650 c vs. 700 c

[bfloyd]

Hello all. What are the advantages with 650 c wheels, that most tri bikes come with (?), over 700 c wheels? Sorry for the newbie question, but I never found the answer . . . Thanks.

[P2SL Marc]

The reason most bikes come with 700 wheels is because the frames are too big to accomidate a 650 wheel size. The advantage of a 650 wheel is that it will be light - keeping the overall weight of the bike down. You'll only be able to get a bike with a 650 wheel size if you go into the <52~ sizes.

[Triguy]

It has to do with geometry. Before the days of integrated headtubes and shaped tubes it was hard to build a tri bike on 700 wheels in sizes under 54. Then a bunch of people won races on 650 bikes, so companies made all bikes in 650s. Then we all realized how bad it looked to have 650 bikes in 55-58cm and how it wasn't really needed.

Now it is a geometry thing for smaller bikes. They do spin up faster, but it's basically a wash in almost everyway.

[bfloyd]

The reason most bikes come with 700 wheels is because the frames are too big to accomidate a 650 wheel size. The advantage of a 650 wheel is that it will be light - keeping the overall weight of the bike down. You'll only be able to get a bike with a 650 wheel size if you go into the <52~ sizes.

Thanks. Then those of taller height (say someone who needs a 58 frame size) is unable to get a 650 c bike?

[Talewinds]

Thanks. Then those of taller height (say someone who needs a 58 frame size) is unable to get a 650 c bike?

There's plenty of 650c size frames in sizes like 58, 60, 61 still out there on Ebay, and they can be had for next to nothing compared to the same bike of a 700c.
The downside is this, and I hate to be so superficial, but they look downright stupid. Looks like a folding tri bike.
Also, 650c is a thing of the past already, I wouldn't invest my money in it right now, now they're strictly made for small people/ small bikes.

[Triguy]

I agree with talewinds, I ride them now and you can get ridiculous deals. But 56-58 there isn't a real use to them. If you're bigger and looking for a good deal on a frame check out chucksbikes.com, I believe they have some Jamis tri frames in 56 top tubes.

[Talewinds]

I agree with talewinds, I ride them now and you can get ridiculous deals. But 56-58 there isn't a real use to them. If you're bigger and looking for a good deal on a frame check out chucksbikes.com, I believe they have some Jamis tri frames in 56 top tubes.

I guess I didn't need to be so scathing in my post, but everytime I'm surfing Ebay and come across a wicked deal on a very desirable tri bike in my size, it's undoubtadly a 650c wheel size, that just burns me. Not that I dislike 650c so much, it's just that there are 5 road bikes in my house and in an effort to keep things compatible, all of them are 700c, I'd be dumb to add a 650 to the stable, and I'd love to find a 700c bike at a 650c price, ya know?

[Triguy]

The Jamis frames I mention are 700s.

[Berns]

I think that everyone is on the right track. I'm 5'2" so 650c is the way to go for me. I like the feel for sure. Something else to consider is what you want to really use the bike for. Correct me if I'm wrong but if you ever want to do Time Trials then you'll need to have 700c wheels. If you're strictly going to stay in Triathlons/Duathlons/Multi-Sporting Events, then 650c should be fine.

[Talewinds]

I think that everyone is on the right track. I'm 5'2" so 650c is the way to go for me. I like the feel for sure. Something else to consider is what you want to really use the bike for. Correct me if I'm wrong but if you ever want to do Time Trials then you'll need to have 700c wheels. If you're strictly going to stay in Triathlons/Duathlons/Multi-Sporting Events, then 650c should be fine.

Hey Bernie, that's an AWESOME Zipp you've got!

[^*^BATMAN^*^]

Well the thing with the difference, and why the changes have been made, also have some science behind them. 650 wheels, are lighter, but that weight change is in a vital area. It is in the rim, so it is outside rotating weight. A smaller wheel will accelerate faster, thus people came to think that 650=fast. So that means the 700 wheels spool up slower, BUT!!! because the rotating weight increase on a 700 wheel, it allows the wheel to retain its speed easier. So it means that once you get up to speed(though it may be slightly slower to do so), it is alot easier to keep that speed under a lower power output.

Aesthecics only count for so much, alot of changes in the high end bike manufacturing process isnt always due to the LCF.

[Berns]

Hey Bernie, that's an AWESOME Zipp you've got!


Thank you. You're too kind. I only wish I was as fast as it deserves. ;)


Back on topic:

One other point to consider is part(s) availability. So as the future progresses and evolves the bicycle and technology, it will eventually progress away from 650c wheels (IMHO). This is bad for me because I'm on 650c bikes. Hopefully bike manufactures will continue to work with 650c but... majority rules and that belongs to the 700c.

I hope that helps, and it's coming from someone with 650c wheels.

Take care and good luck.

[merlinextraligh]

Personally, I'd buy a bike with 700c wheels if you can find one to fit you. If you're very small, you might need to go 650c. The performance advantages are a wash, and its alway nice to be using something mainstream, from borrowing a tube on a group ride, to finding a replacement spoke on a trip away from home at a bike shop in the boonies, to selection of wheels, to availability of wheels 10 years from now.

[Ex-rower]

As others have said, the reason to use 650C wheels is geometry. On smaller bikes it allows for less toe overlap with the front wheel, and lets you get lower on the front end.
For example, my P3 (51cm) uses 650C wheels. My position is not achievable on the newer P3C, which uses 700C wheels in my size (well, it might be with a seriously negative-rise stem).

http://www.cbss.ca/images/CBTG2006/15kITT/DSCF0118.JPG