[Closed] Lightweight HT, how light?

Never worked out why, but bikes always seem to weigh more than the sum of their parts!

People never quote the error in their measurements. Weigh all the parts seperately and you have to sum all the errors. If you have lots of small parts this can up to be quite a big range. Weight of the final build is probably within this range. I'm sure someone more mathematically competent could do a better job of explaining this!

Cotic bfe, 120 mm Rebas, hope/mavic 719 wheels, rubber queen 2.4/crossmark 2.25 tyres, deore/slx 3x9 drive train, stroker brakes, carbon bars, wellgo mag pedals and stock stem/seatpost/saddle - 26lb exactly.

Funny, that's almost exactly how much my Soul weighs (lighter frame), with lighter wheels + tyres, less gears, lighter brakes, carbon bars, and same fork. 😉

One of us may have dodgy scales, but then these threads always degenerate into such discussions.

Very light bikes are fun, but often fun in different ways and for slightly different things than heavier or more middling bikes, ultimately you'll end up with a bike weight that reflects your personal choices for comfort, reliability and budget.

I love my 19lbs XC race bike, it's ace, I also love my heavier trail bike, it is also ace, I also love my heavy squidgy bike, they are all fun!

Nice thing about my scale is that geometry wise, especially with the 120 fork, its a modern trail bike.

I've got a C456 built to about 25lbs and I think it's a perfect trail bike weight.

A few years ago I went about building a 20lb bike. just coz (Rock Lobster SL, Stans Alpine Wheels, Light tubeless tyres, Carbon Rigid forks etc). It was amazing on the climbs, obviously on the downs there's limitations with the carbon rigids, but barrelling down any straightforward rocky tracks the bike felt like it was being pinged off everything too easily and felt pretty skittish. With heavier wheels and tyres it felt much better.

[quote="njee20"]Who is the latter friend ghostlymachine? That has a whiff of apocrypha about it 😉 😀 It may well do, but seeing as I've not lived (or raced) in the UK for near enough 10 years it's [i]very[/i] unlikely to be anyone you know. And he packed in riding a while ago after a broken arm and a job change.

Aaah, not the UK, I take it back then!

Funny, that's almost exactly how much my Soul weighs (lighter frame), with lighter wheels + tyres, less gears, lighter brakes, 

Interesting 🙂 what is the full spec of your soul?

Interesting what is the full spec of your soul?

Didn't really want to send this thread down the kit comparison route but...

-Soul frame, small, prototype with EBB that adds about 150-200g, but it has thinner walled tubing at front end than a normal Soul and overall frame weight is barely any more than a normal Soul, certainly less than a BFe...
-Diatech cartidge headset
-RS Reba 120mm
-Truvativ Stylo T40 Stem
-Easton Carbon bars
-Bontrager foam grips
-Bontrager RXL Carbon post
-Salsa Liplock seatclamp
-BioFlex Ti/railed saddle
-Shimano UN72 BB + Middlburn ST cranks + SS NW ring (probably concedes 100g to an HT11 setup here)
-SS Nano pedals
-XT 10sp shifter
-SLX 10sp clutched mech
-A cable to the above
-XT 11-36 cassette
-SLX/Deore level chain HG??
-Bontrager Race X Lite Wheels
-Bontrager XR2 tyres 2.2/2.0 (tubeless)
-Hope Mono Mini brakes with Hope 160mm rotors

Have I forgotten anything?

So the EBB and Old school cranks might give away 200-300g so, but then you've got an extra shifter, front mech, chainrings and probably give away at least that in your OEM steatpost and saddle.

I'm pretty sure the weight is about right as my wife has a Charge Duster Skinny that's built with lighter bits again and comes in at 24lbs on the same scales which I'm already a little doubtful of, as that's actually pretty light for something with a steel frame, if the Soul is actually less than it reads then that would put the Duster into 'questionably light' territory on the same scales, and (assuming linear error in my scales which may or may not be a valid assumption) would make my XC race bike weight 'seriously doubtful'

I expect the problem with weighing components is not taking into account cables, ferrules, outers and various greases and oil etc..

Here's one for you weight weenies, how much weight do foam grips save over lockons?

Here's one for you weight weenies, how much weight do foam grips save over lockons?

loads!

foam grips are normally ~15-40g depending on model
lockons (ODI anyway) ~100-140g

@amedias My wife's Soul (26", extra small frame) with a 2x10 drivetrain is 12Kg (plus a few grammes from memory) this is a usable build not one aimed at being ultra lightweight. That was weighed by the shop on their scales, I don't know how accurate those scales are or when they were last calibrated.

As @BANana says: sometimes lightweight isn't actually usable, you need a bit of mass here and there to give you control.

My wife's Soul (26", extra small frame) with a 2x10 drivetrain is 12Kg

This thread a handy reminder that I had some weight wheenieing to do...

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To...

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36 grams, over an ounce, all out of the spares box. Reminder that it really is in the detail! Anyone want a barfly mount? 🙂

C456 18"
Knuckleball 777 bars,On One CNC stem, SRAM foam grips, SLX brakes, Hope spiderless 32T cranks, 10 spd XT 11-42 with expander, Zee shifter, Zee and RADR cage, Pro2 Evo on Arch EX with tubeless Nics, Magura Thor 140 AM fork, Reverb, Spoon, SS Nano pedals. 11.5 kg, 25.3 lbs.
Decent weight, could build it lighter with the Reba, but why would you?- The Thor switches down to 100mm travel for climbing. Not been very far on it, but early signs are promising. Feels like a good hooligan bike.

Soul 17" Answer pro taper carbon bars, Superstar Zenith stem, SRAM foam lock-ons, XT brakes, 2x10 XT drivetrain, Reba 120 fork, Superstar Switch on Crests, Bonty XR4 tubeless, Cube alloy seatpost, Scoop, XT Trail pedals. 11.8kg 26lbs. Great all-day bike, bridleway and ST basher.

Scapegoat, out of curiosity are those your only 2 bikes?

Sounds like a decent weight saving on those foam grips.. tempted but do they absorb water alot?

Not a bit, they're closed cell.

That said I run ESIs these days, not as light, but more comfy. Used to like Bontrager XXX Lites, but they do go slippery when wet - gloveless in summer could get interesting.

People never quote the error in their measurements. Weigh all the parts seperately and you have to sum all the errors

Just depends on scale accuracy. If my scales are 1% out and I weigh all the parts separately it is still more accurate than weighing the whole bike on a scale that is 3% out. It doesn't get worse because I am weighing lots of separate parts, % accuracy is % accuracy.

I have very accurate scales for items up to 2kg but don't have anything accurate for 8kg.

Clearly helps to have a liking for spreadsheets and data but also makes it easier to know what difference swapping a part will make.

Scapegoat, out of curiosity are those your only 2 bikes?

No, I've got a Mojo HD.... had some cash burning a hole and a friend had a frame for sale. I am occasionally spoilt for choice, but my mantra is to read up on a trail/ride and choose the bike to suit what I read and my mood. I then go back and try it on a hardtail if I think I can manage it. I'm 51 and need a new hip, so a bit of flying carpet riding helps enormously. Early signs are the C456 is a bit harsh until my hip has been done, but the fork suits it very well.

Just depends on scale accuracy. If my scales are 1% out and I weigh all the parts separately it is still more accurate than weighing the whole bike on a scale that is 3% out. It doesn't get worse because I am weighing lots of separate parts, % accuracy is % accuracy.

I think it's more because most people (not saying you) miss bits! They weigh their frame and headset and then chuck a load of grease in without adding that. Do think compound error plays a part as well though.

I think it's more because most people (not saying you) miss bits! They weigh their frame and headset and then chuck a load of grease in without adding that. Do think compound error plays a part as well though.

Bonkers - I always use ultra-lightweight grease and weigh it before applying to the component. Wiping away any excess can save crucial microgrammes and makes a huge difference to the way the bike rides. Sam's true of chain lube. I also shave off those tiny rubbery whiskers on new tyres, you can feel the extra acceleration from the reduced mass... 😉

Edit: I'm sure some people don't weigh their dust-caps either. Again these small errors can add up to significant weight discrepancy which could get you in deep do-do when the weight weenie police come calling eh?

I think it's more because most people (not saying you) miss bits

That's where the spreadsheet comes in!

I'm sure some people don't weigh their dust-caps either.

You ride with dust caps on? Just think of all that additional rotating mass makes me feel queasy!

You ride with dust caps on? Just think of all that additional rotating mass makes me feel queasy!

It stops heavy dust accumulating on your valves. Can be worth the sacrifice in some conditions. I also carry a duster in my pocket for dry and dusty stuff generally just to keep weight down. Doubles as a rain wipe if it's wet. Saves vital weight in both scenarios.

Indeed, essential weight weenie kit...

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My ti456 is quite light, how light I don't know, I have a life.

For me a properly light ht is a fun ride , you can blast out of corners and the climbs vanish.
But I can't don't jump much at all. I Can't rember the actual weight of my xc bike as life has got in the way Latley

That's not light.. this is light

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That's where the spreadsheet comes in!

Unless you weigh grease and lube separately they're not included though one presumes. I know a lot of people do have a 'misc' figure tor that reason.

Never done a spreadsheet though!

stevenmenmuir - Member
My ti456 is quite light, how light I don't know, I have a life.

I'd say you've got life/work balance all wrong if you can't make time in your life to weigh your push bikes. It's a bi-annual event in my household. I strip down, clean and rebuild all of my bikes twice a year, before weighing them. I like to remind myself just how light they are!

I have a life alright and a few seconds of that life is taken up weighing a bike part each time i buy one and then noting it. I have probably spent more time replying on this thread than I have on weighing parts...

Tricky, have you got a build list for that niner?!

It's from a MTBR port/thread on the weight weenies board maybe 4/5 years ago at least

Mattock, or matcock or something along the, limes was the username

A rigid SS with Furious Freds? Meh, show bike.

http://forums.mtbr.com/weight-weenies/finally-13s-656281.html

He obviously rides it, so fair play to him. Grinding half the wings off your pedals is definitely a step too far for me! 22-12 gearing too, quite a clever way to save weight, but imagine it feels a bit "lumpy".

Show bike was my first thought, but on that thread he's whipping the damn thing!

njee20 - Member

A rigid SS with Furious Freds? Meh, show bike.

If you are coming to the opening BC XC event at Pembrey that would be the dream bike I reckon! Bar the gearing that is.

's from a MTBR port/thread on the weight weenies board maybe 4/5 years ago at least

Yea following his post history he's just built up a [url= http://forums.mtbr.com/niner-bikes/my-sir-9-build-begins-903815-2.html ]SIR 9 build at 19.5lb with suspension this time[/url]

Show bike was my first thought, but on that thread he's whipping the damn thing!

I was surprised how heavy the frame was for something that's a couple of quid under 2k

I was surprised how heavy the frame was for something that's a couple of quid under 2k

It isn't their top spec frame and is only £1400. The RDO is £1800 and around 1kg. Not a bad price really but I'd probably be more tempted by the Procaliber right now if I had that sort of budget for a race hardtail.

t isn't their top spec frame and is only £1400. The RDO is £1800 and around 1kg.

Don't think it was around when he was building it up. That post goes from 2010 the RDO was released in 2012?

Seems a lot of effort and money to get a bike that light and then weigh over 12st himself.

Don't think it was around when he was building it up.

So frame swap would knock almost a pound off that build.

Seems a lot of effort and money to get a bike that light and then weigh over 12st himself.

but you can't just buy weight loss.

Agree on the gearing, 22/12 would not be smooth. I was running 30/13 in the summer and it was a noticeably rougher drive train than when using 30/14

My cannonade carbon F29 with a lefty was 23lb without pedals, so about 24lbs. Seems to take abuse just fine although I wince when big stuff flicks up and whacks it!

It feels very light and that's with 'not great' wheels.