Ride Quality>> Trad vs. Oversize vs. Double Oversize

[e-RICHIE]

i am trying to wrap my head around this stuff because it remains too conceptual based on my experience. if we remove the style/era/trend component out of the equation (mine, at least...) can someone cite an example of what tube diameter substitution in place of another tube yields what difference in feel. is there a moment in a race, or a ride, when you said (for example), "that (tube type goes here ------ > _________ ) changed this (the "this" goes here ------ > _________ ). i am not talking about the frame design or whether the bicycle fit better - the question relates to the OP and the three choices. thanks atmo.

[Dave Kirk]

Put me in the camp that believes diameter does make a big impact on ride feel.

I've ridden exclusively OOS bikes and only recently, after connecting with a lot of what DK has written about re:" too much stiffness" and yes I'll admit even some BQ articles !!! I put my money on the line to experience std dia tubing (22.2 chain stays) for the first time. I currently have no shop but had Erik at Alliance build me a STD dia bike for my 155 lbs. The ride behavior of this bike is simply night and day in terms of 'fit' for my weight considering same contact points. I now understand what it feels like to have a bike that works 'with' me. It is more smooth, responsive and enjoyable than ANY OOS tube bike in ANY material that I've been spoiled enough to own.

I think though big tubing is popular for looks (nothing wrong with that!), essential for the right athlete (big dudes), but us lighter dudes should give a skinny tube bike a try. Clients should communicate what they want in terms of performance/feel and not tubing diameters and geometry and leave those two, plus construction of course, to the builder.

Very cool.

I make a good number of bikes with old school 1" top tubes for smaller lighter riders (typically women) and sometimes it's a bit of a battle to convince them that smaller can be better. But once they ride it they never look back. In some silly ways it's like condoms. The offer standard and 'magnum' but no one offers 'small' and yet I'm guessing small would be a good choice for some. You think the sales of standard size died when magnum was brought to market? I'll bet they did.

dave

[Dave Kirk]

i am trying to wrap my head around this stuff because it remains too conceptual based on my experience. if we remove the style/era/trend component out of the equation (mine, at least...) can someone cite an example of what tube diameter substitution in place of another tube yields what difference in feel. is there a moment in a race, or a ride, when you said (for example), "that (tube type goes here ------ > _________ ) changed this (the "this" goes here ------ > _________ ). i am not talking about the frame design or whether the bicycle fit better - the question relates to the OP and the three choices. thanks atmo.

I own bikes with all three popular sizes of steel tube - standard, OS and XL - and I like them all. I doubt I'm significantly faster on one than the other two. And yet I feel the difference on every ride, at every corner and going up and down every hill. They are just different. Each one shines a bit more than the others in a given circumstance and falls short of the others in a different setting. But they are all different, all the time. Are they day and night different, black and white, good and bad? No not at all. But they are markedly different. An apt analogy might be comparing a good clincher with a good tubular. Both ride well but they are of course different and most would feel the difference. I think the differences in tube sizes are a bigger deal than the tire analogy but they are similar in concept.

I'll bet if you built three identical bikes for yourself, with the exception of the tube sizes, that you would feel the difference between them.

As a slight aside - One of the very cool things I got to experience while working at Serotta was riding all different types of bikes, built with different materials or different sizes and of different designs. I rode different bikes all the time and when I finally left the company I had 14 Serottas and no tow were alike. Before this I knew that there were certain bikes I like and others I didn't but I didn't really understand why one felt good and the other didn't. But by riding all the bikes on the same roads with the same fitness and the same fit I was able to learn to feel the differences. I do think it's a learned skill and takes time and a variety of bikes to develop.

During that time I would build a Ti bike without a c-stay bridge and ride it and then bring it in and put a bridge in it and take it right back out and see what the difference really felt like. In some cases there was little difference to be found and in others (like the Ti c-stay bridge) the difference was huge. At the same time I was able to ride many bikes, in my size, built by other companies to put things in perspective. I think you don't really know how good/bad your own work is until you've tried something else. In so many cases rider technique could make up for or mask a shortcoming of a given bike and the rider doesn't even realize it. But when spending time on a completely different design the rider realizes that they can set aside the way they were using the previous bike and let it go and this will open up the performance/enjoyment envelope. One of the things I learned was that in some cases our bikes (Serottas) absolutely kicked ass and in others they were behind the competition. With that experience we were able to make subtle but important changes that made the bike more enjoyable/fun and in some cases faster.

In the end I see this as all being shades of gray and and not black and white and what makes one rider smile will make another unsmile (it's a new word I'm pushing). Vive la Differance. To me tube sizes are just another facet to explore in the quest of make the rider not unsmile.

Dave

[jerk]

data point:

i built richard a gaulzetti with the exact same geometry as the os tubed road bike he'd been riding for years. on paper there shouldn't be two more different riding tubesets.

anyway-
c

[e-RICHIE]

I own bikes with all three popular sizes of steel tube - standard, OS and XL - and I like them all. I doubt I'm significantly faster on one than the other two. And yet I feel the difference on every ride, at every corner and going up and down every hill. They are just different. Each one shines a bit more than the others in a given circumstance and falls short of the others in a different setting. But they are all different, all the time. Are they day and night different, black and white, good and bad? No not at all. But they are markedly different. An apt analogy might be comparing a good clincher with a good tubular. Both ride well but they are of course different and most would feel the difference. I think the differences in tube sizes are a bigger deal than the tire analogy but they are similar in concept.

like. feel. just different. shines. different. markedly different.
any or all of these words could be attributed to the weather, or the breakfast meal, or your fitness level.

I'll bet if you built three identical bikes for yourself, with the exception of the tube sizes, that you would feel the difference between them.

that's where this started.

i have. see the above post(s). since the mid 70s i have ridden every conceivable combination, and raced them too. and i haven't said as much already, but while my 'cross career is a hobby at best, i can suffer for an hour if there's a prize list. never have i noticed the difference between the shapes and diameters of the frame parts.

As a slight aside - One of the very cool things I got to experience while working at Serotta was riding all different types of bikes, built with different materials or different sizes and of different designs. I rode different bikes all the time and when I finally left the company I had 14 Serottas and no tow were alike. Before this I knew that there were certain bikes I like and others I didn't but I didn't really understand why one felt good and the other didn't. But by riding all the bikes on the same roads with the same fitness and the same fit I was able to learn to feel the differences. I do think it's a learned skill and takes time and a variety of bikes to develop.

i've had maybe 30 RS frames through the years and the only constant was the design; the pipes, brands, and sizes/gauges varied. that's why my opinions are what they are.

During that time I would build a Ti bike without a c-stay bridge and ride it and then bring it in and put a bridge in it and take it right back out and see what the difference really felt like. In some cases there was little difference to be found and in others (like the Ti c-stay bridge) the difference was huge. At the same time I was able to ride many bikes, in my size, built by other companies to put things in perspective. I think you don't really know how good/bad your own work is until you've tried something else. In so many cases rider technique could make up for or mask a shortcoming of a given bike and the rider doesn't even realize it. But when spending time on a completely different design the rider realizes that they can set aside the way they were using the previous bike and let it go and this will open up the performance/enjoyment envelope. One of the things I learned was that in some cases our bikes (Serottas) absolutely kicked ass and in others they were behind the competition. With that experience we were able to make subtle but important changes that made the bike more enjoyable/fun and in some cases faster.

In the end I see this as all being shades of gray and and not black and white and what makes one rider smile will make another unsmile (it's a new word I'm pushing). Vive la Differance. To me tube sizes are just another facet to explore in the quest of make the rider not unsmile.

Dave

thanks for the reply. these things you describe are visceral. that's good, too. i was hoping to hear why they felt the way they did, or why you likeed them, or what the difference was, or what makes it shine and how. i understand the math and fully acknowledge the engineering back story. my opinion includes that, while the science exists to explain what a pipe would feel like in different iterations, it's not there to quantify what happens when a set of pipes becomes another item completely. we are talking about the bicycle and its feel, rather than the properties of a pipe. i can't separate design, execution, and materials from each other. i guess shades of gray and visceral will have to be all we have to sink our teeth in for now.

[GrantM]

I make a good number of bikes with old school 1" top tubes for smaller lighter riders (typically women) and sometimes it's a bit of a battle to convince them that smaller can be better. But once they ride it they never look back.

dave

For grins and giggles, can you tell me the wall thickness of the tubes and fork you built for me?
I know what SL tubes feel like, i've had many of those frames over the years with very similar geo
to what you made for me, but i also have not known the tube wall thickness on several frames I liked
and didn't like, so i've never been able to narrow that criteria.

-g

[Dave Kirk]

ER - like. feel. just different. shines. different. markedly different.
any or all of these words could be attributed to the weather, or the breakfast meal, or your fitness level.

I feel your frustration and understand it. But feelings are all we can have in this. I can say I have more times than I can to remember gone out for a 10 mile loop on one bike and then switched to another and so on and so forth. I can't give anything but subjective feelings because nothing else exists and frankly it's all that matters to me. If you are looking for hard data like 'bikes with XL top tubes are faster by 10%" I can't give that to you and I can't think of anyone else in the biz that can.


ER - that's where this started.

i have. see the above post(s). since the mid 70s i have ridden every conceivable combination, and raced them too. and i haven't said as much already, but while my 'cross career is a hobby at best, i can suffer for an hour if there's a prize list. never have i noticed the difference between the shapes and diameters of the frame parts.


I'm sorry if I didn't understand that you had built with different tube diameters and shapes. I knew you built with 1" top tubes and then switched to 1 1/8" but didn't think you worked in XL or max or tapered tubes.


ER - i've had maybe 30 RS frames through the years and the only constant was the design; the pipes, brands, and sizes/gauges varied. that's why my opinions are what they are.

I assume here you are speaking of the switch from 1" to 1 1/8" top tubes and different walls within those sizes. Do I understand correctly? I think the brands and alloys will have little to no influence over the ride and wall doesn't change it that much either. As we know diameter changes have the biggest effect. So IMO it makes sense that those bikes would feel pretty much the same to you.

I think it would be fun to have bikes in your size magically appear with a wide mix of tubes - XL, MAX, Colorado, aero......etc. It would be fun to have those all in your size to ride back to back on the same afternoon.


ER - thanks for the reply. these things you describe are visceral. that's good, too. i was hoping to hear why they felt the way they did, or why you likeed them, or what the difference was, or what makes it shine and how. i understand the math and fully acknowledge the engineering back story. my opinion includes that, while the science exists to explain what a pipe would feel like in different iterations, it's not there to quantify what happens when a set of pipes becomes another item completely. we are talking about the bicycle and its feel, rather than the properties of a pipe. i can't separate design, execution, and materials from each other. i guess shades of gray and visceral will have to be all we have to sink our teeth in for now.

Again, I, like the rest of the industry, have little in the way of hard numbers but I know what I like. Like I said above I have 3 bikes with different tube sizes and here are the highs and lows of each. I almost always use the same wheels on each bike. FWIW I'm 6'4" and 185 pounds.

Bike #1 1" top tube/ 1 1/8" down tube / 1 1/8" seat tube - Reynolds 725 main tubes and Kirk by Reynolds stays - this bike is very smooth and quiet. It's the choice for a 'day off' ride where I just want to soak up the sun. While I like the smoothness it's not as torsionally stiff as I'd like for hard charging riding and big climbing/descending. If any of the three feels the slowest this would be it by a very small margin. It has a horizontal top tube.

Bike #2 1 1/8" top/ 1 1/4" down tube/ 1 1/8" seat tube - 953 main tubes and same stays as above - The bike feels nearly as smooth as the above bike but it has better responses and jumps more when I want it to. It makes a different noise and has a different feel which seems to boil down to the torsional rigidity of the front end making the bike feel more precise...... like you can aim it better. There isn't much of a downside to this one. If I had to nit pick I'd say it's behavior on bad roads or dirt could be sharper. When going at 10/10ths it can feel a touch vague and harder to keep on line or to hold the exact line of the wheel in front of you. In short it feels like a more precise and 'better' version of the above bike. 5° sloped top tube.

Bike #3 1 1/4" top/ 1 3/8" down and 1 1/4" seat tubes - 953 front end and same stays as above two bikes. This bike's strong suit is holding a line and putting power down. It holds it's line very well on almost any surface and goes exactly where you point it. It's very stiff torsionally and feels 'all of one piece' if you will. It climbs and descends the best of the three. The downsides are that it's a bit heavier and doesn't ride as smooth as the two above. I don't find I use it if I'm going out for an hour of soft pedaling but it is the bike I seem to grab more than any other. 4° sloped top tube.


If I had to give a few word summary -

Bike #1 - a get smelling the flowers bike.
Bike #2 - the best all rounder of the three. what I would choose for a century ride.
Bike #3 - a race bike and the one I would grab if I were going racing.

All this talk of riding makes me want to get out on the bike before the afternoon winds kick in. Have a great weekend and enjoy the spring.

Dave

[Dave Kirk]

For grins and giggles, can you tell me the wall thickness of the tubes and fork you built for me?
I know what SL tubes feel like, i've had many of those frames over the years with very similar geo
to what you made for me, but i also have not known the tube wall thickness on several frames I liked
and didn't like, so i've never been able to narrow that criteria.

-g

I'd have to go into the way-back machine and look it up but I feel pretty safe in saying the top tube is .8/.5 and the down tube is .7/.4 . The fork blades should be 1.1/.8 .

I hope that helps with the data points.

dave

[e-RICHIE]

I assume here you are speaking of the switch from 1" to 1 1/8" top tubes and different walls within those sizes. Do I understand correctly? I think the brands and alloys will have little to no influence over the ride and wall doesn't change it that much either. As we know diameter changes have the biggest effect. So IMO it makes sense that those bikes would feel pretty much the same to you.

thanks. that's what i was saying. but, yeah - the frames have also included conical main tubes going back to the mid 90s. i've had columbus air frames, i haven't had full on max or MS frames. i've done the 531, the 653, the 531SL, the 725, the 525, the columbus SL, SP, SLX, KL,, EL OS, LIFE, normal EL, and all the iterations that have followed. i spent 6-7 years using all sorts of true temper cromo. and then there's the deda zero, and deda zero uno, and somewhere in the middle i tried a few SEX attempts too. i vow to continue until at least i feel something. the shades of gray thing is painful. i wanna get to the other side.

[Dazza]

A stiff frame is not faster in the majority of cases.
A flexy frame does not raise one's anaerobic threshold. Sorry Jan, it is not true.
Hundreds and hundreds of riders giving feed back is telling many frame builders that designing a frame with the rigidity to suit the rider size and weight is a good thing. They like it riding them. ( Dave Kirk's post)
I do not believe you go faster until the grunt on the pedals gets to significant levels.
Some A.I.S track testing has shown that this is measurable.
If you putter putter on the pedals it all does not matter if you are 90kg and pedal like a daddy long legs spider and corner like you are on tricycle.
I reckon Richie is fine on OS or Std. They will both be rigid enough for him for his size and weight and horsepower.
But any velocity changes cannot be measured.
read below


I wrote this some where else

yes
and the tests and the science shows that flexy frames do not soak up energy more than stiff frames
they do not heat up dissipating energy, this is a huge myth
but the rigid frame will handle and track better
giving confidence to the rider
thus it feels nice to ride!

but importantly the front wheel and the back wheel stay in better plane/alignment if the frame is rigid under high wattage stress
(Stress = the force, Strain = the deflection)
so rolling resistance of the wheels/tyres is lower as the wheels track better.
If the frame bends a lot the wheels are not in the same plane
and rider counter steers the bike with each pedal stroke
This is what riders call responsive when there is less input to direction/handle bars to the pulse on the pedals.
it feels like the bike jumps to the pedal stroke.

An Extreme example is the kilo rider, when they start they generate over 2,500 watts for a few seconds
and the frame distorts huge amounts, but the wattage drops as the pedal rpm increases but it is still WOW. Still over 1000 watts.

1000 + watts on a frame that is as rigid as over cooked pasta (pasta just like how the French cook pasta )
is terrible.
For a road frame we have to ride for many kilometers for a long time
so harshness must be reduced
All road frames are a compromise of rigidity for good feel and responsiveness with flex for comfort
a good builder designs the frame to find this balance for the particular individual rider

I know steel is the best for this
weight is less important
but the market just sells weight as the most valuable item

[Dazza]

Rigidity is about the feel
The correct amount for the rider's size and weight
makes the frame feel nice
In reality not faster, but they rider thinks it is because they like the feel.
Until you do extremes of bike to rider matches then they are all have the same resistance and power transfer
I hate that crap about power transfer. 99% of the time is total bull shit.


I also wrote this some where else
it was a reply about the feel of frame with regards to performance


If we put 300 grams of material in the frame
that extra material will change the way the frame feels.
for example if I make one frame with .7 /.5/.7 mm tubes
and the same frame geomeery and dimensions with tubes .8/.5/.8
then yes the frames will feel different to the rider
It is the extra material, not the extra weight that changes the feeling that the rider is feeling in the frame.
The extra material mass used correctly such as in the frame tubes is a good thing.

The extra weight (Mass) in theory will have effects when changing velocity or working against gravity. In real tests it is never possible to reproduce as the rider's power fluctuates in the tests. And even with SRM measuring data (I was fitting and maintaining the SRM equipment at the Australian Institute of Sport) we can not find the weight against power inputs measurable. In theory it must be there.
With a 75 kg rider and 7kg bicycle = 83 kg then .3kg is not much.
On one climb the rider may perspire .5 to 1.5 kg of water
then air temperature has effects on drag when testing
oh it goes on and on all the problems of detecting 300 grams when riding.
On a calculator it is possible
Out side when riding up mountains science cannot measure as there is so many influences to the measurements. The rider may feel there is a difference, but actual velocity changes is not able to be detected against the input of power. (unless the extra weight approaches 3 to 5kgs, then it shows in the data measurements)


Hookes's law of Springs
Hooke's law - Wikipedia, the free encyclopedia
The same energy is stored in the strain (flex) of the stiff frame tube
as
in the strain (flex) of less stiff tube.

That energy still goes back into the chain as the frame tube returns to normal when the pulse of the pedal stroke reduces at 12 o'clock-6 0.clock

Some say that a flexible frame feels better to pedal on because of this.
I am not sure of this. I like the bike to track smoothly and with out wiggle.

I believe that very flexible frames behave badly when climbing and descending hard in rough corners. (also the fork is very important )
The extra 300 grams is better for performance.
The beautiful part of bespoke custom bicycles, in any material is that a good skilled and careful builder will take appreciation of the rider's circumstances and build a bike to meet the criteria.

There is a limit.
A frame as stiff as Granite is not going to be faster.

[JuanGrande]

Thanks everyone for this discussion - as a hobbyist builder, this is one of the areas that has been most vexing to me as I learn to build... how to select appropriate tube sizes for riders and intended purpose. I am 6'7" tall and weigh 200lbs, and I use myself as the test mule for all my bikes (I don't plan to sell a frame until around #30 or so...). My most recent build was a cross frame based off Dazza's slant 6 lugs. Since I am big and tend to ride my cross big like I am on a downhill mtn course, I felt the larger tubes would be appropriate... so far so good.

Here's my question for Dave - in looking at your three different bikes, how much of the difference in feel is a result of frame design (horizontal vs slanted top tube) vs tubing selection?

The reason I ask is that intuitively I think that a slanting top tube will help stiffen the bike since I am reducing the length of the seat tube, etc... but there are alot of variables to this other than tube selection - in the case of my cross frame, I am using a Thomson seat post in 30.9 size, definitely a stiffer seat post. So as I type this question, the reality of RS's earlier post about what happens when you take a set of tubes and combine them into a completed frame is sinking in... and I have to question the influence of part selection as well.

Again, thanks for this discussion - great food for thought.

Jonathan

ER - like. feel. just different. shines. different. markedly different.
any or all of these words could be attributed to the weather, or the breakfast meal, or your fitness level.

I feel your frustration and understand it. But feelings are all we can have in this. I can say I have more times than I can to remember gone out for a 10 mile loop on one bike and then switched to another and so on and so forth. I can't give anything but subjective feelings because nothing else exists and frankly it's all that matters to me. If you are looking for hard data like 'bikes with XL top tubes are faster by 10%" I can't give that to you and I can't think of anyone else in the biz that can.


ER - that's where this started.

i have. see the above post(s). since the mid 70s i have ridden every conceivable combination, and raced them too. and i haven't said as much already, but while my 'cross career is a hobby at best, i can suffer for an hour if there's a prize list. never have i noticed the difference between the shapes and diameters of the frame parts.


I'm sorry if I didn't understand that you had built with different tube diameters and shapes. I knew you built with 1" top tubes and then switched to 1 1/8" but didn't think you worked in XL or max or tapered tubes.


ER - i've had maybe 30 RS frames through the years and the only constant was the design; the pipes, brands, and sizes/gauges varied. that's why my opinions are what they are.

I assume here you are speaking of the switch from 1" to 1 1/8" top tubes and different walls within those sizes. Do I understand correctly? I think the brands and alloys will have little to no influence over the ride and wall doesn't change it that much either. As we know diameter changes have the biggest effect. So IMO it makes sense that those bikes would feel pretty much the same to you.

I think it would be fun to have bikes in your size magically appear with a wide mix of tubes - XL, MAX, Colorado, aero......etc. It would be fun to have those all in your size to ride back to back on the same afternoon.


ER - thanks for the reply. these things you describe are visceral. that's good, too. i was hoping to hear why they felt the way they did, or why you likeed them, or what the difference was, or what makes it shine and how. i understand the math and fully acknowledge the engineering back story. my opinion includes that, while the science exists to explain what a pipe would feel like in different iterations, it's not there to quantify what happens when a set of pipes becomes another item completely. we are talking about the bicycle and its feel, rather than the properties of a pipe. i can't separate design, execution, and materials from each other. i guess shades of gray and visceral will have to be all we have to sink our teeth in for now.

Again, I, like the rest of the industry, have little in the way of hard numbers but I know what I like. Like I said above I have 3 bikes with different tube sizes and here are the highs and lows of each. I almost always use the same wheels on each bike. FWIW I'm 6'4" and 185 pounds.

Bike #1 1" top tube/ 1 1/8" down tube / 1 1/8" seat tube - Reynolds 725 main tubes and Kirk by Reynolds stays - this bike is very smooth and quiet. It's the choice for a 'day off' ride where I just want to soak up the sun. While I like the smoothness it's not as torsionally stiff as I'd like for hard charging riding and big climbing/descending. If any of the three feels the slowest this would be it by a very small margin. It has a horizontal top tube.

Bike #2 1 1/8" top/ 1 1/4" down tube/ 1 1/8" seat tube - 953 main tubes and same stays as above - The bike feels nearly as smooth as the above bike but it has better responses and jumps more when I want it to. It makes a different noise and has a different feel which seems to boil down to the torsional rigidity of the front end making the bike feel more precise...... like you can aim it better. There isn't much of a downside to this one. If I had to nit pick I'd say it's behavior on bad roads or dirt could be sharper. When going at 10/10ths it can feel a touch vague and harder to keep on line or to hold the exact line of the wheel in front of you. In short it feels like a more precise and 'better' version of the above bike. 5° sloped top tube.

Bike #3 1 1/4" top/ 1 3/8" down and 1 1/4" seat tubes - 953 front end and same stays as above two bikes. This bike's strong suit is holding a line and putting power down. It holds it's line very well on almost any surface and goes exactly where you point it. It's very stiff torsionally and feels 'all of one piece' if you will. It climbs and descends the best of the three. The downsides are that it's a bit heavier and doesn't ride as smooth as the two above. I don't find I use it if I'm going out for an hour of soft pedaling but it is the bike I seem to grab more than any other. 4° sloped top tube.


If I had to give a few word summary -

Bike #1 - a get smelling the flowers bike.
Bike #2 - the best all rounder of the three. what I would choose for a century ride.
Bike #3 - a race bike and the one I would grab if I were going racing.

All this talk of riding makes me want to get out on the bike before the afternoon winds kick in. Have a great weekend and enjoy the spring.

Dave

[Adam Eldridge]

Thank you everyone for the wonderful thread. Rider weight to me personally determines what butt profiles and tube sets get selected. I've up till this point built with trad. and oversize, never double OS. Thanks for the spirited discussion.

My personal steed is Traditional SL,1" HT, Fastback cluster, Flattop crown oval 1.0 wall blades. I'm 5'9 160lbs. It inspires very fast corner entry and holds the line well on spirited group rides. Looking forward to getting it out in the crits when I come up for air. My butt meter tells me the fastback cluster makes for a much more stiff rear triangle.

Thanks again.. now I'm going out on a ride!

[Dave Kirk]

Thanks everyone for this discussion - as a hobbyist builder, this is one of the areas that has been most vexing to me as I learn to build... how to select appropriate tube sizes for riders and intended purpose. I am 6'7" tall and weigh 200lbs, and I use myself as the test mule for all my bikes (I don't plan to sell a frame until around #30 or so...). My most recent build was a cross frame based off Dazza's slant 6 lugs. Since I am big and tend to ride my cross big like I am on a downhill mtn course, I felt the larger tubes would be appropriate... so far so good.

Here's my question for Dave - in looking at your three different bikes, how much of the difference in feel is a result of frame design (horizontal vs slanted top tube) vs tubing selection?

The reason I ask is that intuitively I think that a slanting top tube will help stiffen the bike since I am reducing the length of the seat tube, etc... but there are alot of variables to this other than tube selection - in the case of my cross frame, I am using a Thomson seat post in 30.9 size, definitely a stiffer seat post. So as I type this question, the reality of RS's earlier post about what happens when you take a set of tubes and combine them into a completed frame is sinking in... and I have to question the influence of part selection as well.

Again, thanks for this discussion - great food for thought.

Jonathan

I see it's your first post - cool - welcome to Vsalon.

Thanks for the question. I feel like I'm going to disappoint but to be blunt I have no idea how much comes from the tubes and how much comes from the orientation of those tubes. I could guess.........I'd guess that the tubes themselves have more effect than the slope (or lack thereof) of the top tube but without measuring it I can't say how much stiffness credit should be given to the tubes or the slope. It's pretty damn easy to measure if you have tow frames that are the same geometry but the tubes are different.

This has been a good thread and I feel like I've learned something so that makes it a good deal to me.

Dave

[steve garro]

Tubing is like handlebar width, crank length or stem length.
Small people get smaller dimensions, Larger riders get larger dimensions.
Hope that helps.
Now please explain to me why we need 31.8mm H-Bars.
Fuck, they are stiff.
- Garro.

[Too Tall]

Tubing is like handlebar width, crank length or stem length.
Small people get smaller dimensions, Larger riders get larger dimensions.
Hope that helps.
Now please explain to me why we need 31.8mm H-Bars.
Fuck, they are stiff.
- Garro.

I go this one. Because they don't fit into 26.0 stems without alot of sanding. [blink blink]

[jerk]

Now please explain to me why we need 31.8mm H-Bars.
Fuck, they are stiff.
- Garro.

so they can meet stupid CEN impact standards and not weigh a ton.

[hampco]

and 35mm bars for whom too much is never enough.

[Norman]

i have. see the above post(s). since the mid 70s i have ridden every conceivable combination, and raced them too. and i haven't said as much already, but while my 'cross career is a hobby at best, i can suffer for an hour if there's a prize list. never have i noticed the difference between the shapes and diameters of the frame parts.

dear uncle rich, maybe you ride/race too much cross. i suspect the wide plus low pressure tires, and loose ground muddled your perception about the difference. i bet skinny high pressure tires, long climbs, long twisty descends and >1 hour rides would help you get out of the shades