# frame size and why



## rubez (Jan 3, 2011)

i am 5'10, what mountain bike frame would be best 18, or 20?

all the guides i have read seem to put me at a cross roads.

would it be better to go smaller (as you can put the seat up anyway) rather than bigger?

as i am thinking that if the bike is too big for me, i won't be as nimble on it for jumping off small drops etc and rallying round narrow gravel paths.

what would be best since i won't just be trundling along seated?

cheers.


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## Nenbran (Dec 7, 2010)

I'm around 5'9" (maybe 5'10" by now...haven't checked in awhile) and I ride a 17.5 inch frame on my full suspension. I can ride a 19 inch if I lower the seat, but it just feels really awkward and large. My 17.5 fits me quite well. I'd say you'd probably need an 18 inch, but you should check with an LBS.


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## dbwill (Nov 5, 2010)

I'm 5'10" and really like my medium frame GF hardtail, I think it says 17.5 on the seat tube. After coming from a larger bike, my palms, wrists, and shoulders are much happier.


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## rubez (Jan 3, 2011)

thanks... next size down for the bike is 14, so i guess it will have to be 18... 20 does sound too large now. 

i always preferred my seat down low, as i usually ride standing up and sit and cruise when knackered.


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## trailville (Jul 24, 2006)

I'm 5" 10" and ride mtb frames anywhere from 18" to 19.5 inches. I could probably go 20" depending on the other dimensions of the frame, but since you mentioned jumps and drops, I think you'ld be much happier with an 18". I personally wouldn't want to go smaller than 18", but there are a lot of people the same height that are riding 17" frames. 
Check the ETT (effective top tube length) of the specific frame though. You probably don't want an 18" frame with an unusually short ETT.


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## sasquatch rides a SS (Dec 27, 2010)

One thing to remember is that it is always easier to make a bike feel bigger (longer seatpost, longer stem, wider bars etc.) than make it feel smaller. You need at least 1" clearance between the toptube and you when standing on flat feet, and the rest you change to fit you properly while you are riding the bike and not standing above it.


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## dust3313 (Sep 15, 2010)

Im 6'2 and ride a 19 inch frame with a huge amount of saddle to bar drop. I love it. I could ride a 22 inch frame but I like how the smaller mtb frame handles.


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## C.M.S (Aug 28, 2009)

Your best bet is to sit on a few and figure out what size fits you the best .


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## pfox90 (Aug 8, 2010)

I ride a 18, and I'm almost 6 ft. Look at any of the good custom bike companies, they list people at like 6'2 for a large for a reason. A lot of people only get bent up on the size, when they should worry about geo, fit and feel. Mediums are sold twice as much as any other frame.


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## AndrwSwitch (Nov 8, 2007)

C.M.S said:


> Your best bet is to sit on a few and figure out what size fits you the best .


I was going to say something like this.

OP, are you going to be buying locally or via the 'net?


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## fourthree (Dec 24, 2010)

I am about the same height, but I'm built like a chimpanzee,(30" inseam, 33" sleeve), bikes are like pants, you have to try a few on to know wich one is right. By the way, I normally ride 18" frames.


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## mnigro (Jul 31, 2007)

if you don't have the option to sit on some bikes, try one of the online fit calculators. competitivecyclist.com has one.

at 5'10 with relatively normal torso-to-leg proportions, medium is most likely a good fit. however, sizing a bike based on seat tube length is terrible. most prefer to size via Effective Top Tube and/or stack & reach. In general, a bike with a 22.5 - 23.5" ETT will fit someone in the 5'7 to 5'11 range. "Genreally" being the key word.


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## Itchiee (Sep 17, 2010)

I have an 18.5" Trek and i'm about 6' tall... The 19.5" felt a little too big on me.I was more stretched out, and the bike didn't feel as tight.

The best is to test in person since it can vary from person to the way the bike is setup.


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## hatedg (Aug 18, 2010)

dust3313 said:


> Im 6'2 and ride a 19 inch frame with a huge amount of saddle to bar drop. I love it. I could ride a 22 inch frame but I like how the smaller mtb frame handles.


+1 here I prefer being able to throw the bike around...im 6'3" and I ride a giant large...I could go XL but I like the bike smaller


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## Straz85 (Mar 20, 2009)

Depends a lot on the bike, the top tube is more important than the seat tube. Also, different manufacturers measure the seat tube different ways, or even the same company depending on geometry. For example, I have an 18.5" Trek Fuel EX 8 and a 17.5" Trek "GF Collection" Marlin, the TT length is only .3" different. So, what is the TT length on the two bikes?


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