Has anyone gone from 20.5 to a 20.25 top tube and does it really make that much of a difference?

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12/4/2019 12:24 PM

I have two bikes. I started riding on a 20.5tt and got and got another bike for spare parts that is a 20.25 and about a half inch shorter chainstay. I decided to ride it the other day and noticed how much smaller it felt. Which made spins and manuals noticably easier. I'm just wondering if anyone has experienced a similar situation and if a quarter of an inch actually makes that big of a difference or is it's just in my head? I'm 5'6 and 140lbs. Any info and suggestions are much appreciated, Thanks! Also, I know it's personal preference and all that but curious about how dramatic Top tube length really matters to such a small degree?


12/4/2019 1:24 PM

its mostly in your head, but i too love smaller frames/bars. i'm currently riding a 20" frame with 7.5 bars lol. i'm 5'11


It’s all bmx

12/4/2019 1:28 PM

Shouldn't be much different. The only time I've noticed a difference in frame feel was going from a 20.35'' to a 21'' frame but that was also due to the back end being significantly longer too. But a quarter of an inch won't be much different, if any different, and if the shorter frame is nicer to ride then definitely ride it.


12/4/2019 3:01 PM

Your feeling the rear end most. The 1/4" tt probably not near as much noticeable. Also, the headtube angles can make a big noticeable difference in "felt" bike size. I've been through the entire spectrum of bmx frame sizes and geometries. Suprisingly I ended liking a frame that falls in the middle of the spectrum of sizes currently available concerning geo and lengths..... ride what you feel most fun.


12/4/2019 6:21 PM
Edited Date/Time: 12/4/2019 6:26 PM

I’ve posted this many times before but:

I went from a 20.5” to a 19.69” and it made a world of difference. Likewise, spins and manuals became easier. Paired with a low standover, footjam whips became way easier and consistent. The backend is about 1/3 an inch shorter as well. Running 10” tall bars and a top load and spacers, lol.

I’m 5’, 7” and 110 lbs. Maybe most of it COULD be in your head, but there comes a point where you’ll really be able to feel a change, and I certainly have.

It’s been about a year with it now, and I’ve adjusted to it well. It feels normal now, but I recognize the difference in how it handles compared to my last frame.


Scooter kid trying to ride a bike.

12/4/2019 6:34 PM

If your still growing your going to start smacking your kneecap on your stem


12/4/2019 6:43 PM

TT length is the least noticeable metic of an entire bike geo.


12/4/2019 8:02 PM

I went from my knees constantly hitting the back of my stem on my old 20.5" to it not even being a possibility on my 21.5"...

I'd without a doubt notice the difference between +/- .25" on my TT, but at the same time I'm 6'3".

At 5'6" that +/- .25" on a 20.5" frame would probably be a little less noticeable.


12/5/2019 10:37 AM
Edited Date/Time: 12/5/2019 10:38 AM

I went from 21.25” to 21”
It is noticeable, I really feel the 6mm taken away, it’s less roomy, for the better and the worst, easier to do quick spins and tech stuffs like hard 180’s, also less confidence for big gaps.
I’ll probably end up getting 100% used to it, but for now 360ing a lot of stairs just feel sketchy.


12/5/2019 1:28 PM

readybmxer wrote:

I’ve posted this many times before but:

I went from a 20.5” to a 19.69” and it made a world of difference. Likewise, spins ...more

Your bike must be almost as tall as it is long! grin


I like shorter top tubes and short rear ends (to a point). Not sure I could notice half an inch TT without being told, but a shorter rear is definitely noticeable.

Basically you’ll adapt and it’ll become the new normal.


12/5/2019 2:19 PM

I ride 20.5 right now and I notice top tube a lot. I had 20.75 before this and can’t stand it. The bike felt too long even though the backend was a lot shorter. Made bars and whips and every trick you need to be over the front end for harder. I don’t notice .1 as much like riding a 20.6 or 20.4


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