t2p

Can't recall if they still do the Dirty Dozen race - might have paused due to COVID and not sure if it resumed (?)

Yes - Danny still with us (unfortunately in wheelchair)

PeteHski

With electronic drivetrains you already have the option of fully automatic FD shifting, together with rear compensation shifting to mask the gaps. But front shifting across chainrings can never be as physically slick as rear shifting - which is why the industry has gradually moved toward more rear cassette gears and less front chainrings.

But as you rightly say, natural engineering evolution will pervail. If you think that means triples might make a comeback then you are very likely to be disappointed. But you might get lucky with multiple hub gears taking their place.

PeteHski

So at what point do you think the industry is going to return to 3x7 drivetrains? Or do you think riders are going to start demanding 3x12? I just don't see either of those things happening. My future prediction is a move toward 1x13 plus 2x hub gears for those who need extra range. FDs are horrible crude devices, even in electronic form. So the sooner a more elegant solution is found the better.

Carbonfiberboy 

I bought my last new bike in 2000 when I was 55. I was still riding strong for being 55. I bought a 5200 9 speed, 52-42-30 in front and 12-25 in back. I thought it was a perfect bike for me. Since I ride in terrain from moderately hilly to mountainous, top performance on very long climbs has been my goal, which means a narrow cadence range based around 80, which is what my legs have always liked best for climbing.

That was the last bike I bought because I couldn't see sufficient improvement in the drivetrain to make it worth the money. A few pounds didn't matter to me as I don't race and lose and gain bodyweight anyway, more than bike weights changed. For me, it's all about the frame (perfect match of BB stiffness and vertical compliance ) and gear-inches.

What happened in the marketplace is that the 9-speed triple was replaced by the 10-speed triple. Hardly anyone upgraded from the 9 because why? Adding 1 more cog in back made no financial sense with a triple, so they dropped the triples and went with compacts because they needed an upgrade path.

So let's have a little contest. Here's my factory 9-speed, circa 2000, age 55:
Bicycle Gear Calculator

As I aged, I went from 11-25 in back to 12-27, then to a 11-30, then to smaller rings, 53-36-26. So this is my 9-speed at 77:
https://www.gear-calculator.com/?GR=...N=MPH&DV=teeth

I saved many thousands of dollars in continuing bike and gruppo upgrades and believe that I still have a better gearing range for who I am and what I do.

I should point out that in my current drivetrain I only have 16 distinct gear ratios which I use, out of 27, ranging from 125-23 g.i. My 4 lowest ratios, the ones I really care about, are only 3.5 g.i. apart.

Can anyone match those g.i. numbers and spacings with the latest and greatest road gruppo? Let's see it!

LarrySellerz

He used the term Big Gravel, of course its in jest

tomato coupe

If those are the only gears you really care about, there are a lot better solutions than a triple.

HTupolev

That's not a very useful way to frame the size of a gearing jump. 40gi-to-48gi and 80gi-to-88gi are both jumps of 8gi, but the former will have twice the impact on cadence and torque because it's a ratio change of 1.20 while the latter is only 1.10. The "only 3.5gi apart" of your 20->23->26->30 gears are shifts of 15%, 13%, and 15% respectively, which aren't all that small. With an 11-speed drivetrain, for instance, you could achieve comparable if not slightly better spacing at the low-end with something like a 52-36 paired with an 11-42 cassette. Although, it could easily be argued that such a setup would still make compromises compared with your 3x9 (slightly lower top-end, mildly wider shifts across much of the range, bigger front shifts, may require unusual RD configuration to achieve good behavior).

I do agree that wide-range setups where spacing is still a concern is a big blind spot for modern gearing. For me, that sticks out on my gravel setup, where I'm trying to have a reasonably-fully-fledged road drivetrain with decent spacing alongside super-low bailouts. Currently I have a 3x8, with 48-38-24 cranks paired to an 11-13-15-18-21-24-28-32 cassette. In the foothills it behaves like an old-school wide-range triple, but the two larger chainrings 1.5-step the cassette, so tight shifts are available on the road when I want them. In theory it's worth up to ~19 unique useful gear ratios, although once cross-chain aversion and my riding style are accounted for, it's realistically more like 17. And those 17 ratios are quite well-distributed on the range.
I've spreadsheeted out comparisons to modern alternatives, and even with 12-speed cassettes and two chainrings, it's really hard to assemble something that wouldn't make any compromises.

GhostRider62

Why would I want to match your gearing requirements? That gap between the 12 and 14 cog would drive me bananas. I look for 15-20% gaps in my climbing gears and 1 tooth gap in cruising gears. My current low gear is a 48 x 39 or 34 depending on which 12s wheels. I think a 50/37 double crank would be better for me although the 1x is mostly good. I only care about 3 climbing gears, the 39t, 33t, and 28.

spelger

i think they are fundamentally they are the same as rear derailleurs, i don't see a big difference between the two.

GhostRider62

Velomobiles use such a setup. I think it is called a Schlumpf mountain drive. It is a direct drive normally and therefore no losses and when you need low gets, it is a planetary setup in the bottom bracket. I know very little about them other than velomobile riders LOVE them. They will use a single chainring, usually a 70T and then and 11-39 or maybe 11-46 cassette. I think the ratio is cut by a factor of 2-3 when engaged, IIRC

tomato coupe

Rear derailleurs guide the chain via two pulleys that track the sprocket sizes, whereas front derailleurs just shove the chain to the side. Compared to the former, the latter is pretty crude.

PeteHski

Rear shifting is smooth and fast. Totally effortless with a modern mech. Front shifting is something you just tolerate. It's maybe slightly better with an electronic mech, but still the same crude concept and never really very satisfying. Sooner or later front mechs will get replaced by something more elegant, smoother and faster (probably hub gears). There is less incentive to replace rear mechs as they are quick and smooth in their operation. It's actually a pleasure shifting up and down with a modern electronic rear mech. It's a shame the front isn't in the same league.

This looks very promising as an alternative to front shifting:-

https://granfondo-cycling.com/classi...b-2020-test-2/

Trakhak

Suntour attempted to market the Browning Transmission in the late 1980s: see SpeedofLite's post of a Bicycling! Magazine article on the topic.

I'm very happy with the half-step-plus-granny triple on the 1995 Cannondale H300 hybrid I bought last year for use on wet-weather training rides. Ride a half-step chainring pair for a while, especially if, like me, you're an ex-racer and want to maintain your power output within an extremely narrow band, and it'll become obvious why so many racing bike manufacturers stuck with half-step gearing for so long in the 1950s and into the late 1960s.

PeteHski

Of course you can't match 27 gears with 24 gears precisely. It's more a question of how big the market is for those requiring 27+ gears. All road bikes I've ever been interested in have always been exclusively 2x anyway (with the odd 1x appearing now). The nearest I could get to your setup would be a 33/46 front and 10/36 12-speed cassette. Doesn't quite match your overall range, but not far off and actually has closer spacing at the top end.

What I actually run is 35/48 and 10/33 which has a bit less range at the lower end, but closer spacing and same top gear as you have.

PeteHski

Very interesting thanks. But you can see why it didn't catch on. It still has the awkward issue of moving the chain across large chainrings of significantly differing sizes. Moving to hub gears eliminates this issue entirely.

HTupolev

The use of pulleys does not in and of itself facilitate cog-tracking. Rear derailleurs may employ a jockey offset or b-pivot rotation, but these aspects exist in part to circumvent challenges created by the pulley's role in chain tensioning. Some modern rear derailleurs employ neither of these, like the newer Shadow rear derailleurs intended for multi-ring setups in Shimano's road and gravel lineups: whether it's a Di2 Dura Ace RD-R9250 or a mechanical GRX RD-RX810, the position of the jockey pulley purely follows the round curve defined by the parallelogram.

And while pushing a chain with plates is very simple, I wouldn't call it "crude." It's the reasonable way to do it anywhere in a system that a derailleur isn't also operating as a tensioner.
The main impediments to front derailleur performance are the fact that derailments are initiated on the part of the chain that transmits pedaling forces, and the huge sizes of the shifts that we ask front derailleurs to make. And it's mostly the latter: front derailleurs can be very quick and butter-smooth when the shifts are in the 10T range or smaller, and what this means for shifts between middle and big rings of many triples is one of the main things I like about using triples.

It's also why I think it's silly that interleaved gearing hasn't been brought back. A front shift of just a few teeth could be made extremely snappy and smooth with modern shift gates. Synchro would eliminate the human aspect of double-shifting. With just a 2x11 you could have a gearing range of >500% with all gearing steps in the 7-11% range.

spelger

true, the FD shoves the chain off one ring and onto another. but so too does the RD. the difference being that the FD shoves from the outside while the RD shoves from the inside of the chain. pretty much the same. and those pulleys mainly take up slack after the shift is done.

i think if the difference in number of teeth on the chain rings were not so great the FD shifting would feel much better. and if the difference in cogs were greater the RD would probably not shift as well as they do. a lot of those cogs change by maybe 2 teeth while for chain rings it can be like 10 or more.

tomato coupe

The chain doesn't come in contact with anything other than the pulleys, so if they don't facilitate cog tracking, what does?

HTupolev

Err, I think now that I'm confused as to what you mean by "cog tracking." I had assumed that you were referring to the geometric path that the jockey wheel takes relative to the cassette, but now I'm not sure.

tomato coupe

"Half-step" gearing was great in the days of six speed freewheels, but it's pretty hard to configure such a system so that two chain rings stay interleaved through 11 or 12 gears.

tomato coupe

You introduced the term. What is your definition?

HTupolev

It's difficult as an end user because very few 11/12-speed cassettes are designed with evenly-stepped ratios, and because matching half-step cranksets don't exist. But that's not something that a component manufacturer couldn't work around. For example, here's the interleave on a 50-46 crankset paired with a 10-12-14-16-19-22-26-30-36-42-50 cassette:



I was referring to this:

Carbonfiberboy 

Thanks for the comments. I of course agree about the percentages. What I was hoping for was data rather than opinions which is mostly what I got back. That calculator I posted is very easy to use. I would be interested in seeing what modern gearing could look like, done with a similar range for a club rider.

Our tandem has much more laughable gearing - next week we will be 150 y.o. and still hard at it. It doesn't get easier, you just go slower™. We have a 53-39-24 up front and a 11-40 in the stern. Shifts to and from the granny and middle are not a problem. I don't even run a chain catcher. That is, I used to until I realized it was causing derailments, at which point I took it off. Haven't had a missed front shift since. I am experienced enough not to hit the granny in the middle of a climb. I hit the granny early as I dial the rear up the cassette, then gradually back down. At the top I say, "spin it up," and hit the middle. Middle to big and back are no issue at all - I never call those. I do call the drop into the granny, not for mechanical reasons, just for Stoker's comfort - her pedal is going to drop, then suddenly stop when the chain tightens.

On the tandem, I'm running 10 speed middle and big rings with a 10-speed FD and brifter, still 9-speed in the rear. The tandem's 9-speed FD didn't like the 10-speed rings though my Trek is just fine with 9-speed FD and brifter and also 10-speed rings. I never figured out what the difference was. All Shimano.

On this pass ride, I mostly climbed in my 4 lowest gears and had no problem holding a steady average power as the gradient changed. I also had no problem staying on my companion's tandem wheel during that 4700' descent at 30-40 mph. If I dropped off a little, I could always pedal back on. Love the wide range.

tomato coupe

That's not half bad, if you don't mind the dinner plate cassette. It would be fun to give it a try.

Carbonfiberboy 

Thanks for the inspiration, that's nice. Here's the calculator with that 10/36:
Bicycle Gear Calculator

Maybe I should change to a 24T as granny and use a 12/27. I'd only be 1 g.i. higher at the bottom than I am now and everything even closer than you have it. I'd gain 1 more gear in the granny before I had to shift to the middle. I'd lose 10 g.i. at the top end but those gears would be closer together and I don't cruise at 35 mph anyway. I used to think the 12-27 worked well for me. I have that cassette in my spares box, and I can buy a 24T 74 BCD ring for less than $25 and install it myself..
https://www.gear-calculator.com/?GR=...N=MPH&DV=teeth
Triples are quite versatile.