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tri bike with wheels 650c vs 700c
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 2009-11-15 8:27 AM |
New user 52 |  Subject: tri bike with wheels 650c vs 700cI am looking at getting a Tri bike and am 5 ft 5 inches tall with an average build. Depending on the brand, I think I'll end up with a bike 50 or 51 cm. I notice that some of the bikes that size come with wheels 650c versus 700c. The P2C size 51 for example comes with size 700 wheels, while the Felt B12 size 50 comes with size 650 wheels. For those of you around 5 feet 5 inches and an average build, what size Tri bike to you ride? Basic physics I think tells me (all else being equal) that I'm better off with the larger wheel (cover more distance with the same power. Right? If a slightly smaller frame means a more aero fit, does that offset any potential disadvantage of a smaller wheel? I'm going to be working with a good Tri store, but would like some opinions/thoughts aside from the one coming from the person who is selling me the bike. |
| 2009-11-15 8:48 AM in reply to: #2514549 |
Expert 774  | Subject: RE: tri bike with wheels 650c vs 700c jtm3 - 2009-11-15 8:27 AM I am looking at getting a Tri bike and am 5 ft 5 inches tall with an average build. Depending on the brand, I think I'll end up with a bike 50 or 51 cm. I notice that some of the bikes that size come with wheels 650c versus 700c. The P2C size 51 for example comes with size 700 wheels, while the Felt B12 size 50 comes with size 650 wheels. For those of you around 5 feet 5 inches and an average build, what size Tri bike to you ride? Basic physics I think tells me (all else being equal) that I'm better off with the larger wheel (cover more distance with the same power. Right? Nope. Wheel size difference between a 650 and 700 has an insignificant effect on power. If a slightly smaller frame means a more aero fit, does that offset any potential disadvantage of a smaller wheel? If by more aero fit you mean that the smaller frame fits you better and allows you to ride more aero, then that will imo offset the disadvantages of the rarer 650 tubes and tires which have harder to find tires and tubes, less interchangeability with other bikes, less options for tubes and tires, etc. That is why you find 650 on smaller frame bikes but 700 on almost all current larger frame bikes. |
| 2009-11-15 9:12 AM in reply to: #2514549 |
Expert 1233 | Subject: RE: tri bike with wheels 650c vs 700c I'm 5' 9" and my kestrel uses 650c wheels. My other tri bikes use 700c. I have aero wheels, 650c hed3 on the kestrel, and 700c zipp 808's on my other bike. I can't tell any difference due to wheel size. 650c wheels are lighter compared to the same 700c wheels, and because they are slightly smaller, help out with the problem of the tire hitting the seat tube in a smaller frame with a tri geometry. I hear about trouble getting tubes and tires, but I have never had any problems, and they actually have been cheaper than what I paid for 700c tubes and tires. The worse thing you could do is get a bike that's too big for you, or doesn't fit or feel right. Since you're working with a good tri store, try out various models, and get a bike fit. 650c wheels, tires, and tubes, will continued to be made, as you have noted that they are still on current models, also recumbents use this size. Don't worry, in another 5 years a new size wheel will be out and people will still be asking this question, along with the new size. |
| 2009-11-15 9:17 AM in reply to: #2514549 |
Master 1517 Raleigh | Subject: RE: tri bike with wheels 650c vs 700c I'm 5'5''. I'm riding a Cervelo Dual (48) with 650c wheels. For your height, I'd most likely recommend a size 48 bike. I have a Cannondale r1000 thats a 51 w/ 700c wheels and its a smidge big for me. 48 seems to be perfect overall. |
| 2009-11-15 9:50 AM in reply to: #2514549 |
Champion 7547  Albuquerque, New Mexico Bronze member | Subject: RE: tri bike with wheels 650c vs 700c jtm3 - 2009-11-15 8:27 AM I am looking at getting a Tri bike and am 5 ft 5 inches tall with an average build. Depending on the brand, I think I'll end up with a bike 50 or 51 cm. I notice that some of the bikes that size come with wheels 650c versus 700c. The P2C size 51 for example comes with size 700 wheels, while the Felt B12 size 50 comes with size 650 wheels. For those of you around 5 feet 5 inches and an average build, what size Tri bike to you ride? Basic physics I think tells me (all else being equal) that I'm better off with the larger wheel (cover more distance with the same power. Right? Nope. There are some second/third-order effects of wheel size. 650's are slightly more aerodynamic (smaller diameter) and usually far more responsive for accelerations due to their lighter weight (smaller diameter). 700's have slightly lower rolling resistance due to the larger diameter and the amount of tire deformation associated with the larger diameter. If you've got the power to push 19.6 mph at a cadence of 90 rpm, your bike shop could put you on a bike with 700 wheels and select standard gearing of 39-14 or 53-19 or compact gearing of 36-13 or 50-18 or 650 wheels and 39-13 gearing and you couldn't really tell the difference. (All of these wheel/gear combinations give you 19.5--19.7 mph.). 15 years ago, when 650 wheels were the rage, TT/Tri bikes might come with 54/42 or 55/42 chainrings to compensate for the smaller wheels. If a slightly smaller frame means a more aero fit, does that offset any potential disadvantage of a smaller wheel? I'm going to be working with a good Tri store, but would like some opinions/thoughts aside from the one coming from the person who is selling me the bike. Wheel and tire selection for 650 wheels are more limited, and since most roadies are set up with 700 wheels, you need to be self-sufficient on rides, but plan ahead and keep a few tubes and maybe an extra tire on hand. Because 650's are somewhat "unloved" you can usually find great deals on used race wheels. (Not "race wheels" but I picked up a set of Bontrager Select 650's including Michelin Pro3 tires for $100 last winter. ) |
| 2009-11-15 9:59 AM in reply to: #2514549 |
Master 1702 Southern Ontario | Subject: RE: tri bike with wheels 650c vs 700c I have 650s on my tri bike that I just bought (which also something I questioned before I bought it) and 700s on my road bike. Quite frankly I wouldn't know the difference if it wasn't pointed out to me. My tri bike is faster - but I think that's because it fits me properly. I'm 5'7" and riding a 51cm Cervelo P2K. My road bike is a 54 Devinci Chicane. As other posters have mentioned - you'll need to be self-sufficient. I carry my own tubes and a dollar bill in case of sidewall tear. Obviously no one I ride with has 650s. Someting to consider: Tires range in price from 26$ for the Kenda cheapy I have to 75$ for my Michelin Pro Race 3s - but there are NO colour options for 650s. So you're stuck with black or grey. (I have one blue and one yellow on my road bike - and I'd like to be able to have loud colourful tires - but it wasn't a dealbreaker for me.) Honestly - I don't know what all the stink is about. I understand the physics and all - but really - isn't it the motor not the bike? Sure - 650s are older technology. Yup they apparently are beneficial in acceleration but not so much over long distances. Is it going to make a significant difference in your performance. Probably not. If it fits you and you like it I'd buy it. |
| 2009-11-15 10:10 AM in reply to: #2514549 |
Expert 697 Northern CA | Subject: RE: tri bike with wheels 650c vs 700c Not all smaller frames come with 650s as well. I have a 44" frame and my wheels are 700. I like that because it's more standard so I can borrow tubes if I'm having a bad day with lots of flats. |
| 2009-11-15 6:33 PM in reply to: #2514549 |
Master 1494 Kingston Ontario | Subject: RE: tri bike with wheels 650c vs 700c My road bike has 700's, my tri bike has 650's. I have noticed no difference in speed. However, I am more comfortable on my tri bike, which fits a bit better and this makes a huge difference in how long I can ride. Fit IS key! Wow, how did your 44" frame hold 700's?? Guru swore up and down that they couldn't make mine with 700's and it's a 46"...must be different geometry And yes, carry extra tubes with 650's. I had a two flat day once in a group of 25 and that was the end of riding
Edited by keepitup 2009-11-15 6:36 PM |
| 2009-11-15 7:20 PM in reply to: #2514549 |
Master 2094 | Subject: RE: tri bike with wheels 650c vs 700c I wouldn't hesitate at all in getting 650s. There are a lot of practical and theory-logical advantages. The down side came when they were being used on really large frames. My wife has a 48 cm P3 and I have never had a problem finding tubes and tires. Unfortunately keeping her bike running is one of my duties |
| 2009-11-15 10:47 PM in reply to: #2514549 |
Extreme Veteran 662 Sunny San Diego | Subject: RE: tri bike with wheels 650c vs 700c Climbing may be easier with 650c. I feel like I can climb just as well on my Cervelo P2C with 650c and standard cranks compared to my road bike with 700c and compact cranks. We are about the same height. I wanted to buy a tri bike with 700c wheels, but it seemed the small tri bikes with 700c have limitations with their geometry such as toe overlap and the ability to achieve an aggressive and comfortable aero position. There are ways around it, like super short stems or aero bars where the pads are behind the base bar but then handling might be compromised. . |
| 2009-11-16 9:27 AM in reply to: #2514549 |
Pro 5011 Twin Cities | Subject: RE: tri bike with wheels 650c vs 700c There are plusses and minuses to each--one accelerates a bit quicker, one holds speed a bit better, one weighs more, one is cheaper to find race wheels for, etc. Really, just buy the bike you want and let it have whatever wheels it has. That woudl be my .02. (FWIW, having ridden both and owned both...I wish that they still madfe bikes in my size in 650. I miss mine.) |
| 2009-11-16 9:37 AM in reply to: #2514549 |
Member 53 Nor Cal - Bay Area | Subject: RE: tri bike with wheels 650c vs 700c Not sure if this has been mentioned, but with a small frame, and 700 wheels, there is higher likelihood of your foot hitting the wheel when making slower speed turns. This can be embarrassing, when you fall in the parking lot:-) I would follow the LBS/manufacturer advice. If they use a 650 wheel there is a reason. The other issues (aero, weight, etc.) are not of any serious consequence (IMO). John Edited by johnrsims 2009-11-16 9:38 AM |
| 2009-11-16 10:33 AM in reply to: #2514549 |
| Veteran 867 Vicksburg | Subject: RE: tri bike with wheels 650c vs 700c I have a 700 road bike and a 650 P2, I love my 650 bike. It is alot lighter, accelerates very fast and as far as tubes and tyres just order off Probike kit and problem solved. You can buy race wheels cheap, I got a set of trispokes for 600 with tires on them. By the way I am a medium build guy that is 5'4". |
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