bostongarden

Dear Abby,

For the love of money, I switched to the KMC DX10SC ($26.23 w/ free shipping -- thank you Amazon) from the KMC x10SL (I think I paid about $60 including shipping). The drivetrain feels smooth and the shifting is like buttah. But, I'm concerned that the 15-20 gram difference might come back to haunt me over the course of a 60 mile race, or, when I need to ramp it up quickly for a sprint to the line.

Should I think about replacing other bike parts to compensate for this gain in weight? Perhaps Campy Super Record? And, fyi, I'm already on a diet to lose body weight.

Thank you.

- Gramcerned

BrainInAJar

Just pour out some water for your dead homies, that should save you about 50g

Homebrew01

What thread is this a parody of ? I must've missed it .... or is it 41 in general ?

bostongarden

(In the Training Status thread, I made mention of my new chain. JB suggested, with racing season over for most of us, to toss it into a thread. Although, the post is probably a parody of something other than my life.)

kudude

Abby says it might not matter, but if you need an excuse, hang on to it.

Grumpy McTrumpy

Racer Ex 

First off, is it 15 or 20 grams? That's over 30% margin for error and you're looking for some kind of specific advice?

If you go to analretentivecycling.com you'll find that on a 60 mile, 15% grade there's a big difference between 15g and 20g.

Get your sheet together then come back and ask the question.

kudude

Ex makes a solid point.

cslone

I would bet you could get that down to a reasonable weight by sanding the excess link pin off each side with a Dremel. Maybe even hit the outside of each link itself for ultra savings.

kensuf

it must be getting close to December..

ridethecliche

You should have started this in the 41.

bostongarden

I admit that I didn't even think of visiting that website -- brilliant idea. I will check, however, I still welcome thoughts, comments, opinions and feelings. And, indeed, there is a huge difference between 15 and 20 grams. When I looked online for the weight of each chain, the information was inconsistent. I should have called KMC or gone to their manufacturing facility and sampled enough so that I could state the difference with at least 99% confidence. Please forgive me.

cslone -- Excellent idea. The bonus is that it doesn't cost a dime (assuming I can find my wife's nail file).

kensuf -- Clearly, you are wiser beyond your years.

rtc -- My concern was that it would not be taken seriously in the 41. Seriousness is the difference between a pack finish and crossing the line first. (I'm tempted to say that I'll be riding to win in 2011; but, as I could imagine Dr. Phil saying to me, "how'd that work for ya in 2010?")

waterrockets 

Just use a lighter lube.

The rotating nature of the chain still won't make much difference. The biggest chain rotational accelerations you're going to experience are when you go from coasting to pedaling. Compared to the force needed to accelerate your two 15 to 20-lb legs (>450x heavier), the chain differences only amount to 0.02% of the drivetrain/motor weight.

kudude

Sure you can throw around your fancy percentages and try to wow us with math, but we are talking about REAL WORLD NUMBERS here. 15-20g is still 15-20g regardless of the rest of the world.

ridethecliche

15-20lb legs? Jeez. My bones must weigh that much.

I guess I need surgery.

Racer Ex 

That's common because often they are weighed for a different number of links. Frankly though, you should have bought both, cut the chains to the length you planned to use, hot dipped them in solvent to remove the manufacturer's grease, relubed them, then weighed them on a certified gram scale.

Otherwise we're left to do your homework for you with instructions to "write an essay". Vagueistan is where lazy people live.

He's talking about a 60 mile climb. At 0.02% that's 63 linear feet. And you call yourself an engineer. What if NASA missed all their calcs by 0.02%? We'd have monkeys being shot all over the universe.

I'm sure someone's going to play the "big dump" card soon, like if I have light components on my bike I'm somehow constipated. FWIW knowing they couldn't do anything with their bikes because of the UCI weight minimum, Sky gave all their climbers high colonics prior to the mountain stages at the TDF, along with having a professional manicurist do both finger AND toenails down to the bare minimum, and had their fillings replaced with titanium (along with the zippers on their kits BTW).

Marginals gains add up.

Grumpy McTrumpy

some dumps are chain-like

lovestoride

hahaha

Dean V

Take a few links out. The derailleur will probably cope with it and you will save your 15gms without spending anything!

Homebrew01

For criteriums, where you only use the smaller cogs, you can grind down the larger cogs so that they are just spacers ... saves a ton of rotating weight.

walshconor

this

wanders

there's a road to the top of Everest?

ridethecliche

Actually 15-20 grams makes a HUGE difference.

(If you're using a micro centrifuge and it's unbalanced.)

carpediemracing 

I remember running multiple "small" cogs because I wouldn't need more than an 18 or 19T. This was on a freewheel so I couldn't use all small cogs. I was so dumb.

On the other hand, the chain grinding idea gave me an idea - drilling out all the locknuts on my hubs and such. Spacers too.

bostongarden

I appreciate the wisdom. This would be a very cool looking cogset imho.

I am far from a wrench. Is this a part near the bottom bracket?