Light aero bike - pointless or best of both worlds?

Discuss light weight issues concerning road bikes & parts.
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Lewn777
Posts: 396
Joined: Thu Mar 09, 2017 5:35 am

by Lewn777

I like a light bike, but I also like it to be functional too. I live in area with very flat and smooth roads but around 45-60kms away there are a few ranges of 1000 meter or so mountains with plenty of 600-700 meter passes mostly cat 4 and cat 3 with the odd cat 2.

I mostly ride on my own and I currently have a a Fuji SL with lightish 1300 gram alloy DT Swiss climbing wheels and SRAM Force components, bike weighs about 7kg. I could have it lighter, but I'm kind of happy with it as is, mostly because I still need to get a few kgs off my body.

I recently fitted carbon fibre clip-on TT bars and I've been enjoying the boost in average speed on the flats, so I've been thinking about getting an aero bike, simply because I have local conditions that are able to exploit the extra speed of this kind of bike.

So I have a few questions for people that have or had aero bikes......
  • How comfortable are bikes like the Madone, Propel and aeroroad especially for all day enduro rides?
  • What kind of weight do you think you could realistically build an aero bike to without getting ridiculous, let's say 5000 euros or us dollars complete bike.
  • What wheel depth would you consider ideal for normal use?
  • How much time do you think you lose on the climbs if any?
  • Do you think you descend quicker or slower on twisty mountain roads given the geo?
My heart is in the mountains, I just want to get there a bit quicker. :thumbup:

Also anyone know of an aerobar that can take clip-on TT bars?

by Weenie


alcatraz
Posts: 1346
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

As the bike gets lighter in it's design the less aero it gets. It's not black and white.

The frame contributes to one of the smallest aero advantages compared to other properties of a rider on the road. By this fact alone the money should really be spent elsewhere if watts/dollar is a concern.

It's the position of a rider on the bike that aero/tt bikes get most of their watt savings from.

Study those positions and make yourself a picture what is needed to be comfortable while still be able to put out power.

If I were on the fence on buying a single bike then aero is a good place to start. It's also possible to have an ultra light climber and a tt bike like I'm sure others have (including me). Had I not bought a climber as my first purchase I might not have needed to get two. :lol: n+1 I guess...

Because the watt difference is small between aero bikes, you'll benefit more from comfort and stiffness. Madone isospeed has something from both worlds. Unfortunately it's way too expensive for me.

If you want to have the competitive edge on both flats and climbs you might need two bikes. Like to KOM on Strava? :D

/a

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Lewn777
Posts: 396
Joined: Thu Mar 09, 2017 5:35 am

by Lewn777

alcatraz wrote:
Sat Feb 03, 2018 2:26 am
As the bike gets lighter in it's design the less aero it gets. It's not black and white.

The frame contributes to one of the smallest aero advantages compared to other properties of a rider on the road. By this fact alone the money should really be spent elsewhere if watts/dollar is a concern.

It's the position of a rider on the bike that aero/tt bikes get most of their watt savings from.

Study those positions and make yourself a picture what is needed to be comfortable while still be able to put out power.

If I were on the fence on buying a single bike then aero is a good place to start. It's also possible to have an ultra light climber and a tt bike like I'm sure others have (including me). Had I not bought a climber as my first purchase I might not have needed to get two. :lol: n+1 I guess...

Because the watt difference is small between aero bikes, you'll benefit more from comfort and stiffness. Madone isospeed has something from both worlds. Unfortunately it's way too expensive for me.

If you want to have the competitive edge on both flats and climbs you might need two bikes. Like to KOM on Strava? :D

/a
Well I'm n+1 all the way. :lol: Yes I like to do Strava segments, but I'm too old to be able to KOM anything that's popular, but I'm happy so long as I'm in the top 10%. :)
Buying bikes, renting bikes, and borrowing bikes are how I learn what I like, and I get a huge amount of enjoyment out of building a bike that is the best tool for a particular job. I've got a long travel Enduro MTB, XC bike, steel BMX, steel disk CX etc.

I suppose another way of framing my question is....I have a climbing bike that I'm happy with, but how much aero gains could I realistically make by switching to an aero bike with clip-ons vs a climbing bike with clip-ons and how much would I lose?

There is a point at which you don't really need another bike and things just become unused bike clutter you can only ride one at a time. :D for example, bike packing/touring/commuting/CX/gravel/hardpack dirt needn't be six bikes, one bike really can do all these jobs sometimes with a change of wheels or tires.

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wheelbuilder
Posts: 542
Joined: Wed Feb 08, 2017 2:10 am

by wheelbuilder

Seems like you want an aero bike if you are putting clip-ons on your more traditional road bike. I think the descending question is a good one and look forward to hearing responses. I love descending on bikes that descend well. Under steer, and over steer sucks. The bike I have is a traditional roadbike. Not a climbing bike and not an aero bike by any means. It climbs well, performs well, and most importantly descends well. I feel like I enjoy riding this bike so much that I have not even considered an aero bike despite its growing popularity and marketing push. I have no direct experience, but always imagined an aero bike with deep wheels to be a poor descender. Hope to hear responses regarding descending.

alcatraz
Posts: 1346
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Clip-ons complicate things. They bring you lower but often too low and too far forward to benefit at all from them. To optimize I need to bring the seat forward (maybe even swap the seat) and put on 5mm shorter cranks. Shorten the stem perhaps to give you skeletal support on the pads. (90 degree elbow angle)

Otherwise I can't get comfortable. Even with all the changes I detect a higher heart rate on the clipons than off. Don't know if that's right.

Lets say you optimize for the clip-ons, then your upright position is all wrong.

I think the best way to let an aero bike make use of both worlds is to really choose a bit shorter cranks. Have a set of clipon bars that can be mounted high with several spacers, and where the elbow pads are not a part of the clamp but separate so they can be brought closer to your body. Then a seat with a special linkage underneath to enable a forward position when needed.

Then you'd really be able to get into a comfortable tt position on a road bike that wasn't designed for it.

I don't have these things. I just have a normal road bike where I've put base bars, short stem, forward seat (forward offset seatpost) and just optimize for tt position alone. I call it my flat road bike. I am on the lookout for a tt frame though. I want that 78 degree seat tube angle that no aero/climbing bike has.

/a

waltthizzney
Posts: 218
Joined: Mon Jun 20, 2016 6:35 pm

by waltthizzney

realistically when every part is proprietary you are going to drive yourself crazy if you ride and travel a lot. The aero gains of a aero bike vs a traditional bike are not much in terms of the frame.

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Lewn777
Posts: 396
Joined: Thu Mar 09, 2017 5:35 am

by Lewn777

alcatraz wrote:
Sat Feb 03, 2018 3:48 am
Clip-ons complicate things. They bring you lower but often too low and too far forward to benefit at all from them. To optimize I need to bring the seat forward (maybe even swap the seat) and put on 5mm shorter cranks. Shorten the stem perhaps to give you skeletal support on the pads. (90 degree elbow angle)

Otherwise I can't get comfortable. Even with all the changes I detect a higher heart rate on the clipons than off. Don't know if that's right.

Lets say you optimize for the clip-ons, then your upright position is all wrong.

I think the best way to let an aero bike make use of both worlds is to really choose a bit shorter cranks. Have a set of clipon bars that can be mounted high with several spacers, and where the elbow pads are not a part of the clamp but separate so they can be brought closer to your body. Then a seat with a special linkage underneath to enable a forward position when needed.

Then you'd really be able to get into a comfortable tt position on a road bike that wasn't designed for it.

I don't have these things. I just have a normal road bike where I've put base bars, short stem, forward seat (forward offset seatpost) and just optimize for tt position alone. I call it my flat road bike. I am on the lookout for a tt frame though. I want that 78 degree seat tube angle that no aero/climbing bike has.

/a
I came from mountain biking, I have always preferred a smaller frame, it's just more fun handling, hate large frames, but can always seem to work around smaller ones. I also have done a lot of skiing and the TT bars were originally inspired by downhill skiing tuck position, and Giant slalom was always my favourite kind of skiing other than powder. For me a TT bar has a permanent place on the front of my bike, I just feel that extra 300 grams is worth it for me, it seems so natural, gives me more enjoyment and an extra position on very long rides. People say they are dangerous, they are if you use it in a group or heavy traffic.

There's nothing quite like flying along at 45 km/h with a light tail wind or taking the worst bite off a head wind. It's obviously not an optimal position on a climbing bike, but I think it's good to work around less than ideal positions. I feel my position on a bike that's marginally too small works rather well for a TT-clip-on application. I think 172.5mm cranks are ideal and I think you are right - if I used 175mm cranks they would be a bit too long for this purpose.

Whatever bike I have its number one job will always be technical mountain descending, I like DH/enduro mountain biking, skiing and motorcycle track riding. Second is climbing, third is going fast on the flats. If my number one interest was going fast on the flats then I think I'd set my bike up more optimally for it or maybe just buy a TT bike.

What I'm really trying to get at here is can someone with experience compare the handling characteristics on technical descents between:
1. A traditional road bike
2. A climbing bike
3. An aero bike
4. A TT bike

Also how well does each bike deal with being lent over on rougher, off camber or wet surfaces?
Also to try to describe the long distance (all day) comfort levels between each bike.

So far I'm very impressed with the way my slightly too small climbing bike (Fuji SL 52cm) descends, and slightly less enthusiastic with my Enduro road bike (Specialized Secteur 56cm) and similar with my steel frame CX bike.

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Lewn777
Posts: 396
Joined: Thu Mar 09, 2017 5:35 am

by Lewn777

waltthizzney wrote:
Sat Feb 03, 2018 4:51 am
realistically when every part is proprietary you are going to drive yourself crazy if you ride and travel a lot. The aero gains of a aero bike vs a traditional bike are not much in terms of the frame.
This seems less of an issue with the cheaper end of the market or self building and some manufacturers are worse than others. Although yes, that seatpost will always be an irritation. :(

User avatar
wheelbuilder
Posts: 542
Joined: Wed Feb 08, 2017 2:10 am

by wheelbuilder

If the number one job of your bike is technical descending (which is my favorite as well), I'm assuming that you have to climb to get to those descents. That puts riding on the flats in third place. Which makes me wonder why you would want aero extensions at all? Not being sarcastic or anything, so please don't take it that way, but aren't clip on aero extensions a detriment to climbing and descending? Especially if riding the flats is your third favorite thing to do.

dim
Posts: 228
Joined: Fri Oct 13, 2017 11:25 am
Location: Cambridge UK

by dim

get a light climbing bike such as a Scott Addict, or a Giant TCR, and upgrade the wheels to tubeless.
Giant TCR
Canyon Endurace AL
Specialized Allez Sport

User avatar
TonyM
Posts: 2650
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

Lewn777 wrote:
Sat Feb 03, 2018 2:13 am
I like a light bike, but I also like it to be functional too. I live in area with very flat and smooth roads but around 45-60kms away there are a few ranges of 1000 meter or so mountains with plenty of 600-700 meter passes mostly cat 4 and cat 3 with the odd cat 2.

I mostly ride on my own and I currently have a a Fuji SL with lightish 1300 gram alloy DT Swiss climbing wheels and SRAM Force components, bike weighs about 7kg. I could have it lighter, but I'm kind of happy with it as is, mostly because I still need to get a few kgs off my body.

I recently fitted carbon fibre clip-on TT bars and I've been enjoying the boost in average speed on the flats, so I've been thinking about getting an aero bike, simply because I have local conditions that are able to exploit the extra speed of this kind of bike.

So I have a few questions for people that have or had aero bikes......
  • How comfortable are bikes like the Madone, Propel and aeroroad especially for all day enduro rides?
  • What kind of weight do you think you could realistically build an aero bike to without getting ridiculous, let's say 5000 euros or us dollars complete bike.
  • What wheel depth would you consider ideal for normal use?
  • How much time do you think you lose on the climbs if any?
  • Do you think you descend quicker or slower on twisty mountain roads given the geo?
My heart is in the mountains, I just want to get there a bit quicker. :thumbup:

Also anyone know of an aerobar that can take clip-on TT bars?
I used to live in a area like yours (in Switzerland). I had some mountains around my home but quite nice big mountains approx. 50 km from my home.
The ride for the 50 km was actually nice and relaxing before I had to put much more watts for the big mountains with 1000 meters to climb. I had the feeling that my C60 was the perfect bike. Comfortable for the flat ride and stiff and not too heavy for the big mountains. Also very good for the descents. I used low profile wheels when I climbed these big mountains. The 50mm was not an option for me (also because my Bora 50mm were carbons and the low profile Fulcrum Racing Zero were aluminum for safety). I would not have enjoyed being with an aero bike in the big mountains actually.

If you love to climb (and descent) I think you should get a light and stiff bike. Aero would not really be any option IMHO.
And if you want to be faster at the bottom of the climbs, the best way is to put some more watts to get there! :mrgreen:

AJS914
Posts: 2481
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

Lewn777 wrote:
Sat Feb 03, 2018 2:59 am
I suppose another way of framing my question is....I have a climbing bike that I'm happy with, but how much aero gains could I realistically make by switching to an aero bike with clip-ons vs a climbing bike with clip-ons and how much would I lose?
Look at the the Tour Magazine aero test thread. They show how much you save on hypothetical 100km rides. Looking at the various charts, the difference between a Madonne and an Emonda is around 2-4 minutes based on the course.

IMO, to save 2-4 minutes on a 3+ hour ride, doesn't justify going out and buying a new frame especially if you are out riding by yourself.

User avatar
TonyM
Posts: 2650
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

Lewn777 wrote:
I suppose another way of framing my question is....I have a climbing bike that I'm happy with, but how much aero gains could I realistically make by switching to an aero bike with clip-ons vs a climbing bike with clip-ons and how much would I lose?

There is a point at which you don't really need another bike and things just become unused bike clutter you can only ride one at a time. :D for example, bike packing/touring/commuting/CX/gravel/hardpack dirt needn't be six bikes, one bike really can do all these jobs sometimes with a change of wheels or tires.
The aero bike with clip ons will save you a few minutes on your ride on the flats but you will loose these in the ascent and descent. So overall more or less the same.

I have to admit that I have some difficulties to picture a nice climbing bike with clip-ons however Image

Why not buying an excellent wheelset for climbing and another for aero and switching depending on the day, climb, weather or mood?


alcatraz
Posts: 1346
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Slapping clip on bars on and not adjusting the fit won't do much.

Getting an aero bike and not dialing in an aero position won't do much.

Climbing bikes have a more traditional fit. They are more upright so you can put out power comfortably.

You might be surprised to actually be slower on an aero bike because you are not used to the fit yet. Getting the bike is just the first step of many to becoming faster. You might have to start doing stretching and putting up with an uncomfortable position for a few months before you see any real gains.

/a

by Weenie


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Lewn777
Posts: 396
Joined: Thu Mar 09, 2017 5:35 am

by Lewn777

wheelbuilder wrote:
Sat Feb 03, 2018 5:21 am
If the number one job of your bike is technical descending (which is my favorite as well), I'm assuming that you have to climb to get to those descents. That puts riding on the flats in third place. Which makes me wonder why you would want aero extensions at all? Not being sarcastic or anything, so please don't take it that way, but aren't clip on aero extensions a detriment to climbing and descending? Especially if riding the flats is your third favorite thing to do.
That's a fair point. I don't live in the mountains though. If I did I'd never bother with clip-on TT bars. The mountains are 50km away from where I live, also the roads are very flat, smooth and straight on the way there. Also I don't really feel the clip-on bars are in my way particularly other than adding 300 grams to the bike, let's face it, it's a half full bottle of water.

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