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dw

Wiffle Ball ninja
Sep 10, 2001
2,943
0
MV
Sure they do.

People also like to kill each other in order to get the resources to make "new stuff."

At some point encouraging the lust for "new stuff" has negative consequences, especially in a world where resources are finite and the population is always increasing.

A good MTB part designer/maker would key into this fact. Maybe find a way to recycle parts that aren't as hip or blingy as they were 15 minutes ago. Maybe find a way to stop encouraging Buy And Throw Away culture.

A less... uh... moral one would keep boosting wasted resources (impulse buying with the affiliated discarding of usable items).

I suppose I should just never mind on this line of questioning. After all, for some, there's money and a career in Shiny New Objects.:confused:

/rant
Don't read into it so far.. Jeff is my friend and I was just having a little fun with him. He knew that I think..
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
OK, so in geometry, think of a triangle, then a square, then a pentagon, then a hexagon. The more sides you add, the closer the polygon becomes to representing a circle. A chain is made up of straight segments, no chainring is compltely "round".

Because of this, chain / driven chainring systems all inherently have some amount of RPM variation at the driven chainring output shaft for a constant velocity at the chain.

So in laymans terms, if you pedal a constant RPM, your chain will speed up and slow down as it passes over the teeth. This same phenomena is repeated in the output. In larger sizes it becomes imperceptible, but as you move smaller on sprocket size, the effect is magnified. Ever notice how pedaling in the big front ring on an XC bike feels "smoother"? That's why.

Dave
That's what I was trying to say with my DJ comment. I run a 25:10 drive on my dj bike and rode my friends 23:9 and they feel really akward compared to my big bikes. The effect is noticable. Even more when I used a mtb chain.
 

w00dy

In heaven there is no beer
Jun 18, 2004
3,417
51
that's why we drink it here
Its a conspiracy by manufacturers to make you buy new parts and then replacements more often! :thumb:
It's not just a cog wear issue. The chain doesn't run smoothly on a cog with a radius that short, so you're losing efficiency. I think an 11t runs poorly.
The chain sees considerably more tension with a 20% smaller cog, so it will wear out super fast as well. BMX chains are burly as hell and they break regularly with the microdrive setups. This is asking for chain failure.

This is probably the wrong place to start an uprising based on Eco-drivel.
I'm going to side with Angrypants. This is poorly conceived. It'll surely sell more stuff, but the gains are negligible.
 

w00dy

In heaven there is no beer
Jun 18, 2004
3,417
51
that's why we drink it here
Lol @ the retrogrouch tag. I'm running a carbon belt drive, stealth hub, and a hydro gyro on my gravity bike. Smaller chainrings are hardly a tech breakthrough. If something makes sense I'm behind it. This is pointless standard splintering.
 

manhattanprjkt83

Rusty Trombone
Jul 10, 2003
9,644
1,214
Nilbog
I am all for smaller more compact drive trains, think they are great and the smaller we can make things in that area the better. w00dy's points about the 9t BMX setups are entirely true w/ feel & wear...I am assuming some ppl in here don't know much about BMX (it is an mtb forum) but those setups do break chains...

I am torn because I love the idea, but not sure how it can be implemented effectively...I think it's an intermediary until we have a widely used gear box.
 

squiby

Chimp
Jul 26, 2010
91
13
It's not just a cog wear issue. The chain doesn't run smoothly on a cog with a radius that short, so you're losing efficiency. I think an 11t runs poorly.
The chain sees considerably more tension with a 20% smaller cog, so it will wear out super fast as well. BMX chains are burly as hell and they break regularly with the microdrive setups. This is asking for chain failure.
I'm going to side with Angrypants. This is poorly conceived. It'll surely sell more stuff, but the gains are negligible.
Meanwhile at the evil genius hideaway of a top mountain bike industry manufacturer.....

"and then, after everyone buys in and starts breaking chains, we will make a minilink chain from unobtainium that is more efficient, lighter and stronger. Every internet mtn biker will have to have one!.... and we can sell them for ONE MILLION DOLLARS!"
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
Meanwhile at the evil genius hideaway of a top mountain bike industry manufacturer.....

"and then, after everyone buys in and starts breaking chains, we will make a minilink chain from unobtainium that is more efficient, lighter and stronger. Every internet mtn biker will have to have one!.... and we can sell them for ONE MILLION DOLLARS!"
The funny thing is that what would actually happen. If that drivetrain goes to sale expect a dedicatet special super dooper chain in 1-2 years.
 

Slater

Monkey
Oct 10, 2007
378
0
Oh for sure, interesting post for a guy who seems to have spent a lot of time forming opinions on technical matters. (just based on a quick glance at your past postings) What's your agenda?
Haha no agenda. Doesn't everyone who nerds out on technical stuff form an opinion? I have no more than you, just different.

My comment was "half in jest, whole in ernest".

I think the "pulsing" that a 9t sprocket offers though would be a much more perceptible feature than the increas in Anti-Squat in most cases. Its kind of like riding a bike with an idler. The smaller the idler, the more you feel each link as it makes contact with the idler. Make it too small and it ends up feeling like crap.
 

EVIL JN

Monkey
Jul 24, 2009
491
24
I dont see that the 9t sprocket would really cause that much more wear for dh, i know that i rarely need to push the heaviest gear while riding or racing. If i do its just for short stretches so i dont think it will make that much of a diffrence on how often i will need to change my chain or casette. I maybe change chain and casette once a year or year and a half and move the replaced ones down to my dj or am and grind on them for a good time longer.
 

JCL

Monkey
Aug 31, 2008
696
0
I dont see that the 9t sprocket would really cause that much more wear for dh, i know that i rarely need to push the heaviest gear while riding or racing. If i do its just for short stretches so i dont think it will make that much of a diffrence on how often i will need to change my chain or casette. I maybe change chain and casette once a year or year and a half and move the replaced ones down to my dj or am and grind on them for a good time longer.
Totally agree. It's not like people are going to be climbing in the 9T!

People seem to be ignoring the aspects of this that make real sense IMO.

135mm hub with wider flange spacing than a 150mm hub.

Smaller/lighter chain guides and potentially more compact DH rear derailleurs with higher spring tension etc.

Better chainline and lighter cassettes etc.

I look forward to hearing what the naysayers say when the Sram/DT DH groupset is released. I think XC components and 9/10 speed cassettes, 36T chainrings will look clunky and dated rather quickly.
 

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
Totally agree. It's not like people are going to be climbing in the 9T!

People seem to be ignoring the aspects of this that make real sense IMO.

135mm hub with wider flange spacing than a 150mm hub.

Smaller/lighter chain guides and potentially more compact DH rear derailleurs with higher spring tension etc.

Better chainline and lighter cassettes etc.

I look forward to hearing what the naysayers say when the Sram/DT DH groupset is released. I think XC components and 9/10 speed cassettes, 36T chainrings will look clunky and dated rather quickly.
Why cant we just make the same thing in a 150mm, and give it 3x the flanges of a 135. If they cant stretch a 135 why cant they stretch a 150mm?At least this way we keep the standard
 

w00dy

In heaven there is no beer
Jun 18, 2004
3,417
51
that's why we drink it here
135mm hub with wider flange spacing than a 150mm hub.

Smaller/lighter chain guides and potentially more compact DH rear derailleurs with higher spring tension etc.

Better chainline and lighter cassettes etc.
Hope, chris king, profile, american classic, and probably a few others already make single speed hubs which take 6 or 7 cogs. I have one of the profile ones and I love it. Strong wheel, lighter weight, better chainline, it's great. This is not news though. I'm only railing on the weaknesses of a narrow chain running over a tiny cog.
 

JCL

Monkey
Aug 31, 2008
696
0
Why cant we just make the same thing in a 150mm, and give it 3x the flanges of a 135. If they cant stretch a 135 why cant they stretch a 150mm?At least this way we keep the standard
135mm is already a standard. 150mm came about from the stupidness of DH frames dunning XC gearing. 150mm will probably die off if this group happens. I don't know where that would leave 142mm? IMO that was a pointless standard.
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
135mm is already a standard. 150mm came about from the stupidness of DH frames dunning XC gearing. 150mm will probably die off if this group happens. I don't know where that would leave 142mm? IMO that was a pointless standard.
What about the 83mm bb chainline?
 

Dogboy

Turbo Monkey
Apr 12, 2004
3,208
581
Durham, NC
Good luck with tire clearance going back to a 135/73 setup. It can be done but it is extremely limiting from a chainstay design perspective.
 

kidwoo

Artisanal Tweet Curator
Good luck with tire clearance going back to a 135/73 setup. It can be done but it is extremely limiting from a chainstay design perspective.
Nah. All previous specialized demo bikes (cept the 9) showed otherwise. Shortest chainstay made and up until very recently, 135.

And the offset rear end was much more insigtful than people gave it credit for.
 

Dogboy

Turbo Monkey
Apr 12, 2004
3,208
581
Durham, NC
Nah. All previous specialized demo bikes (cept the 9) showed otherwise. Shortest chainstay made and up until very recently, 135.

And the offset rear end was much more insigtful than people gave it credit for.
Yeah, I had a Demo 8. Like I said, it can be done...
 

xy9ine

Turbo Monkey
Mar 22, 2004
2,940
353
vancouver eastside
dunno if this has been posted, but i like it - from pb interview w/ brandon sloane: "On my Enduro, I have a 1x10 setup with a 31-tooth up front and custom 9/36 cassette in the rear"

down with that.
 

zdubyadubya

Turbo Monkey
Apr 13, 2008
1,273
96
Ellicott City, MD
I could be totally wrong, but I think you guys are seeing this wrong.

The bike is still a 83/150. Because of the little teeth on the outside, they had to use a 135 hub and then put that little piece on the outside of it.

I could be wrong, but every single bike that I have seen pictures of with this had a 150 rear end. So your DH bikes will still be 83/150. The hub just had to be narrower (a 135) to accommodate the smaller cogs.
 

4130biker

PM me about Tantrum Cycles!
May 24, 2007
3,884
448
I love the idea of this on my trail bike. I agree that the 9t bmx set ups do have their problems, but like everything in life, there is a trade-off (and IMO, this one is worth a fast wearing chain). I think it's crazy that it's taken this long for mountain bikes to catch up, but interesting to see a bmx trend/innovation come to mtb instead of the other way around.
 

UiUiUiUi

Turbo Monkey
Feb 2, 2003
1,378
0
Berlin, Germany
i really like the idea with a 6 or 7 spd cassette but why not just build regular 11-23 cassettes and put the on the trials freehub bodies?

i have a hope pro 2 trials rearhub on my dj bike would love to see that thing in 150x12 and normal gearing... oh well )
 

OGRipper

back alley ripper
Feb 3, 2004
10,647
1,116
NORCAL is the hizzle
I could be totally wrong, but I think you guys are seeing this wrong.

The bike is still a 83/150. Because of the little teeth on the outside, they had to use a 135 hub and then put that little piece on the outside of it.

I could be wrong, but every single bike that I have seen pictures of with this had a 150 rear end. So your DH bikes will still be 83/150. The hub just had to be narrower (a 135) to accommodate the smaller cogs.
I am pretty sure you are wrong. There is a difference between axle spacing and the size of the hub shell.

"It measures out at 12 x 135mm because Sam, Brendan and Troy were looking for a slimmer back end compared to the full sized 150mm standard. Interestingly, the spoke flanges are actually wider than what you would find on a common 150mm hub, due to the shorter length of the freehub."

If it was still 150 it would not achieve the goal of a narrower rear end, so I'm pretty sure he means what he says - the axle spacing is 135.

But, the hub shell can be made wider than usual with 135 spacing. They are using 7 cogs, but still using the narrow cog spacing of 9 or 10 spd, so they can stretch the hub shell to cover the space that would have been taken up by 2 or 3 missing cogs.
 

zdubyadubya

Turbo Monkey
Apr 13, 2008
1,273
96
Ellicott City, MD
I'll be honest. Totally glazed right over that quote. Thanks for pointing it out. :thumb: But that quote does bring about an interesting point... When everyone was complaining that the demos had a 135 rear end, people were pointing out sam's and brendan's which had a 150 as the future direction. Sure enough the new '11 demo has a 150mm rear end. Why even go to a 150mm rear end if you are just going to go back to a 135 for a "slimmer profile"?

sounds kinda daft to me...


"It measures out at 12 x 135mm because Sam, Brendan and Troy were looking for a slimmer back end compared to the full sized 150mm standard. Interestingly, the spoke flanges are actually wider than what you would find on a common 150mm hub, due to the shorter length of the freehub."
 

w00dy

In heaven there is no beer
Jun 18, 2004
3,417
51
that's why we drink it here
I'll be honest. Totally glazed right over that quote. Thanks for pointing it out. :thumb: But that quote does bring about an interesting point... When everyone was complaining that the demos had a 135 rear end, people were pointing out sam's and brendan's which had a 150 as the future direction. Sure enough the new '11 demo has a 150mm rear end. Why even go to a 150mm rear end if you are just going to go back to a 135 for a "slimmer profile"?

sounds kinda daft to me...
The cutting edge doubles back on itself once in a while.
 

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
I'll be honest. Totally glazed right over that quote. Thanks for pointing it out. :thumb: But that quote does bring about an interesting point... When everyone was complaining that the demos had a 135 rear end, people were pointing out sam's and brendan's which had a 150 as the future direction. Sure enough the new '11 demo has a 150mm rear end. Why even go to a 150mm rear end if you are just going to go back to a 135 for a "slimmer profile"?

sounds kinda daft to me...
this5 150 is the current standard, why deviate from it, doesnt matter why it was made that way, and maybe one day we can go back to 135, but i think it should be a slower change, It seems like the hub companies want the manufacturers to switch yearly to boost sales. :mad:
 

Slater

Monkey
Oct 10, 2007
378
0
The changeup to 150 on a demo was purely to follow the trend for Specialized.

Anyone who has riden an older 135 demo has never complained about a flexy rear end that I've ever heard/read. Mine is stiffer than many 150mm rear end bikes I've riden.
 

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
Want to see my straitline bash that looks like I used in street for grinding? Does diablo have no places with high probability of bash hit?
Its certainly possible to hit it, but like always, better technique yeilds better results, 4X4 drivers go across gullys/logs crooked, same deal, wheelie over/into a log. My bash is nearly 3 years old, hardly any marks on it, and most of them were just cruising around the woods locally. I feel that its like improving the ground clearance of a jeep than putting a body kit on it. You may gain an inch (id think less) on the bash, but your pedals still hit and so does your derailleur.
I go through pedals alot, but my bashs are usually pretty clean. Maybe im just the next sam hill, but i feel that many people wheelie over logs, or unweight the bike. to gain those 3 inches of sag. Both of these are of course skipping the obvious bunny-hopping over it. (and i havent personally seen a log across a DH trail *especially at a resort* that 80% of the people couldnt hop over. I assume that 85% of the new (product) bikes are sold with the intention of riding at a resort. I doubt (product) is thinking about john smith who builds shady dh trails in his backyard.

This is different for XC riding.
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
Its certainly possible to hit it, but like always, better technique yeilds better results, 4X4 drivers go across gullys/logs crooked, same deal, wheelie over/into a log. My bash is nearly 3 years old, hardly any marks on it, and most of them were just cruising around the woods locally. I feel that its like improving the ground clearance of a jeep than putting a body kit on it. You may gain an inch (id think less) on the bash, but your pedals still hit and so does your derailleur.
I go through pedals alot, but my bashs are usually pretty clean. Maybe im just the next sam hill, but i feel that many people wheelie over logs, or unweight the bike. to gain those 3 inches of sag. Both of these are of course skipping the obvious bunny-hopping over it. (and i havent personally seen a log across a DH trail *especially at a resort* that 80% of the people couldnt hop over. I assume that 85% of the new (product) bikes are sold with the intention of riding at a resort. I doubt (product) is thinking about john smith who builds shady dh trails in his backyard.

This is different for XC riding.

I actually hit my bash much more than my pedals. I came to dh from xc so I know how to time my pedal strokes.
As for bash and technique this argument is silly. I've met trails where even with proper technique the chances of sliding on a rock/root with your bash were just too high. Not to mention we all make mistakes and it's then when we hit our rings.
Also more clearance gives us the possibility to choose more agressive lines in hairy sections. I doubt you can manual over a very long rockgarden.
 

SylentK

Turbo Monkey
Feb 25, 2004
2,287
854
coloRADo
So to me this would work, even with the pulsing, if you don't need to use the 9 cog for very long. Like doing short sprints on smoother sections, for example. I mean, how much do you really use your fastest gear? If you use it a lot, then maybe you should up your front chainring? But that last gear is def great for a race when your are really going ninth gear pinned and you wish you had one more.