NSMB Tests SRAM XX1 On the Trail

[jvp]

Originally Posted by BJC

Maybe, maybe not. It's not the design that's an issue, it's the inherent efficiency of gearbox versus chain drive. It is a big deal when you only have a fraction of a horsepower to work with. IMO the maintenance issue and costs with the current system are no big deal in any case. Simple, light, efficient - an engineers wet dream.
Cheers Ben

Agreed. Gear box is a pipe dream. Derailleurs will always be more efficient, lighter and cheaper for the same quality.

Hey, I get as annoyed as the next guy when I smash a rear derailleur - I go through about 1/year (I really need to switch to Shimano. SRAM get sloppy easily, but that's another thread). But how many X9 or XT can you buy for the cost of a Rohloff or Pinion?

[nick]

Originally Posted by jvp

Agreed. Gear box is a pipe dream.

so was going on the moon...

[BJC]

Originally Posted by nick

so was going on the moon...

Not quite the same....they weren't already going to the moon in a lightweight highly efficient lunar travel module!

Cheers Ben

[morgman]

Originally Posted by BJC

Not quite the same....they weren't already going to the moon in a lightweight highly efficient lunar travel module!

By today's standards or the ones back then?

[BJC]

Originally Posted by morgman

By today's standards or the ones back then?

Pretty sure they weren't by either standard....

Cheers Ben

[nick]

My point is dare to dream and don't let naysayers stop you. If it wasn't for guys/companies like that you would still be living in a hut. I see it every day at work (I work at UBC) the stand out students are the ones that think that way. Not always the smartest but they rarely give up and think out of the box, or in this case in it!

[Oldfart]

It's an issue of the laws of physics. Both a derailleur system and gear box use a chain drive. The gearbox has have equal internal friction to two pulley wheels to be as efficient as current derailleur systems. Fill a hub with numerous tiny gears which rub against each other to achieve different ratios and drive and you have internal friction. As some one said above, when you have many horsepower this is not a big deal but a cyclist has at best 1/2 a horse and mostly less than that, it is a big deal. For dh and shuttling it may be OK but for actual riding where you climb as much as you descend, it will drag you down.

[syncro]

the one thing i find a bit superfluous is the notion about all the tension on the upper part of the chain and how this affects chain design where it must sit loose for chainring shifting to work. while technically this is a valid point, sram's idea of chain tech that holds the chain to the chainring better strikes me as a solution to inefficient shifting of the front deraileur. unload the chain and a properly adjusted front deraileur will shift smoothly - up or down.

for a DH/FR bike i think the 1x11 setup makes perfect sense. for an AM bike i think it's a bit of grey area, but that mostly depends on the rider and their trail preferences. i'd say on an XC bike you're leaving far too much on the table in botht he high and low range with this type of setup.

personally and with system cost aside, i'd find myself spun out way too much in a 28x11 to make this setup a viable option for anything other than a DH bike.

[nick]

Originally Posted by Oldfart

It's an issue of the laws of physics. Both a derailleur system and gear box use a chain drive. The gearbox has have equal internal friction to two pulley wheels to be as efficient as current derailleur systems. Fill a hub with numerous tiny gears which rub against each other to achieve different ratios and drive and you have internal friction. As some one said above, when you have many horsepower this is not a big deal but a cyclist has at best 1/2 a horse and mostly less than that, it is a big deal. For dh and shuttling it may be OK but for actual riding where you climb as much as you descend, it will drag you down.

Funny, I work in the physics department. Don't misunderstand me, I'm not saying that it's practical today but who knows about tomorrow, don't underestimate materials engineering...

[Oldfart]

Originally Posted by nick

Funny, I work in the physics department. Don't misunderstand me, I'm not saying that it's practical today but who knows about tomorrow, don't underestimate materials engineering...

You may be right. I think it is just really hard to do better than one of the most efficient mechanisms we have ever invented, the roller chain. Maybe a fluid coupling like those Nuvinci things or something along that line.

[nick]

I may be wrong as well, but it's pretty cool to see the evolution

[tundra]

Anyone using XX1 right now? Any updates? I am looking at making this upgrade to my race bike... bit lighter, bit simpler. But yeah dropping $1500 on a system untested is a tough reality!

[kperras]

Best innovation for bikes since the dropper post. < All that needs to be said.

[BJC]

Originally Posted by kperras

Best innovation for bikes since the dropper post. < All that needs to be said.

So....best bike innovation in the last 18 months. Are you saying it's good or give it a miss?

Cheers Ben

[morgman]

Originally Posted by kperras

Best innovation for bikes since the dropper post. < All that needs to be said.

And for the great unwashed, clutch derailleurs will stave us off until XX1 trickles down...