Mountain Bike Reviews Forum banner
1 - 11 of 11 Posts

·
XC iconoclast
Church of Real Metal
Joined
·
2,198 Posts
Discussion Starter · #1 ·
Before I get into the title discussion, let me say that it's really hard to get a bike under 23 lbs, even a hardtail, without either compromising performance on the trail and/or spending way too much money trying. So really, this is about hardtails between 23-35 lbs that are under $5000. Maybe that weight range is too heavy for this forum, but a lot of people ask, or guess, what the real weight is of a low-to mid-range bike, and you know how common it is for a manufacturer to either refuse to list the bike's weight or to shave off 1-3 lbs from the real weight, not include pedals, etc. There needs to be some method to quickly find out how off the listed weight is, for people looking to buy a bike and making sure they are getting their (lack of) weight's worth as well as their component's worth. That method would NOT be exact, to the gram, or to the 100th of a pound. It may be off 0.5-1.0 lbs, but at least the prospective buyer would know the actual weight within +/- 0.5 lbs or so before they took the plunge and bought the bike. That's the goal, not to be perfect, to be practical.

I've noticed a lot of hardtails are listed at 27-28 lbs, with a lot of older, cheaper components. Those numbers don't seem accurate. I'll give an example of how I upgraded a bike and it wound up weighing 34.4 lbs, 3.6 lbs above the listed 30.8 lb with pedals. Instead of assuming 30.8 lbs is correct (I think it really weighed 32 lbs stock), you have a baseline 'reference bike' weight, based on avg. steel/aluminum/carbon frame weight, along with the average (or known) major component weights --- fork, drivetrain, wheelset, tires, and then you have the misc. weight of everything else, handlebars, kickstand, headset, bottle mounts, etc. No, this is not exact! But it's fast. It won't take 20 hours analyzing every bike.

34.4 lbs: aluminum frame, 4.5 lb air fork upgrade, dropper post, minimal drivetrain upgrade (assume 7-10 speed 3x10 drivetrain), stock or weight-equivalent aluminum wheels, heavy (Maxxis) tires with tubes & sealant. Pretty run of the mill low-end XC/trail hardtail.

What was added to the bike that either added or subtracted weight:
Stock fork was 6.0 lbs = -1.5 lbs
Dropper post replacing normal post = +0.5 lbs
Drivetrain probably around the same weight as before, no major changes
Wheel weight roughly same as before
Tubes w/sealant = +0.75 lbs, assuming sealant needed anyway w/tubeless, so adding tube weight only
2.5 to 2.8 Maxxis tires roughly +2.0 lbs more than the stock 2.1 WTB Nano's (that sucked)
Misc. components: two bottle holders +0.5 lbs, otherwise roughly same as stock

Total Change: +2.25 lbs, so stock bike was probably around 32.0 to 32.2 lbs. That's 1.2 to 1.4 lbs more than the claimed stock bike weight.


So...based on this information about the reference bike above, can someone be confident that:
A carbon frame would drop around 2 pounds off the bike
High roller/racing tires would drop 1-2 pounds off the bike
A carbon wheelset would drop around 2 pounds off the bike
Taking off the kickstand would drop roughly 0.75 pounds off the bike
Air forks generally go down to around 3.5 lbs, so maybe 1 more pound off the upgraded bike, but up to 2.5 lbs off the stock bike
Not giving up the dropper post (!!!)
1x 11- or 12-speed drivetrain around 3.8 to 4.3 lbs; most 3x drivetrains are around 5.5 lbs, so let's say for simplicity 1x would drop the weight roughly 1.5 lbs
Tubeless = 0.75 pounds off the bike
Misc. components --- a little smattering of carbon here and there, seat, handlebars, etc. may take off around 0.5 pounds off the bike

Total Estimated Weight Loss: 9.5 to 10.5 lbs off the 34.5 lb bike (rounding up from 34.4 to 34.5) = 24.0-25.0 lbs total including dropper post, but no kickstand. Obviously with a new carbon frame, that original 34.5 lb bike would cease to exist. It would be a whole new bike. The old bike is just being used as for reference weight.

Are the numbers realistic above, and if not, why?
 

·
Ride Fast Take Chances :)
Joined
·
3,627 Posts
Yes you can absolutely tell how much a bike is going to weight if you know accurate weights for all the parts. I have a spreadsheet I use. Finding real world weights can be tricky, especially on frames. Don't forget that cables, grease and bolts all factor into the weight game.
My 2007 XL Blur XC is 22.7lb with pedals ready to race. add .45lb if I swap to a dropper.
 

·
Formerly of Kent
Joined
·
13,144 Posts
Before I get into the title discussion, let me say that it's really hard to get a bike under 23 lbs, even a hardtail, without either compromising performance on the trail and/or spending way too much money trying. So really, this is about hardtails between 23-35 lbs that are under $5000. Maybe that weight range is too heavy for this forum, but a lot of people ask, or guess, what the real weight is of a low-to mid-range bike, and you know how common it is for a manufacturer to either refuse to list the bike's weight or to shave off 1-3 lbs from the real weight, not include pedals, etc. There needs to be some method to quickly find out how off the listed weight is, for people looking to buy a bike and making sure they are getting their (lack of) weight's worth as well as their component's worth. That method would NOT be exact, to the gram, or to the 100th of a pound. It may be off 0.5-1.0 lbs, but at least the prospective buyer would know the actual weight within +/- 0.5 lbs or so before they took the plunge and bought the bike. That's the goal, not to be perfect, to be practical.

I've noticed a lot of hardtails are listed at 27-28 lbs, with a lot of older, cheaper components. Those numbers don't seem accurate. I'll give an example of how I upgraded a bike and it wound up weighing 34.4 lbs, 3.6 lbs above the listed 30.8 lb with pedals. Instead of assuming 30.8 lbs is correct (I think it really weighed 32 lbs stock), you have a baseline 'reference bike' weight, based on avg. steel/aluminum/carbon frame weight, along with the average (or known) major component weights --- fork, drivetrain, wheelset, tires, and then you have the misc. weight of everything else, handlebars, kickstand, headset, bottle mounts, etc. No, this is not exact! But it's fast. It won't take 20 hours analyzing every bike.

34.4 lbs: aluminum frame, 4.5 lb air fork upgrade, dropper post, minimal drivetrain upgrade (assume 7-10 speed 3x10 drivetrain), stock or weight-equivalent aluminum wheels, heavy (Maxxis) tires with tubes & sealant. Pretty run of the mill low-end XC/trail hardtail.

What was added to the bike that either added or subtracted weight:
Stock fork was 6.0 lbs = -1.5 lbs
Dropper post replacing normal post = +0.5 lbs
Drivetrain probably around the same weight as before, no major changes
Wheel weight roughly same as before
Tubes w/sealant = +0.75 lbs, assuming sealant needed anyway w/tubeless, so adding tube weight only
2.5 to 2.8 Maxxis tires roughly +2.0 lbs more than the stock 2.1 WTB Nano's (that sucked)
Misc. components: two bottle holders +0.5 lbs, otherwise roughly same as stock

Total Change: +2.25 lbs, so stock bike was probably around 32.0 to 32.2 lbs. That's 1.2 to 1.4 lbs more than the claimed stock bike weight.

So...based on this information about the reference bike above, can someone be confident that:
A carbon frame would drop around 2 pounds off the bike
High roller/racing tires would drop 1-2 pounds off the bike
A carbon wheelset would drop around 2 pounds off the bike
Taking off the kickstand would drop roughly 0.75 pounds off the bike
Air forks generally go down to around 3.5 lbs, so maybe 1 more pound off the upgraded bike, but up to 2.5 lbs off the stock bike
Not giving up the dropper post (!!!)
1x 11- or 12-speed drivetrain around 3.8 to 4.3 lbs; most 3x drivetrains are around 5.5 lbs, so let's say for simplicity 1x would drop the weight roughly 1.5 lbs
Tubeless = 0.75 pounds off the bike
Misc. components --- a little smattering of carbon here and there, seat, handlebars, etc. may take off around 0.5 pounds off the bike

Total Estimated Weight Loss: 9.5 to 10.5 lbs off the 34.5 lb bike (rounding up from 34.4 to 34.5) = 24.0-25.0 lbs total including dropper post, but no kickstand. Obviously with a new carbon frame, that original 34.5 lb bike would cease to exist. It would be a whole new bike. The old bike is just being used as for reference weight.

Are the numbers realistic above, and if not, why?
Your basic assertion that it is hard to build a sub-23lb hardtail without compromising performance on the trail or without spending a boat load of money is inherently flawed.

You can absolutely do this. Hell, you can build a 23lb FS with a dropper that could survive for several years of every day riding for $5k.
 

·
Registered
Joined
·
3,356 Posts
Before I get into the title discussion, let me say that it's really hard to get a bike under 23 lbs, even a hardtail, without either compromising performance on the trail and/or spending way too much money trying.
Not really true. My Norco Revolver was under 22 pounds and very trail capable. But if you go burlier you are about right, my Ibis HD3 with dropper, Pike dual and 2.35 tires is under 25 with pretty much the same components.

As far as predicting bike weight as long as you have the correct weights of the parts of a bike and you count everything all you are missing is the weight of some lubricants.
 

·
Registered
Joined
·
5,800 Posts
I can tell/guess the weight of a bike, just by looking at it ;-)

I do suffer from Clyde'ism which makes me hyper sensitive when it comes to weight.

I can also tell/guess the weight of riders +/- 1-3kg's, just by looking at them.

e.g. I weigh 107-108kg's (1-3kg's accuracy right there!).

A fellow tall, slenderly built rider looked at me one day whilst we were discussing our bikes/sharing our setups... and suggested, I weighed a mere 95kg's!?

NB, I also have atomantium covering 80% of my bones.

'Born to ride!'
 

·
XC iconoclast
Church of Real Metal
Joined
·
2,198 Posts
Discussion Starter · #6 ·
I think I was off on the carbon wheelset vs. aluminum wheelset though. Most of the carbon ones I've seen are 3.60 lbs and a decent alumium set is around 4.85 lbs, so 1.25 lbs difference, not two entire lbs.

It's really hard to lose bike weight! When I finally build up my carbon frame I'll see the difference between what was calculated and what it really is. I'm guessing it's going to weigh 1.0-1.5 lbs more than calculated.
 

·
Formerly of Kent
Joined
·
13,144 Posts
I think I was off on the carbon wheelset vs. aluminum wheelset though. Most of the carbon ones I've seen are 3.60 lbs and a decent alumium set is around 4.85 lbs, so 1.25 lbs difference, not two entire lbs.

It's really hard to lose bike weight! When I finally build up my carbon frame I'll see the difference between what was calculated and what it really is. I'm guessing it's going to weigh 1.0-1.5 lbs more than calculated.
Not if you use accurate weights...

I've never had a bike be more than 50g off expected weight.

Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
7,850 Posts
I think I was off on the carbon wheelset vs. aluminum wheelset though. Most of the carbon ones I've seen are 3.60 lbs and a decent alumium set is around 4.85 lbs, so 1.25 lbs difference, not two entire lbs.

It's really hard to lose bike weight! When I finally build up my carbon frame I'll see the difference between what was calculated and what it really is. I'm guessing it's going to weigh 1.0-1.5 lbs more than calculated.
1.25lbs is a big difference.

I have a set of RF Next Carbon wheels and a set of RF Next Aluminum wheels and the difference is 80grams for the set. The difference between DT Swiss Carbon and Aluminum wheels is less than 100 grams.
 

·
Registered
Joined
·
302 Posts
There's almost a pound difference between two of my carbon wheel sets

Chris King on 27.5 SC Reserve 30 w/DTswiss spokes/nipples is 4.07lbs
Vs
DT Swiss XMC 1200 25mm 29ers are 3.19lbs

So, to say 'a carbon wheelset will save me x' is a little flawed, you need to specify what you are upgrading from and to.

Low weights are getting harder, as kit gets tougher and, more specifically, wheels go from 26 to 27.5 and 29, and wider rims and tyres, plus droppers, however the advantages these things offer far outweigh (heh) the grams they add.
 

·
XC iconoclast
Church of Real Metal
Joined
·
2,198 Posts
Discussion Starter · #10 ·
So check this out.

A customer at work didn't pay their $1920 bill in 2018. Wrote it off as a loss a couple of weeks ago for the 2018 tax return. Got a call at work this morning. She asks remember me. I said yes, and then I looked at the file, and then was like omg, yes, now I really remember her. No contact for 16 months, took her to collections and everything.

No one would ever know if I spent the $1920 on bike components, not the accountant, the CPA, my wife, the IRS, no one. lol. Tempting, isn't it. Hey, I sometimes check the business mailbox with my bike, so that's a business expense right??? I already have the $340 frame, bike build is just over $2500...
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top