I own both... my road bike has 700c and my tri bike has 650c. On the 650 I'm running 165mm cranks. The trick is finding bikes in these smaller sizes... my 650c bike is a Felt DA1 (2012), which no longer comes in that size. But their B-series tri bikes do. Highly recommend Felt, great bikes. As far as which is better, Rinny rode the DA1 in 2012 on 650c wheels and now rides the IA on 700c. She seems to have done just fine either way, ;)

I'm 5' 4" been riding 650c since 1996 and LOVE them. Really not intending to ever go to 700 (unless the industry forces me to).
One reason that I will stick to my P3 and not upgrade to a P5, is my size is 48 and cervelo now do this in 700.
They do the smaller size (45) in 650. Trek make their 45 bikes with 700 wheels and having seen them - they look like a bar jammed on a pair of wheels - literally. Can't imagine that the handling is ideal. I know that they have to compromise the original design geometry in order to do this.

Just my 2 cents.

For your height, there are lots of fit reasons to go 650C if at all possible.

However, that is IF you can find the appropriate race wheels, training wheels, race tires, and training tires.
And that is not a trivial consideration.
The right tires and wheels are important

---

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
--

To a very large extent pro athletes ride what they are sponsored for ( it is how they make their living)
One example, from waaay back is Lori Bowdon who won Hawaii twice. Both times she won she was on a Cheetah. But mostly she was sponsored by Specialized and so for most Hawaii's she rode Specialized. The other lady who was winning a lot back then, Natascha Badman, rode a Cheetah. I always wondered why Lori chose not to ride the Cheetah more often?

Jess,

My wife is your size and has ridden an extra small 650c wheeled Trek Speed Concept to Kona twice. It is absolutely a dream to ride stability wise particularly in strong and gusty wind. She still holds her age group bike course record at IMSA set on a hellaciously windy day back in 2012.

Both Zipp and HED make excellent aero wheels in 650 and tires are not a problem either if do just a time bit of preplanning. Latex tubes are not currently made but you use 700cs without much hassle. For your size 700c is just silly. Although I love both her and Jim Felt, Rinny looks like she's riding her big brothers bike with the 700cs.

Hugh

---

Genetics load the gun, lifestyle pulls the trigger.

are you thinking of our road bikes? our smallest Speed Concept (OP asked about tri bikes) is designed around 650c wheels and the handling-related geometry (e.g. trail) is almost exactly the same as the 700c SCs. no compromises :-)

---

Carl Matson

I think the geometry and fit of bikes with 650 wheels is much better for those of us on the smaller end of the height scale. I ride a 47 Cannondale Slice on 650s and love them. Rinny used to ride a size 47 slice with 650s when she was sponsored by Cannondale, so it's a perfectly fine bike if it fits you.

There is a bit of a logistical complication with 650 wheels. I can't borrow my boyfriends race wheels, or use the same set of race wheels for my road bike since it has 700 wheels. If you get a flat, you better be carrying your own tube because no one else's will fit yours. If you have some major mechanical with your wheel or tire on race morning, people will offer to let you borrow an extra wheel but they will all be the wrong size. These have all happened to me, but certainly can be mitigated by proper preparation. I make sure to bring my own extra tubes/tires/wheels to any race.

You have fewer choices in equipment, but I'm more of a "competitive on a budget" athlete than someone who needs very particular specs in wheels. I've actually done really well buying used disc/aero wheels because there's such a small market of buyers, the sellers are desperate to sell for even a very low price. Goes the other way if you like to buy new and resell for an upgrade though. The big tire mfgs all make most popular tires in 650, so that's never seemed like much of an issue to me.

---

http://trainingwheelsrequired.wordpress.com
@KellyNCollier

Yes, your road bikes.

The DA1 comes in a 47 (650)

It's in the drop down list here:
http://www.feltbicycles.com/...es/frameset-da1.aspx

While it's not in the dropdown list here, it is in the frame geometry chart
http://www.feltbicycles.com/...I/DA-Series/da1.aspx

The more I read about geometry, advantages & disadvantages of switching to 700 CC, the more I get to the same conclusion... it's smarter to keep my 650 cc frame. Maybe I can look for options to upgrade my headset from aluminum to carbon or find a nice pair of wheels. Thanks for the responses!

Ah, there you go. My mistake -- I neglected to look at the standalone frameset sizes. Good on them for still offering the option.

You can use a 700 tube in a 650 wheel. Couple of weeks ago I had 3 punctures and 2 tubes. Borrowed a 700 tube and put a fold in it at furthest point away from valve.

Worth knowing in an emergency. It will get you home and ride smooth but I wouldn't do it by choice!

In fact many riders of 650c wheel enfold a 700c latex tube so they too can ride get the benefit of lower rolling resistance.

Hugh

---

Genetics load the gun, lifestyle pulls the trigger.

Yeah, I'm used to carrying 3 spare tubes for that same reason.

Even though is a hassle to be one of the few with 650cc, I want to make sure I'm on the right bike without compromising performance.

Has anybody change their aerobars lately? That's the only piece on my bike that is aluminum and was thinking of upgrading them to carbon.

Upgrading and cleaning up your bike will probably be the most beneficial depending on what your setup looks like. A good fit, fast wheels and tires, a clean aerobar and some clean cable routing will put you right up there in terms of being aero. That would personally be my choice.

You can pick up 650c Zipp discs for $500, $300 for an aerobar (Felt Devox Bayonet), $200 for a fit, and $100 or so to have your bike cables replaced and cleaned up. Of course if your pockets are deeper you can go with the new TriRig setup (Alpha - super aero bar, Sigma - aero stem, and Omega - aero front brake).

I'm 5'4", on a 48cm P3C from 2007 with 650c wheels. I'm really disappointed that Cervelo switched their 48cm bike to 700. I'd happily buy a new P3C, if only Cervelo still made their 48cm model in a 650cc wheel size. Instead, I'm going to ride my bike into the ground and not upgrade, because I really love the fit and feel of the bike on 650s. Years ago, I purchased a custom Serotta road bike that I had to get with 700c wheels, because they didn't offer 650s in that frame size, and I HATED it. Way too much toe overlap with the front wheel, and it just didn't feel "right."

What's interesting is if you go to the Cervelo website, they have a writeup on 650 vs 700. It states that there can be several advantages to 650s over 700s for smaller riders, but then goes on to say that Cervelo only offers its 48cm in 700, because of wheel/tire availability. To me, that's a chicken and egg argument. Their decision to move away from 650s makes it that much harder for those of us who love 650s to find them. But, Michelin race tires still come in 650s, as do Continentals and Kendas. Several manufacturers make 650 tubes. I've got Hed race wheels, and as others have said, Zipp also makes race wheels in 650 sizes. I'd love to know which manufacturers still make 48cm tri bikes with a 650 wheelbase. When I do finally upgrade, those are the manufacturers I'll be looking at.

You exactly echo my thoughts. I've read that white paper too :-)
Moreover Cervelo seemed. to indicate that the decision to go to 700 wheels on the 48 was 'market driven' - not engineering.
What a shame.

My only beef with the NP2 to NP5 is that on the 45 they shortened the Front Center to 553 and that is just a little shorter than the 568 on the older 48 P2. They also lengthened the rear center, I don't know why except to maybe accomodate the fairing around the rear wheel.

It's a minor issue and would not stop me from buying any of those bikes.

What I do like is that they lowered the stack on the 45...a lot. With the head tube being 21mm shorter I would be able to get a lot lower on that/those bike(s). They did give it a little more BB drop but that short head tube more than makes up for it.

jaretj

26 vs 29er again?!?

Oh sorry, wrong forum ;)

All the best in finding a new ride!

My wife is your size and went through a similar decision last year. She ultimately went with 650's on the new Speed Concept. Loves it, no regrets, and her bike splits have improved.

You guys have been a huge help on my decision. This is my first time posting in this forum and I'm impressed by the quick and honest responses from people.
I'll stick with 650cc and make some upgrades to my current frame. Looking at the Cervelo P5 45 frame and it's just a super nice frame but $7K for it?!!
I will check out the speed concept.

At 5'10" and riding a 54cm road bike, I truly LOVE having 650c's on my tri bike. Even at my height there are advantages to the 650 size when the seat tube angle is steep.

The only reason to go to 700's is if you're road racing and need to swap wheels from neutral support.

BTW -- J&B Importers has 650cx25mm tires listed in stock.

---

---------------------------------------------------------------------
Some are born to move the world to live their fantasies...

https://triomultisport.com/
http://www.mjolnircycles.com/

Have you looked at the felt da or b2? Both do 650 for 47cm frames

Look at the cervelo P3/P2, put a fast aero bar on it and it is very very close to the P5. Speed concept is another good choice. A P3/P2 with a great aero bar is probably going to be pretty close the speed concept and both would probably be faster than Felt DA with its carbon aero bar.