Is bike geometry rubbish?
Comments
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Imposter wrote:Trivial poursuivant wrote:Imposter wrote:964Cup wrote:If you want to experience the difference geometry can make, get a track bike drilled for brakes, like a Bianchi Pista, and compare it to an endurance geometry road bike like an Enigma Etape.
Well obviously. You probably wouldn't want to ride a frame designed for downhill mtb around a velodrome, for the same reason.
But within the confines of road frames (which I'm assuming is the context for this discussion), then I think the point that frame geometry differences are subtle/marginal at best is a valid one...
In the confines of road bikes, the geometry can still differ a lot. Look at a Giant Propel compared to a Defy. The Propel wheelbase brings the rear closer to the crank (look at bikes with seatstay cut outs for the rear whee)l. with shorter chainstays which improve power transfer and is a lot stiffer. With a much lower front end and shorter head tube is makes the steering a lot more responsive and allows the rider to get lower and more aero. It is a lot longer and lower compared to the high up sloping geometry of the Defy. This is just two bikes from the same brand. Lots of bikes differ in many ways depending on their target discipline.
Nobody is arguing that there are no differences in geometry - obviously there are. I suspect the argument is whether those differences actually have any real world impact, in which case I would argue the answer is 'no'. I've seen a Defy take the win in a 3/4 circuit race, and the guy had a perfectly good 'race' position on it. Like I say, the argument is not about whether there are differences - it is more about whether the differences actually matter as much as some people claim.
Beyond a point, all equipment choices offer marginal differences. The geometry of a road varies within a pretty tight range, and as Imposter points out, you can get into a 'race' position on most bikes which are roughly the right size and have drop bars. Of course you can ride and race on nearly any road bike.
Regarding head tube 'height', this tends to get 'lower' on race oriented bikes, because the user of such a bike is on average going to be more performance oriented and lower position will be more suitable. This just tends to correlate with price. But there are also some pretty expensive 'endurance' road bikes out there too. Is there any evidence that racers have a longer position?0 -
Trivial poursuivant wrote:Head angle on a Defy is 71 - 72.5 degrees (going smallest size to largest.
Head angle on a Venge is 72.5 to 74 (small to large)
The difference in stem length will effect handling and so will this angle. It may not sound a lot but then a few mm in stem length can effect steering just as much. A few mm seat height can make massive difference to optimal power output but many don't believe that either even though bike fits can show a minor adjustment can make big differences. Its not that hard to believe small measurement will make big differences. 2mm difference in tyre width make a lot of difference. 2mm! yet not many dispute that.
Well, 2 mm tyre width makes some difference, but again, it's marginal in most situations. I suppose you could lose a time trial by 2 seconds and blame your poor tyre choice. Seat height is a bit of a special case. That's why it's adjustable and head angle generally isn't.0 -
DaveP1 wrote:Yes! Marketing bullshit. Can anyone tell the difference between 1 degree at the head angle, or 10 mm more in stem height, or 1kg in total weight ? Or 25 and 28 mm tyres? 80 psi or 100 psi? I don't think so.
Some people can. There is a big range in sensitivity to such things. As an example, apparently Geraint Thomas is happy to ride 'pretty much' anything. Ben Swift gets upset when his spare bike has a newer saddle because he can feel the difference that comes vs the slightly compressed padding of the older saddle. Some pro teams have stems in 1 mm increments.0 -
Alex99 wrote:Trivial poursuivant wrote:Head angle on a Defy is 71 - 72.5 degrees (going smallest size to largest.
Head angle on a Venge is 72.5 to 74 (small to large)
The difference in stem length will effect handling and so will this angle. It may not sound a lot but then a few mm in stem length can effect steering just as much. A few mm seat height can make massive difference to optimal power output but many don't believe that either even though bike fits can show a minor adjustment can make big differences. Its not that hard to believe small measurement will make big differences. 2mm difference in tyre width make a lot of difference. 2mm! yet not many dispute that.
Well, 2 mm tyre width makes some difference, but again, it's marginal in most situations. I suppose you could lose a time trial by 2 seconds and blame your poor tyre choice. Seat height is a bit of a special case. That's why it's adjustable and head angle generally isn't.
So you’re picking and choosing which to believe. That’s a bit of a cop out.0 -
Trivial poursuivant wrote:Alex99 wrote:Trivial poursuivant wrote:Head angle on a Defy is 71 - 72.5 degrees (going smallest size to largest.
Head angle on a Venge is 72.5 to 74 (small to large)
The difference in stem length will effect handling and so will this angle. It may not sound a lot but then a few mm in stem length can effect steering just as much. A few mm seat height can make massive difference to optimal power output but many don't believe that either even though bike fits can show a minor adjustment can make big differences. Its not that hard to believe small measurement will make big differences. 2mm difference in tyre width make a lot of difference. 2mm! yet not many dispute that.
Well, 2 mm tyre width makes some difference, but again, it's marginal in most situations. I suppose you could lose a time trial by 2 seconds and blame your poor tyre choice. Seat height is a bit of a special case. That's why it's adjustable and head angle generally isn't.
So you’re picking and choosing which to believe. That’s a bit of a cop out.
I'm starting to think that you're not really reading the replies.0 -
There's a very noticeable difference between my venge and my domane. It's not marketing bs, it's reality.
I've tried to make the domane more aggressive like the venge with a -17 stem...but it's still way off enough for me to feel the difference. Believe what you want peeps0 -
CookeeeMonster wrote:There's a very noticeable difference between my venge and my domane. It's not marketing bs, it's reality.
I've tried to make the domane more aggressive like the venge with a -17 stem...but it's still way off enough for me to feel the difference. Believe what you want peeps
The Domane head tube is about 2cm taller, for a given size, than the Venge. As people (ie, me) seem to be repeating ad nauseam though - nobody is disputing that there are differences. The only thing up for debate is 'how much' it matters.0 -
People are confusing frame geometry, frame geometry in certain sizes and bike fit.
There are two discussions, the first one is different ballparks of geometry which are designed to have you sitting in a different position, a different bike fit - this discussion is no different to a general "do bikes in general feel different or not" and of course they do.
The second one is that when the bike fit is identical between bikes, ie the exact relative positions of BB, Handlebar and Saddle are exactly the same, what do the effects of different geometry on the bike underneath you have - this discussion is a better one, for people who make sure their fit is identical bike to bike. In this instance, bike to bike the geometry differences are only one set of differences at play and if you're not careful you can still assume all sorts through confirmation bias and get conclusions wrong.
Any discussion based on the differences in feel between different bikes on which you are sat on in a different position is all a bit daft I think.
Note, you also get all sorts of people who still comment, I've heard people comment on how a bike handles that I've then ridden with and they drag the brakes down the slightest slope and never go around any corner at speed, but they still have opinions. People like to talk about anything though, it's like OAPs talking about their new dishwasher or breadmaker being lovely when they're on an perpetually endless coffee morning really.0 -
Imposter wrote:CookeeeMonster wrote:There's a very noticeable difference between my venge and my domane. It's not marketing bs, it's reality.
I've tried to make the domane more aggressive like the venge with a -17 stem...but it's still way off enough for me to feel the difference. Believe what you want peeps
The Domane head tube is about 2cm taller, for a given size, than the Venge. As people (ie, me) seem to be repeating ad nauseam though - nobody is disputing that there are differences. The only thing up for debate is 'how much' it matters.
Its not just one thing, it’s many things, head tube, wheelbase, seat & chain stay length, top tube length, a little bit here and a little bit there all add up. You get obsessed on one bit without looking at the bigger picture. That’s what marginal gains are. When you change certain parts on a bike they may not do much on their own but that’s got to do with the balance.0 -
Trivial poursuivant wrote:Imposter wrote:CookeeeMonster wrote:There's a very noticeable difference between my venge and my domane. It's not marketing bs, it's reality.
I've tried to make the domane more aggressive like the venge with a -17 stem...but it's still way off enough for me to feel the difference. Believe what you want peeps
The Domane head tube is about 2cm taller, for a given size, than the Venge. As people (ie, me) seem to be repeating ad nauseam though - nobody is disputing that there are differences. The only thing up for debate is 'how much' it matters.
Its not just one thing, it’s many things, head tube, wheelbase, seat & chain stay length, top tube length, a little bit here and a little bit there all add up. You get obsessed on one bit without looking at the bigger picture. That’s what marginal gains are. When you change certain parts on a bike they may not do much on their own but that’s got to do with the balance.
It makes a difference. We already get that. Anyway, I'll leave you to it...0 -
Trivial poursuivant wrote:Its not just one thing, it’s many things, head tube, wheelbase, seat & chain stay length, top tube length, a little bit here and a little bit there all add up. You get obsessed on one bit without looking at the bigger picture. That’s what marginal gains are. When you change certain parts on a bike they may not do much on their own but that’s got to do with the balance.
You can also get obsessed on the overall conclusions you can call the bigger picture. It helps if you are buying into marketing to do this, as most marketing is based around saying all the little things add up, otherwise they'd have nothing to say past a quick sentence.
A lot of people know what will fit them and what won't and the shortlist of possible purchases are informed by this. Past this, once aesthetics and preconceptions are accounted for the list gets shortened still. What someone ends up with they probably have a tolerance to the ride qualities the particular bike has.
You'll get another few people who are daft enough to buy anything they like the look of, thinking they can pick a size that will fit them.
Anyway, you won't find many people who could spec geometry for a custom build, and certainly naff all that can do it without being informed by the geometry charts of something they have or do own.0 -
Yes, but I rode the Etape to work today and will ride the Pista to work tomorrow, so it's not as though they don't/can't both do the same job. I wouldn't personally ride a downhill MTB anywhere, but I certainly see people riding full sussers to work. Lord knows why - perhaps they only own the one bike, i poveri.Imposter wrote:964Cup wrote:If you want to experience the difference geometry can make, get a track bike drilled for brakes, like a Bianchi Pista, and compare it to an endurance geometry road bike like an Enigma Etape.
Well obviously. You probably wouldn't want to ride a frame designed for downhill mtb around a velodrome, for the same reason.
But within the confines of road frames (which I'm assuming is the context for this discussion), then I think the point that frame geometry differences are subtle/marginal at best is a valid one...
This thread is very internet. Lots of people shouting, not many listening, as far as I can tell. The OP's question was "is bike geometry rubbish?" Answer, no.
If the question is "can you tell the difference between two otherwise identical bikes with 0.5 degrees of difference in the head-tube angle?" then perhaps the answer is also no, or more likely "it depends". Some riders are more sensitive than others (as evidenced in this thread, some rider's arses are more sensitive than others, it appears).
If the question is "is bike geometry the only contributor to differences in how bikes feel?" the obviously the answer is no. I have an R5Ca and an S3 painstakingly built to have an identical riding position (to the millimetre). They have exactly the same effective geometry. Do they feel and handle identically? No.
If the question is "can you win pro races on an 'endurance' bike?" then obviously the answer is yes - look at Cancellara, for instance.
If the question is "can you win endurance events on a 'race' bike?" then equally obviously the answer is yes - look at Matt Hayman, for instance.
So if the question is "is it all about the bike?" then the answer is no.
So WTF is the question?0 -
Paraphrasing the original question:
Are the seemingly small geometry differences seen in entry level vs high end bikes are feature worth paying for?
The answer: generally, race-focused (also usually more expensive) bikes are preferentially built to a particular geometry. They are marginally more suited to racing or fast riding and will be noticed /appreciated by some people. The geometry isn't the main factor in the cost, rather the tendency for these bikes to be race-focussed models.0 -
I am a fairly new cyclist (been riding about a year and a half). I have 2 different road bikes, one an endurance frame, the other aero. I can certainly tell the difference in geometry between them, but neither is uncomfortable to ride. My longest ride to date has been on my aero bike.0
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Geometry isn't really about comfort. It's mostly about handling. A bike with a short wheelbase and tight angles will be "twitchy" or "responsive" depending on how you feel about these things, while one with a long wheelbase and slack angles will be "stable" or "steer like a cow" depending on the same. This is one reason people bleat on about pros with long stems - the further the hoods are forward of the stem (and the wider apart), the slower the steering of the bike will be (i.e. the larger the movement needed in the bars to effect the same change of direction).Jayme wrote:I am a fairly new cyclist (been riding about a year and a half). I have 2 different road bikes, one an endurance frame, the other aero. I can certainly tell the difference in geometry between them, but neither is uncomfortable to ride. My longest ride to date has been on my aero bike.
There's a huge amount of science in this with regard to cars, where suspension geometry has a vastly more perceptible effect due to the higher speeds and greater masses involved, and of course the fact that all four wheels follow different paths around any given corner - so we know the physics is real; the question is "can you feel it?" (and "do you care?").
I notice it most when riding my old bikes (ALAN Carbonio and Vitus 979, which have the same geometry) and my track bike. All of them turn in faster and are more "flickable" than my modern bikes; the Vitus and ALAN mostly because they have narrower (40cm) bars, shorter chainstays and less fork trail, the Pista because of steep angles, short stays and narrow (38cm) bars - because track bike, basically.
On the other hand, my cross bike (Felt F3X) although it has "road" geometry in terms of angles and trail (73x72, 45mm) has a much longer wheelbase (1033mm plays 967mm for the Pista) and wider bars (44cm) so it feels more stable.0 -
The picture I couldn't post at the beginning of the thread. (If this works)
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pbassred wrote:The picture I couldn't post at the beginning of the thread. (If this works)
I think you need to google ‘clothes horses’0 -
They matter as much as (or probably more than) anything else about the bike does. The bloke winning the race on the Defy would doubtless have won it whatever he was riding, but if anything was going to stop him it would have been the geometry and setup of the bike rather than whether he had deep section wheels, a bike that weighed a kilo less, 23 or 25mm tyres, 1mm less deflection of the BB at 300w, or most of the other things that the marketeers like to tell us are critically important but actually make minuscule differences.Imposter wrote:Nobody is arguing that there are no differences in geometry - obviously there are. I suspect the argument is whether those differences actually have any real world impact, in which case I would argue the answer is 'no'. I've seen a Defy take the win in a 3/4 circuit race, and the guy had a perfectly good 'race' position on it. Like I say, the argument is not about whether there are differences - it is more about whether the differences actually matter as much as some people claim.
I went to the Cycle Show in Birmingham a few weeks ago and tried out a bunch of bikes on the test track, including a Pina Dogma, Bianchi Oltre XR3 and Canyon Aeroroad disc. Good fun but a complete waste of time in terms of making any meaningful comparisons because the bikes were all set up slightly differently - I made sure the saddle was at the same height before jumping on each bike but couldn't check the saddle setback, reach, stem length etc. Now, these things are adjustable within certain bounds, unlike frame geometry, but to the extent that they are aspects of total-bike-geometry they are of comparable significance. The only differences I could really detect between the bikes were almost certainly due to either setup or frame geometry. The Dogma rode like an elephant because it had a really long stem fitted, the Canyon felt a bit lacklustre under sharp accelerations probably due to the disc frame having considerably longer chainstays, and the Oltre felt great, probably simply because it happened not to have the setup or geometry deficiencies of the other two.
The point someone made about frame sizes is spot on however - geometry is rather important, but we hardly ever hear about how it usually differs significantly between frames of different sizes within the same model. The classic example is trail - because manufacturers are tight b*stards who know that most of us are too ignorant to sell geometry to, they nearly always specify either one or (at the most) two different fork rakes across the entire size range, despite the head tube angle often varying continuously. So small frames tend to have too much trail and large frames too little, while there can be massive differences between a 53 or a 55 size if the latter has the "big frame fork" and the former the small one. Of course when they do talk about frame geometry it's to try to convince us that a gravel bike is different from a 'cross bike (which it usually isn't significantly), when in fact you could detect a greater difference by choosing to go one size up or down than you could by choosing one bike model over the other..0 -
Check out the frame comparison tool at Velogoicfit.com a brilliant tool, and free!0
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proto wrote:Check out the frame comparison tool at Velogoicfit.com a brilliant tool, and free!
Thanks. Altho' it is https://www.velogicfit.com/ and I am not sure if I ought to do it because it might tell me my bikes are all wrong! Ignorance might be more blissful...0
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