Google sponsored links
Why do cyclocross bikes have a double instead of a triple? In fact, why don't all bikes just come with 30 gears? It seems like all it could do is help. Unless you are doing a fixed gear for crazy fitness reasons. But then again I've seen a lot of used, hand-made, $1000, fixed-gear cyclocross bikes out there. Why? I don't get it.
This is an archived thread, you can find the full version of this thread, with images, links and more content
here.
Ready to buy? Check out these two online bike stores:
-
http://www.nashbar.com (you can find the latest bike nashbar coupons in
this thread)
-
http://www.performancebike.com (you can find the latest performance bike coupons in
this thread)
Cya on the forums,
- The BikeForums Team
-
http://www.bikeforums.net
less weight, less stuff to break.
Then why buy a bike at all, why not just walk? That's a ridiculous thing for me to say, but really it seems like buying an Ultegra single or whatever to me is just a waste because you're missing out on more options for gears. There has to be something else.
Then why buy a bike at all, why not just walk? That's a ridiculous thing for me to say, but really it seems like buying an Ultegra single or whatever to me is just a waste because you're missing out on more options for gears. There has to be something else.
Ok, I'll bite. Why?
Triples suck. They're heavy, difficult to tune and they usually end up providing a bunch of gears that are nearly worthless or over-lapping gears that you could get with a regular double.
I don't know of any Ultegra singles out there, they only make a double and a triple. The people I know with singles are all people who ride fixed or single-speed, and they have their own reasons for that.
If you're asking why one would ride a 1x9 or such, the reason is because they usually feel that the nine speeds provided is enough for racing, and because riding without a second or third chainring greatly reduces the risk that you'll drop your chain, which is easy to do when you throw your bike around like you do in CX.
I suddenly feel like I am attacking the bike community, which was not my intention! I'm just coming back to biking and realized how much I don't know, so I'm asking a bunch of questions.
Your point is well taken, people buy bikes for different reasons: fitness, commuting, racing, etc. And then there are the freaky purists. I guess my reason is touring and commuting so it makes sense for me to have a bunch of gears. I've never raced, so racing probably is all about being in the highest gear for most of the time. Apologies jhota! And thanks to both of you for the replies!
Even better, thanks bonechilling.
Triples suck. They're heavy, difficult to tune and they usually end up providing a bunch of gears that are nearly worthless or over-lapping gears that you could get with a regular double.
+1 Triples are a PITA. If I ever went back to a triple I would only do it with a barcon or other friction shifter. Also, the compact double gets a close range while eliminating some redundancy.
Between the overlap and the unusable gear combinations, a so-called 30-speed bike does not really have 30 gear options. I raced cyclocross with a 1x8 drive train and probably only used 5 of my gear options, though were I in better shape I probably could have used a few more. Keeping things simple is lighter, cleaner, and more reliable.
I ride fixed gear and single speeds too. There are definitely times when I would like to be able to shift, but having just the one gear is really quite liberating. It's hard to describe, so I will leave it to those more eloquent then myself. If you are at all curious, I highly recommend giving it a try.
I'm building a fixed/ss CX bike later this summer because i'm hoping the single speed race catergory won't be as competitive... :p
Well tomorrow morning I go to look at a used 2005 Kona Jake. One of the reasons I was interested was because it has a triple, as opposed to the much more expensive (and new) Redline, which has a double. Now I'm wondering if I should even get a triple. Hmmm, you guys have got me thinking again, which is something I try to avoid doing as much as possible.
I want a cross so that I can have one bike to go lose road races, sprint triathlons, and cyclocross races as well as commute and get around for fitness. But I certainly don't want a tank.
This decision keeps getting more difficult. If I get it and decide to go more simple with a double or single, how much is a "middle-of-the-road" gearset or whatever you would call it? I know that I should be able to just look online, but I honestly don't know what the gears are called.
Can you tell I'm new to this?
Triples are a pain to tune, and offer redundant gears. My 46/36 compact chainrings with a 12-25 cassette gives me from the mid 30's to over 100 gear inches, which is plenty of range, and I don't find myself wishing I had a finer selection. Maybe if I was doing some heavily loaded touring, somewhere outside of Florida where there are things called "mountains", I might want something lower, but I'd just put a wider range cassette or 34t chainring in there for that.
First off, triples don't suck. If properly adjusted, they work fine. I've had quite a few bikes with triples and they worked fine. Just as good as the doubles I've had. That being said, I think it depends more on the terrain you're planning on riding. Got some good 6% grades you want to ride? You'll love that triple. Live in a place like Florida, skip the triple. If you have a bike that you really like and it has a triple, get it. Learn how to adjust the gearing and you'll have no issues with that setup.
The thing with having one bike to do all those things is you'll have to be that much better in order to be competitive. A cross bike that is not a race oriented bike will be ok to good at all types of riding, but not great at any.
This is what I did. I got rid of my road only bike and got a Tricross Sport. It's got a triple and works fine. It won't win any races, but it'll get me places. As I've once heard, "it's not about the bike".
yeah, a cross bike setup with a triple will be good but not great at anything. if adjusted right the shifting will be good, but not lighting fast. I live in the san francisco bay area with lots of hills and with a compact double, I pretty much have all the gearing I need. I'm not going out looking for the steepest hills and I'm not going to carry 50lbs of cargo...I don't race, but I just don't want everyone riding away while I shift into the right gear.
I just switched from a triple to a 1x9. (42x11-34, yup its pretty wide.) Why? Several reason, one because I wanted something a little more durable and something I wouldn't have to hassle with. Another reason is I got bored with the triple. I noticed that when i was riding I would keep shifting till I was comfortable. I wanted something that would be a little more challenging and force me to get stronger, the 1x9 seems like it's doing the trick.. Since the spacing is so wide I really have to choose a gear and stick with it (similar to a single speed but with more options).
I'm riding this bike everywhere... Trails, Road, Commuting, etc. It's a freaking blast! I will probably switch to single speed one of these days (once I get tougher!). The logical choice would be to choose a setup that gives you more options not less, but Logic != Fun! (For racing I will probably change the rear cassette to something like a 12-26 or around that since I really won't need the 34.)
Now for the geeky stuff... Here are the gear inches between my old triple and the new 1x9 setup.
http://chriscowan.us/skitch//Notebook.vpdoc_GearCalculations-20080425-100411.jpg
Now if you look at the triple you will see that all three sets of gears (30-42-50) overlap quite a bit and there are a bunch of redundant gears. Do I really need all that redundancy? Nope, but the trade off is the difference between each shift is bigger. When I shift into the lower gears that doesn't seem to bother me cause I'm usually looking for some relief (climbing a hill) but when I shift into a higher gear it means I need to work a bit harder to get it up to speed (my way of getting stronger). Another trade off is I loose a few of the top gears which makes my max speed slower. I notice that I start spinning out around 25+ mph (descending down hills).
Part of the bicycle's beauty is its simplicity and elegance of design. Every added gadget diminishes this aesthetic. An added gadget that serves no useful purpose or that serves an intellectual preference rather than an applied purpose is just ugly and wrong. In my world the question "why not a triple?" might as well be why not spoke protectors or handlebar tassels? Then I see a true 'cross bike as a very specific thing, one intended for contesting cyclocross races.
Cross bikes don't need triples. Most mountain bikes don't need triples for that matter, not for racing anyway. Why have overlapping gears, or gears that you'll never use. I see the burden of proof falling on the guy who wants to add something, not the one who is simplifying.
Triples make sense for some people and terrains. Not me where I live. And not on a "proper" cyclocross bike.
Part of this 'cross bike confusion and controversy results from the scarcity of proper road frames in recent years. People have been buying cross bikes in reaction to the weird idea that a road bike should be built like a road race or criterium bike. In the real world it makes sense to ride 28 - 38mm tires with a geometry that's stable and comfortable. Too many road bikes are stupid light, high strung thoroughbreds that have no business under the butts of ordinary riders in ordinary terrain. So those ordinary riders go shopping and end up with a cross bike and wonder why it doesn't have a triple the way a real-world road bike probably should.
Only ostentatious idiots would drive a modern race car through traffic. Almost as dumb is being a middle aged pedal twiddler riding paved park trails on a Madone. The 'cross bike, properly, is itself a fairly specialized racing machine - just specialized for a broad range of surfaces and terrains. This makes it much more suitable than a road race bike for ordinary riding. Still, if you want a triple on it, or suspension or other doodad, it isn't really a cross bike you're looking for. Feel free to use any bike for anything that is fun or beneficial to you. And it makes a lot of sense to press a cross bike into service in this world where sport-touring bikes are nearly extinct. But like the many people who buy comfort bikes instead of roadsters you're really making do with something because it is more available or more in keeping with current fashion.
My cross bike used to be a 1x8 and only got two chainrings to accommodate long downwind training runs of which there were never really enough to justify it, but it was fun blasting along even faster when it did happen. It then went to 2x9 to accept modern parts replacing the old worn stuff.
I say keep it practical and suit the bike to what you actually do with it. I'm currently building up a single speed cross-like bike for fun riding on and off road. Why a single, because the mechanical overhead of a derailleur bike doesn't make sense for the 3 gears I'll actually use. Down the road I'm going to look into an internal shifting system for that bike. That will probably make a great deal of sense. We'll see.
Anyway, the answer for the OP is that a lot of us have no use for triples, so there's no reason to add it. Your mileage will vary. Enjoy the riding and the shopping and bike building too. All of it's fun as long as it is all done to serve your riding and you are suiting the bike to what you do with it rather than some other idea.
+1 to CrankyMonkey's post.
I'm a long time advocate of the 1x9 set up, it is simple and effective.
Before I went to the 1x9, took a look at the gear ratios I actually used.
Two were most often used, mid 30s and mid 60s gear in. Rarely used
anything above 80s, live in a very hilly area- used ratios in the 20s often.
So for me the 1x9 set up with 34 t chain ring and 11-34 cassette optimally
fit my needs; gives me a range of 28 to 86 gear in. Now after a few thousand
km with that set up, still use the ratio that is 36 and 63 most often. I'm a FOG,
so once in a while I'd like a lower ratio for going up the hills- down hill I coast.
What is the downside to a 1x9 ? More stress and wear on the chain and RD,
however riding conditions probably are more of a factor. Both are fairly
inexpensive to replace when worn, no FD is a real plus.
Have as many gear ratios as you want or need, nine are the most pragmatic for me.
And big thanks to Ronsonic for the thoughtful answer. That was exactly what I did not get; now I do.
Another thing- does anyone have a suggestion as to where I can learn some basics on gear ratios? I was an English major and everything you have each said about the gears has been over my head, especially that chart.
The GOD of all things cycling... Sheldon Brown
http://sheldonbrown.com/gearing/index.html
(I used his online calculator to create those charts... RIP Sheldon!)
Thanks I think I kind of understand. The yellow numbers are the number of gear teeth. What are the white numbers? The gear ratio?
If that is the case then it looks like the only thing you lose is 10.5 of whatever the white number is when going up a steep hill, and 2.2 when going downhill.
Pretty cool. So the bottom line is that going 1x9 gives you the same RANGE but the jumps between gears are larger. Correct?
Thanks I think I kind of understand. The yellow numbers are the number of gear teeth. What are the white numbers? The gear ratio?
If that is the case then it looks like the only thing you lose is 10.5 of whatever the white number is when going up a steep hill, and 2.2 when going downhill.
Pretty cool. So the bottom line is that going 1x9 gives you the same RANGE but the jumps between gears are larger. Correct?
The white numbers are the gear inches, which is the number of inches the bike moves with one revolution of the cranks.
You're correct on the bottom line. Same range, bigger jumps.
Ahem, fewer gears, English major.
I'll throw my hat in the ring on this topic.
Road compact and triples exist because the standard road racing gearing (53/39 11-23) isn't low enough for the steepest hills, especially for non-pros or someone carrying bags. They've even been used by pros for the gnarliest, steepest mountain stages.
Neither solution is perfect. The triple adds (a slight bit of) weight and makes shifting a bit more fidgety, especially with integrated shifters. The compact double gives a really big jump between the two chainrings, 47% change compared with 36% change for standard double, so shifting between rings almost always requires changing your sprocket, which is not the case with standard double.
IMO the triple is the better solution. You basically have a standard road double, plus the granny ring when you need or want it. Even if you only use the granny ring once in a ride, you're happy that you have it.
There is, however, a macho thing that road cyclists have about triples. It implies Freditude.
For cyclocross racing, on the other hand, I think a single chainring is the best way to go, given the nature of the beast. If you can't get up a climb, you just hop off and run.
Ok, ok, fewer... jeez. Although actually I could argue against it. From Websters:
"Even though less has been used before plural nouns (less words; less men) since the time of King Alfred, many modern usage guides say that only fewer can be used in such contexts. Less, they say, should modify singular mass nouns (less sugar; less money) and singular abstract nouns (less honesty; less love). It should modify plural nouns only when they suggest combination into a unit, group, or aggregation: less than $50 (a sum of money); less than three miles (a unit of distance). With plural nouns specifying individuals or readily distinguishable units, the guides say that fewer is the only proper choice: fewer words; fewer men; no fewer than 31 of the 50 states.
Modern standard English practice does not reflect this distinction. When followed by than, less occurs at least as often as fewer in modifying plural nouns that are not units or groups, and the use of less in this construction is increasing in all varieties of English: less than eight million people; no less than 31 of the 50 states. When not followed by than, fewer is more frequent only in formal written English, and in this construction also the use of less is increasing: This year we have had less crimes, less accidents, and less fires than in any of the last five years."
Also, thanks for the thoughts on the gears. I'll try and stay away from the Granny and see how it feels. Maybe one day I'll go for the double. When I go pro I'll beat everyone on the single gear.
I've been aware that the less/fewer distinction is not universally held, but "less gears" still rings not quite literate to me.
Regarding gears, interesting article about today's Brasstown Bald stage at TdG:
http://velonews.com/article/75386/
No triples, but lots of big sprockets.
The white numbers are the gear inches, which is the number of inches the bike moves with one revolution of the cranks.
Not exactly. see here...http://www.sheldonbrown.com/gloss_g.html
Gear inches are the theoretical diameter of the wheel if your cranks were attached directly to the hub, like a high wheeler. Heres another way to put it.....a gear ratio giving you 76 gear inches would be equivalent to pedaling a 76" diameter wheel with a 1/1 gear ratio. The distance traveled per revolution would be 76" x π.
Not exactly. see here...http://www.sheldonbrown.com/gloss_g.html
Gear inches are the theoretical diameter of the wheel if your cranks were attached directly to the hub, like a high wheeler. Heres another way to put it.....a gear ratio giving you 76 gear inches would be equivalent to pedaling a 76" diameter wheel with a 1/1 gear ratio. The distance traveled per revolution would be 76" x π.
Good catch. You must multiply by 3.14159 for distance traveled. :)
Well... as long as this conversation is still alive... could you explain something else to the English major please?
I get that different gear combinations result in longer or shorter inches-traveled-per-crank-rotation (symbolized by a theoretical giant front rim).
So could you tell me what the percentages are between the different gears? I am referring to the chart on the preceding page. Are those gear ratios? If so, what is the point of knowing which gear ratio is active? It doesn't seem to offer much useful information.
(A little background: I have chondromalacia in my knees and need to keep my cadence up around 95-100. In other words, I can't mash or come close to mashing the pedals or else I will pay for it in the morning. I'm going to be using Shimano's Flight Deck to help me out with visualizing the gears until I get a better feel for it. But the more I know now, the less painful these trips might be for me.)
So could you tell me what the percentages are between the different gears? They are percentage jumps between the sprockets and chainrings. For example:
13/12 = 1.083 = 1 + 8.3%
42/30 = 1.4 = 1 + 40%
Fiddling around with the gearing applet might give you some intuition in these matters:
http://sheldonbrown.com/gears/
I quite like a triple in the front. What I have a problem with is the always increasing number of positions on the rear cassette. It's as if more is better but it's not.
I don't know a lot about gears but hope that you experts can consider this laymens opinion. The ideal number of rings on the rear cassette if using a triple in the front is 7. With this combination each of the front rings has the option of utilizing 3 cassette positons in closest proximity to the corresponding front rings - left, center or right. Here is an illustration:
1 2 3 (the 3 chain rings)
1 2 3 4 5 6 7 (the rear cassette)
The # 1 (easiest) chain ring uses 1, 2 or 3 positions from the rear cassette.
The # 2 (midrange) chain ring uses 3, 4 or 5.
The # 3 (most difficult) chain ring uses 5, 6 or 7.
Notice that each of the front rings shares a rear gear position from the cassette with it's closest neighbor. This makes it possible to sequence the gears changes in a logical and smooth manner.
Here's a scenario of the combinations one might use on a typical long climb and decent:
1. You find yourself going up a long hill, so already you are in the lowest gear - #1 chain ring with #1 position on the cassette).
2. As you approach the summit but still climbing (but now on a lesser grade), you change the rear cassette to #2, then to #3 as you being to pick up speed.
3. You are now more or less on the summit were it is generally flat. You change the front chain ring to #2 while maintaining the rear cassette on #3. As you gain more speed, you change the rear cassette to #4 then to #5.
4. You now begin the long decent. You change the chain ring to #3. As you accelerate (now very quickly) you finally change to #6 then #7 positions on the rear cassette.
In this scenario, you have effectively used all of the gear combinations, which do not over stretch the chain from left or right position extremes. Additionally you have used only 9 of the total 21 possible gear combinations. That's adaquate in my books.
What I find is that 8 or 9 position on the rear cassette, screws up the system as the sequencing just doesn't work in combination with 3 chain ring positions. One finds oneself in the awkward position of having to change both the front and rear gears at the same time, in order to avoid being in gears were there maybe too much sideways tension on the chain.
Mathematically 10 positions on the cassette works as well but now one has a total of 12 usable combinations - 4 cassette positions for each of the chain rings.
I hope that the above is at least half understandable. Comments welcome.
Leo
Makes sense to me. And using your theory with my 8 speed cassette, can't I just avoid either the 1st or 8th position and still achieve your progression?
(A little background: I have chondromalacia in my knees and need to keep my cadence up around 95-100. In other words, I can't mash or come close to mashing the pedals or else I will pay for it in the morning. I'm going to be using Shimano's Flight Deck to help me out with visualizing the gears until I get a better feel for it. But the more I know now, the less painful these trips might be for me.)
I would say that a 1x9 or Singlespeed is probably out of the question for you. I find myself mashing a lot more with the 1x9 then I did before, especially on trails. The triple is good for spinning due to the large amount of gear choices. You should take your health into consideration. I'm pretty sure that I will either have to continue riding year round with this setup of switch to a double if I take any amount of time off from the bike due to the physical demand.
I was hoping that someone would challenge the concept about a 7 ring ring cassette being the ideal in combination with 3 chain rings. Since no one has, I'm now considering changing my 9 ring cassette to a
7. I'd probably do it right away but am wondering if the change is just that simple or are there other complications such as changing derailleurs etc.
Another possible slight advantage to a 7 ring cassette in combo with 3 chain rings when using the sequencing technique mentioned above, is that at no time does the sideways tension exceed one position to the left or the right of each chain ring. In other words, assuming the front and back are lined up perfectly (a big assumption?), each chain ring would have a cassette ring direct in line with it, as well as a dedicated cassette position to the left and to the right of the one dead center. Although similar sequencing can be used on a 10 ring cassette it does not have the beauty of the 7 ring. Reason being, there would not be a single cassette ring lined up perfectly with any of the chain rings. The dedicated cassette rings would be 2 rings to the left and 2 rings to the right of dead center. This further substantiates my argument that 7 is the ideal.
It's been my experience that bikes with a 7 ring cassette are not all that common on new bikes. It may be that manufactures/marketers are on an agenda to always increase gear options assuming the public will always want more choices. Heh, recall when safety razors had one blade? Many years later, a product was developed that had 2 parallel blades which ads claimed would yield a closer shave. It was obviously successful because there has been an ever increase in the number of blades added to the point were now a product has been launched with 5 blades in succession. Come on now, enough is enough already! Or is it, I'll bet their R&D departments are busy making a 6 blade prototype.
Bryroth, if you are sold on the concept of a 7 ring cassette, maybe ask the dealer were you are considering buying your 8 speed, what he thinks of going to 7 and what if anything are the complications. Maybe they will do the changes for free if it means getting a sale? You might want to keep the same ranges that the 8 ring provides or maybe maybe even go a little lower due to your knees not able able to stand very hard pedaling.
Hope this helps.
Leo
I will ask, the mechanics there are a good group of people. However I'm a noob at the mechanics. Will my current Shimano drivetraine work with a 7 speed cassette?
I was hoping that someone would challenge the concept about a 7 ring ring cassette being the ideal in combination with 3 chain rings. OK, I'll bite. Your whole thing with the 7-cog is just that 7 = 3 x 3 - 2.
But 10 = 3 x 4 - 2. Therefore, ten is the perfect gearing!
I think you are overemphasizing the problem of crosschaining. In my experience it's not that big a deal, if anything at the very extremes of the cassette.
Interesting diversion here into 7s. Actually, seven does work great, but not in any way that makes it worthwhile to convert down. If you just have to have a quieter drivetrain for stealthy ninja cycling 6 is even better.
The 7s cassette will go on a "modern" 8-10 freehub with a spacer. The spacing between cogs is either the same or so close as to make no difference between 7 and 8. In fact you can use an 8s shifter for 7 without trouble. For shimano, every rear der since the SIS stuff of the 80s will work for any of this (except for the 80s dura ace which was just weird - apparently they hadn't thought it all through yet).
My thinking is if you've got 7 roll with it - more gears beyond that really do start down the road of diminishing returns. But since the spacing is the same as 8 you can also look at it as the 7 plus a spacer and spacer = unused cog (for me that'd be the little one). IOW 8 is the same as 7 but with a longer axle so why not use it if you got it.
So I can stop babbling, here's a link to lots of smart stuff about gearing: http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946
Oh, and a personal disclaimer, I live in Florida we don't have hills. We have terrain that looks like a slice of swiss cheese on a table top. OTOH we've got wind, we got head winds that'll make you fear it'll flip you and the bike over backward and we've got tailwinds (very rarely) that'll leave you suffocating and sweating in hot, dead air at 25+ mph watching your sweat drop straight down onto the top tube. That is the only time you'll have a tailwind. My gearing problems are different but I've got 6, 7, 8 and 9s bikes and they're all great for what they are.
The main reason for the use of a double/single and not a triple is that you are better off running if you need to go as low/slow as using the granny.
I personally would never go with anything beyond an 8 spd rear. In very muddy conditions I used to have shifting issues with a 7spd. Granted, one should have their second bike clean and ready at the pits on those really muddy races. :lol:
Previous -
Top -
Next
Copyright 1999 - 2007
BikeForums.Net - All rights reserved.
Common bike forum topics in clue bicycles, cycling, mountain biking,
cycling jerseys, shorts, socks, shoes and bike equiptment selection.