|can we talk a bit more about the Anvil vs. TJeanloz debate?||ET|
Mar 13, 2002 8:35 AM
|In a recent thread, these two argued about the merits of a custom frame (not to be cynical, but Anvil, a custom builder, lauded its benefits, while TJeanloz, an ex-LBS guy with his heart clearly still with Litespeed, questioned it).
What was left unexplained in that thread is around how much two adjustments to a bike, 1) stem length/height and 2) fore/aft seat adjustment, affect the ride. I was wondering if we could talk about just that alone in the context of both comfort and performance (balance, turning, steering twitchiness, etc.). (Let's leave aside for now other aspects of custom, e.g. getting what you want, the good feeling of knowing you have a perfectly-fitting bike and how much you're willing to pay for it, as well as that most customs are priced competitively anyway.)
I'd like to talk about these things in a practical sense; that is, not enormous changes indicating it's the wrong bike, but ones perhaps indicating just that another bike might have been a theoretically better fit. Here is an example: Someone buys a 57 c-ttt stock bike with a 73-deg STA, 56.5 TT and a 110 stem. How terrible is it if he must move the seat foward one cm from center of rails with given setback and come down to a 100 (or even 90) stem? (This is more the kind of thing many of us face, but whenever I say so, the 6'3" guys with the 29" inseam come out of the woodwork. :-)) If it's not so terrible at all, maybe TJeanloz has a point about most people fitting fine on a stock bike. If it has a noticeable effect, Anvil's case is even stronger.
I think I recall reading that USPS riders all ride stock frames and that some of the riders had to swap for stems of both different length and angle, as well as fiddle with setback, given that OCLV frames come in only even sizing combined with somewhat deceptive and nonstandard geometry (you know, a size 56 is really a 54, and all that). While not a proof, these changes didn't seem to hurt them too much in the TDF. Do all the compacts out there (3-sizes-fit-all with extreme stem combinations allowed and encouraged) offer any insight? Do changes matter more for one frame material over another?
BTW, welcome back, Anvil, and please join us more often in discussions, and not just ones involving the custom debate.
|I'm going to try to stay out of this one||TJeanloz|
Mar 13, 2002 8:53 AM
|But I can't resist a few points.
First, a clarification, I too believe that there are benefits to custom bikes. I don't happen to believe that dimensional fit alone is one of those advantages.
Second, Eddy Merckx insisted that all his bikes be built with a top tube length that allowed him to use an 11cm stem. He believed it gave the best handling. I think it's a personal preference- I have used 13's, 12's and 11's, and I think a 12 gives me the best 'feel'. But I can't prove it.
My basic feeling is, it's not about the bike, period. If the bike fits, ride it- don't concern yourself with spending 1,000's of dollars to see if you can find a bike that handles better.
|Eddy and Andy||gtx|
Mar 13, 2002 8:59 AM
|yeah, apparently Andy Hampsten slapped a 12 or 13cm stem on one of Eddy's bikes when he was on Mototrola and Eddy freaked. He had them build a bike for Hampsten with a longer tt that would allow him to run an 11cm stem. And apparently Andy thought it felt much better that way.|
|re: can we talk a bit more about the Anvil vs. TJeanloz debate?||gtx|
Mar 13, 2002 8:55 AM
|to me, there are two issues--fit and center of gravity. Sure, by messing with stems and seatposts I can "fit" on tons of bikes, but they won't necessarily feel right to me. I am very particular about my saddle position relative to the cranks--I have same saddle setback on all my bikes. So when I set up a bike, I set up my seat first, then figure out where the bars need to be. If I need to resort to some funky stem setup, the bike generally isn't going to feel that good to me. I generally look for bikes with STAs between 72.5 and 73, with tts between 56 and 57--these bikes usually work just fine for me with a normal -17 rise 11cm stem.|
|Call me Mr. Switzerland...||AaronL|
Mar 13, 2002 9:13 AM
|since I'm not convinced one way or the other.
My personal experience has been that I can get an acceptable fit on a stock bike, as long as it has the correct dimensions I need. But, since I have long legs and a short torso, I'm always looking for a frame with a short TT compared to S/T length. Then, I need to search the ends of the earth to get short reach bars.
It would be nice, for once, to get a frame that was sized just for me. As I said, I feel I have always made my bikes fit to a point that is acceptable. But, maybe if I ever put some miles on one that was custom made, I would never go back to stock again.
See, I just can't make a stand. :)
|Sounds like you can fit on a Colnago well...||Pedal Jockey|
Mar 13, 2002 9:17 AM
|Given that they are built with very short top tubes relative to seat tube length.
|Well, that's the rap, but||djg|
Mar 13, 2002 11:08 AM
|it's really not true in the middle sizes of the range. For instance, a "56" from Colnago is 56 cm measured from the center of the bottom bracket to the bottom of the seat tube collar. Measured to the top of the top tube--the more common way to measure c-t--it's pretty close to a 55. Top tube? Also very close to 55 cm. With a steepish (although not radically so) seat tube angle, it's hard to describe that top tube as really short relative to the seat tube.
The "freuler" (sp?) type frames at the large end of the range are a different story.
|Call me Mr. Switzerland...||koala|
Mar 13, 2002 10:12 AM
|You are built like me. I was using 7 and 8 cm stems and I finally went full custom. I love it now that I have everything dialed in I feel less fatigue but even more the handling of the bike semms just right. I got off it today and wonder why I didnt do it sooner. All this is considering my inseam is long relative to my torso.|
|never had a custom, but here is a theoretical question||ColnagoFE|
Mar 13, 2002 9:16 AM
|Someday after I win the lottery I might pop for either a C-40 or a custom Calfee. I know I fit pretty well on a 62cm Colnago with a 110 rise stem (actually a coupla spacers too--easier on my back) and the saddle set back just a touch. I like the way that Colnagos handle. Could I request Calfee to make me a bike that was almost exactly like the C-40 but even more dialed in as far as fit goes? Or if we were talking steel could Anvil build me a steel bike that rode exactly like my Master XL but that didn't require me to use a rise stem or any saddle setback and still have it handle nearly the same. How exact of a science is framebuilding I guess I'm asking...I realize this has a lot to do with the builder's skill level somewhat.|
|yes, in theory||SteveS|
Mar 13, 2002 12:30 PM
|My riding buddy had the old Ibis (Sebastopol) make him a titanium frame to replicate his favored Tesch and they came quite close. Recently he rode the Tesch for the first time in quite a while and said it was his favorite bike. Probably had to do with differing fork rakes as that was a Tesch standard, at least at one time. Don't know if the head tube angles were the same or not. The point is that you would have to make almost an exact replica of the Colnago. However, I have no doubt that Anvil could fine tune your fit, extend your headtube, etc.
In my fantasies, I have thought of having a custom titanium frame to match the feel of my ancient Olmo, just lighter, longer top tube, etc. Would be an interesting test. My guess is that in my case, the handling would be somewhat different as I would have a shorter stem, longer ttube, and probably couldn't find a carbon fiber fork with the same 50mm of rake as the Olmo.
|When I had my custom (TiCycles) rigs built...||brider|
Mar 13, 2002 12:42 PM
|each time I already had the cockpit dialed in, but wanted to change the ride characteristics of the bike. What I did was to bring in the stock bike with the set-up I wanted (saddle/handlebar/BB relations), and told them how I wanted the bike to feel. They took it from there, and I was more than happy with the result. Any good frame builder should be able to do the same.|
|long time lurking, first time posting...here I go....||Krypton|
Mar 13, 2002 9:21 AM
|Well I guess you can't really say that the only reason for going custom is for fit. There are alot more advantages to a custom bike than fit.
If you go custom only for fit and you're body's pretty much normal, then, I guess you could get a perfect fit with a normal bike with minor adjustements. I've never had a frame custom built and I have pretty normal mesurements (6ft, ~ 32-33 inseam, normal torso lenght) and I've always felt perfect on all my bikes with some adjustements. One of my good friends has pretty much the same mesurements as me and had a custom bike built last year. I tried it for a 50k ride (sorry about the metric measurement, I'm french canadian ;-)) and felt as good as on my bikes.
So I guess that the advantages of a custom frame, if you pretty much have normal measurements, are not in the fitting departement, the advantages are elsewhere...
|From what I have discovered...||Pedal Jockey|
Mar 13, 2002 9:35 AM
|For the vast majority of riders combined with the many different geometries used by all of the manufacturers, there is a nearly infinite number of possibilities for fitting a stock frame properly. My body dimensions are perfect for an Eddy Merckx/Lemond like geometry, given the long top tubes, and laid back seat tubes. Other tall riders who have short legs relative to their upper body length seem to fit well on Colnago or Pinarello for example.
Issues with STA really equate to whether or not one can get the right KOP set up. This is a problem for me because I have a really long femur. For most this may not be an issue. Other wise, by changing stem length, one can dramatically change the overall reach. Of course, if one comes from the Merckx mode of sizing relative to a specific stem length, then fitting via top tube length is critical.
This is not to discount the reasons for choosing to go with a custom frame. My newest bike is custom, and it rides 100x better than my Merckx. I went with custom to ensure the frame was a perfect fit for me, but also to be the owner of a unique ride. I chose the paint, the color of the decals, and which braze-ons and where they were mounted. Overall, it was a great experience for me, and one I will do again. Cost was not any more than a quality production frame of the same material.
My 0.02 lira's worth.
|Since no one seems to be answering your question.........||Len J|
Mar 13, 2002 10:24 AM
|I'll try to rephrase it in my words (Maybe someone will answer it):
If you start with a bike that seems to fit, how much does moving the rider back (or forward)(By moving ths seat back (or forward)10 MM & reducing (or increasing)the stem by 10MM) change the riding characteristics? What are the extremes? It might be easier to think in terms of starting with the riders center of gravity exactly over the bikes center of gravity (50/50 weight distribution), and try to define what changes in ride characteristics each change would result in.
I hope this is what you are asking, because I am also interested in this. I also agree that the larger the range of change within which ride is not affected, the more stock fit can be adjusted to work. The opposite is also true.
|I like my wording better than your rephrasing :-)||ET|
Mar 13, 2002 11:26 AM
|You're keeping fixed the ideal frame and then making adjustments to it (why?). That's awkward, since your seat is already in the ideal position for the rider (e.g. to achieve KOPS) before you start moving it and making stem changes. Your scenario also considers only an ideal frame but with rider position altered over it.
I'm keeping fixed the ideal rider position and asking what if anything you lose if you have a slightly less-than-ideal frame and make minor adjustments to obtain that position, which is what many of us experience when we buy a bike.
You're right that no one seems to have answered the question yet.
BTW, that Merckx story everyone keeps bringing up (with his 110 stem) is legendary. Does anyone know how tall he was (I think pretty tall) and how normal was his torso/leg/arm proportions? Maybe the 110 was good only for him.
|wait, what was that question? ;)||gtx|
Mar 13, 2002 12:33 PM
|I think it gets back to the Postal riders on their OCLVs, and some of the weird stem and seatpost setups those riders use. After trying the 56 and 58 OCLVs extensively, I know for myself that I could get them both to "fit," but neither really felt "right" to me. I think it's a center of gravity thing, like I mentioned in my first post. However, I don't think it's such a big issue that it is slowing any of the Postal riders down.
Regarding Merckx, I think he was a little under 6'. I'm about that height, and my 57cm Merckx with an 11cm stem feels perfect to me.
Mar 13, 2002 12:46 PM
|My first OCLV was a warranty replacement for my Trek 2500, however, as most of us know the OCLV's are sized smaller, so my 54cm OCLV was closer to a 52cm frame in true standover even though the top tube was quite close to the preceeding 2500. I never could get the 5500 to feel right. The shorter headtube required me to go to rise stems as it took me several tries in reach and rise to get close to where I wanted the bars. Even then, I didn't like the way the bike handled, which may indeed have been due to center of gravity.
My point being that one might get various frames to "fit" by adjusting stems, saddle height etc., but the feel of the bike might not be anything close to what you want.
In my case, when I got the 2nd OCLV as a warranty replacement, I sold the 5500 frameset and went to something else, as I knew that though I could make the bike rideable for me, it would never be enjoyable.
|I like my wording better than your rephrasing :-)||Len J|
Mar 13, 2002 12:50 PM
|Two sides of the same coin.
Aren't you really trying to determine what differences in the realtive position of the riders center of gravity vs the bikes center of gravity do to the ride?
I think your wrong when you say "...since your seat is already in the ideal position for the rider (e.g. to achieve KOPS) before you start moving it and making stem changes." I don't agree that the ideal position is KOPS, I think rather it is more related to the balance between position relative to the pedal & the CG over the bike.
It just seems to me that the real "Subjective" thought underlying TJ's & Anvils' discussion was the significance of movements of the rider fore & aft on Bike "feel". To me this is entirely related to balance front to rear, which is why I phrased it the way I did.
ET, you have demonstrated yourself in the past as much more an expert on fit than I am. I was merely trying to clarify the question (since soo many people seemed to have misunderstood).
|now I disagree over your disagreements :-)||ET|
Mar 13, 2002 1:18 PM
|No hard feelings though. Regarding saddle position, whether it's KOPS or some other standard, whether it's a time trial setup (higher and more forward seat) position or standard riding position, the seat-pedal relationship for that rider is more or less fixed for the given circumstances. Just about all fitters zone in on that position first (e.g. through a fixed size cycle where CG isn't felt) and also deduce ideal STA from that before moving on to other things. Sure, the CG will affect how the bike feels, but altering your seat because of it is not the way to go. If that bike doesn't feel right due to CG, that bike isn't for you. What kind of change will bring on that feeling or loss of performance is part of the question.|
|Clarify please, this is interesting.||Len J|
Mar 14, 2002 6:09 AM
|Are you saying, that a given rider (However he sets up his seat pedal relationship) has a unique Center of gravity and therefore true fit is about balancing this CG over the bike (In addition to comfortable reach & seat to bar drop)?
If this is true, then perfect fit (On a stock frame)would start with an understanding of where the CG needed to be on each and every size of every stock frame (To be perfectly balanced), and matching the riders particular CG with the a Frame CG . Custom sizing would only be needed in the event that no stock frame was a perfect match (Notice I said needed, By this I mean necessary, this doesn't preclude other reasons to go custom). Am I way off the mark?
This is an interesting problem as every individual has a somewhat unique CG. If you could figure this out mathematically you could create a computer program that would store all stock frame CG's & by inputting enough measurements of a rider (In addition to the normal measurements you would need some indication of weight disposition torso vs. legs ) the program could select a number of frames and sizes, that would result in a near perfect fit. This would be further complicated by the variability in sizes that TJ has alluded to in earlier posts (i.e. not al 56's are the same size). Interesting possibilities.
Am I way off in my understanding?
|I think this whole thread got carried away on a tangent||ET|
Mar 14, 2002 7:33 AM
|You can't look at a rider's CG without looking at the bike too, e.g. frame weight distribution, butting of tubes, frame angles, materials, components and a whole other bunch of quirky things.
There's no need to unnecessarily complicate things here and keep re-wording what I'm saying. You test-ride a bike to see how it feels (pretty basic). You have a typical comfortable riding position that you're gonna need to get to(pretty basic--if you don't your measurements, you can go to Anvil for a fitting, and he'll give you STA and seat distance from BB, TT length, stem length and height, maybe HT angle too, but even without the measurements you're gonna make adjustments on a non-perfectly-fitting bike till you get there). You test-ride a bike that needs some adjustments. You slide the seat a cm or so fore/aft and swap stem sizes by one or two cms to get to that position. Here is the question:
Do nonextreme seat and stem adjustments such as these measurably decrease comfort or performance, and if so by how much?
I don't want to hear about custom being more than just fit, that you get your own color scheme and unique bike, or that a 6'3" guy with a 25" inseam needs a custom, or theoretical physics arguments. Or anything else like that. I just want an ANSWER.
|Answer to your question||Anvil|
Mar 14, 2002 8:08 AM
|"Do nonextreme seat and stem adjustments such as these measurably decrease comfort or performance, and if so by how much?"
Yes. No. Maybe.
Look ET, you may not want some theoretical arguments, but you're asking a theoretical question. You can not leave the rider out of any bike equation when that equation requires rider input. I wouldn't get myself in a twist over it. Let me put it to you this way:
If you by a bike that is your approximate size but you find you need to use more saddle setback to achieve your preferred knee/pedal spindle position. Now to make the top tube length work, you need to shorten the stem by 1cm. Will that make a difference that is measurable? Yes. Steering will quicken for a given input, weight bias will shift further to the rear. Will that difference matter to the rider? You need to ask the rider.
I've built bikes to meet customer demands that I considered way beyond what I would want for my personal bike. One guy insisted on 370mm chainstays on a rather conventional crit frame. 370mm! No way, not for me. To me it felt like it would turn out from underneath me the front end was so light and you had to pay attention to it every second. But, he raves about how that bike works for him and I'm sure in fast, tight, and aggressive cornering it's the cat's meow. People are different and they react to the changing variables on bikes differently. This is why I find it impossible to separate proper fit from ride and handling. They're all part of the same sandwich.
|Answer: No nm||scottfree|
Mar 14, 2002 8:19 AM
|different factors helped me make my choice...||DINOSAUR|
Mar 13, 2002 11:35 AM
|I think finding the perfect balance has a lot to do about your personal anatomy and the STA of your bike.
I have long legs (87cm) my Klein has a 74 STA. The stem that come stock with my Klein (130mm) was too long for my short torso. I swapped to what I thought was a 120 90o (it turned out to be a 125).
Still this didn't feel right. I felt over extended and I felt I needed to get down lower. I thought about this for two years. Finally I started looking around at stems, it got very confusing with the rise factor. I even ordered one and turned around and cancelled the order two hours later.
I called up my LBS and told them I didn't know exactly what I wanted but if I could see the stems they had in stock I would know which one would work for me.
So I dragged my bike down to my LBS, looked at their stems and they installed a 11cm 72o rise. I could feel the difference immediately when I rode. However I felt a need to push my saddle back further in the rails, so I did, as far back as it could go. Then I leveled it off using a small carpenters level and lowered it about 2mm. This makes me feel perfectly centered on my bike. I feel like I could put my hands behind my back and ride with no hands (old guys shouldn't try to do this).
My problem is the tt of my bike is too long (59.5) as I should be riding a 59 c-t instead of a 61 c-t.
I was all set for a fitting for a custom bike. I started to add up the cost for fitting, building, and the 150 mile one way drive to the custom builder. The figure was a little too high for my pocket book.
On a lark I called the owner of my LBS and told him what I was doing but I wanted to talk to him first. He set up meeting before his store opened and we had a dicussion about what I wanted. I also told him I wanted a fitting. He took some measurements and with my input we decided on a 59 Colnago Master X-Light. I wanted a steel bike that was strong, durable and that would fit my anatomy. He also gave me a $600.00 discount as I was a long time customer. Bottom line is he said they wanted my business.
Would a custom do the job? Sure. Will the Colnago work? I have a money back guarantee that it will. The cost factor was the deciding factor for me. Also the convience of purchasing locally from a LBS that is 15 minutes away, and no charge for a fitting or building. He also said I could swap out stems if the one they installed didn't work.
Maybe when I turn 64 in four years I can convince my wife that I need a custom.
The deciding factor for me was cost and convenience.
I also like being on a first name basis with the owner of my LBS and doing business with someone I can trust because of 12 years of personal contact.
Mar 13, 2002 11:47 AM
|ET, most of "normal" people would fit well on stock frames. The exception would be the vertically challenged people (5'-5'5" or under) or weirdos with short/long torsos and/or legs. In smaller sizes mfg tend to screw up geometry (75deg seat/71 head angles etc).
THere're basically 2 separate questions: pedaling efficiency and handling.
In terms of pedaling efficiency the seat/BB offset probably the most important. Not that I campaign for KOTS if you're used to certain moving seat back/forth will offset the muscle balance. It will also change effective TT length and that's why some builders refuse to publish TT length.
Other important issue is the angle btw torso and legs. Conventional wisdom says that if you lower your body too much you'll restrict airflow to lungs and also change pedaling angle (and use muscles in diff proportion).
There's a lot you can do with offset seatpost to get "right" fit - effective seatangle. Compacts offer even more freedom as you can get long 2.5" offset layback seatposts.
GIven "fixed" position on frame relatively to BB there will be more then one sweetspot for handlebars. Changing stem length will alter handling (weight distribution, also effective handlebar width).
Still there're alot of other things which affect handling even more like head angle, fork rake, handlebar type/width, wheelbase, so the statement "stem shall be 11cm no more no less" is pretty much pointless. Amount of spacers to run will depend on headtube length, headset stack, stem etc etc etc.
and the last you have to change a lot to make bike handle different by big margin and even if it happens it will take less time to adopt to different handling then to pedaling.
|huh? What are you talking about?||ET|
Mar 13, 2002 11:57 AM
|Why are you contorting the rider and then saying he won't feel good? For the final time, keep rider position fixed and make minor adjustments to bike to get that. Like, you walk into an LBS, try out a bike, but need to slide the seat one cm and swap stems by one or two sizes, and you wanna know is that essentially good enough, whether for Joe Blow, Joe Blow Pro, or Joe TDF. That is, is anything noticeable lost?
Is anyone gonna discuss this? I'm almost ready to give up.
|re: huh? What are YOU talking about?||cyclopathic|
Mar 13, 2002 12:30 PM
|I think I pretty much answered your question.
IT doesn't matter average bike is made for average Joe and minor adjustments won't screw feel much IMHO.
The only important thing is saddle/BB offset and some cannot get it on stock frame. THis usually happens on very small or very big frames. Or riders with very short/long legs.
WIth your question of is there anything lost noticable is very subjective category and something hardly noticable for one rider/conditions will be very annoying or perhaps impossible for other.
Why don't we drag on about Q-factor or handlebar style? it may be even more important.
PS there's a lot more to custom frame then just fit
|Trying real hard to understand your premise.||scottfree|
Mar 13, 2002 1:05 PM
|Can't quite grasp what you mean by 'keep rider position fixed.' And are you saying that all bikes sitting on the LBS floor start out in some neutral, Platonically ideal position -- correct for that particular bike -- and that scooting a seat or changing a stem is somehow corrupting the ideal?
This is an interesting topic, but I think we're having trouble with your premise, ergo the confused answers.
Mar 13, 2002 1:37 PM
|Don't answer that. :-)
Here's an example: You have a certain ideal STA, say 73, such that you'll end up on the middle of the rails. Switch to another bike with 72.5, and you'll have to push your seat forward of center to get back to your riding position. Get it? No, not all showroom bikes are ideal, but part of your ideal (fixed) rider position includes, or, if you prefer, is determined by, a 73 STA. You also have a certain ideal or preferred reach to the bars. Imagine you riding your favorite bike set up so everything feels perfect. Freeze that rider in that position. Take him off that bike, make adjustments on new one so frozen rider fits to saddle and bars. None of this is new. Can't I ask a simple question? I'm really getting sad. Shoulda never asked.
|Light bulb on.||scottfree|
Mar 13, 2002 2:00 PM
|Which is why you can't just know certain human measurements (reach, saddle height, overall height) and apply them to bikes the human has never sat on.
You could say, well, with this bike I can achieve these measurements by jiggling seat position, stem length etc.
But the human might well be unfomfortable -- or at least not in ideal position -- on that particular bike, even though all the numbers add up.
|re: can we talk a bit more about the Anvil vs. TJeanloz debate?||brider|
Mar 13, 2002 12:33 PM
|Given that a race bike is in the nieghborhood of 1000mm in wheelbase (okay, some are less, but let's just start there), and you're moving the rider forward 10mm, that's only going to achieve a 1% difference in weight distribution (ignoring the change in leg angle, which will have a tendency to lessen the change in CG). I don't think that 's going to make an appreciable difference in the ride characteristics of the bike. Now the 10mm difference in the stem length is going to make a BIG difference in how the steering feels, as you're making more like a 10% change in the distance from the steering axis to the bars (less of a % change if you consider hand position on drops or hoods). This WILL be noticeable, but not necessarily negative (depending on the steering geometry). Now considering a 57cm frame, with a 73 degree STA, the change in saddle position will result in an effective STA change of about .5 degree. Not huge, but we're talking about something that is VERY individual. Like I said earlier, it's not going to chcange the ride characteristics of the bike much, but muscle recruitment WILL change somewhat, and WILL be noticeable. Whether that's bad is up to the rider.|
Mar 13, 2002 7:47 PM
|Reading your question over again I would think that a persons anatomy plays a major factor in this question. A change in a setting would be different depending on the rider.
That's why saddles go up and down and stems come in different lengths. I know there are zillions of mathematical formulas to deal with position, but for most of us it's probably been done by experimentation until you find what feels comfortable. And if you ride enough, you know what geometry works for you and what doesn't. And if you really know your stuff, you can have a custom built to your specs. Does this sound right?