Results 1 to 18 of 18
  1. #1
    mtbr member
    Reputation:
    Join Date
    Nov 2017
    Posts
    39

    Need help with frame geometry.

    I have a 2018 Roscoe 7 that I've been riding for 3 months. My issue is after about 10-12 miles I've having quad burning and soreness of knees.

    I have my seat set all the way back and I have a Thomson setback seat post and my knee is still 2"+ in front of the pedal spindle. From what I've read when your knee is front of the pedal you will be using your quads more.
    Name:  j.jpg
Views: 132
Size:  110.2 KB

    Name:  0luD8Ui.jpg
Views: 155
Size:  48.0 KB

    Name:  e.jpg
Views: 125
Size:  94.1 KB

    I'm 6' (barefoot) with a 33.5" inseam (barefoot ground to crotch). What exactly do I need to look for in a frame to where my knees can fit the frame properly? Below are my Roscoe specs....

    Need help with frame geometry.-2018-roscoe-7-2.jpg
    Last edited by RRsRRs; 04-27-2018 at 03:53 PM.

  2. #2
    mtbr member
    Reputation: jeremy3220's Avatar
    Join Date
    Jul 2017
    Posts
    1,080
    I'd try moving the seat forward and up. Should activate your hamstrings.

  3. #3
    Life's a ride, enjoy it! Moderator
    Reputation: life behind bars's Avatar
    Join Date
    May 2014
    Posts
    3,976
    Pic with you on bike and pedal at the bottom of the stroke please.
    Wanted, SRAM GX 2x11 rear derailleur

    It ain't supposed to be easy.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Nov 2017
    Posts
    39
    Quote Originally Posted by life behind bars View Post
    Pic with you on bike and pedal at the bottom of the stroke please.
    I added one pic. I'll have to get a full shot when I get back home later. I have a full shot of me on the bike but only with the cranks at the 3 o'clock position.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Oct 2016
    Posts
    543
    That bike looks way too small for you. Slack seat tube angles kill my knees, try going the other direction.

    Also, knee over pedal spindle stuff is outdated and mostly meaningless.

  6. #6
    mtbr member
    Reputation: mack_turtle's Avatar
    Join Date
    Jan 2009
    Posts
    8,489
    Get all the KOPS stuff out of your head.

    https://youtu.be/SZhWVZq2qUc

    That frame is too small for you.

  7. #7
    mtbr member
    Reputation:
    Join Date
    Nov 2017
    Posts
    39
    Quote Originally Posted by mack_turtle View Post
    Get all the KOPS stuff out of your head.

    https://youtu.be/SZhWVZq2qUc

    That frame is too small for you.
    I'm not really stuck on it, I'm more concerned about the discomfort I'm feeling and since I can't adjust my knee back the pain could be due to my knee position and being too far forward.

    I don't know what I don't know...so I would like a frame where I can move my knee back if need be just to try it out. I could move my knee back 2" and it be perfect, I just don't know since I'm stuck in this position.

  8. #8
    Life's a ride, enjoy it! Moderator
    Reputation: life behind bars's Avatar
    Join Date
    May 2014
    Posts
    3,976
    I'd try out the next size larger if I was doing this.
    Wanted, SRAM GX 2x11 rear derailleur

    It ain't supposed to be easy.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Nov 2017
    Posts
    39
    Quote Originally Posted by life behind bars View Post
    I'd try out the next size larger if I was doing this.
    I found one at the same shop / different location so I'm going to check it out tomorrow and if it fits good I can just trade my current one in and pay the difference.

    Hopefully the larger frame fits better. I'll update tomorrow.

    Thanks for the help everyone!

  10. #10
    mtbr member
    Reputation: J.B. Weld's Avatar
    Join Date
    Aug 2012
    Posts
    10,991
    It's tough getting fit advice because very few people are really qualified to do it, me included. I have sold quite a few bikes though and from those pics that frame looks a little small (short) to me. Seat height looks pretty good, handlebar to seat height looks ok to me but that's subjective.

    Sizing up might improve overall fit but it shouldn't change the kops at all if it has the same seat angle, and I'm sure it probably does. That frame already has a fairly slack seat angle so I don't know what to say, maybe you have freakishly long femurs?

    One other thing is to check the saddle, some are a lot longer than others and/or have more fore/aft range on the rails, it's possible you might be able to move back a couple of inches with a different one.
    I brake for stinkbugs

  11. #11
    mtbr member
    Reputation:
    Join Date
    Nov 2017
    Posts
    39
    Based on my pics would I fit a 21 or could I even fit a 23 frame? Just based on the specs and comparing it to my position, I think I would be better off on a 23" frame.

    Unfortunately none of my LBS even in other cities keep a 23 frame in stock.


    Current frame 19.5:
    Seat Tube: 18.5"
    Effective Top Tube: 25.11"
    Heat Tube Length: 3.93"

    21:
    Seat Tube: 20.5"
    Effective Top Tube: 25.94"
    Head Tube Length: 4.72"

    23:
    Seat Tube: 22"
    Effective Top Tube: 26.50"
    Head Tube Length: 4.72"

  12. #12
    mtbr member
    Reputation:
    Join Date
    Sep 2017
    Posts
    169
    Im 62 on a Trek Stache XL 21. My two cents would be try a Stache if youre considering a trade in but Ill leave the rest to the experts.

  13. #13
    mtbr member
    Reputation:
    Join Date
    Nov 2017
    Posts
    39
    Quote Originally Posted by JDHutch View Post
    Im 62 on a Trek Stache XL 21. My two cents would be try a Stache if youre considering a trade in but Ill leave the rest to the experts.
    I'm in Central FL. The Rosce is more than enough bike for what I'm riding and probably overkill at that.

    I probably could've bought a Marlin and been happy but I wanted a 1x.

  14. #14
    mtbr member
    Reputation: J.B. Weld's Avatar
    Join Date
    Aug 2012
    Posts
    10,991
    I'm a little over 6'2" with 36.5 inseam and long arms and fit really well on an xl hardtail frame that's similar to the 21" Trek you referenced, based on your measurements I think the 23 would be too large for you.

    One thing I always do when shopping bikes is to measure the seat height on a bike where I know it's right so I don't have to fool around trying to get it right on different bikes, just bring a tape measure and set it at the right number. One less variable to think about when comparing bikes.

    I think the seat height in the pic looks pretty good but if you haven't already I think it's worth the time to double check it using one or more of the methods that fitters use to make sure it's in the ball park. I like the heel on the pedal method because it's easy and fast.
    I brake for stinkbugs

  15. #15
    Ride Fast Take Chances :)
    Reputation: alexbn921's Avatar
    Join Date
    Mar 2009
    Posts
    2,609
    Reach is the important number is sizing a bike and that bike looks to small for you. You are basically sitting up right and that makes it harder to push on the pedals. Shifting your upper body forward and down will change the muscles you use too.
    Making shit harder than it needs to be isn't awesome, it's just...harder.

  16. #16
    mtbr member
    Reputation:
    Join Date
    Nov 2017
    Posts
    39
    So I went to my LBS and test rode a 21" Marlin. The geometry is very similar to the Roscoe. Even with all stock components it rode so much better. Hard to explain but I felt opened up.

    The Roscoe I want is at another location so they're going to pick it up Monday and then swap all of my components over to my new bike. I'll update once I get a chance to test it out.

    Thanks for the help everyone!

  17. #17
    damned rocks...
    Reputation: Aglo's Avatar
    Join Date
    Dec 2014
    Posts
    2,078
    What kind of pedals do you use, flats or clipless? I can't figure it out from the pics.
    If you are using clipless pedals your cleats may be wrongly installed. If the cleats are not at the right angle it may force your legs and strain your knees. This will cause knee pain, believe me, just don't ask how I know .

  18. #18
    mtbr member
    Reputation:
    Join Date
    Nov 2017
    Posts
    39
    Quote Originally Posted by Aglo View Post
    What kind of pedals do you use, flats or clipless? I can't figure it out from the pics.
    If you are using clipless pedals your cleats may be wrongly installed. If the cleats are not at the right angle it may force your legs and strain your knees. This will cause knee pain, believe me, just don't ask how I know .
    Flat pedals.

Similar Threads

  1. Anyone know of a bike Geometry calculator to compare frame geometry?
    By lacofdfireman in forum General Discussion
    Replies: 17
    Last Post: 04-30-2017, 02:09 PM
  2. Frame Geometry Opinion ? geometry attached
    By madpanda in forum 29er Bikes
    Replies: 9
    Last Post: 05-08-2015, 10:10 PM
  3. Effect of G2 geometry with Niner geometry
    By yourdaguy in forum Niner Bikes
    Replies: 7
    Last Post: 03-22-2013, 04:40 PM
  4. ASR5 Alloy geometry vs ASR5-C geometry
    By biggusjimmus in forum Yeti
    Replies: 2
    Last Post: 12-13-2011, 02:21 PM
  5. 650b Cusotm Frame Geometry - Need Help
    By 650 Cent in forum 27.5
    Replies: 18
    Last Post: 11-17-2011, 12:03 AM

Members who have read this thread: 2

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.