Bullbars.....(Show us yours?)

For discussions about bikes and equipment.
User avatar
531colin
Posts: 12624
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Bullbars.....(Show us yours?)

Postby 531colin » 19 Apr 2017, 6:48pm

reohn2 wrote:Are we forgetting forward/aft saddle position?


Completely ignoring it, i would say . :wink:
cleat position got a mention, though.

Theres pelvic tilt as well. As the pelvis rocks forward on the iliac tuberosities, the acetabulum moves forward and down
Last edited by 531colin on 20 Apr 2017, 6:00am, edited 2 times in total.

User avatar
531colin
Posts: 12624
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Bullbars.....(Show us yours?)

Postby 531colin » 19 Apr 2017, 6:49pm

Gattonero wrote:
531colin wrote:...
Well, in a moment of weakness i put my saddle up 4cm.
I'm so glad I did......its the biggest laugh I've had for days.....I never got past the end of the road....no surprise, really, as i couldn't get the pedals all the way round.....its like being 8 years old again, trying to ride my big brother's bike.
You are having a laugh, aren't you? I do hope so, because i still am!


So with an inseam of 82cm you cannot get to the pedals if the saddle is set at 75cm?
What crank length do you have, and are you sure you are not dropping the heel? It sounds to me like you are, and I may be dropping the toe, that would explain such big difference ins saddle height between two people with the same inseam.


I couldn't drop my heel with the saddle at 74cm......the pedal was trying to pull my shoe off!

User avatar
531colin
Posts: 12624
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Bullbars.....(Show us yours?)

Postby 531colin » 19 Apr 2017, 7:01pm

Samuel D wrote:The toe-versus-heel dropping differences would have to be large to explain the differences between the four of us.

531colin:
inseam 84.5 cm
saddle 70 cm
170 mm cranks

Gattonero:
inseam 82.5 cm
saddle 74–74.5 cm
(unknown cranks)

NATURAL ANKLING:
inseam 84 cm
saddle 76 cm
170 mm cranks

Me:
inseam 87 cm
saddle 73 cm
172.5 mm cranks

531colin uses SPD shoes, which may have a lower stack height than road pedals.

Gattonero: did you actually measure your inseam? You ‘sat’ on a hardback book pushed gently into your crotch and square against a wall, while wearing only underwear, feet about pedal-width apart?

My guess is that toe-versus-heel dropping is at least as much a response to saddle height as it is a natural pedalling style. That is, if you raise the saddle, you’re going to point your toes whether you like it or not. And vice versa to a lesser extent (lesser because pedalling with excessive knee-bend is possible).

Whether it feels normal will depend on how long you’ve ridden like that. I’m not sure feeling normal is a good guide here. Merckx used to fiddle endlessly with his saddle height as if tiny differences mattered. I suspect they only mattered in his head.

Pointing the toes must require less force from the calf muscles, thereby saving some energy. That and the aerodynamics argument are probably why some pros point their toes. But there are counter-examples: Froome, Wiggins, and Merckx rode with low saddles and relatively low heels. Anquetil, on the other hand, rode with an extreme toe-pointing style.


I do use SPD shoes.
Steve Hogg would agree with you that toe dipping can be a response to a too-high saddle, rather than a natural thing. If the saddle is too low, I see people riding with an exaggerated bend in the knee.
The act of pointing the toes requires the calf muscles to contract, so it probably needs more energy than simply holding the foot level.
What I can't get my head round is that people tell me (correctly) that you get maximum force for minimum muscle work when your knee is nearly straight....so at the very point where they get maximum force, they are extending their ankle down in order to reach the pedal. Much more efficient to put the force on the pedal with the foot flat.

User avatar
Gattonero
Posts: 3666
Joined: 31 Jan 2016, 1:35pm
Location: London
Contact:

Re: Bullbars.....(Show us yours?)

Postby Gattonero » 19 Apr 2017, 9:41pm

Should we rename this thread? :wink:
It is by riding a bicycle that you learn the contours of a country best,
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...

fishfright
Posts: 181
Joined: 11 Feb 2014, 11:18am

Re: Bullbars.....(Show us yours?)

Postby fishfright » 19 Apr 2017, 9:48pm

Gattonero wrote:Should we rename this thread? :wink:


I suggest " Yet another innocuous thread derailed by the usual suspects"

Brucey
Posts: 37242
Joined: 4 Jan 2012, 6:25pm

Re: Bullbars.....(Show us yours?)

Postby Brucey » 19 Apr 2017, 11:07pm

some bullbars;

Image

don't get too excited; if you attach these to a bicycle it will suddenly weigh double and you may find that the tube diameters are 'not quite compatible' with standard fittings.... :wink:

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

User avatar
Gattonero
Posts: 3666
Joined: 31 Jan 2016, 1:35pm
Location: London
Contact:

Re: Bullbars.....(Show us yours?)

Postby Gattonero » 20 Apr 2017, 2:25pm

fishfright wrote:
Gattonero wrote:Should we rename this thread? :wink:


I suggest " Yet another innocuous thread derailed by the usual suspects"


:mrgreen:
It is by riding a bicycle that you learn the contours of a country best,
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...

AM7
Posts: 285
Joined: 18 Jul 2014, 10:24pm
Location: North West Essex

Re: Bullbars.....(Show us yours?)

Postby AM7 » 20 Apr 2017, 3:56pm

Back on topic with my fixed gear Moulton TSR. Using a Travel Agent so I can use the reverse brake lever with a V brake.

Image
Last edited by AM7 on 21 Apr 2017, 7:15am, edited 2 times in total.

rjb
Posts: 3621
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Bullbars.....(Show us yours?)

Postby rjb » 20 Apr 2017, 7:33pm

Brucey wrote:some bullbars;


don't get too excited; if you attach these to a bicycle it will suddenly weigh double and you may find that the tube diameters are 'not quite compatible' with standard fittings.... :wink:

cheers


Careful chaps or we will be on cowhorns next. :lol:
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D

User avatar
Gattonero
Posts: 3666
Joined: 31 Jan 2016, 1:35pm
Location: London
Contact:

Re: Bullbars.....(Show us yours?)

Postby Gattonero » 20 Apr 2017, 9:28pm

AM7 wrote:Back on topic with with my fixed gear Moulton TSR. Using a Travel Agent so I can use the reverse brake lever with A V brake.
...


That
is
nice!
8)
It is by riding a bicycle that you learn the contours of a country best,
since you have to sweat up the hills and coast down them.
Thus you remember them as they actually are...

User avatar
willcee
Posts: 996
Joined: 14 Aug 2008, 11:30pm
Location: castleroe,co.derryUlster

Re: Bullbars.....(Show us yours?)

Postby willcee » 20 Apr 2017, 10:19pm

As regards Merckx , yes he adjusted his position many times and most of that was due to the serious crash he was involved in behind a derny, driver died, afaik his pelvis was twisted and it was never quite right afterwards, sacroiliac issues and he admitted he never had the same power after that smash..will

User avatar
531colin
Posts: 12624
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Bullbars.....(Show us yours?)

Postby 531colin » 19 May 2017, 10:06am

I'm not going to apologise for continuing to discuss riding position......what is handlebar shape about, if it isn't about riding position?
I think Samuel has shown us where this 0.88 magic number originates....
Samuel D wrote:..............
The 0.883 × inseam method was popularised in Lemond’s book but first put forward by Lemond’s coach, Cyrille Guimard. However, this is what Lemond’s book actually says about it (I have it in front of me):

“That is the overall distance, in a straight line, from the centre of the bottom bracket to the top of the saddle. Remember, though, that what’s meant by the top of the saddle is the cupped part where you actually sit, not the lip that rises to the back of the saddle.”

That’s a bit vague, but I don’t think he means to measure in line with the seat tube. I think he means where the sit-bones rest. If you take his formula and measure in line with the seatpost, you’ll end up higher than even Lemond recommends............

Previously I was measuring my saddle height from BB axle to saddle top along the seat tube, and the result was 70cm.
However, if I measure from BB axle to about the middle of the dent my bum bones make in my saddle, my saddle height is then 72.5mm......which is fairly close to the 74cm which the Lemond method seems to suggest.
So, where has the missing 15mm gone?
My bullbar grips replicate this "hoods" position...
Image
when I had drops, with the "tops" level with the saddle, this was my "drops" position...
Image
Thats certainly not an extreme position by to-day's standards, but my pelvis is rotated further forward when I'm on the drops than it is when I'm on the hoods. If I had a significant saddle to bar drop, then my torso would be closer to horizontal and my pelvis would be rotated more, but my hip flexion would be extreme (belly interfering with thighs), and i would need to put the saddle forward to reduce hip flexion, and up to compensate for moving it forwards. I would also need a longer reach.
You can see here https://commons.wikimedia.org/wiki/File:Pelvis_(male)_02_-_lateral_view.png that my hip joint moves forward and down as I rotate my pelvis forward, which increases effective leg length. Moving the saddle forward makes it more likely that I would ride toe down ....you can think of the body "rotating around the pedal spindle".
So if i put the bars down and forward, the saddle forward and up, and i rode with my pelvis rotated forward, my toes down and my cleats forward, its possible that i could actually find my missing 15mm saddle height and ride with a 74cm saddle height as per Lemond. However, this is an aerodynamic racing position suited to an athlete (originally a Tour de France winning athlete).....it requires good biomechanics and functionality, as well as flexibility and core strength.
It seems to me that modern fashionable road bikes with steep seat tube angles and pronounced saddle to bar drop force the rider to attempt to adopt a riding position as described by Lemond.
The average person who spends 35 hours a week sat at a desk isn't going to be comfortable in this sort of position unless they devote a considerable amount of time and energy to developing flexibility, functionality and core strength (like a professional athlete).
I have never read "Lemond's book" but I would be interested in what it has to say about riding position in general......I don't think its wise to just pick out a part of the whole position and make it a universal recommendation, to anybody who just wants to go for a nice bike ride in the country.

Brucey
Posts: 37242
Joined: 4 Jan 2012, 6:25pm

Re: Bullbars.....(Show us yours?)

Postby Brucey » 19 May 2017, 10:18am

it is as well to remember that, back then, Lemond was almost certainly also talking about a riding position that included the then fashionable 'LOOK' pedals. IIRC these have a considerable thickness (i.e. ball of foot to pedal spindle centre) vs some other pedals, plus the distance will vary with the thickness of the shoe sole in use. I think you could easily get a 1cm variation in saddle height using different pedals and shoes.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Samuel D
Posts: 2894
Joined: 8 Mar 2015, 11:05pm
Location: Paris

Re: Bullbars.....(Show us yours?)

Postby Samuel D » 19 May 2017, 2:04pm

531colin wrote:I have never read "Lemond's book" but I would be interested in what it has to say about riding position in general.

To clarify, the book I have is Greg Lemond’s Complete Book of Bicycling, second Perigee edition, 1990. I got mine on AbeBooks (where I also got Vivian Grisogono’s Sports Injuries: A Self-Help Guide on your recommendation. She knows her stuff and explains it well).

Lemond’s fit advice in the book boils down to a series of formulas, variously attributed to Guimard and Hüggi (more below). He goes into saddle position deeply. The rest is mostly the usual hand-waving with vague talk about responsiveness, “benefit better from the momentum my bike creates" (p. 140), etc. Nothing worth buying the book for. Lemond was a slightly better racer than you, but I’m sure you’ve spent ten times longer thinking critically about bike fit.

For interest, Lemond gives his own inseam (84.3 cm) and saddle height (74.4 cm from centre of bottom bracket to “top of the cupped part of the saddle”).

A few titbits from the book:

  • “Although it is true that your body can adapt to virtually any position, you will not get the full benefit out of your riding if you don’t set up the correct position. I rode with my saddle position too low for six years and won a lot of races. Had the information been available to me at the time about the correct position, I might have done even better.” (p. 119)
  • He explains that Cyrille Guimard enlisted the help of Dr Ginet, “one of France’s top physiologists”, to approach bike fitting in a scientific way in a series of studies in Nantes in 1978–1979, and that his findings were verified by “Swiss engineer” Wilfried Hüggi.
  • Guimard’s position ideas were based on wind-tunnel research at Renault. The impression I get is that aerodynamics played an important role in his thinking. There is no talk about comfort for casual cyclists. In fact, throughout the book Lemond seems to be talking to young, seriously dedicated racers or would-be racers. His detailed training plans start at 300–390 km per week for a 15-year-old and the distances rise sharply with age.
  • “[Guimard] measured my inseam and told me I had to raise my saddle an inch and a half. I was shocked. Although he told me to raise it slowly, I increased my position the entire inch and a half just for one day to see how it was. It felt as if I could barely touch the pedals.” (p. 121)
  • “Some top racers ride too low on their bikes, like Irish superstar Sean Kelly. […] Personally, I’m convinced that if Kelly improved his position he could do even better than he has the past few years. Actually, I’m not sure his inefficient position is so bad, for my sake.” (p. 129)
  • “In fact, many of the top pros also have incorrect positions—I think their success should not be attributed to their position but to their talent.” (p.131)
  • There is an interesting discussion about the effect of saddle height on oxygen uptake on p. 130. Suffice to say it goes against Lemond’s high-saddle idea, but he explains that away.
  • “BE WARY OF STEEP SEAT TUBES” (p.133)
  • “I have found in my cycling clinics that these very aggressive seat tube angles – seventy-four degrees – often make it impossible to move the saddle back far enough to achieve the right pedalling position.” (p.133)
  • He goes on to give his interpretation of why seat tubes became so steep, and says that he prefers 72 degrees and won the 1986 Tour de France with that angle.
  • He has much more, involving handlebar position, etc.
I’m glad I have the book, but I don’t treat the fit recommendations as gospel. They contradict other sources including, as Lemond admits on p. 130, then-director of the US national cycling team Eddie Borysewicz.

Brucey wrote:it is as well to remember that, back then, Lemond was almost certainly also talking about a riding position that included the then fashionable 'LOOK' pedals.

No: “Remember that this overall height formula was determined with the standard Campagnolo racing pedals and standard, medium-thickness cycling shoes such as Brancale, or Sidi nylon mesh shoes.”

However, he later concedes: “Remember, when you’re within a centimeter of your correct correct overall height measurement, you’ll be fine.”

Brucey
Posts: 37242
Joined: 4 Jan 2012, 6:25pm

Re: Bullbars.....(Show us yours?)

Postby Brucey » 19 May 2017, 5:17pm

Samuel D wrote:
Brucey wrote:it is as well to remember that, back then, Lemond was almost certainly also talking about a riding position that included the then fashionable 'LOOK' pedals.

No: “Remember that this overall height formula was determined with the standard Campagnolo racing pedals and standard, medium-thickness cycling shoes such as Brancale, or Sidi nylon mesh shoes.”


also similarly tall, IIRC (by comparison with many modern pedal/shoe combinations); Lemond was certainly riding LOOK when he won the TdeF (and I think carried on doing so for the rest of his professional career...?) and he would hardly have bothered recording his saddle height etc without an allowance for this had it caused any variation.

IIRC Hinault & Genzling's book was the first publication of the system that was (in essence) what Lemond is on about.

FWIW the exact shape of the saddle (and where you happen to sit on it) can make a big difference to some of the setup variables. Similarly any discussion of seat angles is predicated on what type of saddle and seat pin you use. With the kind of kit used in the 1980s, it arguably makes sense if you have a frame/seat angle that allows the saddle to be almost as far back on the rails as possible when you are sitting correctly; this allows the saddle rails to flex as much as they can do which improves comfort.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~