Monday, February 06, 2017

Cogs: How Many Do You Really Need?

Cogs: Some say "All You Need Is One".
Friday in my "Friday News And Views" post, I was talking about upgrading my Black Mountain Cycles rig from 9 speed to an 11 speed drive train. There was a comment left asking if there had been any studies done on the differences, (if any), in efficiencies between the older 7/8 speed stuff and the 11 speed drive trains of today. There was also an expression of the oft heard/read feelings of many cyclists that "we don't need no stinkin' 11 speeds!", or 10 speed, or 9 speed........

In fact, that sentiment goes all the way back to when 6 speed drive trains were introduced in the 1980's. ......well.....Probably when the first multi-speed hub gear was developed and came out against the single speed, fixed gear bike is when that happend.


So, here is my reaction to all of that. First, it must be pointed out that whenever the cycling world sees a change, there is a lot of resistance to that change. The hackles get raised, the fur stands on end, and you can find many comments of rejection, sarcasm, and downright nastiness aimed at anyone who might suggest that some new thing is "good". I could name six component changes right off the top off my head that caused the sale of pitch forks and torches to increase for a time. But who would now say that threaded steer tubes and head sets are "better"? (Besides Grant and his Disciples of Antiquity), Or who would say that suspension forks have no business in mountain biking?

Generally speaking? No one would argue those points today. But go back to when those things were introduced, and others I have not mentioned...... Whoo Boy! Talk about negativity!

So, if you merely mention the fact that 11 speed drive trains are "the new kid on the block" in terms of most bicycle drive trains, you can be sure the rebels will be out in force against it. don't here much quibbling about 8 and 9 speed stuff anymore. But back when that came out?

Yeah........ Major uproar! 

 So, anybody that says "we don't need (fill in the blank) speed drive trains", well, that falls on deaf ears here. That kind of talk is fully expected to occur.

The once hated, "we don't need it" 9 speed cassette. Now loved by millions.
Now, with that said, I would say two other things about adding "more gears" to a bicycle.

First- Closer ratios mean more efficient motors. Look at the automobile industry as your example. In the 1960's, automatic transmissions were 2 speed or 3 speeds at most. Now in 2017 they are often 6,7, or more speeds, or "constantly variable" in order to increase efficiency of the motor. Closer ratios, so the motor does not fluctuate in revolutions per minute (RPM), and can be kept in its most efficient powerband. This is exactly why we have more ratios today than we did ten years ago. Closer ratios keep the rider in a cadence and power output range that is most efficient for the rider in question. That's harder to do if you have major jumps between ratios in a similar range of ratios overall. Like a 2 speed Powerglide equipped car would "wind out the RPM's" at about 70mph, then shift, and the engine would suddenly be loping along at several thousand RPM's lower, so too will the cyclist have major adjustments with greater leaps between the gears. 11 speed, theoretically, should provide the rider with a way to maintain momentum, accelerate easier, and do all of that without drastic changes in power output and cadence. (Assuming for a 2X set up, not 1 X 11, or 1 X 12 which compromises on this and is actually worse than 2X 10 in this regard.)

Second- The way things are being jammed into the same spaces as we have had for decades is the "real issue" here. Look, the first thing you should try to wrap your mind around is just where the "meat is being cut from". Thinking about chains and cogs, there are two major parameters that have not changed in decades. Those being the pitch of the chain (one half inch) and the width of the chain roller pins between the inner chain plates. Everything else has changed. The metal has been removed from the over all width of the chain and the cogs to make more fit in the same space we've been using since the 1980's. So, chains are thinner, overall, and cogs are thinner to make fitting eleven in an axle spacing that hasn't budged in years possible. Less "beef" means accelerated wear, right? 

Well, to a degree, that is certainly true, but not to the degree that one might think. Material technologies have been brought to bear that were not in use ten years ago. Certainly, they weren't even possible twenty years ago. Bevels, chamfers, and shaping have made chains able to move from cog to cog so much more efficiently it isn't even an argument. This causes less wear, so getting thinner cogs and chain plates are not the deal breaker they would have been without these advancements.

So, the benefits are many, the detriments are fewer. That is why we have 11 speed cassettes today. Could all the newer technology be brought to bear on a premium level 8 speed cassette and chain? Sure they could. Totally possible. It would last longer, shift better, and have a marginal effect upon many cyclists who wouldn't care about big jumps between ratios. But you are not going to see that from SRAM or Shimano because that is not a market that is profitable for them.

And I still say all you really need is one gear!


Phillip Cowan said...

Basically what I'm seeing is a multiplication of ratio points between a set high and low range. What you're doing is beginning to approximate a continuously variable transmission (CVT). If some form of CVT is what's wanted then Shimpagnolram should probably work towards a torque sensing electronically controlled race weight version of the NuVinci hub. I understand that the human body is a piss poor engine with narrow power band. I've also so noticed empirically that people who always train in that narrow band are usually not strong riders. It's a rare fixed gear rider who can't out climb his geared buddies on short to medium hills even though he's probably pushing a seventy something inch gear. Long climbs are another story. The old time coaches understood this instinctively which is why they often had their riders on fixed or single speed in early season training. I think it may be good to race in the narrow powerband just not to train in it. Anyway I'm veering off course here, back to transmissions. My real objection to 11 speed isn't the number of gears, but rather the fact that they're trying to cram to much into too small a space. Just bite the bullet and increase the rear spacing. Of course if you had all that new real estate some silly bastard in marketing would insist on filling it up with even more gears.

Unknown said...

My main objection is the cost.

Tyler Loewens said...

Hey Roger. Have you priced out SLX 11 speed lately? Very affordable!

Kenny Cyphers said...

SRAM also has extremely reliable 11 speed stuff that is very affordable. And with a $80 wolf tooth upgrade kit you can switch out a 49t cog on a standard 11-42 cassette and have an 11-49 range on a standard road/mountain hub. I have beaten the crap out of my 1x11 and never dropped or broken a chain in over 2000 miles. 11 speeds may be pushing the limits of what a standard hub will hold... but it's in no way too much. I have zero doubts about my drivetrain no matter where I'm going.

MICHAEL said...

Hear, hear. I personally prefer 9-speed, triples. And 10-speed doubles for fatbikes. I don't ride road bikes, so cannot comment. Ride what you like and hopefully the Industry will adjust to the demand.

Unknown said...

I don't have as much a problem with the 11spd offerings as a cassette but with the gearing ratios on the cranks. I think the 11-32 is a great (for me and where I ride) cassette but wish that the big companies like Shimano and Sram would offer a greater choice in crank gearing. That cassette with a 30 by 46 up front would be great but you can't have it unless you go with a White Industries Crank (which is probably what I'll be doing). This is also my problem on the mtb side of things as I like to use a closer ratio cassette and larger range of gears on the cranks, I've gone to the Surly O.D. crank on a couple of my builds recently and set them up with a 20/36 and a 11-36 10spd cassette which for me has worked great...