Frame help - small rider

Discuss light weight issues concerning road bikes & parts.
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Martin.F
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Joined: Sat May 28, 2005 9:21 pm
Location: Norway, Drammen

by Martin.F

Hello!

I'm going to build a bike for my girlfriend, but I'm having trouble choosing frame. She is a centimeter or two below 160cm, so she needs a short frame (<50 cm top tube). Another requirement is that it looks like either a Bianchi frame or like a r5ca. So either Celeste or stealth matte black.

She weighs 40 kgs and it's her first bike, so stiffness will be no problem. There for I'm starting to think in the paths of Chinese frames. But I have a hard time finding something small enough.

The bike will be built with the following:

Sram Force groupset in black
All black components, either 3t or 4za
Handbuilt wheels (some nice hubs and chinese carbon 20mm clinchers or notubes rims) in 20/24

Does anybody have a suggestion for a small frame that meets the requirements?

Thanks!

:beerchug:
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strobbekoen
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Joined: Wed May 18, 2005 6:24 pm
Location: BELGIUM

by strobbekoen

Tough one. Years ago I had been looking at this too building a bike for a small woman (152cm).
I then looked into the geometry of smaller frames and "WSD" and found them to be pretty odd.
Generally they have a steeper seat tube (74 or more) angle and shallower head tube angle (70.5 pr 71 or so).
The reason they do is to make 700C wheels "work" on extra small bikes.
The top tubes are not that short either considering the steeper STA makes the reach longer.
For example, a Giant WSD XS bike has a top tube of 51.5cm with a STA of 74.. go figure.
Add in the fact that on average women have a bigger leg/torso ratio than men, it doesnt make sense to me.
In the end, I built a bike with 650C wheels which I built myself. The bike and geometry is way more in proportion for smaller people. I know this doesn't answer your question as to which specific frame to get, but I'd consider this option for smaller ladies.

by Weenie


fio
in the industry
Posts: 106
Joined: Mon Sep 26, 2011 10:34 pm
Location: Madison, WI

by fio

Take a look at Cervelo. I've looked a tons of geometries across brands, and Cervelo has definitely done their homework on small bike geometry. The reach on their small frames is actually short the way it should be, as in they don't just slam the seat tube forward and pretend like that'll make the frame fit smaller riders. I stand 162.5cm (5'4") and ride a 48cm R3 with absolutely no problems. Even though the top tube is 51.6, the reach is much shorter than any other bike that I've seen. Because of this, it's by far the best fitting bike I've ever ridden as it's allowed me to achieve my optimal position with no compromises. Take a look at their fit presentation here: http://www.cervelo.com/en_us/engineering/tech-presentations/. It's a pretty good look at why they made the decisions they did with their small frames.

Just as a quick example, a 48cm R3 has a TT of 51.6 and a reach of 36.0, whereas a "comparable" size 50 Bianchi Sempre with a TT of 51.0 (notice: shorter than the Cervelo) has a reach of 38.2! That's over 2 cm longer than the R3, despite the shorter top tube!

I can't help you in the looks department (although you could go with an R5ca!), but you could pick up a Cervelo frame and spec it the way you want.

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elviento
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Joined: Thu Aug 25, 2005 7:09 pm
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by elviento

BTW, top tube less than 50 might create handling issues and major toe overlap. I have seen some 650c wheeled bikes which are quite nice.

Martin.F wrote:Hello!

I'm going to build a bike for my girlfriend, but I'm having trouble choosing frame. She is a centimeter or two below 160cm, so she needs a short frame (<50 cm top tube). Another requirement is that it looks like either a Bianchi frame or like a r5ca. So either Celeste or stealth matte black.

She weighs 40 kgs and it's her first bike, so stiffness will be no problem. There for I'm starting to think in the paths of Chinese frames. But I have a hard time finding something small enough.

The bike will be built with the following:

Sram Force groupset in black
All black components, either 3t or 4za
Handbuilt wheels (some nice hubs and chinese carbon 20mm clinchers or notubes rims) in 20/24

Does anybody have a suggestion for a small frame that meets the requirements?

Thanks!

:beerchug:
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cyclenutnz
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Joined: Tue Jul 18, 2006 5:18 am
Location: Cambridge, New Zealand
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by cyclenutnz

Find a 48cm Cervelo RS (650C) frame and repaint...
You won't find anything from the no-brand manufacturers - they don't push the limits on sizing. Unless she is long in the torso there are going to be position compromises to fit a 700C bike. RS works very well for little ladies.
Velocity aeroheads for light 650 wheels
http://www.speedtheory.co.nz
http://www.velogicfit.com - 3D Motion Capture and Frame Finder Software

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strobbekoen
Posts: 4446
Joined: Wed May 18, 2005 6:24 pm
Location: BELGIUM

by strobbekoen

and the RS XS is actually the same in size as a R3 48cm but with 650 wheels. It has a 72 degrees HTA versus 70.5 on the R3. Unfortunately it has the same rear-center as the R3..

virenque
Posts: 278
Joined: Fri Oct 21, 2005 4:08 am

by virenque

the specialized amira comes in 44cm, very small and is 700c

NGMN
Posts: 1536
Joined: Mon May 30, 2005 7:13 am

by NGMN

I too would look at a bike with 650c wheels.

Why not go with a Tsunami? Only a couple hundred more than a chinese frame and you are practically guaranteed better geometry and the right paint.

davidalone
Posts: 589
Joined: Fri Feb 10, 2012 4:27 pm

by davidalone

My sister is 160 and needs a small bike. She's had success with the following:

1) Cinelli little wing 650c. was her first bike and it fit her well.

2) Pro Lite frame. this was dirt cheap and she really liked it, she only sold it because the paint finish wasn't so good. but overall a great frame.

3) currently she's riding an argon 18 gallium.

A smaller female rider who's very good rides a cervelo R3.

Unless you have real problems getting 650c wheels or tubes/tires for 650c, I'd advise you to go with that. 650cs just fit smaller riders better. going 700c for a smaller rider is just for vanities sake. well, yes it's tough luck if you go riding with your friends and you flat and no one else is on 650c wheels and hence no spare tubes...

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strobbekoen
Posts: 4446
Joined: Wed May 18, 2005 6:24 pm
Location: BELGIUM

by strobbekoen

Here's one I made for small lady. wheels i built with velocity aerohead.
I know it's a very tiny bike! :wink: she's 150 or 152, forgot. shortish legs, 165mm cranks, short-reach levers for small hands.

Image

by Weenie


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