# sloping top tubes vs. traditional



## r_mutt (Aug 8, 2007)

if sloping top tubes are really created by the bike companies as a cost saving measure (they only have to make 5 frames rather than 10++ or so) why is it that custom frame builders like carl strong, vanilla, etc... all make sloping top tube frames? 

i'm not trolling, and forgive me if you think it's a stupid question. 


happy holidays!


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## DaveT (Feb 12, 2004)

r_mutt said:


> if sloping top tubes are really created by the bike companies as a cost saving measure (they only have to make 5 frames rather than 10++ or so) why is it that custom frame builders like carl strong, vanilla, etc... all make sloping top tube frames?
> 
> i'm not trolling, and forgive me if you think it's a stupid question.
> 
> ...


A sloping top tube can accomplish several things. A certain "look" is one, some folks really like it. Another is that the top tube can slope 'up', from the seat tube to the head tube and create a taller front end for someone that needs their handlebars higher than a horizontal tube would allow, without lots of spacers, a tall head tube or a very upright stem. The pic of my Quiring and Kirk illustrate this point very well. Both bikes have the same contact points, same seat height, bar reach and bar height.










Or the top tube can slope 'down', from the head tube to the seat tube and allow more stand-over for those who want it.


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## Kerry Irons (Feb 25, 2002)

*False premise*



r_mutt said:


> if sloping top tubes are really created by the bike companies as a cost saving measure (they only have to make 5 frames rather than 10++ or so) why is it that custom frame builders like carl strong, vanilla, etc... all make sloping top tube frames?
> 
> i'm not trolling, and forgive me if you think it's a stupid question.


When Giant first introduced their sloping top tube line, they made the claim that it would allow for fewer frame sizes. When you think about it, there is no logical reason for this to be true. And, as it turned out, it wasn't true. The fact that most companies now offer fewer frame sizes than in days of old just means that they have hired (or bought into) inventory managment specialists. If you offer fewer frame sizes, then your customers have to be comfortable with a wider range of stem lengths, stem spacer stack heights, and seat post extension than they were when you offered more frame sizes. This is true whether the frame has a sloping top tube or not.


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## dekindy (Jul 7, 2006)

Kerry Irons said:


> When Giant first introduced their sloping top tube line, they made the claim that it would allow for fewer frame sizes. When you think about it, there is no logical reason for this to be true. And, as it turned out, it wasn't true. The fact that most companies now offer fewer frame sizes than in days of old just means that they have hired (or bought into) inventory managment specialists. If you offer fewer frame sizes, then your customers have to be comfortable with a wider range of stem lengths, stem spacer stack heights, and seat post extension than they were when you offered more frame sizes. This is true whether the frame has a sloping top tube or not.


This is absolutely 100% true. Cervelo used to have a technical paper on their website but I am unable to find it anymore. The level and sloping top tube theoritcally have engineering advantages depending upon what area of the frame you want to emphasize maximum stiffness. Carbon frame technology has advanced such that this may not even be true anymore. Otherwise, purely comsetic.


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## danl1 (Jul 23, 2005)

It's not a stupid question at all, and really points to a more fundamental problem: Seat tube length is nearly useless as a way to describe the 'size' of a frame, until a few other assumptions are made. 

The core of a 'good' bike size are the distances (horizontal and vertical) between the bottom bracket and the top of the headset. Get those in the right place, and you'll nearly always be able to find a post and stem that will yield a properly fit bike. 

The challenge is that for many folks, choosing those dimensions proper to their fitness, flexibility, and riding goals creates a bike with a higher standover than most folks are comfortable with - something a sloped frame can easily address. A sloped frame can also be somewhat lighter - though by the time the longer seatpost is added, that advantage largely disappears. The stiffness argument is a red herring as well - the frame itself may be stiffer this way, but by the time the bike is built into a complete structure, (stems, posts, and all) a traditional frame would usually be stiffer between contact points.

It's a bit overstated that sloped tubes are all marketing and aesthetics, but it is largely true that they exist in large part to appeal to people accustomed to the sensibilities of mountain and BMX biking. There, standover matters more, and somewhat more upright positioning is familiar, making sloped tubes part of what 'seems' right. That's also the 'launch point' for most of today's market of riders.


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## terry b (Jan 29, 2004)

I have chosen to do a slightly sloping top tube on every custom I have built for a very simple reason - with a hair more exposed post, I can clamp my bikes in my Park shop stand without changing the height of the seat.

It makes life easy for me, and there is no cost in design, performance, cost or anything else.


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## Keeping up with Junior (Feb 27, 2003)

*Fashion*



danl1 said:


> It's a bit overstated that sloped tubes are all marketing and aesthetics, but it is largely true that they exist in large part to appeal to people accustomed to the sensibilities of mountain and BMX biking. There, standover matters more, and somewhat more upright positioning is familiar, making sloped tubes part of what 'seems' right. That's also the 'launch point' for most of today's market of riders.


Never underestimate the importance of giving the customer what they want - even if it does not serve a purpose. I recall reading an interview with a builder a few years ago when the carbon craze was just starting. He was asked why he was putting carbon seat stays on the steel and Ti frames he was building. He said something like it really serves no purpose from a performance standpoint as steel and Ti have excellent absorption properties and in fact the carbon stay bikes weigh more but that is what customers were asking for because carbon was all the craze. The frustrating part was that what would normally be an easily repaired steel frame was now basically disposable because of the carbon stays. 

So now that folks are used to seeing sloping top tubes that is what they expect and want to buy.

Me - I like the look of a traditional frame.


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## wim (Feb 28, 2005)

Keeping up with Junior said:


> The frustrating part was that what would normally be an easily repaired steel frame was now basically disposable because of the carbon stays


Little bit off topic, but isn't that where it's all going anyway? Most people nowadays get rid of a bike long before it's worn—driven by boredom and/or the incessant drumming of the marketeers. And how many actually take advantage of the fabled repairability of steel frames?


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## CurbDestroyer (Mar 6, 2008)

I'll just thrown this out. When I build a frame, adding a sloping top tube adds another point of complexity . . . at least on my jig.


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## adimiro (Jun 28, 2007)

In cyclocross specific bicycles, the straight top tube is preferred for easier/roomier shouldering when runing with bike.


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## PeanutButterBreath (Dec 4, 2005)

r_mutt said:


> . . .why is it that custom frame builders like carl strong, vanilla, etc... all make sloping top tube frames?


Every so often a mountain biker gets the custom roadie bug.



r_mutt said:


> i'm not trolling. . . .


Oh. In that case, disregard the above comment.


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## batroadie (Oct 3, 2008)

Here's my 2-cents... For years I have owned a couple of Cannondales Cadd 3,4 
(traditional frames). For a sprinter, I find myself hitting my inner thigh up against the top tube as I whip the bike from side to side (Just felt big)... Then the compact frame was produced and BOY!! WHAT A DIFFERENCE!! It just fits my body structure so much better and increased my sprinting abilities... In my opinion, pick a bike that fits,comfort, etc. It's all a matter of preference..Personally, I like the look of the sloping top tube. Just recently built an 09 Giant TCR Advanced which are the pioneers of the compact design.. Checkout my profile for photos...
Hope this helps.


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## CurbDestroyer (Mar 6, 2008)

Compact. 









Compacting


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## drop dead (Mar 31, 2012)

I hate sloped top tubes the bike does not track well making you have to re adjust your line many times. It was meant for Mt bikes so you could stand over when hitting a stump and don't get you nuts squashed. I like the comments here all correct it is a bunch of crap and any pro that says anything about it gets his mouth taped soon afterward. Return cycling to some sense of sanity and get ride of these girls bikes we want level top tubes. When I sprint it is about the bike moving forward not side to side ...


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## config (Aug 16, 2002)

drop dead said:


> I hate sloped top tubes the bike does not track well making you have to re adjust your line many times. It was meant for Mt bikes so you could stand over when hitting a stump and don't get you nuts squashed. I like the comments here all correct it is a bunch of crap and any pro that says anything about it gets his mouth taped soon afterward. Return cycling to some sense of sanity and get ride of these girls bikes we want level top tubes. When I sprint it is about the bike moving forward not side to side ...


Comment from a true pro ---- not really!


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## Kontact (Apr 1, 2011)

drop dead said:


> I hate sloped top tubes the bike does not track well making you have to re adjust your line many times. It was meant for Mt bikes so you could stand over when hitting a stump and don't get you nuts squashed. I like the comments here all correct it is a bunch of crap and any pro that says anything about it gets his mouth taped soon afterward. Return cycling to some sense of sanity and get ride of these girls bikes we want level top tubes. When I sprint it is about the bike moving forward not side to side ...


"Track well". If you can explain the connection between the top tube angle and handling or alignment that makes any sense, I'll send you $20.


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## onefastbiker (Mar 23, 2012)

I believe the manufactures who call sloping top tubes: "Compacts". Indeed, they have less net material which leads to a slightly lighter frame with a tall seat tube. I went from a Trek 5200 with a level top tube to a Madone 5.9 with a sloping top tube. Both bikes have similar geometry and both track and corner with the same aggression. I weigh a little under #150 and both bikes are/were solid climbing platforms. This appears to be a discussion between gram counters and traditionalist. Have fun with it - I'm going for a ride!


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## erickB (Jan 3, 2012)

when you have few zise, sloping tube help to sell wrong bikes to small people


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## Hiro11 (Dec 18, 2010)

This is a purely aesthetic thing. The only thing that matters is the relative position of the bars, saddle and BB center. The frame in between these points could look literally like anything as long as those they are in the same position in space and the frame will fit. Under certain situations, compact frames allow for more seatpost showing and less spacers, but again that's purely aesthetic.

Having said all of that, compact frames look weird. Flat top tubes are where it's at.


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## gordy748 (Feb 11, 2007)

Compact does help make a lighter frame, there's just less material. Of course, in a minute someone will observe that we are talking a few grams between the two designs, and they're quite right.

Compact also helps make a stiffer frame, with tighter main and rear wheel triangles it helps to prevent flex. Of course, in a minute someone will observe that we are talking semantics, and besides a compact frame has a longer seat post, which is more flexy.

There is always the hybrid approach. Dario makes his frames with level top tubes but they connect the head tube well below the top-most point. End result is a compact-ish rear triangle, and a level top tube, which keeps everybody happy.


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## TBarnaby (Mar 1, 2012)

drop dead said:


> It was meant for Mt bikes so you could stand over when hitting a stump and don't get you nuts squashed.


Have you ever ridden a MTB?


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## T K (Feb 11, 2009)

drop dead said:


> I hate sloped top tubes the bike does not track well making you have to re adjust your line many times. It was meant for Mt bikes so you could stand over when hitting a stump and don't get you nuts squashed. I like the comments here all correct it is a bunch of crap and any pro that says anything about it gets his mouth taped soon afterward. Return cycling to some sense of sanity and get ride of these girls bikes we want level top tubes. When I sprint it is about the bike moving forward not side to side ...


First post is on a 3 plus year old thread? Well, at least he dazzled us with his brilliance.


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## pinkmaddogz (Dec 19, 2009)

I prefer slightly sloping top tubes. Well curved at least, like the Tarmac S-Works SL2.


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