Bike Fit Question
So, I just got a Trek Marlin (15.5" frame) and when I test rode it around my LBS parking lot, it seemed to fit fine. (Please note that this is my first MTB so I really do not know what to look for in a bike.)
Last night, my kids and I did a nice 7-7.5 mile ride along an asphalt pathway. Even after adjusting the saddle as far back as it can go, my butt still seemed to hang off the back edge of the seat. As a result, I could not get comfortable during the ride and my butt is sore this morning.
As a comparison, I test rode an 18" frame Felt Nine 80. It seemed a tad bit too big on me. However, I am wondering whether that is more what an MTB should feel like. I come from a BMX background so I *think* the fit would be different. Maybe, I am used to the more cramped fit of a 20" BMX bike versus a 29" MTB bike.
I reached out to my LBS about my options with them (they are not open yet, so I have not heard back from them), but I was wondering what your all opinions are. Should I look at a bigger frame with the 17.5" Marlin? Compare to a 16" Felt Nine 80? Re-consider the 18" Felt Nine (which they said the seat post would need to be cut in order to fit my legs, but would not because I did not purchase it).
I feel stuck, but don't want to be unsatisfied with my purchase. A $600+ purchase is a lot of money for me and my family.
You didn't mention your height, which is fairly pertinent to your question.
Start by setting the correct seat height, there are many methods but you can get in the ballpark by sitting on the saddle (barefooted) and letting your legs hang freely. With one of the crankarms at the 6 o'clock position your heel should just brush the top of the pedal, it's helpful to have an assistant. When you get the height set measure from the top of the pedal spindle to the top of the seat and write that # down, that way you can set seat your height on any size frame without guesswork.
Saddle height is only the start of the fitting process and though reach is probably even more important you can usually get a fair idea whether or not you are on the approximate right frame size by the amount of post showing.
Re: Bike Fit Question
Did your bike shop fit the frame and adjusted it for you? That's what mine did to fit the Hardrock for me.
They had to adjust seat height and move it aft ward.
What works for me may not work for you. What's best for you depends on many factors. We are different from each other.
Hard to answer that since you dont state your height or inseam etc ... try this and see if it helps
Fit Calculator - Competitive Cyclist
Sorry, I am 5'6", 30" inseam, and 165lbs.
The seat height is correct. My LBS set it before I even took it for a ride.
Your method seems to say my seat is a little too low. It is currently set to where I have a slight bend in my one on the 6 o'clock pedal. I seem that I would need to raise it about 0.5 - 1.0 inch.
The way my LBS set up the seat also coincides with the various videos I have seen on Youtube (and another thread on seat position). However, I have not seen many videos that go further than seat height.
You definitely want a slight bend at the bottom of your pedal stroke, the straight leg/heel on pedal should give you that when you move your feet so they are on the pedals correctly.
Sounds like you're in the right range, if you have a long torso for your height you might do better with a longer top tube- arguably the most important measurement on a bike frame.
Just wanted to add that I (and anyone else responding) can only guess and point to decent starting places, pics might be helpful.
If I use this calculator, it proves that my seat-handlebar distance is too close. My current distance is 18" and this calculator says that it should be 20.25-20.75 for XC.
Originally Posted by Zoke2
I think I am going to see if I can exchange for the bigger frame.
I will try to get a couple pics a little later. The first showing me how I feel comfortable with my butt hanging over the seat and a second where my butt feels comfortable on the seat.
Originally Posted by J.B. Weld
Do you want my feet/pedals at 3 and 9 or 6 and 12?
I called my LBS since they did not respond to my e-mail. The person on the phone suggested buying a longer stem. I hate spending more money on something that may or may not fix the issue.
How would a longer stem affect my handling, etc.? I am new to this so any guidance would be appreciated.
Two current threads on "Bike Fit"
Bike fit saddle position
Help me out with a fit issue, please. . .
one or both contain links to bike fit how to pages
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