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Discussion Starter · #1 ·
Whats the difference between 18inch and 20 inch?

Hi,everyone.I am a new comer and I am from China.Hope my poor English can make all you people understand what I am talking about without much difficulty.

I started riding not long ago,and I want to build a bicycle of my own.The first thing is to choose one frame.I found a new 20-inch DiamondBackRacing Axis-R frame,which is not manufactured any more in the world.I like it very much,but my height is 180cm which fit to a 18 or 17-inch frame.

I read Scanner's post of fitting the size,but its hard for me give up the Axis-R frame,so my question is,2 inches really means a lot?Can I just ignore the frame size by moving seat down and using a short stem?

Thank you for answering my question.
 

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Two inches can mean the difference between manhood and ... Sorry I won't go there. But two inches, in frame speak is a lot.

If I do my calculation right you should be on a 16 to 18 inch frame, yes that is two inches but when speaking of different bike makes, their sizing varies - but not enough for you to go up to a 20 inch.

Where are you going to ride? If it is on trails don't get the 20 - it won't be a good deal if you hurt your self or you don't enjoy riding. If you just want a road cruiser... 20 isn't good but, I guess you could do it.

Yes, you can lower the seatpost and you and get a shorter stem but the bike still won't fit you. Ideally a bike should have a stem that is around a 110mm or close - except Gary Fisher with his Genises geometry.

Year ago I really wanted a Kestral Mountain Bike (yes, I am an old guy) but I just did not fit the bike. One size was two small and I would have to put a huge stem on it and the next size up felt too big and I knew I could never get comfortable on it or have it handle the way I wanted. The bike was a great deal, very light, but I had to pass. It was a hard thing to do, but it was the right thing do do.

Pass on the Axis, other bikes will come along.

My two cents worth.

Tad
 

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I agree. Fitment should be priority #1. Don't worry, there's TONS of bikes out there and I'm sure you'll find one in your size that you like.
 

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LBguy said:
Just out of curiosity, how can you guys say that with such certainty. I'll agree that in general, it sounds a bit too big... But 20" does not mean much, and neither does 180 cm. How do you know if this guy is not all legs, or all torso? What about the frame? Are you familiar with it? I'm 5'8" and I'm pretty sure I could ride 19" Giant XTC without any problems????

I'm not trying to start too much of a debate, because there is a good chance you are both right, but it seems to me the right answer should be more along the lines of "You need to go get on the bike and try it. If you are purchasing online and therefore can not see it (or for any other reason, like it is not assembled) then I would not get it, but if you can ride this frame, then try it out, and pay particular attention to the amount of clearance you have over the top tube. Also, pay attention to how stretched out you might be, you don't want to be too stretched out if you will be riding a lot of trails, etc...."

Anyway, if at all possible, try to find a frame that you've test-ridden and by all means employ the services of a LBS (if there is one near you) to help you choose a good frame for you.

Oh yeah, and ... "Fitment"?
 

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20" should be fine....

I'm 1.75m and I need a 18.75" frame (my Giant Warp 18.5" fitted like a glove).

For your 1.80m 20" should be just fine. You're right on the limit.

That said your need a Large frame. Medium is for people UP TO 1.78m.

Go ride!!!
 

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Just out of curiosity, how can you guys say that with such certainty. I'll agree that in general, it sounds a bit too big... But 20" does not mean much, and neither does 180 cm. How do you know if this guy is not all legs, or all torso? What about the frame? Are you familiar with it? I'm 5'8" and I'm pretty sure I could ride 19" Giant XTC without any problems????
I just wrote out a big response and then deleted the whole thing. Yes he/she could ride the 20" Axis. But without seeing him and from 25+ years of doing this my gut feeling is it will be too big. And like I said before it depends on riding style.

Too me DBs always felt "large" for their size. I think he/she would be happier with a smaller size. But without being able to see them on the bike, or better yet take some body measurements, it is a tough call and one that should be done with out knowing for sure.

I will take back what I said before... if the frame is a reallllllllllly good deal, and you think that you could sell it on ebay for what you paid, go for it! Build it up and see how it feels. But keep in the back of your mind that you may have to tear it down and sell it again.

At 5'8" I bet you could ride a 19" XTC. but you could also "ride" my 21 Ritchey (if I would let you ;)) and you could "ride" my wife's 15.5 K2 (she is 5'9" BTW - short torso) but I don't think you would be comfortable for long on either bike.

There are four essential measurements to fit anyone on a bike: Saddle height; saddle setback; saddle to handlebar reach; and handlebar rise or drop. In that envelope, which should be created for each individual and their riding style and preference, you place the size of the bike. This will differ depending on brand, model, riding style, comfort requirements, et cetera. In this sport there is no standard in the industry that says all bike will be measured the same way.

Bike fit is not magic, and a good shop can do wonders for your comfort and enjoyment. Find a good shop, use the good shop, recommend the good shop to others. A lot of bike shops are in danger of not being around in a few years, so if you find a good one support it as best as you can.

Enjoy!

Tad
 

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Discussion Starter · #7 ·
Thank you people for answering my question.

From the discuss I became to realize that a bike is a bike for riding,not for good looking or collections.

Scanner's suggestion is quite right to me.A wrong size frame may cause serious accidents.I just suffered a serious knee injury during a accident two monthes ago,I just know it well if you got injured all enjoyment will be ruined.

So I will have a test ride on my pals' 20inch axis and 18inch apex before I make my choice.

Everybody here,welcome to ride in China,you will have wonderful experience.If anyone here decide have a tour in China,please inform me.Maybe I have a chance to ride with you.
 
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