Custom Bike - 650 vs. 700 wheels

I'm one of those short women riding a 43cm bike with 650c wheels.

I have a Profile Design BSC fork (I would guess the 1-1/8" steerer size) which I'm told has clearance for fenders, but I haven't tried . . .

I've not yet had to replace the stock tires that came on my bike, but I feel that there are some good quality options available, so I'm not worried about it. Are there specific tires that you like on your current bike(s) that are not available as 650c?

I did notice, after many months with my bike, that I do still have a little bit of toe overlap. I would have to be pedaling through a pretty sharp turn for this to be an issue, and it hasn't been.

I like the lower center of gravity that the 650c wheels give me. When I was shopping for this bike, I just couldn't get comfortable on a 700c wheel bike (never mind that all the bikes in stock were just a bit large for me), since I had some back/hip range of motion issues and balance issues.

I have not had the opportunity to ride a 700c wheel bike that is the right size for me, so cannot comment on comparison.

Quote:

---

Originally Posted by Susan Otcenas

Those of you with 650s, am I unreasonably concerned about tire/tube availability?

---

What MM_QFC said -- just have to be prepared that ride support or unfamiliar LBS's might not have what you need in a pinch. Luckily hasn't happened to me, but I think I will take the advice to port a spare tire on my next out of town ride.

Since R+E/Rodriguez has made a niche of building small bikes with 650c wheels, they ALWAYS have parts in stock for that wheel size. And they're a 10-minute ride from my house, so it's easy for me to drop in there and get what I need.

My road bike is 650's. It's a gorgeously proportinate bike, too. My previous two road bikes had 700's and they looked odd in comparsion (small frame, big wheels).

I love the 650's and have had really no problems getting tubes. In fact, my first flat on this bike happened as I pulled into a rest stop on a century. The SAG at that stop actually had a 650 tube for me, so I didn't even need to use my own.

If you want fatter tires, finding bigger tubes/tires IS harder. But for a road bike with 23mm tires - it's really never been a problem (in 2.5 years). I do not have fenders on that bike - it only gets ridden in nice weather.

Honestly, in comparison to my commuter that has one 700 and one 24", two 650's is a piece of cake. Of course, if you have wheel troubles, stopping by a fellow cyclists house to borrow a wheel could be harder. Unless, of course, it's my house. ;) :p

Based on your pro and con list, I'd go with the 650s.

as an owner of 650's I would go for the 700. It is hard to find tires. All the cool or useful ones are never in my size. There is never a sale on them and they are never an 'overstocked' item.

I also have bikes with both 700's and 650's - I prefer the 700's. I don't find them aesthetically displeasing at all.....

Tubes - no problems finding 650 tubes, but then again I do live in the big city and have tons of shops to pick from. 650 long stem tubes for my deep V's are a little harder, but still not impossible. If you have to rely on chain stores you probably won't find much.

Tires - definitely less of a selection. My 650 wheel bike is my commuter and getting hold of good puncture proof winter tires was a bit difficult. They always are a special order and many models are not available at all. I had Kendas that I really liked, but they stopped making the 650 size :mad: and I went with Gatorskins, that I don't like as much, when I replaced them.

Rims - the selection actually is kind of sucky.... Yeah you can get high end tri wheels, and they are often cheaper than the same in a 700, (this came in handy for outfitting my TT bike, which is also 650) but try looking for a more heavy duty rim. Like I said my 650 bike is my commuter/winter bike. I found the selection of nice sturdy rims to be sadly lacking

As far as the cons of 700's

I don't find my 700 wheel bike to be odd looking or disproportionate
I don't find the handling of my 700 wheel bike to be twitchy or even any different from that of my 650 bike
I don't have any toe overlap.... (though I will admit to having very small feet)

Hi Susan,
first of all let me throw in a little disclaimer: I am not an expert or a pro, so put whatever I say in perspective.
I would strongly recommend 700c. The advantages are enormous - one above all being the endless choice of wheels and tires for 700c. You can find the best wheelsets in this size, both clinchers and tubulars.
The perceived 'issues' with 700's on small frames are really not a deal in my opinion:
The slower acceleration is rarely an issue - as most pro racers can demonstrate, since they race 700's.
People that suggest 650's to avoid toe overlap make me wonder whether they plan to ride in a parking lot at 4mph. Toe overlap is basically never an issue in road riding because 1-we do not usually steer, and 2-we do not ride slowly enough to even encounter that problem. So that is sort of a myth the way I see it.
I would go with 700c wheels, and pick a wheelset you like.
Oh, and by the way - CONGRATS on your custom build!!! :)

I, as an owner of a Bella Lightspeed with 650c wheels, had little choice for my selection. At 4'10" when I looked for a new road bike, I wanted a bike that fit. I was tired of 'make do' with what was out there. Now, at 4'9.75" or less, I am happy with the 650c's on my bike. I sure wish I could ride a bike with 700c wheels, but I can't:rolleyes:!! or do I say, I shouldn't:( ... I am happy with Bella, because it will be the last road bike I purchase, I hope:rolleyes:/... My mom, bless her heart, had shrunk in inches to 4'6" before she died. My twin still holds out to be 4'11". I know, as I get older, I won't be as tall and at close enough to be 56, I want a bike that will last me until I can no longer ride and that probably means when I am dead because I hope to be riding in some fashion until then:)!!! I am in the market for a new commuter and it has become increasingly difficult to find something that will fit me until I am 65 and hope to retire...I may just save enough pennies for that custom bike :p

I ride a 48cm cervelo RS w 650c wheels. Its the best handling bike I ever had, and there is no toe clip overlap. I have no problem getting tires (love the schwalbe stelvio 23c), and in a pinch you can use a folded over 700c tube. The aesthetics are great too (see pic attached). I posted the pic to make the point that everything on a bike needs to be proportional, so it makes sense that a small frame will have small wheels, shorter reach bars, etc.

If you want wider tires (terry makes a 28c) or do like Deb, and ask your builder to make it so you can swap out 650c and 26" wheelsets.

I think its crazy to build a small frame around 700c wheels unless you require neutral race support that only carries 700c.

Regarding the gearing, its true that the gearing will be lower for the same chain rings, but I found for me it made it easier to gear the bike a tad lower which is great for climbing. Mimi, there is no reason to believe you would work harder with smaller wheels as long as you choose an appropriately sized chain rings and casette.

So, while there are more choices in wheel and tire for 700c, there is no shortage of excellent wheels and tires in 650c, although you may have to mail order.

Wheelsets. Wheelsets. Wheelsets.

700c wheels allows me options and benefits that just aren't possible with 650's. I can borrow wheelsets from teammates to test them out, experiment with types/weights, and get great deals with members of the local community. I've experienced tubulars, deep rims, carbon, ultralights, bladed spokes, you name it -- and marvelled at how the different technologies transform how my bikes roll. Speaking for myself, I know I would be sorely disappointed if I didn't have those options. YMMV.

Reading between the lines. You WANT the 650 bike. So maybe you should just get it. And see what the fuss is about.

Seems the only negative to the 700 is the toe overlap. And aesthetics, PLLLEASE, nothing beats a new ride. Besides you will be on it, not looking at it ride by.

sarah

It a little more complicated than that. Cervelo has some good info. on this at their website, as they offer 48cm riders a choice of the RS w 650c or the R3 with 700c, which they think are the two most accptable solutions, which I agree with: http://www.cervelo.com/bikes.aspx?bike=RS2009#G.

To build a small framed bike with 700c wheels, one of three things have to happen to fit the 700c wheel. One is severe toe clip overlap, which some people think isn't a problem, especially at high speeds on a racing bike, but clearly there are mixed opinions on this, especially for a more multi-use bike (and I have friends that have taken bad falls, or just got sick of always having to think about it, and some of us do need to navigate moving in and out of parking lots a couple times a day or traffic at slow speeds where it is a problem, but this is clearly an issue we will all have to agree to disagree on, it is very personal). There are many good racing bikes built this way, including the R3, blue, etc., so its clearly an option, especially for women who race and want access to a wider variety of high end wheels as blue tree mentioned.

The second option is changes to frame angles to accomodate the larger wheel in an attempt to reduce tco. Usually this means increasing the fork rake to push the front wheel further away from the rider, but this results in a bike that is too stable and handles poorly (I test rode a 50cm trek madonne that had this problem, it was very hard to get it to turn, felt like I was driving a mach truck).

The third option is to build the bike with too long a top tube, and expect the rider to accomdote with a very short stem. This also results in a bike that handles poorly, because it is too twitchy since the steering arc is dramatically reduced. (Or in this situation a rider could also push the saddle too far forward which effects their effeciency and balance on the bike).

SO, pros of 650c wheels are no toe clip overlap and good handling, with a reduced but adequate (at least for most of us) supply of high end wheels.

THe pros of 700s are a wider supply of high end wheels, but either severe toe clip overlap or compromises to the frame geometry that will effect the handling.

From what Susan says she wants this bike to do, I would recommend 650.

To understand better why its hard to fit a 700c wheel in a small framed bike, view the videos here: http://www.terrybicycles.com/videos
especially frame design 1 and 2.

FYI, I pasted this nice explanation from the link I gave above from the cervelo website which I think gives a pretty balanced explanation of the issues (and they do sell 48cm bikes with both wheel sizes):

You will notice three geometric changes on the RS.

Longer headtube, to match the higher handlebar position.
Longer chainstay length. Because a higher handlebar position rotates the rider’s torso and therefore his center of gravity backwards. Longer chainstays ensure the weight distribution between the two wheels remains balanced for optimal handling characteristics.
Eliminated toe-overlap by using 650c wheels for the XS size. Toe overlap is not a problem for experienced riders, but can be intimidating for some. Using 650c wheels in the XS size is the only way to solve this problem without compromising the weight distribution and thus handling. Every solution that eliminates toe-overlap but keeps 700c wheels suffers in handling.
Explanation for the 650c wheel solution on the XS size: A smaller frame means the front wheel moves closer to the rider’s feet, causing toe-overlap. While inconvenient at walking pace, this issue disappears at normal riding speeds as the actual steering angles become very small. There are four ways to deal with this:

1) Accept toe overlap, after all it is not a problem if the rider is aware of it at low speeds, and it does not occur at higher speeds.
2) Use 650c wheels, which allow us to move the wheel closer but thanks to its smaller diameter it will never touch the rider’s toes.
3) Leave the front wheel far out front, but then the weight distribution will not be balanced.
4) Mess up the rider position by moving the rider forward instead of the wheel and handlebar rearward. But a changed position will not be comfortable, and the weight distribution will again be compromised.

Compromised weight distribution and therefore handling make options 3 and 4 unacceptable, leaving options 1 & 2. If you are a racer and neutral support is important, or you want commonality of parts with other 700c bikes, then option 1 is the best solution. We offer this on most of our road bikes. Option 2 is a great solution if you are concerned about toe overlap, never need neutral support and carry a spare for yourself (since your riding partners will likely have only 700c spare tubes, although even those work in a pinch, just fold them in – no problem).

One more point Susan, in your original post you commented the the FIT would be identical with either design, but ask about the *handling* and TCO. Fit just describes your contact points on the bike, basically the points where your bottom, feet and hands contact the bike. You can keep that constant on bikes with many diff geometries (using diff. stems, etc), but the bikes will not always handle or perform the same. On some, you may even have pain if your body is not well balanced. I assune with a custom build both designs that are being proposed will have you balanced, but you need to understand if the only difference will be TCO w the 700c, or there will also be compromises that effect handling.

I certainly agree that choices in geometry affect handling and thus the geometry considerations when considering 700c vs. 650b should also be looked at from a handling perspective.

However, I've gotten the impression from this thread that if you want a 700c wheel on a small bike then you are going to have to live with either a) a horribly sluggish slow steering bike with the wheel way out in front of you b) a horribly twitchy bike or c) some weird compromise in your seat vs. pedals position.

As a 5' tall rider with two 700c road bikes (one an XS Giant and one a 47cm Wilier) I disagree. Yes, the geometry on both bikes is slightly different than the medium versions. However both of them have different handling characteristics that fall well within normal and are in fact adjusted to the purpose of the bike, just like the bigger frame sizes. The Giant is more stable, but it's also an entry level, relaxed geo bike. The Wilier is a race machine and acts every bit of the part, including the quick handling (but not twitchy). I rode quite a few bikes before I bought the Wilier, all of them 700c. I could feel different handling characteristics in most. None of them had horrible handling IMO (I didn't like the Trek for other reasons).

Anyway my point is that yes there are compromises for both wheel sizes. Handling is not necessarily one, especially not to the extremes in some of the other posts. A good builder is able to get the bike to handle the way they (you) want it to, at least in my size (46, 47cm) with either wheel size.

Me, I ride 700c and have no desire to change that.