# Horizontal vs. Sloping top tubes - what do we think?



## simon.r (22 Apr 2016)

I ride a frame with a 57cm horizontal top tube (centre to centre) and a 61cm seat tube (centre to top). I have about 18cm of seatpost showing.

A different frame from the same manufacturer has a effective top tube of 57cm and a seat tube of 53cm, so I'd need about 26cm of seatpost showing.

From a purely aesthetic point of view I much prefer the horizontal top tube and not too much seatpost showing, but if I'm looking for a new frame that severely limits the choice.

Why are sloping top tubes so prevalent at the moment? Is it just fashion or are there practical reasons?


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## Pale Rider (22 Apr 2016)

I prefer sloping top tubes for the same reason you prefer horizontal - aesthetics.

But I'm not aware of any practical reasons for one or the other.

Tempting to say standover clearance is better on a sloping top tube frame, but when I hop forward off the saddle I'm close to the head tube so the top tube may as well be horizontal.


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## kiriyama (22 Apr 2016)

I prefer horizontal. Aesthetics I suppose, bit more of a classic style.


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## dan_bo (22 Apr 2016)

The original argument for sloping frames was the smaller triangle provided a stiffer structure whilast the longer seatpost dulled vibration mre effectively. I can see the point. 

For what it's worth, I like both.


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## Smokin Joe (22 Apr 2016)

Sloping gives you one less dimension to worry about, you only have to concern yourself with top tube length. It also means manufacturers can offer a smaller range of sizes which keeps costs down for them and ultimately for us. It is worth noting that many pro teams now use frames that are from stock rather than each rider's being custom made.


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## Bollo (22 Apr 2016)

My old litespeed has a horizontal top tube that looked old fashioned when I bought it as sloping top tubes were just taking off. I still think its quite handsome.


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## Bollo (22 Apr 2016)

User13710 said:


> For sheer ugliness, this takes some beating. When I acquired it, I found it only had about an inch and a half of seatpost in the frame as well. It's been rehomed now (with a longer seatpost).
> 
> View attachment 125798


Aaaaarrgghhhh! My eyes!

A step-through kinda hybridy MTB. The world's gone to hell, TMN. To hell.


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## simongt (22 Apr 2016)

According to the late Richard Ballantyne, sloping top tubes are a development of the mountain bike. The idea was / is that with a sloping top tube, when one is belting up and down 'mountains' and the bike is moving around under you, it gives you more manoeverability, thus control. Also, if you come to a sudden stop and slide off the saddle onto you feet, it is less likely to be an eye watering experience. Well, for men at least.


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## 3narf (22 Apr 2016)

Smaller triangles = more stiffity between head tube via BB to back wheel spindle. The seatpost can then provide a degree of flex ergo comfort.

Back in the '70s (I choose this decade 'cos that's when I grew up) and prior, the idea was the biggest possible main triangle as that took out a bit of the harshness. Aluminium components were relatively weak, flexible and inconsistent, so the exposure of the seatpost etc was purposely limited.

Please correct any of this; I'm making it all up as I go along! 

The point I was going to make is that with modern technology and materials, a well-designed and executed bike can have either. Imo a modern-looking carbon or ally bike looks better with some slope; horizontal top tubes seem more natural with skinny, steel tubes.

Having said all that, I'm intending building a steel road frame with a sloping top tube...


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## raleighnut (22 Apr 2016)

Sloping top tube allows a longer head tube on the same size frame, stiffens it up laterally.


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## ColinJ (22 Apr 2016)

simongt said:


> Also, if you come to a sudden stop and slide off the saddle onto you feet, it is less likely to be an eye watering experience. Well, for men at least.


I suspect that most women would probably find that an 'eye watering experience' too!


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## MichaelW2 (23 Apr 2016)

With sloping top tubes, short arsed riders with long torsos can fit better. With a selection of seatpost laybacks and stem length, fewer frames can fit more riders. Giant used to do this with the original TCR, but I think they dropped this service.


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## Accy cyclist (23 Apr 2016)

My Scott expert bought in 2000 was my first sloping top tubed bike.





(Not my bike but 95% like it) The colour scheme looks a bit dated, don't you think?

I prefer sloping but don't mind horizontal top tubes.


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## cyberknight (23 Apr 2016)

http://www.cyclingweekly.co.uk/news/latest-news/icons-of-cycling-giant-tcr-206346


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## Blue Hills (23 Apr 2016)

ColinJ said:


> I suspect that most women would probably find that an 'eye watering experience' too!


Now now colin, stop trying to be so "new man"  not quite the same is it?

On main topic, i can see that horizontal looks more classic and even more aesthetically pleasing. For practical purposes i much prefer sloping, and am prepared to accept that when you stand well back from my bikes and look at them they do look somewhat odd/not big enough. In short, i prefer the ride and sod how the bike looks.


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## betty swollocks (23 Apr 2016)

I prefer the aesthetics of a horizontal top tube and have specified this requirement in my upcoming handbuilt, steel bicycle.
Here's a preliminary drawing the builders sent me, which I have approved.


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## simongt (23 Apr 2016)

ColinJ said:


> I suspect that most women would probably find that an 'eye watering experience' too!


Though less likely to experience a 'squelch' as they come in contact with the top tube - !


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## samsbike (23 Apr 2016)

out of curiosity what is the geometry?


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## GrumpyGregry (23 Apr 2016)

simon.r said:


> I ride a frame with a 57cm horizontal top tube (centre to centre) and a 61cm seat tube (centre to top). I have about 18cm of seatpost showing.
> 
> A different frame from the same manufacturer has a effective top tube of 57cm and a seat tube of 53cm, so I'd need about 26cm of seatpost showing.
> 
> ...


Why? Because with sloping top tubes it means the manufacturers can get away with making a more limited number of frame sizes and still cover all the bases
-plus-
On an aluminium alloy frame a good length of seatpost showing can go an awful long way to taming some of the frame zing as the saddle is free to flap about in the breeze
-plus-
Lots of folk came to road biking from mtb backgrounds in the States and were used to the aesthetics of sloping top tubes because mtb's tended to have huge amounts of standover compared to road frames.

Me? Give me a steel frame with only a fist of seatpost, tops, showing, and I'm a happy rider.


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## GrumpyGregry (23 Apr 2016)

betty swollocks said:


> I prefer the aesthetics of a horizontal top tube and have specified this requirement in my upcoming handbuilt, steel bicycle.
> Here's a preliminary drawing the builders sent me, which I have approved.
> View attachment 125828


Some would argue that is still too much seatpost and too big a stack on the headset but it is a good compromise between classic and contemporary.


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## alecstilleyedye (23 Apr 2016)

a lot of budget frames with a sloping top tube are not true compacts but have just been designed with a sloping top tube without the true compact geometry.

i've got both compact and horizontal top tubed bikes (see sig), and can ride both for a good distance. the carbon compact is a smaller (50cm) frame than the alu horizontal (57cm), and while a lot of seatpost is visible with the former, it's barely enough to mount a couple of lights on with the latter…


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## Stinboy (23 Apr 2016)

Accy cyclist said:


> My Scott expert bought in 2000 was my first sloping top tubed bike.
> 
> 
> 
> ...



That's the same colour scheme on my Scott MTB (pretty much anyway)


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## Accy cyclist (24 Apr 2016)

Stinboy said:


> That's the same colour scheme on my Scott MTB (pretty much anyway)



How old is your mountain bike? Is it something like this?


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## slowmotion (24 Apr 2016)

My Spesh Secteur has a sloping, bent and tapered top tube. It's just so wrong that it's silly.


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## Blue Hills (24 Apr 2016)

Yes, seen those.

What's the theory?


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## betty swollocks (24 Apr 2016)

GrumpyGregry said:


> Some would argue that is still too much seatpost and too big a stack on the headset but it is a good compromise between classic and contemporary.



They are only preliminary drawings. I like these proportions, but agree with your comment about the head tube stack. This will disappear during the bike fitting stages. It is very important to me that the bike should look beautiful as well as be fully functional.


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## Fab Foodie (24 Apr 2016)

Blue Hills said:


> Yes, seen those.
> 
> What's the theory?


Marketing ....


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## winjim (24 Apr 2016)

slowmotion said:


> My Spesh Secteur has a sloping, bent and tapered top tube. It's just so wrong that it's silly.
> View attachment 125936


It wouldn't look quite so daft if it wasn't for that brake cable.


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## Blue Hills (24 Apr 2016)

Fab Foodie said:


> Marketing ....


yes, did wonder. I'm no engineer, but doesn't the bend make the tube weaker?


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## Profpointy (24 Apr 2016)

dan_bo said:


> The original argument for sloping frames was the smaller triangle provided a stiffer structure whilast the longer seatpost dulled vibration mre effectively. I can see the point.
> 
> For what it's worth, I like both.



I've always been a bit skeptical of value of that argument. Just to be clear I rather think it may be literally true, it seems odd to simultaneously claim a stiffer rear triangle is a good thing whilst at the same time having a longer wobblier seat post supporting the heaviest part of the bike (80kg rider) is perfectly OK. I'd have though the sear post should be as short as possible if overall stiffness was so important.

I suspect the reason for slopping top tube is to allow fewer fram sizes to fit A wider range of riders. It does reduce the risk of walloping your bollocks though.

Aestheticall I prefer the "trad" look -horizontal preferably with pretty lugs.

Anyhow, what's all this "top tube" malarkey - it was a cross-bar in my day


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## Fab Foodie (24 Apr 2016)

Blue Hills said:


> yes, did wonder. I'm no engineer, but doesn't the bend make the tube weaker?


Most likely. So to give the same strength it needs to be heavier?

It does however give the 'impression' that there will be some flex in the tube however and that will make the bike more comfortable .... I think with Aliminium in particular it's a myth.


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## Blue Hills (24 Apr 2016)

Profpointy said:


> Anyhow, what's all this "top tube" malarkey - it was a cross-bar in my day



yes, and somehow folks managed to keep control of their bikes without a cockpit.


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