Jar_head's WCB-M-062

[Jar_head]

I got them out before the resin was hard..

The new seatpost is here. Scratching off the paint only gave me -2 grams  not much paint on that one ^^
But anyway its almost half of the one I had before. Tested on trails today 







Wanna have a 7.xx kg bike  still far away..

[rapsac]

Wanna have a 7.xx kg bike  still far away..

Get a Lauf fork?

[Jar_head]

Too expensive for me.. maybe I'll get a Race Face Next SL Cranks. Another 100 grams saved. A lighter rear thru axle from Shift Up, another 30 grams.

And then lighter wheelset and fork. That's the plan.. but it will take so time for me to get the money together (student).
But I will begin as a military pilot in October, so this won't be a problem for a long time ;-)

[SportingGoods]

Well, you could get there (<8kg), but why? What would your bike accomplish being 500g lighter that it can't do in the exact same way now?

It's good to get a lighter bike but you have to draw a line and determine the benefit. In real life, a lighter bike is not faster then a 500g heavier one, at all.
I'd recommend focusing on optimizing bike fit (so that you are efficient), sturdiness (so that you can push hard on it). A 500g heavier bike that you can confidently push hard and where you gain 5% efficiency (down or up) WILL be a lot faster.

Then, if weight is still a primary concern, the cheapest way might not be bike parts. It can be light bike shoes, light helmet, jersey (can save 100g total on clothes), bottle, multitool, pump, spare tube, etc... All that is fairly cheap and can gain a lot of weight.

[carbonazza]

What would your bike accomplish being 500g lighter

Well... it depends where they are removed from.
Having 500g less on the front wheel makes a big difference when placing the wheel fast on difficult terrain.
On the rear wheel too, to accelerate. On other static parts ok, eating a bit less is cheaper

I will compare soon my Lauf and Lefty, on my second bike( CS-041 ), when I will finally get my Eagle gear( my brother got it for his 036, will post pictures later ).

[SportingGoods]

I will have to disagree with you on that Carbonazza  . Again, weight is not the primary factor, function is!

You take wheels as example. That's the perfect example. My 27.5+ wheels are 400g heavier then my 29" (total wheel with the tire, sealant). 200g more for each wheel. Well, I'm faster with the 27.5+ setup.
I could take the seatpost as well. I'm faster with my Reverb despite this seatpost being about 300g heavier then my carbon post.
Same with the brakes, I'd be slower with light brakes as I need all the power of my SRAM Guide.

That being said, for a given function I always shoot for the lighter component (if budget permits!). But function comes first. That's why I question "why targeting lighter?". The real target should be "faster" which sometimes comes with heavier components.

[Jar_head]

The "eating less" option is not an option for me, since I weigh only 63 kg. My bodyfat is at a minimum, less would be no good.

My gear is the lightest I can get. S-works shoes, Specialized helmet. Bibs, jersey, gloves, socks.. everthing at a minimum.

I really wonder how you can be faster with a 400 g heavier wheelset, doesn't make sense at all. But it's also a totally difficult thing to compare 27,5+ with a 29er.
As well as it would make no sense to compare hardtail with a full suspension.

For me it's about how light can I go with full function. I don't want to have parts, that fall apart while riding (my bike is built for racing). And I totally agree with you, function comes first. But my bike works for me as it is. It has everything I need, nothing is missing (even 2 bottle cages, which I need of course on long distance marathons).

And why shouldn't I use a Race Face Next SL, a XX1 cassette, when I can save ~150 grams on rotating parts? And the XX1 cassette has more advantages: wider range 10-42 <=> 11-40). With that wider range I can run a larger chainring (36t) and get faster by that  So here we have your target SportingGoods 

Lighter = faster, as long as the function is given. And that applies for the whole system (the bike, the rider and the gear). And I try to optimize every part of the system (and the bike fit has already taken place).

[MTB2223]

I really wonder how you can be faster with a 400 g heavier wheelset, doesn't make sense at all. But it's also a totally difficult thing to compare 27,5+ with a 29er.
As well as it would make no sense to compare hardtail with a full suspension.

Maybe because these wheels have more grip in the corners, so he can take the corners faster ?

[carbonazza]

I really wonder how you can be faster with a 400 g heavier wheelset, doesn't make sense at all. But it's also a totally difficult thing to compare 27,5+ with a 29er.
As well as it would make no sense to compare hardtail with a full suspension.

Maybe because these wheels have more grip in the corners, so he can take the corners faster ?

Or maybe SportingGoods spends more time going downhill than climbing or pedalling hard on the flat

[Jar_head]

So than this will be a question of what one rides?!

For me time savings can be made in the uphill (which is where I mostly take over other riders  ) and that's why I want to save weight in the system. In the downhill on a marathon or XC course this doesn't really matter.

[SportingGoods]

True, I don't have many flat sections. It's either up or down. With my heavier wheels I'm faster both up and down, thanks to better grip and comfort.

What I mean is that the last few 100 g are the most expensive and when you are already down to 8.5kg you don't really need anything lighter. I agree that it would be a real upgrade to go with an XX1 cassette and Next SL cranks but dropping weight for the sake of dropping weight should not be the end-goal.

I recall a GCN video where they timed a climb with a 3kg backpack. The difference with no backpack was minor. You need to remember that 0.8kg saved on a 8kg bike is not 10% saved. It's 0.8 out of (your weight 63 + bike 8 + shoes, water, helmet... 2 minimum)=73 kg minimum. That's 1% for 800g saved.

[bxcc]

I'll add my 2 cents. After racing in a 25k a couple weeks ago on my WW-062 SS, the bike definitely seems to gain weight as the ride goes on. I do think you can reach a point to where you won't gain much for the money spent but the lighter the bike the better. But it still needs to be able to properly serve it's purpose. I had an acquaintance on his Scott 27.5 plus bike (geared and squishy on both ends) pass me within the first couple of miles. I passed him on a long sustained climb about 20k in to the race and that was the last that I saw of him. I've also been on rides when I didn't slip as much as other riders on their fat bikes. So I guess what I am getting at is that it's a package deal which includes the bike (build kit, weight, tire selection, suspension) and the person (riding ability, packs, shoes, helmets, body weight).

[cklein]

But don't forget, the weight on the rims are rotating and rotating mass is more than the normal mass.
I don't know how to say it in English, but with a wheel set which is 800g heavier you are slower. I could test it and that's the reason why I only have wheel sets <1500g

[bxcc]

But don't forget, the weight on the rims are rotating and rotating mass is more than the normal mass.
I don't know how to say it in English, but with a wheel set which is 800g heavier you are slower. I could test it and that's the reason why I only have wheel sets <1500g

Definitely! Getting a 2200g wheelset up to speed is a lot more work than a 1500g set. The other part to that is the part that centrifugal force plays on the spinning wheel. A front wheel / tire  setup that weighs 400g more than another is going to be harder to get it to change direction. Think of spinning a toy top, the heavier it is, the longer it spins and the more stable it is. One of the main reasons why a light wheelset makes a bike "feel" lighter is because it is easier to move at high speeds.

But back to the cost vs weight vs purpose discussion, the 1725 gram 35mm wide wheelset on my wife's Tallboy feel's pretty light. It's not superlight but it isn't super heavy either and I feel we found a good balance between usage, weight, durability, and cost. We could have gotten it below 1600 grams just by using different hubs and not having Peter paint the rims but that would have cost us an extra $150 or more and put us over the $999 wheelset budget.

[Jar_head]

Well.. I think it's much about the ratio price/gram. Everything up to 1,50 € per saved gram is okay for me..
The Shift Up axle for the rear end is about 1,70 € per gram saved.

Other things like the Race Face Cranks come at 3,33 € per gram saved. That's pretty much, I think. But if you consider that you can sell the old part (SRAM X0 BB30 Cranks at 150 €), you may come to ~1,50 € per gram for the cranks. So this will be okay again  Almost the same for the cassette..

This is a new design for the seatpostclamp. Inspired by a friend of mine. Also I used more material, since you can easily grind of what is too much. The weight is with a steel screw. Titanium ones will come on the weekend. So finally it should be ~5 - 6g.
It tested this one with 4 Newtonmeters on the screw and it holds.

The next ones I build will get a titanium nut as well. This one is aluminum, just as the washer.