The truth about clearance between frame and crotch...?
 

Dear All:

I am currently shopping for a new bike -- my first in almost 30 years.

I am looking at hybrids, and have been trying bikes at a couple of different LBS in Los Angeles.

So far I have tried some Trek FX, Fuji Absolute and Schwinn.

I am 5'11.

At one store, I was told that one needs about 1" clearance between the top of the frame and one's crotch when not on the saddle. As a result, I was given a few 19" bikes to try. (Fuji)

At the other store, the guy told me that it was more about riding position, and that a 20" was better for me (no space between the frame and my crotch there). So therefore I tried a couple of 20" bikes (Trek).

Riding-wise, I did not feel any difference really, but I also only did two laps around the block...

Who is right? Does it matter?

Thanks for the advice.

EBZ

Ya, it will probably matter if for some reason you end up flat footed with the tires sitting on something higher than normal. Like smacking a curb or something and coming off the front seat. One shop I that I was checking my bike made a point that it is a safety issue. Find a bike with a sloping frame giving you the reach and I bet you will feel more comfortable about the bike. I sure would have if both of my road bikes were an inch lower.

Sort of depends on the definition of "crotch". An inch of clearance between the top tube and the pubic bone is the minimum I would recommend. This doesn't mean you can't be touching the top tube as you stand over the bike. But it does mean that if you can't lift the bike an inch before it hits something that won't "give", you probably want a smaller frame.

Casual, JRA a taller frame, Less clearance, aggressive, particularly MTB off road you want more clearance.

Thank you all for your thoughts. I went to another LBS today to try some Giant and Specialized bikes. The guy seemed very knowledgeable and said I was in between two frame size (Medium/large) or around 19/20".

He felt for city riding in Los Angeles, I was better off with the slightly shorter frame an some clearance. The more I think about it the more I tend to agree.

While the larger frame was not uncomfortable, there was a little... should I say potential danger :p mounting and getting off the seat quickly...

I also remember in the past having to jump a curb to avoid some !#!*?! car not paying attention...

I'm 5'5" and am comfortable on 52cm/20.5" vintage bikes with straight top tubes. Depending on tire size there is generally at least 1" before I bottom out.

I like flat handlebar bikes with a 56cm top tube.

My 15" Mongoose has 56cm ETT (effective top tube) as did a 1999 18" Trek 4000, so they both fit perfectly but the goose has about 1.5" more standover than the Trek.

Looks like both the Trek fx and Fuji Absolute have a nearly 55cm. I'd probably go with those personally and get a longer stem if necessary.

It might take you a while to figure out what ETT fits you best. You also need to figure out what back angle you'd like. 20 deg from horizontal for a racing posture, 80 degrees from horizontal for upright pleasure cruise, or somewhere in between. For upright you may want to go shorter ETT but you may need to swap stem or bars to get lost bar height back.

What size are your wheels? the 700 could be making the difference, or you may just have longer legs than mine.

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I think I'm going to chose between a Giant escape and Fuji absolute.

I will try them again in different size and talk to the LBS about posture.

Wheel size is 700c. Tire size makes a difference. Top tubes are 54-55cm. Bar height, stem length, saddle and crank length all factor into rider position/fit.