Super Lightweight Components From XC Race Bikes

 @landscapeben: the caption says the combo is 9.5g heavier, might be worth it for unbruised testes...

 @landscapeben: it's directly proportional. Less metal heats up quicker and also cools quicker. There'll only be the same amount of heat energy put into the rotor, but if there's a 3rd as much metal, it gets 3 times as much heat per gram of metal. Really, rotors shouldn't be polished, I fit radiators and chrome plated ones have a much lower heat output than an equivalent white one, and that won't put out as much as a black one. So all rotors should be dlc coated.

 @inked-up-metalhead: but the chrome towel rails are hotter to touch. It's a bit odd.

 @deli-hustler: it's because they hold the heat, instead of transferring it to the air. So yes the radiator is hotter, but the room is cooler.

 @Altron5000: maths was never my strong point!

 @inked-up-metalhead: dunno , I use a full carbon fork 720g for 29" but use mt5 caliper and Shimano xtr lever. f*ck weight watchers if I can't breake for ever ...

 So basically it depends on your style of braking. If you brake hard and short, you may be able to get away with one of these. If you tend to continuously drag the brake, these aren't for you. I realize this may be a very unkeyboardwarriorish thing to say but, I'd expect these riders have tested these rotors before they raced them at the world cups. Those who couldn't get along with them probably didn't race with them. Then of course, please prove me wrong. Show me the pikachu face of the rider who overheated these rotors at the worldcup race.

 @vinay: yup. I'd say these guys use less brake over an entire lap than most of us would down one tech feature. I feel my 200mm ice tec rotors get a bit warm sometimes...

 If you want to loose weight work out, your bike will feel better.

 @vinay: You can see in the picture that the rotor is already burnt.

 @vinay: if you start and stop at the same respective velocity, the heat produced as a loss of kinetic energy is the same. The only difference is time it's taking to produce the heat. So, if anything, braking faster would produce heat faster and the peak temperature would be higher because if done over a greater period of time the temperature won't be as high since it can also dissipate heat longer.

Overall though, these are cross country racers. They can afford to blow through pads and warp a disc by the end of each race. I'm sure these were tested.

 @jorgeposada: Be willing to be most of these World Cup XC riders 'work out' on the regular.

 @thustlewhumber: Yeah, it appears as if it is the area near the spokes which is burnt, but not the actual brake track. Could it be that the pads have already "dub" a bit into the rotor so that the edge near the spokes is constantly dragging even when the actual brake track is free?

@conman1395 : Not sure there. I think brake definitely heat up more when you drag them than when you dissipate all that energy in shorter bits. I do agree that for the same change in velocity, the same amount of energy is dissipated. That's some basic mechanics. I just think that the short hard braking causes a more rapid temperature rise and (when the brake is released) this larger temperature difference (rotor vs ambient air) also causes a quicker cooling. So in the same time, more of the absorbed energy is actually radiated compared to a dragged brake that only reaches that high temperature near the end.

Either way, the brake rotor in the picture is a rear brake rotor. I've once tried a 160mm Marta SL brake rotor in the front (with the 2007 Marta brake). It was black and blue in a single ride with some steep but very short descends. I've stuck with bigger front rotors ever since. However, for years I've happily run a 140mm brake rotor in the rear and it has been fine. I only moved up to 160mm in the rear because my current frame has a 160mm PM brake mount so I can't go smaller than that. So yeah, I'm heavy on the front brake but quite light on the rear brake. I suppose it would work. I'm just not one to experiment with untested combinations (third party brake rotor) for silly gains (like saving weight) but that doesn't mean it can't work in a more closely monitored situation (like WC racing with team mechanics and factory support).

 @Serpentras: Shigura for the win. I have a similar combo on my dh bike and they’re amazing.

 @vinay: the riders racing WC with weight weenie rotors probably don't have factory support, or probably even team mechanics.

 @vinay: If I am not wrong WC courses are not that brutal DH wise and the amateur dude can maybe ride in the Alps and get 2000hm down to the bottom in one go, would you ride with the WC weight weenie rotors there?
That is another reason I never go full weight weenie. I hate to walk, gimme some beefed up weenie stuff please. I am also not in the Alps but I can send 1000hm constantly if I want and that is a no go for this weight watcher part bin stuff.


@Altron5000 : Yeah they are the real deal,l consider how cheap the Zee-MT5 Combo is and how it beats the MT7 in everything except the high price, haha.

 I have those rotors on an XC race bike - yes they are light - they work .. but the make the front brake judder. They are soon to be swapped for something else with a bit more metal.

 @bman33: Been there and do it boy.

 @Serpentras:
I know this is a 2 year old thread but I would like to know what brand and model of fork you mention here. Full carbon 720 grams in 29"?
Thanks

 Agree. Anyone can buy the lightest stuff but I really enjoy seeing the creative ways people will try and save even more weight. It adds to the fun of the sport.

 Right, you don't have to want it for your own bike, nobody's selling you this stuff, it's super elegant design and engineering

 @Doradora: Some of the solutions here are actually wiser and more durable than what most of us are using. An aluminum seatpost clamp subject to bending is pretty stupid actually. A thin titanium or even steel strip subject to tension is the way to go.

 Or even your digestive organs!

 The Berk saddles are actually the most comfortable saddles I've ever owned. Many people focus too much on padding, when in reality it's so much about shape. Other factors are flex of the saddle shell (that one is truly "soft") and a full carbon model like that makes for way less friction between your bibs and the saddle, which equals less chafing.

Another thing not often talked about is how much comfort a lightweight well made seat post like that gives, they flex a lot which is a really good thing on a hardtail or when having your suspension locked on fully.

Side note: The integrated combo is actually the flex version, with rails so the shell can flex for better comfort. The really lightweight version features no rails at all but vertical carbon "plates" but then the shell is rigid at the center and only has got a little bit of wing flex.
Both combos features the same shell shape, but it's not the Rogla as stated in the caption but a model that's not in production (old prototype shape). But they have the molds and would most likely make you such a saddle if asked to.

/Dangerholm

 Testes removed - 100 grams!

 @Doradora: maybe for roadies. -1kg for some of the freeriders.

 Those saddle makes me cringe

 I got a cheap ebay all-carbon saddle with a bike I bought a few years back and tried it just for laughs. Surprise! It was the most comfortable thing ever. No padding to sink in to and distribute pressure to the wrong places. Just drop it for chunky terrain. Who sits down when it gets rough anyway? I bought a second one for my other bike. Best $30 bike upgrade ever! That said, leaving the seatpost up on the fun parts can be like a session with a dominatrix...

 @bicyclerider: while I conceptually understand your point, I pretty much exclusively opt for this kind of saddle:
www.specialized.com/us/en/power-pro-elaston/p/155906

Edit: after a google search, this does seem interesting though: www.probikekit.com/bicycle-saddles-seatposts/selle-italia-slr-c59-saddle-black/11446836.html

 @bicyclerider:

 Those saddles look like they'd slice or stab you in a wreck.

 Is it possible that Spinergy were just shit? Friending for an ask

 Cvnt but true @GZMS:

 I broke my current carbon frame also. If parts are designed to be as light as possible, then edge cases of heavy riders and hard rides get factored out. Super light XC parts are really amazing bits of engineering and I love looking at them and they're amazing to ride...when they don't break on you. It's simple engineering. Every part is made to hold a certain load. Manufacturing and material tolerances have to be accounted for during design because not every part is going to be the same. The less strength overhead you have in your design, the more failures you will have in your production parts. The spox wheels did suck for durability, but they had nothing to do with the broken handlebars or frame.

 @Explodo: I'm 210 and have been riding XC bikes 4-5x a day for years, and never break parts. Some people just break things.

 @Explodo: well I take that back, I cracked a pair of carbon bars this summer

 @Explodo: people always think that people use carbon on dh bikes to make it lighter, unless you're scott they're almost always made out of carbon for the stiffness, carbon frames are strong if they aren't for xc...

 I'm searching fot that animal print lycra kit for years

 That's what a lot of people don't get. The designers of this stuff are pushing current tech and materials to their limits as they want minimum weight but it has to last the length of a race. Take the chain guides as an example. They're finding out how far they can push it with clever designs. These designs can then be beefed up for longevity and suddenly you have a chain guide that is lighter than your current one but just as effective. Do this over the whole bike and you can easily lose a kilo from your Enduro bike. Remember when DH bikes had massive alloy discs with top and bottom rollers to keep the chain on? Now we have bikes riding similar terrain that only need a small piece of plastic and a small alloy mounting bracket. Yes, N/W chain rings have helped but even on bikes without those the small chain guides work. Progress that started at the top and filtered down.

 With lockdown in South Africa in in April / May and all the trails closed, I spent a lot of time on my carbon 6,8kg carbon road bike. Man, getting on my trail bike (still a light 12,7kg Intense Primer 29er) felt so f*cking weird after that. Not only like the bike was HUGE, but so slow and squishy. hahaha. Not to mention then shuttling afterwards on my DH bike.

Can only imagine how awesome a light XC bike must be. But I'll keep my trail bike thanks.

 Same here. I had my Commencal Meta at the bikeshop for service last week and they told me that they were really busy and that it might take up to 4-5 days until they would get around to service my bike. But the rep offered me that I could rent one of their bikes on a big discount while I was waiting for my bike to be done. So I rented a Trek Supercaliber from them for the weekend for next to nothing. Man, it was a paradigm shifting experience. I'm now seriously considering buying a XC race bike.

 Yes except for that your hanger isn't going to be $8 anymore. Try $25 -50. Still cheaper than a new derailleur though

 Because these people don't pay for or repair their own parts. Some of these parts are probably more for the head game than the accumulated marginal gains. But also, if you're working your ass off to get to the absolute limit it makes sense to apply that same philosophy to every part on your bike.

 The real reason for a replaceable hanger is so you don’t have to throw away a frame.
They don’t save deraileurs. Never have.

 @bigtard: so true in that they are meant to save frames. They used to save derailleurs too but were so soft that they caused lousy shifting. They are generally very stiff now and are solely frame savers.

 Lmk the hook up for $8 hangers ?!?

 @bogey: yep, they're more to save manufacturers from having to deal with idiots cross threading derailleurs. Stronger the better in my experience, I've had more just fatigue and randomly fall off (destroying a mech and wheel), than bend due to an impact.

 @taletotell: my fully aluminium hanger on my Commencal was about £30 so $40ish very expensive

 Wonder if the carbon hangers are designed to fail under high stress loads/impact. The nice thing though with the carbon hanger should it not fail under stress, is that you will not be riding around for a while struggling with shoddy shifting due to a slightly out of alignment alum hanger that was not so evidently bent.

We should all be riding with a spare hanger on our rides anyway, so if the carbon hanger is (a) designed to fail under a predetermined force and (b) would not bend slightly from a low impact and finally if only (c) the price was low, then it could be a good material generally for der. hangers.

 @HairyLegs: did'nt hangers used to be mounted with a breakaway bolt as to hopefully not damage the hanger but just the bolt? Been awhile, I might be thinking of a derailleur bolt on a fixed hanger instead.

 @HairyLegs: One downside would be that the hanger and frame have to me manufactured spot-on. You won't be able to tweak the hanger/frame combo into perfect alignment like you can with alloy. But yes, assuming it's designed to snap before the frame, a hanger that can't bend sounds really nice to me!

 @MikeGruhler: the Syntace X12 hangers still utilize a hollow bolt (that fit an allen head) that is designed to shear in an impact. You then extract the piece of bolt from the burly thick hanger, and reinstall with a new bolt.

 @PHeller:
I’m not sure if you’ve had personal experience with the syntace hanger but it was largely a failure for a few reasons besides its breakaway bolt.

 @bigtard: I’ve had it on two bikes now and it’s worked fine, what were the issues?

 @bigtard: After some research into the topic, it sounds like the Syntace design relies on the "alignment pin". If the hole in the dropout that the pin fits into gets ovalized or enlarged, it can result in the hanger alignment going out of wack and shifting issues - especially on 12spd setups.

 @PHeller: It’s a design that relies heavily on things being right in a manufacturing setting where they just won’t be. Hole/pin tolerance and placement, and frame mating surfaces often not being flat. Combined with clutch derailleur abuse loosening the bolt.
Ha then there was the version where it got in the way of your derailleur moving back enough to get the wheel off so you had to remove the derailleur!
I’m sure your bike would run more fine without it.
With 12 speed there isn’t any room for it. And with the state of most peoples bike maintenance game It’s a recipe for disaster regardless of the number of gears.

 I've never been faster when my bottle is empty.

 This is always brought up. I don't think the people buying these bits are doing it so that they can skip the morning dump.

 Yeah I've never understood this line of argument. Why not do both?

 I don't mean to brag, but i can lose much more than a pound with a morning dump.

 Similarly, what's the deal with fast rolling tires? The same gains can be had by not towing your toddler in a trailer.

 @IntoTheEverflow: I bet that line gets all the ladies

 @kylar: bought syncros bars so I can skip 2 days worth of dumps.

 Do you not take a dump before you ride anyway? Am i the only one who doesn't ride around with my a*shole clenched the whole time desperate to finish so i can finally void my bowels?

 I'm working on it........1/4......1/2.....3/4.....1..............

Do you have a scale I can weigh this on?

 The lightest thing you can have for an XC bike is an XC thoughts

 @takeiteasyridehard: weight yourself before and after, it's less messy

 You think they haven't already thought of that? Do you know literally 0 XC racers? Taking a dump is part of every XC racer's pre-race prep.

 @IntoTheEverflow: these people need fiber in their lives

 Heavy,proprietary hub,etc.

 Bad torsional rigidity, and heavy. The new SID is amazing too.

 Styrofoam can compress.

 @phops: That depends, some styrofoams are pretty stiff. And even if there was a little compression, so what? This compression could actually be measured, and the token be made correspondinlgy larger. But the difference is ridiculous, adjustments are made by entire tokens, not 5% of a single token, which is insignificant.

 I throw a full carbon saddle and seat post on all my DH rigs. Saves a shit load of weight and hardly ever sit down... no fucks given about the cringe looks all the dropper post chamois guys give.

 Why is your back is in front of the saddle when going downhill?

 @IntoTheEverflow: super attack position, bro!

 @IntoTheEverflow: Wait a second, you guys don't get in the Froomey position when going down the trails?

 Agreed. I once took a friend's roadbike for a spin and he had a carbon saddle and stem installed. Felt surprisingly nice. But I think that might have been down to the fact that the stem had some sort of carbon leaf spring integrated right below the top where the saddle rails mount.

 Yes, I was planning to replace the full carbon one on my road bike for a (slightly) padded version but did 308 km on it the other day with no problems whatsoever at that area. As for mtb use, I rode my xc bike when it had a saddle like that to a nearby DH track once to watch a National Cup Race, but riding down it afterwards I actually broke the rear part of the saddle with my thighs. I have now replaced it for an equally full carbon one, but which is rounded at the back, so it doesn't get stuck or broken with high-saddle downhilling.

 Power/Weight accounts for the vast majority of difference between xc competitors. I'd say even more so than road, since aero is much less of a factor at XC speeds.

 @dthomp325: aren't power and weight to very different things? I'd love to see a study that controlled for bike weight. I'm sure it helps but a couple of pounds on a rider&bike of 150+ seems negligible. Except for rim tire weight. That I noticed in small increments as the power/leverage needed to accelerate is significantly impacted by weight at the edge of the wheel. I definitely am no expert though, obviously

 @jesse-effing-edwards: power/weight spans a small range in the elite WC field, even very small 0.5% differences can gain or lose positions at that level.

 @dthomp325:

I guess for the less than elite it's probably just simpler to lose a few pounds haha

 @jesse-effing-edwards: even most competitive amateurs in the top 1/3 don't have any body weight to lose, that s pretty much required.

 "If you worry about the ounces, the lbs will come"

 Absolutely. The gains are so, so low, that they'd be better off with aero shaped components.

 I buy anything that’s handmade in Germany.
I don’t need to explain myself to you.

 @scary1: I do what I want!

If a 6g seatpost does the job why use an 40gr one?
If a 30gr chainguard keeps your chain on why use a 100gr one?

 @clink83: I tell my g/f that

 If you build your bikes from the frame up why wouldn't you choose the clamp or insignificant part that weighs half or less? Those carbon clamps are only 1-2 dollars more than the aluminum ones if you're not buying name brand parts.

I probably am stupid for doing this though... I have 2 760mm carbon bars that weight under 170g each. I paid under $30 for each brand new. They've lasted years though. I just wish they were backswept more than 7 degrees.

 @joaovasco: Right!! I wondered many times how much watts could be saved with aero in xc. We'll probably never know since it weights more but still...

 @Warburrito: I think they might snap...

 @clink83: Right, thats exactly how progress happens. Why settle for less if you can do better?

 @freebikeur: The real aero gains would be had in DH. It drives me crazy to see clothes flapping in the wind in World Cup races won by fractions of a second.

 @nattyd: aero kit are banned, sadly... but the frontal area of the bike could be vastly improved indeed.

 @freebikeur: What defines “aero kit”? Surely there’s a workaround. And yes, an aero shaped bar and other bits would be a big improvement.

 @freebikeur: tell that to Loic

 They are good on micro bumps... like the shit that you'd just suck up on a rigid fork.. lol

 Would you say they're laufable?

 They wouldn't ride any better if their travel is zero. Is their travel zero? I very much doubt it, so your comment is puzzling.

 @DavidGuerra: Well the issue is that it's a spring with no damper
plus leaf springs not super rigid

 @Civicowner: "leaf springs not super rigid" You mean there is a lack of torsional rigidity? As for the lack of damper, yes, it's an obvious problem, but I imagined that it was mitigated somehow, if they are selling this product. In principle, an uncontrolled spring is not something you want to ride.

 @DavidGuerra:
" In principle, an uncontrolled spring is not something you want to ride."

Yes. Hence the shitty performance. It's good on small washboard type bumps, but that's it.

 What do you have with the name, it's f**cking brilliant.

 @vid1998: In Cockney rhyming slang, berk is short for Berkshire Hunt, which is short for…

 @deadlyhifi: Ohhh, well that's unfortunate It's the owners last name. And I thought that you knew what Motika means, it means hoe (working tool) and well hahaha

 aerodynamics

 Debridement is much easier sans hair

 Vanity

 @radrider: hairodynamics

 Peeling off bandages. HUGE difference in pain.

 Well when you finish the days stage at the Giro d Italia, your soigneur doesn’t want to massage your hair legs now do they? Nope! So shave them legs

 To save weight