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compact versus standard geometry(25 posts)

compact versus standard geometrycmp
Apr 6, 2002 6:36 AM
I am trying to decide between compact geometry and standard geometry for a road bike. My bike would be on the small side, 51 cm. From what little I could learn from cruising the web, it seems the compact geometry bike is easier to control and lighter than a standard geometry frame bike. Other opinions?
Compact vs. Standard framesNessism
Apr 6, 2002 7:27 AM
I wouldn't expect any significant differences in weight and/or ease of handling. The weight reduction from the shorter tubes is somewhat offset by the need for a longer seat post. And the only handling difference will be an increase in the standover height - which may be important for a small frame.

It may be better to look at the specific measurements of the frames you're interested in. The small details are likely to be more significant than a general comparison between standard and compact. For example, how high is the front end of the frame relative to your expected seat height? How much standover clearance do you have? Ect.

Good luck.

Ed
Wrong!!!!elviento
Apr 6, 2002 9:58 AM
What do you think of this claim: If you eat a lot of fatty foods, the additional calories will be offset by the use of more energy in digesting the food, so you end up not gaining weight.

Obviously wrong. Agree? Whenever you talk about two offsetting effects, it's stupid not to compare the magnitude in order to find out the net effect.

On the compact frame, the shorter seattube is offset by the longer seatpost, so you are even in that respect.

But with a compact geometry, the toptube and the seatstays are also shorter and lighter, resulting in net weight reduction.
not reallyJekyll
Apr 6, 2002 10:15 AM
When you look at weights on comparable compact frames vs the same manufacturer's traditional designs you typically see a difference of around 1 to 2 oz (for instance LS Siena vs Tuscany or Classic - if you wanted a noodle like the Ghisallo in a traditional design you could probably get to within 2 oz's as well)... Take a look at the difference in weight between a MTB post and a traditional road post - probably around the same 1 to 2oz. Granted the seat stays are shorter but where is the weight benefit?
This is just like any other gimmick. Something new for manufacturers to do to both generate sales and reduce production costs (most compacts come in rather limited sizes).
Really?elviento
Apr 6, 2002 12:12 PM
"Granted the seat stays are shorter but where is the weight benefit?"

I believe shorter tubes are lighter. Also you can probably debate how much weight a longer post adds, but XTR post is 210g and Dura Ace post is 195g. That's 1/2 ounce. If the frame saves 2 ounces, then there is a 1.5 ounce net savings. Well maybe that's not a lot, but if there is no sacrifice in stength of the frame, why not take the weight savings?

You might want to say a couple ounces weight reduction is no big deal (one less water bottle, etc.), but that's not the topic of debate here. Afterall, Trek 5900 is $800-900 more than the 5500, which is only about 4 ounces heavier. So that's $200+ per ounce.

As for limited sizes, it's the manufacturers separate decision, and not inherently a part of the compact design. Specialized's sloping models come in many sizes, with 1cm incremental, for example. Some italian brands do that too.

On the other hand, a level toptube model can also come in very limited sizes. I believe a few companies actually do that, with each size 3cm smaller/larger than the next size.

It's like you see a lot more race cars in red, but you can't say red makes cars faster. Because it's a separate decision not inherent in the design of race cars.
ReallyJekyll
Apr 6, 2002 1:22 PM
The lightest common road post is around 130gr (Alien) while light MTB posts (like Easton) tend to run around 180gr. Roughly 2 ounces.
The Trek price/weight example does not correlate. Trek uses different materials to make the bikes (which they would argue accounts for cost - true? doubtful but people will pay for it therefore they will make it). Notice they do not use compact geometry in either case.
The car analogy is another nonsequitur (like the food analogy before it) and argument by analogy is not an argument.
Red cars are perceived as being "faster" by the human eye because of the way we perceive different frequencies of light within the visible light spectrum.
In the end there is probably no advantage to compact frames over equally well designed traditional frames or for that matter the other way around.
It all comes down to simply a style thing. You like compact, ride it. But be honest enough to understand that it has a hell of a lot more to do with style than with substance, and that there is nothing wrong with that.
Reallyelviento
Apr 6, 2002 9:35 PM
"The lightest common road post is around 130gr (Alien) while light MTB posts (like Easton) tend to run around 180gr. Roughly 2 ounces. "

three problems with this:

1. The Alien has a much lighter clamp design than the Easton, so the comparison is invalid. But the XTR/Dura Ace comparison is a much better one because they have the same clamp design, therefore the weight difference is ONLY in the SHAFT LENGTH.

2. Most compact designs today uses a seattube about 7-8cm shorter than the traditional seattube, which means the post only needs to be 7-8cm longer, but the Easton MTB is 13cm longer than the Alien Road.

3. Besides, 50 grams is less than 2 ounces, 60 grams is about 2 ounces.

I don't understand your hostility to analogy as a means of persuasion or argument, but it's used widely in human speech for argument and persuasion. Even if I don't use analogy, truth is compact design does not prevent making adequate sizes. You can make as many sizes as you like with compact design, just like Specialized and many brands actually do. Therefore Giant's lazyness is to blame, but not the sloping toptube.

Compact design DOES save some weight, whether that's significant or not depends on personal opinions, but I certainly don't mind my frame being 2 ounces lighter.

I do agree that style is also a big part of the mix, as is the case with virtually every product/industry (Heck, even shampoo bottles and CD players are getting more aerodynamic these days). But I don't think there is anything wrong with that. At least manufacturer aren't charging more for compact models.
the USE alien is available in a MTB versionweiwentg
Apr 8, 2002 5:30 AM
156 grams, as I recall. also, compact frames are stiffer by virtue of the shorter tubes. mind you I'm biased (ride a Giant TCR). and Giant actually charges a lot less - the TCR0 and the specialized E5 S-works have almost identical equipment. the TCR0 costs $3k, and the S-Works costs $4110. if you fit on a Giant, as do I, the choice is obvious.
Significant?Nessism
Apr 6, 2002 1:31 PM
I could imagine that a couple of ounces could be saved but that is not reason enough to choose one frame over another in my book.

If one wants to shave every gram from their frame, go for it. Nothing wrong with that really. But please just don't call 2 oz. a "significant" difference.

Ed
Significant? Noelviento
Apr 6, 2002 9:07 PM
I don't know why you use quotation marks. I never said 2 ounces is significant. In fact I don't think it is significant. But if a manufacturer wants to save as much weight as possible, even if by small amounts, I don't see anything wrong with that either.
Compactmwood
Apr 6, 2002 9:14 AM
geometry is supposed to save weight w/less frame tubing (isn't that why many triatheletes use them?), but wouldn't handling characteristics just reflect head angle, length of stays etc.?
I, for one, just think the compact bikes look too strange...kind of like mtb without the fat tires.
You either love them or hate them...agilis ti
Apr 6, 2002 11:28 AM
you can add this to shimano vs campy. Factory vs custom wheels, ti vs steel vs aluminum vs carbon vs jello. I own one compact and one standard and the only difference I know for sure is that at my weight the smaller triangles make the ride stiffer for me. Ride and try.
It's like anything else; ride 'em and see how you feel.Leisure
Apr 6, 2002 12:00 PM
I got a mildy compact frame for myself because of the difference in handling. That's a "compact" frame, not a "compact geometry" frame. That may be different from what you're looking at. For the same person and fit, a smaller frame will have a shorter wheelbase and longer stem, but otherwise no sloping top tube or anything. It probably does weigh just slightly less than a larger frame with a shorter seatpost/stem, but I don't care about weight and really couldn't say how much difference there is. It's really the handling I'm after. It's not worlds of difference that will make or break me in a hard turn, but the feel is noticeably different, and for me, aesthetically pleasing and a bit more confident. For me it emulated the handling I had dialed into my mtb. It was legitimately better performing for my riding style in my mtb; in my road bike it's more a matter of taste and consistency. Other people have different tastes and styles. You should test ride and see what you like, paying attention to low speed versus high speed, forks, stems, head tube angle, etc.
If you were talking two frames with identical head tube angles, wheelbases, etc., the only difference being a sloping top tube, than there should not be a big difference in handling. If I were shopping all over again and had the option, I might be tempted to get more slope than I have right now just 'cuz, but that too would be a matter of taste.
I own bothkeeter
Apr 6, 2002 2:00 PM
I am the proud owner of both a Merlin Agilis and a Merlin Extralight. I can tell you that, when i climb, the compact Agilis puts the power down more efficiently. Both of the frames have matching geometry other than the sloping top tube.
From the Serotta web sight.Len J
Apr 6, 2002 4:04 PM
• Compact Geometry

Is this the latest fashion statement from the Euro crowd a trend that has practical advantages?

The answer is, both. Contrary to marketing hype, Compact Design doesn't save a lot of weight or make the drive-train extra stiff. However, it does allow for a higher handlebar position while maintaining adequate stand-over height. You will need a longer seat post, so make sure you choose one that will support your weight when fully extended. We believe Compact Design will have a place in the future. All 2002 models are available in standard or compact geometry.

Sounds right to me. Weight savings negligible.
More about fit.

One oponion.

Len
bingo...... andJohnG
Apr 6, 2002 5:36 PM
Anyone claiming that compacts climb better is so FOS it makes me laugh!!!

I own both and know what I speak of.

JohnG
bingo...... andgtx
Apr 7, 2002 3:48 PM
Looks like Tom Kellogg disagrees with you ;)

http://spectrum-cycles.com/616.htm
No doubt...Nessism
Apr 7, 2002 7:04 PM
...compact frames are the comming trend. A little lighter, a little stiffer (maybe), and a lot more mountain bike like. Threadless forks/stems are here to stay, are compact frames next?
Are compact frames here to stay? Maybe.Leisure
Apr 8, 2002 12:32 AM
One good thing about mountainbiking is how it's made everyone rethink why/how everything's been done for so long. Having a level top tube obviously is no longer held as one of the Holy Grails of good frame design. Heck, I don't even remember the old school esoteric rationales they used to justify why. I would guess it did nothing more than help early welders keep their geometry straight. That would be justification enough for me if it were still an issue; since it apparently isn't, I'd rather have just a bit of slope for those extremely rare occasions where extra standover would be convenient.
re: compact versus standard geometrymbologna
Apr 6, 2002 4:08 PM
I'm pretty new to cycling and bought a Klein Quantum about a month ago (standard geometry). I also looked at a compact frame, an 01 Sepcialized Comp. Being completely new, I can't talk technology like some of the others, but to me the compact frame was much more responsive on test rides. The standard frame was not as responsive, but seemed to be a little smoother over the bumps.

I went with the standard frame because I figured I would be using the bike more for long flat rides, than hard uphill racing. I guess it depends on what you're using it for. I also think the smaller (both in height and weight) you are, the less difference it makes.

mbologna
Weight vs. Aerodynamicsliu02bhs
Apr 6, 2002 4:50 PM
Compact frame generally will weight less than the standard frame. However, this means it'll be stiffer too, because there isn't much room for flex. Ever ride a small aluminum frame? Well, it's kind of like that.
A draw back is that compact frame is less aerodynamics according to the tests at Texas A&M (I think, P.S. it's all about UT, GO HORNS). So it don't think it'll be as advantageous for TT/Triathlon purposes.

In conclusion, go with compact for climbing, and standard for TT/Triathlon.
That makes sense, becauseelviento
Apr 6, 2002 9:27 PM
a level toptube hardly adds more drag but a sloping toptube does.
HOOK 'EMriney
Apr 6, 2002 9:44 PM
Come early, Ride hard, Break late...Win 'em all

Class of '98
Standover height to considerelviento
Apr 6, 2002 9:43 PM
For shorter guys, standover may be an issue so a sloping toptube surely doesn't hurt in that respect especially if you expect to get on and off the bike a lot. The handling is not likely to be affected much assuming same angles, wheelbase, fork rake, virtual toptube length, etc. Compact will be a little bit lighter but many believe that's a very small weight advantage, as you can see from other messages.

So unless you have a very strong preference in terms of style, this should not be a huge factor in your decision. But if you are getting a frame custom made with exactly the same demensions except standard toptube/seatstays versus compact, then I say go with compact.
re: go with the fitcyclopathic
Apr 7, 2002 7:35 PM
try both bikes and get the one which fits and rides better. Besides the "compact vs std" geometry many other things like stem size, rake, wheelbase etc etc etc will influence ride quality

a few notes on "compact" vs "standard":

- Since you need 51cm frame more then likely compact "small" would have longer TT. This maybe good or bad (good if you have longer torso, bad if you have longer legs)

- Compact frames are generally stiffer and if frame is Al it maybe too stiff for longer rides on bad roads

- Small compact may not have enough space for large water bottle on seat tube

- weight saving if any won't make any noticable difference