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oceanrider 07-28-02 03:29 PM

26" vs. 650cm
What's the difference on these tire/wheels sizes? Is it comparable to 27" vs. 700cm?

mechBgon 07-28-02 04:10 PM

650C is commonly used on triathalon and time-trial bikes, since the theory is that their smaller frontal area makes them cruise faster than 700C. Bigger chainrings are usually used to make up for their smaller circumference.

26" is more commonly used to refer to mountain/all-terrain/city-bike wheels and tires. They have a different bead-seat diameter than 650C does, so they're not interchangeable. 650C is sometimes referred to as 26" as well.

Are you considering a bike based on 650C wheels?

oceanrider 07-28-02 04:47 PM

Yes, I am. I'm thinking WSD road bikes which are 650's and wondering how the wheels themselves (besides the tires) differ from MTB's. I'm also thinking of making modifications to my comfort mountain bike to make it more road/touring efficient for longer distance riding. This is what happens when you have a lot of time on your hands. You think weird thoughts, right?

mechBgon 07-28-02 05:15 PM

The main downsides I could see with 650C would be that spare parts are harder to get if you're on a tour or at a remote event, etc. Wouldn't hurt to bring your own spare tire and the proper lengths of replacement spokes, if so.

The "road 26in" or 650C use a bead-seat diameter of 584mm edit: oops, it's 571mm, my bad, if I remember correctly, while the "mountain 26in" use 559mm. There are some pretty fast tires available for mountain bikes, like the 195-gram Continental Grand Prix MTB, if the bike's rims are narrow enough to jive with them. Combined with the appropriately-sized tube, a pair of these can lop between 1 1/2 and 2 pounds of rotating weight off a typical mountain bike, all of it at the rim where it matters most.

A side effect of the small tires is that the bike will sit much closer to the ground than it was designed to, so you could catch a pedal while cornering when you ordinarily wouldn't. Naturally, this tire would also be more susceptible to pinch flats and punctures because of the small casing and thin tread. Also, the rims on a comfort-class mountain bike are typically too wide to consider the Grand Prix MTB. Something like a 1.25" to 1.5" width might be a good bet.

D*Alex 07-28-02 06:00 PM

Actually, there are a half-dozen different 26" diameters, according to Sheldon Brown. If you are sticking to the 'road' 26" size, though, yes, they are smaller. This size is usually used for smaller road bikes (for people shorter than, say, 5'2"), and for the front wheels of track bikes. This is usually a hard size to find on the road, and the selection of tyres is limited.

MichaelW 07-29-02 03:08 AM

650c are useful for small competition bikes and very light fast day touring bikes. The range of tyre sizes is quite small and they are all narrow, and only specialist shops stock them.

26" (MTB) size is better for pretty much anything else. You can use MTB rims on road hubs. Lightweight rims are available, and tyres size ranges from 1" (ie 25mm) upwards.

Its true that using 1" tyres on a bike designed for 2" ones will lower the bike, but most MTBs are built with high bottom brackets anyway. Purpose built road-touring bikes (like the Thorn range from SJSCycles) are designed from the ground up for fast road riding using medium sized mtb slicks.

You can't easily swap between 650c and 26"MTB wheels, the braking surfaces are at slightly different diameters, and usually the rear axle width is different. If you want to mess with braking systems, you can convert, but its not worthwhile. Better to get a lightweight MTB wheelset and narrow slicks.

The other 26" sizes, such as 650B are of no consequence, you cant readily get rims or tyres for them, and they are for collectors (or Frenchmen) only.

mechBgon 07-29-02 09:02 AM

Hehe, I also want to add that 650B has been a thorn in the side of American mechanics since... let's see, I believe it was 1990, when Schwinn used 650B rims and tires on the Frontier and Mirada city-mountain bikes. To this day, many shops stock the funky "26 x 1 1/2" tires to fit these, and often the wheels as well. The 1 1/2" designation is mathematically the same as 1.5", of course, but the fractional format indicates it's the "special" tire.

Schwinn's reason for using them? They had begun importing bicycles from China, and the tarrif was higher for bicycles with more than xx millimeters of space between the seatstays at the tire area (this was an attempt to tax mountain bikes more heavily than others). Schwinn built a frame that met the lower tax bracket, but looked enough like a mountain bike to sell. To ensure that no one could attempt to put in bigger tires than the frame would take, they used the 650B wheel and only provided one tire.

GT tried adopting 650B and calling it "700D" about a year later, on a couple models whose names I've forgotten. Anyway, that's my trivia contribution for the day :)

oceanrider 07-29-02 09:28 AM

Those Continental Grand Prix MTB tires look real impressive. A bit on the pricey side at 35 each but just what I'm looking for. My LBS ordered a set so I can try em out. I have Bontrager 750 rims which should accommodate the 1" width according to the Continental people. We'll see. Thanks for the info MechBgon.

lovemyswift 07-29-02 06:35 PM

I've ridden 650c's wheels for 7 years now. Because of the WSD bikes more of the sag wagons are stocking tubes and tires on tours. But you don't know that until you get to the tour so I always have a foldable tire and extra tubes with me.

I don't know about other shops in this area but the shop I use always has tubes and tires for me or they will order some in for me. Also, the shop built the wheels for me, they are Mavic Open Pro's. They discouraged me from carrying extra spokes because I'm such a lightweight! They actually laughed at me when I suggested the need!

In 7 years I've only ruined 1 tire and that was on my local bike trail.

If you're considering an aluminum frame remember that aluminum gets very stiff as it gets small and I'm not sure that the components are as good as you can get for the price. So think about your goals. If you plan to only ride 20 - 30 milers you'll be ok. As I grew in my riding and started doing metric centuries etc. and tours the aluminum frame was wearing me out and beating me to death. I'm much happier on carbon fiber and the bike I have now will be the last one.

If you plan to start with something cheap and move up later go for the WSD. But if you plan to stay with the bike for a long time then you should also consider a small steel or CF frame. Just be aware that some of these companies make the standover height shorter but the TT lengths still can be to long.

I was looking at an Italian company called Orbea. They had steel framesets starting around $500 - $600, then you put the components on it that you want. They had 46cm but the TT looked long, at least for me. I think this is a more fun way to go because you get exactly what you need, not what some company run by men think you need!

If you want a good book to read while your rehabing I recommend Gale Berhardt's book "The Female Cyclist, Gearing up a level". Published by Velo Press. It's full of info for women cyclists, including training plans. It's my training bible, so to speak.

Have fun dreaming, good luck with the rehab and remember "this too shall pass" and you'll be back on the bike again soon.

oceanrider 07-29-02 08:00 PM

Thanks for the experienced feminine viewpoint. You're absolutely correct about focusing on determining the goals here. I know I love distance first, speed second. More and more I'm looking at the two bikes I have; one is a steel vintage road bike and the other started out as a comfort bike but when I get finished with it, it should be pretty road worthy.

The road bike is a sport touring Nishiki with a hi10 step through frame that most people here have told me is not worth the money it would take to bring the components to my desired specs. Funny, but in my opinion, the frame is the best thing about the bike. I don't care about the step through one way or another. This bike fits and I like the feel of the ride I get on it. I'm seriously thinking about first finishing my modifications on the Trek and then moving on to the Nishiki. Money's tight and I don't want to keep buying entry level bikes. I already have two!!

Despite all the bad rap on ladies or mixte frames (and there is a difference), that top tube that's a problem with so many of us women isn't an issue. I know it looks wimpy but that's a western bias.

mechBgon 07-30-02 09:23 AM

oceanrider, I'll be really interested to hear your impressions on those Continentals. They should accelerate really fast, and since they plow a much narrower path through the air, hopefully they will cruise fast too. :) Keep us posted!

Feldman 07-30-02 05:19 PM

Another thing: Terry is showing a 650c x 28 tire in their catalog.
This seems like a good thing as not every cyclist who needs a small-wheeled road bike wants as racy a tire as what has previously been available. Another question here; why are US market bikes with the smallest frames NOT spec'ed with 559mm (26") rims and tires as the variety of available rubber is tremendous; Rivendell seems to be the only company with a clue on this. I'd also be curious, light women, is a bike with 650 x 23 tires and a stiff aluminum frame really and truly more comfortable when you only weigh 90 to 110 pounds? It seems like the spec on a lot of "womens' specific" small road bikes is really stupid for a light person--you'd think they would use non-aero rims and light butted spokes to build the wheels, and the lightest steel tubed frame possible, for ride comfort. Am I missing something or am I really smarter than the product development schlongs at the bike companies?

lovemyswift 07-30-02 06:46 PM

This is my gripe with The WSD bikes. An aluminum compact frame with 650 X 23 wheels is most uncomfortable bike a 100 lb person will ever ride. If the road is rough you feel the vibrations through your whole body. I used to feel like I was running a jack hammer all day. On rough road I'd have to cut my speed 3-4 mph because I was asorbing all of the road shock.

I bought my Cannondale compact in 95 because it was a much better fit than what I was riding. Right before I got the Aegis I put Mavic Open Pro wheels on it and got a better ride but I'm not sure any wheels or tires will make an aluminum frame comfortable for a small person.

I put a cf fork on the Cannondale. That helped for a while. I also had to put Terry handlebars with the indentions so I could reach the brakes.

One day I was looking at the Aegis website and found a shop here that sold them. I wanted to see if there was really a difference. They had one small enough for me to try. Even though it was too big the ride was awesome. I could tell before I left the parking lot!

Some of the other stupid things the manufactures do is put regular reach handlebars and a 53 X 39 crankset on them. I needed shortreach handlbars and a 51 X 38 crankset is more efficient for me. They also put on shimano components which are very uncomfortable for small hands and no one has bothered to manufacture small shifters.

When I was on a tour last year there was a Trek rep pushing the CF Postal bikes. I asked why they didn't make a small one. The rep said there would be no market for it! I showed him my Aegis. He said that they are a small company and they can take the risk to build bikes like that. A big company like Trek can't?

I was disappointed that Wylder ( a woman run company) is making their road and mtn bikes in aluminum. They do have a Ti frame.

Aegis is the only company that I have found that makes a quality frame for small, lightweight people. Some of the better companies make small frames but either the standover height is wrong for me or the tt is too long.

In defense of my Cannondale, I rode it for 5 years. Because it was a better fit I rode more and farther. When it came time to build up my Aegis Swift I knew exactly what I needed in a bike
and guided my shop in building it.

I can ride my Swift with 120 lbs in the tires and barely feel the road.

Maybe the newer aluminum frames are better but I'm sticking with cf and steel from now on!

Feldman 07-30-02 07:24 PM

I have a bike repair business, most of my customers are triathletes and roadies and many have high end bikes. The three or four Aegis owners who have me do their work love those bikes! With your small hands, take a cue from the triathletes and technology skeptics (yeah, I know, a weird combination!) and ditch the STI shifters, switch to bar end shifters and Dia Compe short reach brake levers. The problem with dual-control shifters isn't just the length of the levers, it's the sweep of the shift control especially for front shifts. It isn't absolutely necessary to have dual-controls on a road bike--for many riders and many situations there are other things that can work much better!
Especially with triple front chainrings, dual-controls can become another torture device for small cyclists.

Feldman 07-30-02 07:26 PM

PS, two Northwestern brands who do well fitting small riders are Rodriguez and Lyon. Rodriguez: R&E Cycles, 206-527-4822, Lyon 541-476-7092

oceanrider 07-30-02 07:40 PM

Lovemyswift and Feldman, do you get the feeling that the leading manufacturers are making a few "token" bikes for women and charging us up the wazoo for less is more? Also, and this is a bit off subject, does your LBS take you as seriously as the guy who walks in and drops the same dime? I've had several experiences like that and only one of the guys discounts my purchases despite the money I've dropped there. I recently started looking at stuff at another LBS and the guy treated me like royalty when he took a look at my 2002 Trek ride. I've already decided if I do buy a new bike, it won't be at my current LBS.

lovemyswift 07-30-02 07:41 PM

Thanks for the advice.

I use a double crankset and Campy components. Campy hoods are much more comfortable. I switched the Terry handlbars for the Deda 4 girls short reach handlebars and the reach problems were pretty much resolved.

I had to get a Specialities TA crankset to use the Campy components because Campy didn't make a 165 crankarm.

This bike was truly designed for me and I love it!

Feldman 07-30-02 08:16 PM

I am a middle-aged male bike business lifer and worked in a large bike store in the nearest city to me for twenty years before starting my own home=based and mobile repair business. The Big Bike Companies design every model around two concerns--how the bike will feel on a parking-lot test ride (they want purchases based on quick impressions) and the coolness factors of the moment. What you end up with is a racing bike designed for a 20 to 40 year old fit 150 lb. man of medium height, available with triple chainrings so that someone can delude themself into thinking that it might also be good for touring! Bicycles for larger and smaller riders are compromised because the marketing parasites at the Big Bike Companies are scared to death of asking dealers to have to explain why different sizes in the same model are equipped differently. I once asked a product planner for the Big Midwestern Bike Company why they couldn't spec 36 spoke wheels on 58cm and larger road bikes--you'd think I asked if I could cook his cat for dinner! These idiots are scared to death of any spec change that would either add so much as an ounce of weight to a bike, or use a component that some ignorant shopper would perceive as "retro" or "obsolete."
My thirty-plus years of experience tell me that these people truly do not care about the end user's experience with the product as much as how many stars the Stupid Slick Paper Magazine's road tester gives the bike! I agree that the womens' specific bikes are token gestures--those bikes would look very different if they were truly designed and spec'ed for smaller, lighter riders. And I forgot about TA cranks--they manufacture their excellent Zefir and Alize sets down to 150mm. Wouldn't you know it--the only US bike manufacturer that has used them on a production bike is Terry!

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