Inferior performence of a 12lb bike

[rustychain]

Reading an article in Velo news http://tour-de-france.velonews.com/arti ... es-for-the
In regards to the French rules that will be applied to the TDF. A short way down they mention the "inferior performence" of 12lb bikes. Could this be true? What limits on performence could we see if we lost the 6.8 rule?

[GrahamB]

Broken frames? Dropped chains due to flexy derailleurs and cranksets? Wheels rubbing on brakes while climbing?

Obviously the limit could go lower since some teams are already running ballast, but I think some limit is useful: it's meant to be an athletic event, not a technological competition...

[mathi]

Descending is a nightmare on a uberlight bike , its scares me trying to keep up with freinds

[kinky_cowboy]

A right wing nutter writes:
Why impose rules? A rider has an inherent interest in riding the fastest bike which is still adequately safe. If a 12lb bike really is prone to chain drops, poor handling or catastrophic failure, it will be rejected by the rider because it compromises his chance of winning. The 'level playing field' argument is spurious; the big money doesn't go into marginal equipment advantages, it goes on training, nutritional and medical support. Those things make more difference to a well funded rider than any bike could.

Look at the GB track squad; they didn't start dominating track racing because their million dollar bike program is better than those of AIS/BT or KNWU/Koga, they did it by funding athletes to commit full time with good expert support to world championships and Olympic medals.

Even if you wanted to level the playing field, weight is a small part of the issue. Aerodynamics are far more important, especially when the Tour is usually decided by time trials, and weighing a bike tells you nothing about the hundreds of thousands of dollars which have been spent in the wind tunnel to optimise the bike/rider package.

If you let Lance keep his bikes but provided no other support, making him work for his living, he would never have won the Tour. If you let him keep all the non-bike support and sent him out on a $4000 machine from the LBS, he would still have won all seven

[djconnel]

Exactly. Let the riders optimize performance, not the rule makers. The rules should preserve safety, not performance. If a 12 lb bike is dangerous, it shouldn't be allowed. But then if a 18 lb bike is dangerous, it shouldn't be allowed, either.

It's quite clear the threshold below which all bikes are dangerous is well below 6.8.

[iliveonnitro]

The riders don't choose the bikes the ride. And I'm sure, just like with doping, they would choose less/unsafe options if there is even a slight hope that it will help them win.

[gregclimbs]

I dunno...

I have a 5.9kg bike.

no tuning, with the srm and race numbers added.

I have no issue with it and I climb and descend all the time...I typically average 10-15k vertical feet a week.

I suspect that user "confidence" is an issue...

of course, all the roads I ride on I have ridden on the ducati over 100mph before making it track only which might help with the whole confidence thing...

fwiw, imho, ymmv etc. etc. etc.

g

[mdeth1313]

funny, w/ a set of 967g wheels I just had built, my bike just got under 12 lbs. I did rides of 20, 22, 36 and 106 miles 4 days in a row. Yes, my chain dropped twice, then I adjusted the limit screw on my front derailleur, never dropped again. I had no issues climbing, descending, having to bunny hop over a bridge joint that had raised about 4 inches above the road surface, shifting (other than aformentioned) and oh yeah, without those wheels, my bike weighs in around 12.75lbs and I've been riding that version for over a year now.
It can be done and it can be done safely!

[mathi]

Must be me getting old and not having the balls any more

[Chiho]

Our roads around here suck, and I do not like descending on them with race wheels (under 1200g). The wheels seem to want to skip when cornering and are less confidence-inspiring. On smooth roads, it isn't an issue, but around here, riding super-light wheels isn't always that much fun.

On a mountain bike: there is no doubt that a bike can be too light. The optimum trailbike is around 25-27lbs if it has 5" of travel. Anything lighter and it starts to handle very funny when descending, or just riding the typical technical, challenging trail. Sure, a lighter bike climbs well, but I like a confidence-inspiring bike for tough trails. A race bike would be a different story, but trailbikes can definitely be "too light". That quick Cyclingnews review of the new Scott trailbike (the 6" one at 22 lbs) basically said that the heavier, 25lb version was a better bike in all aspects except climbing. Light weight for the sake of light weight doesn't make sense if it compromises overall performance. It is nice to be "grounded", especially with a solid wheelset and beefy tires, on a trailbike.

[Hyde]

I think the weight limit is good. It sets a standard. The 6'4" 180lb pedal crushing sprinter rides a bike of the same weight as a 5'3" 100lb pure spinner. I think it gives designers a set of rules to build a bike by while attempting to build what works best for a certain type of rider and keeping things somewhat even. Note: "Somewhat"

[djconnel]

What's fair about that? For the 100 lb rider, it's 13.0% of total mass, while for the 180 lb'er, it's 7.7% total mass. If they have the same power/mass, the 100 lb'er ends up 6% slower in weight-limited riding.

[Hyde]

It's fair because they essential are starting with the same tool regardless of the size or style of the rider.

[rustychain]

I have only put any miles on a few bikes and they were all around 13lbs (+ or -) That is not enough to say any particular handling properties for light bikes in general but in my case they did not decend as well as some other bikes I've used over the years. Is there any way to measure/predict (ie science) performence while decending? Could it be more a lightweight wheel effecting handling rather then the whole bike? The whole question may be bunk but it keeps coming up that very light bikes have handling issues. Perhaps the riders weight would effect the issue as well. I think making a 12lb bike safe and reliable has been done (sometimes anyway) so thats not my question.

As to the fairness issue of weight limits. The light guys already have a hudge advantage on the hills. Why give em more? Further, you would have to administer weight classes for specific bike weights. IMO not very practicle. Teams would have to stock more bikes. Support would be more complicated and what if I gain or drop some weight, do I need a new bike?

[djconnel]

It's fair because they essential are starting with the same tool regardless of the size or style of the rider.

The higher the minimum weight, the more this is "fair" to heavier, more powerful riders, and the minimum weight is clearly presently above the safety threshold. Heck, even tall Thor Hoshovd's sprinting machine is close to the UCI limit. The UCI rule is basiclally the "SRM subsidization rule" more than a safety rule.

Cycling isn't a pure athletic endeavor: it's all about athletics PLUS tactics, teamwork, luck, and equipment. Being able to make trade-offs in equipment is part of the game. Or if you disagree, perhaps we should just give every rider the same bike, as they do at the Indiana Little 500.