orcanova

I am trying out Dr. Pete's Oval Concepts 110cm stem on my Orbea.



https://ovalconcepts.com/productsDeta...i=43&idProd1=2

Very stiff stem (noticeably stiffer than the ITT Visia 120mm stem I had on there) and I like it, but its advertised at 135 grams. It tips my digital kitchen scale at 156 grams. (The scale is accurate and it weighs a 5 lbs. dumbell at exactly 5lbs.)

I e-mailed them and am waiting for a reply, but I talked to the US distributor to see if explain the discrepancy. He didn't have a 110cm in stock but he weighed a 100cm and it weighed in at 153 grams. This would suggest that I don't have a defective stem that was manufactured outside of factory tolerances. He did say they distribute over 18,000 parts and that "they all do that," meaning all the manufacturers low-ball the truth.

Interestingly, Oval Concepts markets a titanium upgrade kit for the stem that shaves 20 grams off, so I suppose if I paid for the kit (don't know the cost) I could get the stem back down to the advertised weight. Sorry...not interested.

Deda Elementi introduced the Zero 100 stem that they claim is a sick-light 100 grams. They call it super light, yet "not quite as stiff" as their Deda Newton stem. There are several threads over on weightweenies with pictures stating that the stem weighs in around 142 grams. Well, that makes it heaver and not as stiff as the Newton. WTF?!?

Now, I know that in the bike world advertised weights are often different than real weights, as a casual survey of the weightweenies will confirm as much. It seems many cyclists accept that, but I don't. Why are these manufacturers getting away with false advertising so freely?

It seems to me that one consumer affairs commissioner from one state could force these manufacturers to comply and tell the truth. After all, when I buy a 12 ounce soda, it really is 12 ounces, not 9.6 ounces. I expect it to be, and it is. I do not believe that manufacturing tolerances vary as much as 10 grams, much less 42 grams. Remember, the OC distributor weighed a 100cm stem and it was only three grams lighter than my 110cm, and I'm sure that any of the 100cm stems he has in stock will weigh exactly 153 grams.

Many cyclists base their purchasing decisions on weight, and many pay a hefty premium for a slightly lighter product. To be more specific, people will buy that 100 gram stem simply because it is 100 grams, not a middle-of-the-pack 142 grams.

This industry needs to be cleaned up, and it really needs an independent testing labratory not only to test weights, but stiffness, compliance and fatigue and failure rates, so people have better knowledge of the performance characteristics of what they are buying.

Thoughts...?

CastIron

I'm neither surprised nor concerned enough about 21 grams to pay more for some quasi-UL sticker to certify the weight.

orcanova

I think you completely missed the point...

weights are grossly misstated all the time, and weight ranks as a pretty high factor in purchasing decisions. This is not a debate about how much you or I would spend per gram...

pcates

my understanding...(and i could be completely wrong) is that those weights listed are calculated as an average of a sample test (nominal weight) of the product and many could be above or below that weight......but you're right, seems most end up on the above side

CastIron

I got your point. I just assume those weights are B.S. and look for independent sources when it matters to me. Is it wrong? Sure. Is it really a problem in my eyes? No.

DrPete 

Weightweenies is a scary resource. My FSA cranks are low-balled by about 150 grams.

It really is ridiculous, but in most cases you can still comparison shop, knowing that you'll just add some to the advertised weight. Or maybe one class action lawsuit for false advertising against a component manufacturer will scare someone into compliance.

onRoffR

these alloys are shot peened or put into molds and no 2 will weigh the exact same the manufacturers give an average weight and most have a disclaimer for anyone that thinks this manufacturing process can produce exact weight clones. the alloys are mixtures and like color lots in paints and other goods there are variences. The nuevations wheels website gives a good example of wheel weight differences and the causes. I wouldn't get too worked up about lawsuits. weight variences are common knowledge in cycling components. thats why most bike manufactuers don't give total bike weights because of the variences of component weights

I_bRAD

I'm sure the tears you've shed over this will make up the 21g. Next time take your scale to the bike shop. I promise they won't laugh at you.

ElJamoquio

The weight variance due to different metal concentrations (while still within the same specification) of aluminum is going to be less than one percent.

Presumably these aren't designed to be porous, so we'll assume that they're originally weighed in at 100% alloy.

So then the only differences, presuming an honest company, are in geometry tolerances. So, if this assumption is correct, we're to believe that the geometry tolerances (length dimensions) have a tolerance of ~15% in every direction, and are always larger rather than smaller.

Um... no. They're lying.

pcates

hahaha thats so funny.....i saw a guy in dukes weighing something. pedals i think. my gf said it was over if i ever reached that point, now i have to weigh everything in the locked bathroom.

PiratePete

Dimensional tolerances for die casting should be less than +-1% and in most cases are even smaller (somewhat depends on the size of the part). The inconsistancies in weight for something like a stem should be a gram or two. Shot peening is shooting a bunch of small metal balls at the part, by the way. Its done to strenghthen the part by creating residual compressive stresses on the surface and/or cosmetic reasons.

Maybe whoever wrote up the specs on that stem is dislexic and meant 153 instead of 135? Or for some reason they're weighing the stem without the bolts and the part that holds the handlebars?

I_bRAD

Or maybe they just do it 'cause it doesn't really make a difference in the scheme of things and people feel good about it when they buy it (if you're into that sort of thing) just like how women's clothing manufacturers put size 4 labels on size 6 pants.

2manybikes

Average weight is all the manufacturers can hope to supply. Each individual part has tolerances.
It is possible to get all of the 8 (not counting four washers) parts on that stem to be on the heavy side. Then they all add up.
There's nothing you can do about it. Every manufactured part in the world had tolerances. The more parts it is made of the wider the total weight could vary. There's nothing wrong, you mistook average weight for absolute weight. Seems like most people do.
As mentioned many places say there are giving average weight. Shimano does for example.

Also all scales have a tolerance too. A spring operated scale will be more accurate in the middle of it's range than at the extreme end of the range.

When you add scale error, and parts tolerances all together you get what you have, normal variations.

lennyk

maybe it was weighed before the logo was painted on

I_bRAD

Imagine what she thinks when she sees you leaving the bathroom with a kitchen scale and a guilty look on your face!

GuitarWizard

Truth in advertising is a noble concept, but not a very realistic one at that.

I_bRAD

The problem is that you weighed it while it was stationary. The revolutionary oval design actually creates lift, much like an airplane wing. the 135 is the net weight after that is considered. If you buy the matching carbon bars, it actually creates a slipstream around the rider and creates turbulence behind you increasing your advantage!

patentcad

You want to get mad, get upset with EPA fuel economy numbers on new car stickers. Long deemed largely bull**** by anyone who can use a calculator to compute real world gas mileage at the pump, they are FINALLY slated to get a long overdue revamp over the next two years with more realistic tests for new vehicles. Most cars will see their EPA numbers drop 10-30%. And you're worried about 20 grams on a bike stem?

You ARE a true bike weenie. Welcome to the club. I would tell you to get a life, but I'm worse.

merlinextraligh

we need Elliot Spicer on this.

blandin

Just re-weighed a few spare parts on the scale that I remembered to be in range, which shows that all weight claims aren't so outrageous. Wish it was true all the time.

Ritchey WCS 4-Axis Stem 100mm stem: claimed- 115 grams, actual- 117 grams
Forte Precision Carbon Seatpost: claimed- 152, actual- 142 grams
Selle Italia SLR XP: claimed- 180 grams, actual- 180 grams
Profile Design Carbon Cage: claimed- 37 grams, actual- 31 grams

Smoothie104

i don't know which is more amazing to me. That the OP is so concerned about this, or that he can tell the difference in stiffness between to peices of rigid aluminum. That being said, maybe the increased stiffness is worth the slight weigth penalty?

orcanova

Loaded statement so why don't you re-read...

I said I like the stiffness of the stem, and I'll probably keep it just for that. I just don't appreciate false advertising. The Deda Zero 100 advertised at 100 grams. Hardly anyone has a stem that light. Everyone has a stem in the 140-150 range. You think its OK that they advertise 100 grams when its really 140 grams? The primary selling point is the weight, making it "super-light", yet a false weight that is 40% off, and no lighter than a plethora of stems on the market.

The Oval Concepts stem...the distributor weighed one on the spot for me (10 cm shorter) and it was only 3 grams lighter. There's no way that factory tolerances ramble 40 grams over or under. Production costs are one of their promary considerations and manufacturers don't waste raw material because they're not paying attention.

My primary criteria for a stem is stiffness, and secondary is weight and price. Twenty grams one way or the other is negligable, and I can save 40 grams anywhere else easily. However, if I chose a stem I think is stiff, and it is lighter than others, and it is a reasonable price, I go for it. Weight is a consideration. I was using the stems as an EXAMPLE of an industry-wide practice of over-stating weight.

I understand the argument that I can go faster if I just dig a little deeper, or that a better rider and a lesser bike will kick my ass. I agree with that. But the purpose of this thread is not a meaningless debate on price per gram.

It is simply about the fact that manufacturers, wheather they are selling wheelsets, brake calipers, whatever, intentionally misstate the numbers. I don't like giving my money who are BSing me. Many of these companies are from overseas and they might get away with that, but I think we're better than that.

If you buy a wheelset that is supposed to be 1500 grams, but it really is 1650, and your OK with that, go for it...

That is all...

PiratePete

I would too be pissed off if somebody lied about advertised weight. By 15%. It's not a matter of 20 g. Most people would probably be pissed if they bought a 20 lb bike that actually weighed 23 lbs. This isn't a question about tolerances at all.

Raw materials costs are actually pretty neglegible when compared to manfucaturing costs (die wear, material processing, etc, etc)

orcanova

^ THank you...I stand corrected, but they do have it down to a science nevertheless. And thank you for understanding the original point. I am not a weight weenie, just a consmer who wants to make the best purchases possible, and you can't do that when vendors are making stuff up.

Another frustration with bike upgrades is there's no quantifiable means to compare stuff like stiffness, tortional rigidity, fatigue limits, etc...just anecdotal comments like, "get the Easton...its wicked stiff."

oboeguy

That's what I was thinking, maybe they fudge it by not counting the bolts.