How important is bike design to the best sprinters?

[mountainrman]

I was fascinated to read about Cav's new bike

http://forum.cyclingnews.com/newthread.php?do=newthread&f=6

Theres a lot of talk about bike design for TT specialists and aerodynamics, for climbers about weight and so on.

It seems to me (with nothing but guessing) that the details of a sprinters bike when it is all about the last couple of metres matter even more.

So is it a handicap to change bike sponsor for a top sprinter? discuss..

 

[Michele]

If we're talking simply of design, the TT bikes are more affected by it.
For the sprinters, I cant see the design itself being a problem; the geometry would be much more of an issue.

As for the weight, it's a well known fact that in some cases the pro of bigger teams dont ride same frameset as the ones you find in the shops; when HTC/Columbia was sponsored by Scott they were using the Addict, well known for having a weight between 800 and 900gramms, but their framesets were around 1200 gramms if I remember correctly.

 

[Waterloo Sunrise]

If we're talking simply of design, the TT bikes are more affected by it.
For the sprinters, I cant see the design itself being a problem; the geometry would be much more of an issue.

As for the weight, it's a well known fact that in some cases the pro of bigger teams dont ride same frameset as the ones you find in the shops; when HTC/Columbia was sponsored by Scott they were using the Addict, well known for having a weight between 800 and 900gramms, but their framesets were around 1200 gramms if I remember correctly.

Aerodynamics is even more relevant to top speed than maintaining a high average speed, so I don't see why it shouldn't be taken every bit as seriously as a TT bike would be, if you're serious about maximising all angles. Clearly power transfer is also key (as is the case in a TT bike as well).

 

[calinmarian]

I was fascinated to read about Cav's new bike

http://forum.cyclingnews.com/newthread.php?do=newthread&f=6

Theres a lot of talk about bike design for TT specialists and aerodynamics, for climbers about weight and so on.

It seems to me (with nothing but guessing) that the details of a sprinters bike when it is all about the last couple of metres matter even more.

So is it a handicap to change bike sponsor for a top sprinter? discuss..

No because Cavendish already knows the Spec McLaren Venge when he was at HTC,when because of his legs and this bike,he destroyed the field at Copenhagen in october 2011.

 

[mountainrman]

No because Cavendish already knows the Spec McLaren Venge when he was at HTC,when because of his legs and this bike,he destroyed the field at Copenhagen in october 2011.

True - but they say in that article that there are other sponsors so his gear shifters must change - is that an issue?

It seems to me that Cav is unique amongst sprinters in riding position - he seems to get his head down far lower than the other sprinters. Also frame stiffness (which should be unchanged) must matter more to him than most considering the power he punches.

 

[hfer07]

before carbon bikes took over the market-I have never heard any script at all from riders & companies about their bike design, other than the TT & on road bikes what mattered the most was the "maker" & the material. Now with all the free forms that carbon allows the manufacturers to come up with- they are just simply adding BS to push their brands as more aerodinamic, stiffer, lighter, etc. etc. as some folk mentioned before- Cavendish still won sprints with Pinarello, regarless how "in love" he's with the Specilized brand-perhaps what does make the difference is the extra perks that they provide to the riders, as far as fitting, biomechanic studies, etc.

 

[Parrulo]

No because Cavendish already knows the Spec McLaren Venge when he was at HTC,when because of his legs and this bike,he destroyed the field at Copenhagen in october 2011.

"destroyed the field"

certainly seems like an overstatement as i don't recall seeing him at all cept for the last 50 meters. . . but i guess that's because i fell a sleep during the most pathetic and boring world championships since zolder.

tl;dr: winning a race in a sprint from a group of 200 =/= destroying the field

but i guess i am going off topic on this one so forgive me.

on the actual topic: it's all propaganda from specialized cav will be the fastest man on any decent bike.

also the reason why he rode a 1200 gram frame at HTC instead of supa dupa light one was simply because there is no such thing as low end carbon. bike brands sell that imagine but is all BS made to fool people without knowledge on composites.

the carbon on the 2 frames is exactly the same, the only difference are enough layers of carbon to make the frame lighter, less stiffer and easier to crack.

carbon comes in rools like toilet paper:

all they do is "glue layers of it and put it in the oven"

but i am drifting again, it's not important, all carbon frames are great and those 500 grams won't make any difference in his power output on a sprint.

like people above said, it's all about fitting

hope i was useful, studying mechanical engineer finally became useful

 

[mountainrman]

"destroyed the field"

certainly seems like an overstatement as i don't recall seeing him at all cept for the last 50 meters. . . but i guess that's because i fell a sleep during the most pathetic and boring world championships since zolder.

tl;dr: winning a race in a sprint from a group of 200 =/= destroying the field

but i guess i am going off topic on this one so forgive me.

on the actual topic: it's all propaganda from specialized cav will be the fastest man on any decent bike.

also the reason why he rode a 1200 gram frame at HTC instead of supa dupa light one was simply because there is no such thing as low end carbon. bike brands sell that imagine but is all BS made to fool people without knowledge on composites.

the carbon on the 2 frames is exactly the same, the only difference are enough layers of carbon to make the frame lighter, less stiffer and easier to crack.

carbon comes in rools like toilet paper:

all they do is "glue layers of it and put it in the oven"

but i am drifting again, it's not important, all carbon frames are great and those 500 grams won't make any difference in his power output on a sprint.

like people above said, it's all about fitting

hope i was useful, studying mechanical engineer finally became useful

Thanks.

On my point about riding position, am I imagining it, or is Cavs head in sprinting position much lower than other sprinters? / leaning forward more? His chin seems to hit the handlebars at times. The kind of position, I use for going down hills into stiff wind! - that must have frame geometry implications.

 

[Afrank]

Thanks.

On my point about riding position, am I imagining it, or is Cavs head in sprinting position much lower than other sprinters? / leaning forward more? His chin seems to hit the handlebars at times. The kind of position, I use for going down hills into stiff wind! - that must have frame geometry implications.

Your not imagining it, one of the reasons frequently sighted for why Cav is such a good sprinter is how low he can get. Multiple other sprinters have also commented on how hard it is to get a draft off him because he gets so low in the sprint.

 

[farmboyjad]

the carbon on the 2 frames is exactly the same, the only difference are enough layers of carbon to make the frame lighter, less stiffer and easier to crack.

carbon comes in rools like toilet paper:

all they do is "glue layers of it and put it in the oven"

but i am drifting again, it's not important, all carbon frames are great and those 500 grams won't make any difference in his power output on a sprint.

like people above said, it's all about fitting

hope i was useful, studying mechanical engineer finally became useful

I don't disagree that fit is more important than frame specifics, but if you're studying to become a mechanical engineer, you better hit the composites book again. Carbon fiber cloth DOES come in different grades (higher grades are baked longer, which makes the fibers more "pure", with more carbon atoms and less hydrogen atoms). Likewise, the use of different epoxies can significantly affect the stiffness and strength of the final product. Cheaper bikes use cheaper epoxies, and since the epoxy isn't as stiff, they need to use more of it, which increases the weight of the bike. Bottom line, all carbon fibers are not equal.

Most importantly, however, fiber weaves and layouts make a huge difference in design. The highest end bikes have the most complex, but best performing, layout patterns. This is the reason that there has been such a huge shift in bike advertising from the aforementioned "only material matters" to the overload of more technical information. Carbon and other composites are unique in the way that they can be precisely tweaked to have different stiffnesses in different directions and different locations based on the layout pattern. You can't do this with steel, aluminium, or cromo.

Coincidentally, that picture is what's called a plain weave, and is almost never used in bikes (aside from the top layer which is strictly for looks) because it's a very inefficient layout. Bikes are actually made of uniaxial carbon cloth, which looks like this (note the lack of the distinct 'square' pattern - in fact, all of the fibers are running the same direction, with only minimal threads holding them together):

 

[Michele]

Aerodynamics is even more relevant to top speed than maintaining a high average speed, so I don't see why it shouldn't be taken every bit as seriously as a TT bike would be, if you're serious about maximising all angles. Clearly power transfer is also key (as is the case in a TT bike as well).

One my friend is an engineer who work in a wind tunnel and worked hand-in-hand with both bike manufacters and clothing brands for some tests in the past years.
As the "aero trend" is very big nowdays I was curious to hear her opinion on the matter as it's what she works everyday with; at my question she explained to me that she even couldnt understand all this obsessing about aero (talking about road bikes, not TT) as she thinks there are too many factors for concentrating only on the aero part so much.
So yeah, her short answer was "its all good for marketing".