700c -> 650c on a Road Bike

[kiwi girl]

You say you are worried about toe overlap - but have you actually checked if it is an issue. I'm 5'1" and yeah both road bikes I've had look out of proportion - not wanting to offend anybody but I refer to them as mutant dwarf bikes - but I think that is part of their charm. I haven't had a problem with toe overlap.

[JoHunter]

Hi everyone thanks for the replies. I was unable to judge the toe overlap on this bike prior because it is a custom made frame (not for me, a second hand one I found in my size). My LBS was willing to fit it with standard parts. I wasn't sure if the fork of the bike was to accomodate 700c or 650c wheels. Now that I actually have it with the 700cs there is a bit of overlap. Depending how I turn it my toes clip the front wheel, so I have to be a bit careful with it. I may end up getting shorter cranks that might help. From various different sources I found that a lot of people recommended the 650c wheels for shorter people to help with acceleration and climbing hills. I have heard of people turning their road bikes into tri-bikes and wondered if they bought new forks or found long-reach brakes.

Actually thinking it about it now, it is very odd that a custom built frame would have the toe overlap problem. I would think most small frames that were made to accomodate larger wheels would make the effort to avoid it.

[fixedgeargirl]

I was doing some investigating re: crank length yesterday. I learned that a longer crank length allows for better leverage but dictates a lower cadence. Better for power on an off-road machine. Shorter cranks allow a quicker cadence, better spin and don't require the knee to achieve as intense an angle (SAVE THE KNEES !)

I also came across some calculations vis a vis crank length as a percentage of femur length. Can't find the link now, but the gist of it is that even 165s can be *too long* for a petite woman. But then there's the study Sheldon Brown links to regarding wattages produced using different crank lenths (from 120-220 I believe) with the greatest wattages being produced using the mid-range cranks.So much information, is that smoke coming out of my ears.... ?

Anyhoo, I'm 5'3", 27" inseam, on a custom frame with 165 cranks. Have 165s on all my bikes and feel loss of power and sad knees on anything longer. Shorter cranks might benefit you in many ways, including eliminating the overlap issue.

[SadieKate]

Depending how I turn it my toes clip the front wheel, so I have to be a bit careful with it.

Is this when you are riding or when you are standing in the parking lot with one foot clipped in?

[Kathi]

Hi everyone thanks for the replies. I was unable to judge the toe overlap on this bike prior because it is a custom made frame (not for me, a second hand one I found in my size). My LBS was willing to fit it with standard parts. I wasn't sure if the fork of the bike was to accomodate 700c or 650c wheels. Now that I actually have it with the 700cs there is a bit of overlap. Depending how I turn it my toes clip the front wheel, so I have to be a bit careful with it. I may end up getting shorter cranks that might help. From various different sources I found that a lot of people recommended the 650c wheels for shorter people to help with acceleration and climbing hills. I have heard of people turning their road bikes into tri-bikes and wondered if they bought new forks or found long-reach brakes.

Actually thinking it about it now, it is very odd that a custom built frame would have the toe overlap problem. I would think most small frames that were made to accomodate larger wheels would make the effort to avoid it.

It's not so odd having toe overlap on a small frame with 700c wheels. It depends on who made the frame and what material it is. I'm planning on building a custom frame and I was working with a well known company that does custom build. I'm looking at a ti or ti/carbon combination. The frame I wanted is only available with 700c wheels because the company doesn't make a carbon or ti rear triangle small enough for 650c wheels. So I would have a 44cm frame on 700c wheels plus the spot where the tt and rear triangle meet wouldn't match up. Also, I would have 1cm of toe overlap.

Since there are other companies that can do small frames with 650's I nixed this design.

[JoHunter]

fixedgeargirl: Thanks for the information, I've read a few articles that agree with you on crank length and have found a place that will sell me the shorter 165mm cranks. I'm hoping this might help my legs as well as help avoid the overlap problem.

[jcl]

Hi JoHunter,
The toe clip overlap problem can be pretty bad on smaller frame bikes. I test rode a 47cm WSD Trek, a 48cm men's Cannondale, and a 47cm Bianchi Eros Donna, all with 700c tires and 170 cranks, and I found the overlap problem significant, significant enough to make me want to avoid it at all costs. Like you, I began to research the idea of retrofitting 650c wheel/tire combos, but was told that the brake setup would not work with the smaller wheels.

I'm 5' 4" and I have a shorter torso, and hence a bit of a reach problem. I need an effective top tube distance of 19.5-19.7 inches.

Eventually I began to research the possibility of a custom-built road bike, and became a regular visitor to the sites of Luna Cycles, Waterford, even Litespeed! Unfortunately, all of these great products were out of my reach money-wise. I'm a cycling newbie, and while I am wildly enthusiastic, some might say even obsessed, with the sport, I could not justify spending 3K plus on a new toy.

Finally, I stumbled upon the site for Rodriguez Cycles in Seattle. They make custom bikes for the hard-to-fit. They use 650c wheels on their smaller frames, and in addition, the women's road design has a more relaxed geometry than is typical - the top tube is sloping, the head tube is longer. I ended up ordering a custom bike from them, steel frame, 650c wheels, 165 cranks, and Campy setup for a little over 2K.

I received the bike this afternoon (waited by window all day for brown UPS van to appear), and I must say, it looks great! Because of all the rain in L.A. today, I was only able to ride it slowly, in circles, around our underground parking. Even with all the customization, there is still a bit of an overlap problem when I clip in to the pedals, but it is far less than it was with the other 700c/170 crank bikes. From my viewpoint in the saddle, it looks like 1cm of overlap, but that's a guess.

So in closing (I know, long post), I would like to say that I do not think that the toeclip-overlap problem can be entirely eradicated in a small-framed road bike design. If you talk to a builder, they'll sketch you a diagram of the bike, and show you the wheelbase and the angles that work, and then I think you just have to decide what you can live with. But smaller wheels and cranks do minimize the problem.

Good Luck with your search!

JCL

[Eden]

I have a Fuji 44cm frame with 700's and 165 cranks. I've been informed by various sources that the setup shouldn't work at all and that the angles are all weird to accomdate the larger wheels, but it fits me to a tee. I'm short with shorter torso and arms than legs. I used to have a bigger bike and can stand over a taller frame, but I really need the shorter top tube. I have no overlap problems at all- I do have small feet - size 4.5 road shoes. As far as the crank length goes - longer ones would mess up my knee position which is pretty darn perfect now, so even if it wouldn't cause overlap I wouldn't want to change it.

I haven't ever had a bike with 650's so I can't say that I know what the difference would be like. I've heard that smaller wheels climb better, but you end up having to spin faster to keep up on the flats. I've also heard that you can compensate with the gearing. I would love to take one for a test spin someday just to see which feels better to me.

[doc]

Toe overlap is a hugely overrated problem. It only occurs when you turn the wheel a significant amount. When actually riding, one turns the wheel very little and uses a shift in weight to take a turn. Shoe size does affect the degree of toe overlap.
As for crank arm length, there are a lot of formulas out there. The one I see repeated the most is inseam (with shoes on) in cm x 2.14 = crank arm length in mm. Here are some websites:
http://www.nettally.com/palmk/crimplic.html
www.sheldonbrown.com/cranks.htm
and so many more...