In my last two “Bike Fit Basics” posts I covered frame size (it’s a myth), top tube lengths, stack, and reach.
Today I’ll talk a little bit about what you can do to modify the fit of a bicycle you already own. In a perfect world you’d buy the ideal frame size, but if you didn’t there are a few tricks. However, some of these changes can also have negative impacts on fit, comfort, and handling. I had a beautiful singlespeed 29er that I desperately wanted to fit me — I made most if not all of the “make my bike” smaller mods below, and eventually had to come to grips with the fact that the frame was just too dang big and I sold the bike.
I’ll be the first one to admit that I’m NOT an expert on any of this — we’re really out there on the fringe of my comfort zone. If you’re reading this, please add a comment below with a bike sizing tip or modification you’ve made to a bike for fit, for better or for worse. Thanks!
My Frame Feels Too Big – What Do I Do?
- Put on a shorter stem. The handlebars will get closer to you, but the bike handling may be “twitchier” than you like.
- Put on a stem with a higher “rise” — meaning, get a stem that angles the bars upwards instead of straight out. If the bars are higher, they’ll seem closer. This is like increasing the bike’s stack. You’ll be less aero, but if it means you can reach the bars without back pain that’s a plus.
- Slide the saddle all the way forward on the rails (stay within the acceptable markings on the rails). However, changing this to make your bike feel smaller, vs. adjusting for ideal knee / pedal alignment, can put your comfort at risk.
- If you have a set-back seatpost, swap to a straight seatpost. However, this affects your position and where your weight is centered over the bike, AND can jeopardize the relationship between where your knee is and the pedal.
If you want your frame to feel bigger, do the opposite of the above. You’ll run similar risks with your knees with any seat position adjustments.
Modifications for Comfort
Here are a few other things you can change on your frame that can help you feel more at home on your bike.
- Saddle – every human has different, uh, geometry and that’s why there’s such a huge range of saddles out there. More padded, less padded, huge cutouts, no cutouts .. the list goes on. Try a few. Usually your local bike shop will measure how far apart your sit bones are and then recommend some saddles in your size. (YES, saddles have sizes! Getting the right size is critical.) A lot of the shops around here will let you return a saddle within 30 days and use the money towards the purchase of another saddle at their shop. Keep trying until you find one that works!
- Handlebar width — I almost always swap out the handlebars on bikes I buy with my favorite pair. Yeah, I have multiple sets waiting in the garage for future bike purchases.
- Handlebar drop or flare – Different handlebars have different depths the drops, or may even flare the ends out.
- Crank length – this is one I haven’t explored much. I’ve been riding whatever comes on my bikes and haven’t had issues. However, when I asked for feedback from other riders when drafting this post I had a slew of shorter riders say that decreasing crank length made them much more comfortable on the bike. One even said it increased her power output!
- Seatpost material – I found this article on different types of seatposts and their pros and cons. Why rehash this when this article does such a good and thorough job?
I read a lot of articles writing this three part series, and here are some of my favorites.
- A great overview of bike fit and geometry terms from Bike Dynamics, a bike fitting business
- This article walks you through a new road bike purchase from start to finish.
- A blog post by a bike shop talking about “reach” and “stack”
- This article talks a lot about what you can change AFTER you’ve selected your bike and/or frame size — this could be useful if you have a bike already but don’t feel like it fits you perfectly yet
- After I dispelled the myth of “frame size” and taught you about top tube, I found this article now saying that top tube measurements don’t even matter!
- Need to learn more about considerations for choosing a saddle that accomodates your lady bits? This article was EXTREMELY helpful for me.