Clydesdales/Athenas (200+ lb / 91+ kg) - Bad posture on my MTB

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Sir-Loin
06-11-09, 12:28 AM
5'8"-295LBS
Short Legs/Medium Torso/Medium arms(per LBS)
Rockhopper frame(09')
I am finding that after the third day and about 15 miles of XC interval training that my knees feel too far forward of the center mass of the crank. I was sized but not in finite detail. Am I hindering my riding/hurting my muscle memory? I can move the seat back but Im not sure how far. My legs are almost locked on downstroke and I am keeping about 30 of my weight on the front bars(or so it feels like). I didnt see a sticky on MTB sizing/setup so I am sorry if I missed it.
P.S. are little crew(5) is putting the effort in and having a blast. We definately agree that this cycling thing is a great lifestyle change! Thanks for the support folks:thumb:
What size frame do you have? Pics? Seat height high enough? Lots of variations out there. Make sure legs are fully extended on pedal downstroke.
c_m_shooter
06-13-09, 03:23 PM
Start with a saddle postion similar to a road bike. When the pedals are level (3 and 9 o'clock) the base of your kneecap of your front leg should be plum with the pedal spindle. It is a good place to start and you can adjust from there. My mountain bike saddles tend to be set a little behind there, but everyone is different.
Don't do intervals every day, you need to recover. One or two days of intervals per week at the most.
Sir-Loin
06-13-09, 05:09 PM
Thanks, I will get some pics up tonight. I am going riding tonight(love the Alaska Summers) and will have some pics tomorrow.
Will make that saddle adjustment C M, I appreciate the help.
WRK101, I have a 17" frame and a 29" inseam. I will have some posture pics asap, Hope I can give a better idea of my issue, Thanks again, James
theetruscan
06-13-09, 05:54 PM
Errr, you've ridden 15 miles. Are you sure your position is wrong, not just unfamiliar?
When your pedal is all the way forward, a plum line from the front of your kneecap should hit right on the ball of your foot.
With the pedal all the way down, and your foot flat you should have (if I remember) around 30-35 degrees of bend in your knee.
Sir-Loin
06-13-09, 06:04 PM
I wasnt sure but the bike felt funnier than my Diamondback 5 years ago, plus I wasnt sized as thoroughly as maybe I needed to be.
I have about 15 degrees of knee bend at max depress(pics in a couple hours after my ride) I wil make that adjustment and see if it feels more natural. Thanks, James
Are you just getting back into riding Sir-Loin? If you have had some serious time off, and then just started riding again you might just need some time to get acclimated to it agian. Also, is mountain biking new to you? I commute (sometimes) on a converted mountain bike and my legs are never fully locked when riding. I think most mountain bikers prefer a seat height slightly below mine for quick exits if the need arises (at least that's what if heard).
How are you measuring your inseam Sir-Loin? Are you using your pant inseam or your PBH. The PBH is longer than your pant inseam and is usually the measurement used when fitting a bicycle and measuring the saddle height. Also check and see if your saddle is level or close to it. Then give enough time to get acclimated before you start making changes if necessary.
It sounds like the bike is about the right size for you given your listed dimensions though.
Sir-Loin
06-13-09, 09:52 PM
Exile, I am just getting back into it after 5 years off. I did some recreational xc stuff in 02-03(100 pounds lighter too). I will give it a little more time before I get nervous on my settings.
29" is my full inside leg inseam, as measured from my ankle.
Just did a 12 mile XC ride and feeling nore balanced and natural on the bike. Couldnt get my buds to ride so I got only scenery pics from tonight!
Given your height and all I do think the Specialized Rockhopper is about the right size for you. I am glad you felt more comfortable riding it today. I am also happy to see you went out for a ride even without your buddies :thumb:.
Saddle height and fore/aft position are different for everyone. I used this one: http://davesbikeblog.blogspot.com/2007/09/saddle-height.html with some tweaking. You can also look for Sheldon Brown"s approach or Peter White's by trying a google search (a lot of information in thier as well). Part of the problem may be that you had so much time off that you just need to get used to riding again.
You might also want to check the stem and see if it is a stock stem or at least what it's measurement is. Sometimes manufacturers will use different stem sizes for bikes within certain size ranges which may be longer than what riders prefer. I know when I bought my mountain bike used (from LBS) it had a 110 or 120mm stem (19 inch frame). It was also the same size stem they used on their 21 inch framed bikes if memory serves me correctly. After swapping out the stem for a shorter one, the bike felt a lot more comfortable. Good luck to you Sir-Loin and can't wait for the pics.
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