Scales for weighing bikes

[Edge_Design]

Can someone please explain to me where/how people come up with the weights for their bikes? I spend a fortune (IMO) on high-end parts for my bikes and don't come close to some of the weights claimed... I have just built a top-end carbon racing HT with 2011 X-0, SID WC, Rocket Ron tyres and barely an excess gram on it which comes in at 9.75kg ready to go with pedals. People advertise Raleigh HT's with Recon forks/Crossride wheels/heavy tubeless tyres/mid-range alu components and they claim they are lighter???

 

My road bike has a light carbon frame, 1360g wheels, SRAM Red, Keo Blades and also light parts throughout and weighs 7.17kg's, but there is someone with Ultegra groupset and Ksyrium Elite wheels on the same size frame, but it's lighter than my bike again???

 

Can someone please explain this to me... And, yes I am jealous and I want my bikes to achieve some of the claimed weights on the hub, but maybe all I need is a new scale?!?!

 

And, no this is not completely serious, but it does make me upset when I see these affordable bikes at ridiculously low weights which gives me such high (low) expectations when I put my new bikes on the scale and then... B)

[gummibear]

What size is your frame?

 

I have seen scales that are up to 500 grams out at bike shops.

I had my road bike weighed at a pharmacy and Mtb at a butcher and when weighed at bike shops they were way lighter.

[andretraut]

I don't think there is a problem with your scale, or your bikes, but rather the over optimistic Raleigh or Silverback owners! You know the story of, ...when I grow up, I want to be a fireman! Same here, ....when I grow up I want to be a Pinarello, weighing just 6.8! But reality is -it ain't going to happen. So my advise to you, be happy with the (true) weight of your bikes, and ignore the far-fetched claims!

[Weight Weenie]

Speaking from personal experience of upgrading my GT :

 

- Frame weights vary allot. I thought mine was around 1,2kg, well its more like 1,5-1,6kg so that ads allot of weight to the bike

 

- Claimed weight is just that, claimed. So mostly its way out...

 

-Seems most carbon hardtails with heavy-ish wheels, a fox, normal tyres and XT type components and brand name cockpit will be around 10,5-10,8kg whereas fitting xtr/xo with carbon/kcnc type cockpit and 1,5kg wheels like mavic (slr?) will bring you to around 9,5kg. Add very light wheels like stans podium mmx and some XX from sram and a dt xcr fork and you'll go sub 9kg. With a VERY light frame and tyres made of condoms and/or a lefty, you can go sub 8kg ie scott scale 899 or 'dale flash

 

- Scales arent very accurate - try and get one of those red scales like Eliflap has (look in the weight weenies forum) they seem to be accurate.

[Shebeen]

weight weenies, a tribe more troubled than an EP rugby supporter

 

you do of course realise that the frame counts for only about 15% of the total weight. so it's all about the other stuff to be honest. as you say, doing the math with those other components it just can't add up.

 

I'd like to actually do a real survey on

bike(per category) weight vs price. the problem is people would most likely not tell the full truth about the weight, and they would definitely lie about the price.

[Minion]

My experience is that spec weights from many manufacturers (especially for frames) are not always accurate (e.g. they give the weight for an XS frame they don't always tell you this). My frame has a spec weight of 990g (XS) and fork at 325g. Actual weights are 1186g (XL) and 382g. If they're just giving a bike weight based on spec, it'll probably be too low.

 

Other areas of 'hidden' weight are:

Handlebars - I've seen road bars weighing from under 200g to above 300g.

Stems - range of over 50g

Seatposts - same range.

Pedals - for some reason, it's acceptable to state bike weight without pedals.

Tyres - the difference between lightweight, puncture-prone racing tyres and tubes and bomb-proof Gatorskins could be as much as 100g/wheel.

[AndreZA]

Alot of people keep a log of parts they put on and then calculate it that way, never even put the complete bike on a scale. And then they miss stuff like grease and headset cups or they just go according to manufacturers claims.

[Minion]

You can get a pretty accurate weight for a bike using some kitchen scales and a bit of maths.

 

1. Find a level surface and put the kitchen scale on it.
2. Put the front wheel of the bike onto the scale and hold the bike upright by holding the rear rim. Record the weight (W1)
3. Put the back wheel of the bike onto the scale and hold the bike upright by holding the front rim. Record the weight (W2)
4. Add W1 and W2 to get the full bike weight.

Provided you don't have massive friction in the hubs and the surface is level, this will give a very good estimate of your actual bike weight.This also assumes that the front and rear wheels have the same diameter.

[andretraut]

You can get a pretty accurate weight for a bike using some kitchen scales and a bit of maths.

 

1. Find a level surface and put the kitchen scale on it.
2. Put the front wheel of the bike onto the scale and hold the bike upright by holding the rear rim. Record the weight (W1)
3. Put the back wheel of the bike onto the scale and hold the bike upright by holding the front rim. Record the weight (W2)
4. Add W1 and W2 to get the full bike weight.

Provided you don't have massive friction in the hubs and the surface is level, this will give a very good estimate of your actual bike weight.This also assumes that the front and rear wheels have the same diameter.

You are not serious! There must be far better, and more accurate methods to get your bike's weight than this one. How about popping in at your LBS and using their top-end Topeak or Parktool scale? Maybe that kitchen scale will be fine to weigh your Avatar's upper lip, but I don't think it is good for bikes!

[Shebeen]

You can get a pretty accurate weight for a bike using some kitchen scales and a bit of maths.

 

1. Find a level surface and put the kitchen scale on it.
2. Put the front wheel of the bike onto the scale and hold the bike upright by holding the rear rim. Record the weight (W1)
3. Put the back wheel of the bike onto the scale and hold the bike upright by holding the front rim. Record the weight (W2)
4. Add W1 and W2 to get the full bike weight.

Provided you don't have massive friction in the hubs and the surface is level, this will give a very good estimate of your actual bike weight.This also assumes that the front and rear wheels have the same diameter.

 

you have got to be joking?! that's not accurate at all, i'm not even going to start picking it apart.

 

What you should do is take your BATHROOM scale (my kitchen scale only goes to 1.5kg), and stand on it alone. Record the weight (W1).

 

Now stand on the scale with your bike in your hands (W2).

 

Since the difference between the two is the bike, (W2 - W1) is your answer.

Suggest you do the same with your luggage when travelling by plane.

[Minion]

You are not serious! There must be far better, and more accurate methods to get your bike's weight than this one. How about popping in at your LBS and using their top-end Topeak or Parktool scale? Maybe that kitchen scale will be fine to weigh your Avatar's upper lip, but I don't think it is good for bikes!

The height of weight weeniness is spending R500 on a scale just to weigh your bike.

 

I'm sufficiently curious to use my engineering knowledge to come up with a workable, accurate and repeatable solution to weigh my bike using materials already available to me. I am not curious enough to load all my bike into my car just to take them to my LBS just to weigh them. Nor am I sufficiently curious to spend R500+ on a scale that's only accurate to 10g.

[Minion]

you have got to be joking?! that's not accurate at all, i'm not even going to start picking it apart.

Please do start.

 

A simple freebody diagram shows that it provides the sum of the reaction forces on the wheels. Holding the other wheel decouples the holding force from the reaction force on the weighed wheel (it can pivot freely about the hub and so cannot transmit the vertical force). If there is significant friction in the hub, then this will affect the accuracy.

[VincentBikes]

Unless you have a scale with a calibration certificate and the scale is sized to measure in the weight range of your bike then do not even try to believe the weight you see. What can be used is if you do upgrades on your bike and you use the same scale the error is constant and the improvement in weight will be real. I can also give you a scale that will measure your bike at 6.2 kg

 

Oh and like ED said what is the accuracy?

[Minion]

What you should do is take your BATHROOM scale (my kitchen scale only goes to 1.5kg), and stand on it alone. Record the weight (W1).

 

Now stand on the scale with your bike in your hands (W2).

 

Since the difference between the two is the bike, (W2 - W1) is your answer.

Suggest you do the same with your luggage when travelling by plane.

It wouldn't work on your kitchen scale, but mine goes up to 5kg. The resolution on most digital bathroom scales is 100g. That's a significant error if you're weighing a sub 7kg bike.

[Eldron]

Performance matters.

 

Equipment reliability matters.

 

Puncture protection matters.

 

Bars that don't break matter (more than you think).

 

Weight? Weight does not matter. It's a manufacturer's way of making your wallet lighter than your new super light titanium bolt kit that will save you 0.0000000000000000000000000000000000000000000001%.

 

Pride of owndership and bling I can understand...weight? C'mon chaps...

[andretraut]

The height of weight weeniness is spending R500 on a scale just to weigh your bike.

 

I'm sufficiently curious to use my engineering knowledge to come up with a workable, accurate and repeatable solution to weigh my bike using materials already available to me. I am not curious enough to load all my bike into my car just to take them to my LBS just to weigh them. Nor am I sufficiently curious to spend R500+ on a scale that's only accurate to 10g.

I think the bathroom scale method is more likely to be accurate, than the kitchen scale one. So give it a try. Do you know why they make those WW scales only accurate to 10k's...cause you should not ride a bike any heavier than that!