45mm rise...
    https://www.bikemag.com/gear/compone...30x-12-degree/
    That's interesting Heist30 & thanks for your reply. Currently I have moved my saddle forward about 15m.m; given the saddle a bit of a lift at the nose & rotated the bars to get the maximum lift from them. However due to the terrible bushfires all around where I live the air has been so smoky for about 4 weeks & a week ago I chose not to ride until the smoke clears.

  13. #13
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    Thank you everyone for your valued input. Currently I have moved my saddle forward about 15m.m; given the saddle a bit of a lift at the nose & rotated the bars to get the maximum lift from them. This has certainly improved the situation, by how much I am yet to determine & see if I can live with this long term.

    However due to the terrible bushfires all around where I live the air has been so smoky for about 4 weeks & a week ago I chose not to ride until the smoke clears.

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