do dropped seatstays work on small bikes (48/49cm) ??

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tireheb
Posts: 124
Joined: Fri Apr 23, 2021 7:05 pm

by tireheb

im small so 48/49 frames are my thing. im looking for a new bike and it would be my first modern dropped dropped seatstay bike.
but a lot of times when i look at pics of bikes this size with dropped dropped seatstays they look a bit weird, top tube inclined which makes me wonder, does the dropped dropped seatstays stop beeing so effective when going down in size? (wheels remaining the same size, which would explain why the aeroad xxs (kinda like a 49 if im right) comes with 650 wheels.
maybe trying to preserve this design when scaling down even looses aero purpose. maybe there is still some aero advantages but i would guess they go tiny
and aesthetically they tend to come up weird. at least in pictures cause i havent seen so much dropped dropped seatstays this size in real life.

what do you people think? for sure other small people here have had thoughts on the topic. only aesthetic opinions are welcomed also
Last edited by tireheb on Thu Jun 06, 2024 6:57 pm, edited 1 time in total.

tireheb
Posts: 124
Joined: Fri Apr 23, 2021 7:05 pm

by tireheb

really no opinion? am im the only one with these sort of thoughts on small bikes?

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Lelandjt
Posts: 940
Joined: Tue Jan 19, 2016 7:10 am

by Lelandjt

You mean seatstays, right?
That bike size is so far left on the bell curve and so few women use this forum (any?), it's possible you're the only one here who has studied them.

tireheb
Posts: 124
Joined: Fri Apr 23, 2021 7:05 pm

by tireheb

Lelandjt wrote:
Thu Jun 06, 2024 12:49 pm
You mean seatstays, right?
That bike size is so far left on the bell curve and so few women use this forum (any?), it's possible you're the only one here who has studied them.
my mistake, my bad english there mixed with fast posting, fixed, thanks.

tireheb
Posts: 124
Joined: Fri Apr 23, 2021 7:05 pm

by tireheb

ok last try then i just leave this die.

curious about cool looking bikes in small sizes

fatpinarellorider
Posts: 255
Joined: Wed Mar 01, 2023 5:30 am

by fatpinarellorider

Maybe put a picture of the bike up?

It depends what your preferences are. Aero? Comfort? Weight? Aesthetics?
If you think it looks weird and aesthetics is your preference, then don't buy it?

I would not buy a bike I did not like the look of, but that's me.

AFAIK, the frame does not come with 650-sized wheels because "dropped stays become less effective in smaller frame sizes", but just for the sake of having better overall geometry and fit.

CarlosFerreiro
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Location: Shetland, Scotland

by CarlosFerreiro

With dropped stays for comfort then the concept is to get more flex in there somewhere, but in smaller sized frames the length of both "less supported" seattube and length of exposed seatpost go down, and then rider weight goes down probably as well, you'd clearly need a different carbon layup to get the same effects.
I'm not sure how easy it would be to get solid information from the brand to confirm that had been done. I guess if you saw lower maximum rider weights for smaller size frames that would be some confirmation it wasn't just the same layup on all sizes, but it might be more complicated than that too......

apr46
Posts: 351
Joined: Thu Aug 26, 2021 1:46 pm

by apr46

I think huge part of the lack of response is that no-one here knows. However, I would offer the thought that there are both tradeoffs to consider as well as the notion that it probably matters less for smaller bikes. For example at this size Cervelo has their aero S5 more or less without dropped stays while the allrounder Soloist gets proportionately dropped stays. However the larger sizes of the soloist do not drop the stays that far below the top of the wheel which is where the stays of the 48cm S5 already are.

I would guess at this size there is probably little aero benefit to dropping the stays, but there is a comfort benefit in that you can move the flex away from the rear triangle to the seatpost cluster.

I would also avoid 650 wheel for road riding. I am all about not making geometry compromises, but Canyon made the quite a few anyway.

mikemelbrooks
Posts: 359
Joined: Wed Jun 16, 2010 10:58 pm

by mikemelbrooks

My 2 Cents
With a standard 700c wheel you have to have a minimum length chainstay or the wheel would rub the seat tube. The seatube itself will be shorter. So the bike will look out of proportion.
It's the same as a very large framed bike. The frame looks ok but the wheels look out of proportion to the frame. There is a reason that most bike sales pictures use a 54 or 56 frame it looks better.

TobinHatesYou
Posts: 13042
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Dropped seatstays don’t become less effective. For smaller riders, the bike contributes more to overall CdA than for larger riders.

Some bikes don’t drop their seatstays as much for smaller sizes due to lazy design or other design limitations. The NDS seatstay/chainstay junction has to be “open” enough to fit a flatmount brake caliper for example.

If you ever look at a bike like the Ridley Falcn, the smallest size looks like it doesn’t even have dropped stays.

apr46
Posts: 351
Joined: Thu Aug 26, 2021 1:46 pm

by apr46

If the position of the seat stay on the small bike that doesnt have a dropped stay design is at roughly same height as as the dropped stay design, the dropped stay design surely is less "efffective" or makes less of a difference. However the aero design and the way the stays are joined and that shape probably continues to make a difference.

Continuing to drop the stays starts to create issues elsewhere depending on the shape of the stays themselves. In the case of the S5 i am guessing that the shape of the seatube has something to do with it, but also that it wasnt worth redesigning the rear end to progressively drop the stays both from an aero and an effort standpoint as the juction is already well below the top of the wheel.

OtterSpace
Posts: 392
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Location: California Silicon Valley

by OtterSpace

I can ride up to a 52 but go with a 49 ±1 for better aero and shorter reach for my t-rex arms. Meanwhile my GF is shorter but prefers a 50-52 but with less seatpost when initially I thought she would like a 650b bike.

Geometry just gets a bit wacky at bikes sub 50 and insane at sub 45. This makes it hard to answer as one 49 frame is not the same as another vendors. In general geo overrides any claims about frame size and doubly so at the frame size extremes.

There are two things going on here dropped stays and sloping top tube. In smaller sizes the top tube can drop more as a % to give more effective seat post which gives less space to drop the stays relative to the BB. They do this for a more compliant seatpost as generally smaller riders want less stiff bikes and larger riders want more stiff bikes.

At a high level certainly look up small size geo and pictures of a bike at that frame size before trying or buying as aesthetically you can get some trash looking bikes at these smaller sizes even if the stays are not dropped relative to the top tube. Head tube geo is also important but thats another matter.

Here are some examples bikes I've tried with very similar touchpoint setup:

Here is an example of a trash aesthetic domane geo in 50cm
trash.jpg
Here is an example of older round tube Izalco Max geo in 48cm
olld.jpg
Better looking modern builds can happen but its hard for a designer to balance dropping the top tube and stays, having the right headtube & spacer height, while giving the seatpost more length to flex in a 700c frame.

SL6 49cm
sl6 build.jpg
Solace 49cm
solace.jpg
Last edited by OtterSpace on Mon Jun 17, 2024 3:47 am, edited 1 time in total.

TobinHatesYou
Posts: 13042
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

OtterSpace wrote:
Mon Jun 17, 2024 3:07 am

Here is an example of a trash aesthetic geo in 50cm
trash.jpg

I mean it's an electric endurance bike. What are you expecting?

OtterSpace
Posts: 392
Joined: Sun Mar 08, 2020 6:28 am
Location: California Silicon Valley

by OtterSpace

TobinHatesYou wrote:
Mon Jun 17, 2024 3:21 am
I mean it's an electric endurance bike. What are you expecting?
I wasn't for the bike initially but we all try to optimize here when we can as we all should to drive the market forward. Also there are trash looking small geo race frames too as they juggle how much to drop the seat tube.

The Solace is even more gravel focused yet has a much lower top tube and looks better while still being the same type of bike. On the Domane+ I was slammed from the get go while on the Solace I was able to drop it lower while maintaining some steerer tube for when I sell the bike in a few years.

thirdsun
Posts: 422
Joined: Fri Aug 06, 2021 3:20 pm

by thirdsun

tireheb wrote:
Thu Jun 06, 2024 2:06 am
which would explain why the aeroad xxs (kinda like a 49 if im right) comes with 650 wheels.
While a few Canyon models come with 650B in the smallest sizes, the Aeroad does not. The Aeroad comes with 700C in all sizes. I know because I ride an Aeroad in 2XS. You can also confirm this by looking in the geometry data for the bike - Canyon has a separate chart for component dimensions on every product page.
  • Canyon Aeroad CF SLX 8 Di2
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