[Closed] Yet more road bike musings - aero or light weight?

http://www.cervelo.com/en/engineering/thinking-and-processes/weight-vs-aero.html

Aero. You can save 175g elsewhere (tyres and tubes, for example). If the non-aero frame was 850g I might be swayed for general riding. And I am lucky to have one of each. I race the aero.

As a Roubaix rider I would go for the more comfortable option every time; I would guess that an aero frame is likely to be stiffer. The aero effect only happens at high speeds and since 2/3 of our riding in Lancashire is up hills, wind resistance is less important that light weight and comfort.

My first proper road bike was a 1990 Harry Hall in Columbus SLX, a horribly uncomfortable bike that beat me up so badly that I felt I'd done a few rounds in a boxing ring after only 40 miles. By contrast the Roubaix is a delight, comfortable even over 100 miles, which definitely saves energy.

2000 feet of climbing over 50 miles isn't a great deal and 100g weight difference will be unnoticeable.

If your climbing isn't going to increase significantly I'd go aero every time.

Probably aero going off those figures as the weight difference is minimal.

Although I reserve the right to change my mind when I know which brand we're talking about as clearly aesthetics win over everything else 😆

OP I've been through the same..my thoughts/experience:

1. The differences will be utterly marginal, esp at 17mph - they are still time at decent racing speeds but might help someone get 36th rather than 37th place...so NO DIFFERENCE HERE

2. Lighter will be more fun to ride due to the light weight alone so TINY DIFFERENCE HERE

3. The lighter frame is likely to handle better and be more comfortable as aero frames are generally stiffer SIGNIFICANT DIFFERENCE HERE.

I'm happy with the non aero frame I bought - I'm a little faster than you and I DO race occasionally (time trialling too, where aero is more important) but I went with what puts a smile on my face.

Aero vote here too. You don't do enough climbing to make the lightweight frame a vast difference.

Again if the lightweight frame was Circa 700g then I'd say do that, but it isn't so no.

You ave 17mph, you'll feel the difference in an Aero at that speed, if you were knocking out <15moh then again I'da said the lightweight. Also you will feel the difference in the road feel on the Aero, it'll feel stiffer and you'll get a good buzz from the road and that will encourage you to hack longer and harder, IMO.

Then race it, or race yourself on it 😀

I went with what puts a smile on my face.

can't go wrong with that approach!

Pick the one you find best looking. It's unlikely you'll be going fast enough to get much aero benefit and you aren't climbing huge mountains where weight might make a difference (assuming you are sub 70kg yourself).

That said, some aero frames are harsh. Some, not so bad. Have you got a chance to test them?

Hmm, looks like aero is edging it then. I agree my local area is not really hilly, more rolling though you do never feel like you're riding on the flat.

Odd question, does it make any difference that said frame will likely be a XL/60cm in size so the weights will likely be somewhat higher than those stated? Also, an answer to the above post, I am somewhat more than 70kg as is fitting someone who is 6'4"!

Lunge what are the two frames you are considering?

The frames in question are both Sensa jobs through Merlin:
[url= http://www.sensabikes.com/bikes/road/189/giulia-supremo-custom?c=24 ]Ligher[/url]
[url= http://www.sensabikes.com/bikes/road/191/calabria-custom?c=24 ]Aero[/url]

Both will have an Ultegra Di2 build and carbon wheels.

aero, aero, aero

Though realistically, al mostly covers it. The aero will be a bit faster, but a frame only makes a very small contribution to your overall aero - at an average of 17mph I'm afraid you're unlikely to be winning anything if you do race, so as he says it will at the most make the difference of one place in the pack. You won't possibly notice the difference if you're not racing. Just pick whichever one you like the look of most, or which you think you'd prefer, ignoring which one is theoretically faster.

at an average of 17mph I'm afraid you're unlikely to be winning anything if you do race

Colour and general appearance trumps both.

Is there any chance you can ride either frame before committing? I test-rode an own-brand bike from a local BS and found it OK but discovered that my heels were striking the chainstays because the tubes were straight, not curved inwards as on my own bike. So that was out of contention straight away.

All else being equal I'd go aero as weight difference is negligible. Ride would probably be the deciding factor though. Put some decent aero wheels and finishing kit on the non aero bike and I doubt there's be much in it.

The frames in question are ..

Whichever one will take mudguards. Then it will get ridden in all weathers. 🙂

Not really seeing the aero in that aero frame.

I don't think there's a right answer here - for the riding you actually do, either will do the job. The aero one is likely to be a little stiffer in ride which may make it slower over long enough rides but if you like the feel of a stiff ride ( 😉 ) and the look of an aero bike then go for that. I suspect that the 'aero' nature of the bike will make a negligible difference to you in real world terms given your height and the relative drag from you/the bike.

Or if you like the feel of a light bike and the carpark kudos (why not?) then go for that though again, the weight saving against your own weight will make negligible difference (though it may feel like it does which can be justification enough).

Or choose the one in the nicer colour.

Only slight caveat would be that as a similar height rider to you, I have found some lightweight frames in large sizes are too flexy for my tastes and aren't nice to ride out of the saddle on steeper climbs. Whether that's an issue is for you to decide.

I timed myself up a steep-ish (6%) hill on two consecutive days.
One day on my cheap alu road bike with mudguards (10kg) and the next on carbon road bike (7.5kg).

Difference over 6 minutes was 6 seconds in favour of the carbon bike. Not really statistically significant.

So I'm gonna sell the carbon one.

I don't race, just go out to enjoy myself and my alu bike (Genesis Aether) is more comfortable, takes mudguards and the 8 speed drivetrain keeps on trucking all year long without any bother.

"Aero"
[img] [/img]

Light
[img] [/img]

I don't see much real aero about the calabria - it looks more like the sort of thing that's just fits what people expect aero to be - eg aero seatpost/seat tube. Proper aero road bikes have aero forks, Rear wheels that have next to no gap to the seat tube/wheel cutout, concealed cables and hidden brakes - like here: http://www.bikeradar.com/road/news/article/best-2015-aero-road-bikes-eurobike-2014-42385/
http://www.bikerumor.com/2014/09/15/eb14-argon-18-unveils-nitrogen-aero-road-e118-next-tri-krypton-xroad-plus-possible-new-dura-ace-di2/

As such, just go for the one you like - the aero does look good IMO
[img] [/img]

One additional word of warning - for aero seatposts, check whether you can get replacements - I know people with expensive frames that they're patching together after a few years because they can't get replacement posts or seat clamps that have failed and they need to be just the right shape to fit the frame.

Actually I'll overide my advice above by saying don't buy ANY FRAME/BIKE if you're not confident you know how it will ride.

epicyclo - Member

Whichever one will take mudguards. Then it will get ridden in all weathers.

If I have to rationalise my bike collection then I am thinking nice road bike with mudguard clearance, and commute on my Brompton.

I can't believe how few high end/fancy bikes come with clearance and mudguard eyes.

yourguitarhero - Member

I timed myself up a steep-ish (6%) hill on two consecutive days.
One day on my cheap alu road bike with mudguards (10kg) and the next on carbon road bike (7.5kg).

Difference over 6 minutes was 6 seconds in favour of the carbon bike. Not really statistically significant.

Errm that's just meaningless - a difference of < 0.5% could have been lots of factors, and you weren't even measuring your HR or power. The real difference will be pretty much 2.5kg/(weight of you plus bike).

If you have a workstand that clamps the frame/seatpost then a round seatpost is much preferable. And as someone said above, aero seatposts can be tricky to buy later on.

The one you like the look of and will make you want to ride. Which for me is usually the lightweight not aero option.

GCN on YouTube did a vaguely scientific test (riding at constant power) and the aero edged it but only marginally.

[quote=nemesis ]The aero one is likely to be a little stiffer in ride which may make it slower over long enough rides

Hmm, do we need to have a discussion on comfort of road frames? I would be extremely surprised if it made any difference at all - at least the aero and weight differences might have a negligible effect.

Having said that, I agree that it isn't really properly aero - though the seatpost and tube are one of the more important bits, so it might still make a difference. Personally I prefer the look of the "aero" one, though I think that's mostly the paint job.

I accept that it's debatable which is why I made sure I caveated it with 'may'. IME and IMO it does make a difference if you ride far enough or on rough enough roads but equally I am often willing to accept that for a bike I prefer the feel of.

Also, an answer to the above post, I am somewhat more than 70kg as is fitting someone who is 6'4"!

i wouldn’t be worried about an aero frame then. your frontal area will have a lot to say about that especially if you are not flexible.
get the one thats nice to ride and some decent wheels which will have more influence on the ride quality than any tangible benefits you may be able to discern from having a bike frame with lower drag.

With this specific choice, I'd get the aero one. Not because of that fact but because it's £200.00 cheaper.

The issue for me with frames claiming to be aero - for many of them there is no published data to back it up. If I was i. The market for an aero road frame I would be looking at tour magazines independent wind tunnel tests as it's about the only time an external comparison gets done. This for me regardless of the test protocol (provided it's consistent) is much better than the manufacturer released papers.

That being said they are highly likely to both be awesome bikes and if the 'aero' one isn't really aero the extra £200.00 nets you a nice skinsuit for racing which will do far more for your drag reduction than any frame.

Iain

I'd question it's benefit on even a propper aero frame, Cannondale had soem figures which showed their Supersix hi-mod (evo?, the original high end one anyway with the 1.1/4 headset not the cheaper 1.5") was only a fraction off the competitions aero frames. Which makes you wonder what frames Scott/Trek/Spesh found to compare their frames against to get the supposed savings.

Although I reserve the right to change my mind when I know which brand we're talking about as clearly aesthetics win over everything else

This +1, having had the same bike for 10 years now I'd say get the one you actualy want. This will probably be for trivial stuff like brand identity, aestetics, or less trivial stuff like ride quality, or tangible stuff like fittings for mudguards, disks, etc.

Going for a cheap bike with a good groupset is a recipie for it just not being right. Look at Hora and his Planet-X! Great bike, won loads of magazine grouptests, but not quite what he wanted in the end even though at some point he probbably did [i]"after more deliberation on everything from build kit to bottom bracket standards, I have now settled on my road build. The only thing left to do is decide the frame"[/i] then pick any old bike that fit his spec list.

I've no idea what those Sensa bikes are like, but I think you've attached the question of "what bike" the wrong way. It should be "What frame do I really want" then "what's the budget leftover for the build". You can upgrade groupsets and wheels at a later date, swaping frames is both more expensive (both financialy, and emotionaly having to admit you actualy got it wrong).

[quote=thisisnotaspoon ]Going for a cheap bike with a good groupset is a recipie for it just not being right. Look at Hora and his Planet-X!

I'm not sure you've correctly identified where the problem is there!

I have a £400 Pedalforce carbon frame with Record hanging off it, and still very happy with my choice - but then I rationalise that there's no real difference between the frame and a £2000 one, whilst you can tell the difference with some of the Record bits (or at least that's what I tell myself). Others might have different preconceptions 😉

I'd say neither of those are aero. I also agree with Al. Ride the bike, get a feel for the frame, then make an informed decision. A nice groupset will not improve a poor frame. New 11 speed 105 is fine for any duties, and the weight savings on a high end frame will off set the lower spec groupset.

Giant Propel, Canyon Aeroad, Ridley Noah Fast, Scott Foil, Cervelo S2. These are proper aero bikes that have been in the wind tunnel. Not generic rebranded carbon.

More fair points made. You're right about the aero qualities (or lack of) in the frame, it does look pretty though!

You're also right about picking good components and a crap frame. I'd like to think I'm not doing this as the Sensa frames seem to get very good reviews both in the Uk and in Holland (I have friend over there and they have a good reputation there). Ideally a test ride would prove or disprove this, however, even if I buy from an LBS most can't/won't get an XL size frame in to try so I'm in the same boat either way.

You're not racing......
Buy the one you think is pretty.

Canyon Aeroad........Scott Foil

Which brings up the other issue with aero frames, one of those has a reputation for being a bit flexible, the other for being uncomfortably stiff! Not something you could nececeraly tell from a picture.

lunge - Member

Ideally a test ride would prove or disprove this, however, even if I buy from an LBS most can't/won't get an XL size frame in to try so I'm in the same boat either way.

Test ride an L then - it tells you how the frame feels. You can work out fit from geometry data.

A friend had a Scott Foil - he found it so harsh he only rode it in crits. Being his only bike, his racing suffered due to lack of training, he lost motivation and practically quit riding altogether.

Since replacing the Foil frame, he's actually enjoying riding and rues the day he chose an aero frame, and the 2 years loss of cycling enjoyment that ensued.

An aero frame is a tool for a specific job, ie to eek out a few watts or saved seconds in a race. The price you pay for that (at the moment at least) is a loss of comfort.

G

lol - If having a harsh bike stopped him training I'd suggest that he was never very motivated...

Still, not many frames can claim to be able to stop people enjoying riding. UKIP will probably shortly mandate the only frames to be sold in the UK are Scott Foils.

Which ever one you'll choose you'll be committed to seeing it all the way through.

I'd choose weightweenism over skinsuits and taped helmet vents.

If having a harsh bike stopped him training I'd suggest that he was never very motivated...

What a strange thing to say! He found the bike uncomfortable giving him chronic back pain, sore wrists and saddle sores to the point that he started to avoid club rides. And because he wasn't made of money, he couldn't afford to take a hit on the frame he'd bought.

He loved racing it, but anything over 40 miles on typical roads was torture. So unless you're buying a bike specifically to race, I'd be inclined to opt for a more comfortable all-rounder.

G

Foil harsh? Rode one on Zipp 404 for the weekend last year around the not too smooth roads of north Devon. Wouldn't say it was perticularly harsh, just felt nice and fast.

Foils ARE harsh. I was an Addict owner as was lent a foil for. Fortnight to test ride to see if I wanted to 'upgrade' after 3 rides I'd taken in back, and stuck with the addict, I hated it, might have felt quick but in reality I think my comfortable bike was faster on most roads.

Difference over 6 minutes was 6 seconds in favour of the carbon bike. Not really statistically significant.

I thought it would be a bit more, but this calculator backs up your findings.
http://bikecalculator.com/

Seconds do add up over a longer ride though, especially if your trying to keep up with a group or just a mate on a mission. Not to mention a light bike will feel different and might be a more enjoyable ride for some.

I'd like to think I'm not doing this as the Sensa frames seem to get very good reviews both in the Uk and in Holland

Great for a race bike, rubbish for a first road bike.

And potentialy less VFM, if that is a factor, than a more mainstream brand when it comes to sell it. My (bought 2nd hand barely used at 1year old in 2005) Cannondale R500 has actualy apreciated since I bought it if ebay prices are anything to go by! Not that I'm planning on selling it, the Tiagra groupsets gone and replaced with Dura Ace, (I think) buying the right (middle of the road/range) bike's worked out cheaper in the long run as I've never really felt too much need to change it, just renewed the bits hung off it as and when they needed it or I felt like it.

On the other hand they might be great and you might still be riding it in 10 years time, but then it will no longer be the lightest or the most aero, so the problem with chasing numbers rather than buying a bike you like the look/ride of is you can never win!

Don't tar all aero bikes with the same overly-stiff brush. My Propel is plenty comfortable for long rides. I won't be taking it to the Ronde as I have another more suitable bike, but I have ridden a fast century on it in comfort. If I didn't have another bike, then yes, I'd take it over the cobbles too. I'm sure the Cervelos are the same. The Scott does have history, however. Which is one reason why you can find them heavily discounted.

For a one bike for everything, I think I'd now pick aero. Quite a few non-racers in out club now have Propels, all out on the club run on the harsh lanes of Surrey, not to mention the three of us racing them week in, week out.

There is more to a carbon bike than tube profiles.

Nothing much to add other than as stated comfy can help speed and useability, never been bothered for road bikes other than a way to get fit for xc racing and to get to work.
Had a Planet X sl with durace, fast and light but no feel and hard to get power down. Convinced by my brother to try a trek madonne, the aero model year, bit heavier than my Planet X but far far faster and comfier. Now even just go for a road ride just because, carbon is not just carbon layup geo etc makes a huge differance. No idea if the aero is helping but ave speeds are higher in general.
That bike calculater is an interesting thing to play with, cheers.

It's pretty funny that in that Cervelo link, they claim the aero bike is faster than a light bike over the Etape course, by a MASSIVE 35 seconds, So in 8 hours of riding you gain 35 seconds. Ie a 0.12% difference! 😆

Thanks again for everyone's thoughts. One of the reasons I'm buying online is that I know the geometry and size I need from previous road bikes, I'm pretty happy with a stiff frame as well, current bike is a very stiff alu framed job. Anyway, plenty of advice to muse over here.

Do frame manufacturers quote chainstay travel so I know how to choose a "comfy" bike?

Difference over 6 minutes was 6 seconds in favour of the carbon bike. Not really statistically significant.

Having ridden a hired road bike some 5-6lbs heavier than my own, I didn't really notice the weight when climbing or riding along, but I really noticed it when accelerating. It took a few extra pedal revs to get it shifting, and I had to pedal noticeably harder which did add to the overall fatigue slightly.

Get the lighter one, especially if you're running shallow rimmed wheels. Aero bikes look awful with shallow rimmed wheels. Also, it takes a standard seatpost, so swap it for a lightweight model and save yourself more grammmz