40T Cassette On A Road Bike

[warey4life]

I have 42t cassette with Sram GX Type 2.1 rear derailleur, works fine with no goat link thingy.

[Jamesh]

Is that rd ∆∆∆ Shimano compatible?

Cheers James

[mcshroom]

I don't think so. However, this one is according to the manufacturer: -
https://southerndistributors.co.uk/prod ... erailleur/

[Stevek76]

Why are triples out of fashion?

Because a modern compact double gives a similar gear range with less complication, due to the much larger range on rear cassette than used to be the case.

Does seem to work well enough for roads sports riding I find. Absolutely terrible however for about town though in my experience of having to use my road bike for the commute etc for a bit when the previous pub hack got retired.

Was having to change chainrings all the time and the 16t jump does not make for a happy shift under load.

Built the new one as a triple.

[roubaixtuesday]

[quote=roubaixtuesday post_id=1623243 .

Was having to change chainrings all the time and the 16t jump does not make for a happy shift under load.

Interesting that, lots of people say similar, but personally unless I'm in really hilly territory, I never get near the small ring, and certainly not around town. I do a 10 mile commute with some reasonable but not very steep hills and don't use it at all.

An 11-34 cassette would give you 50/27 on the third sprocket to avoid unreasonable cross chaining. That's 49", a very low gear around town IMO; the genesis flyer singlespeed comes with 68" by comparison.

Each to their own, of course

[roubaixtuesday]

Following on from the "Shimano 105 B limit screw too short" thread viewtopic.php?f=5&t=146709 , I've been trying to set up my road bike as per "Katie Kookaburra's MY 40 CASSETTE ROAD BIKE SET UP" https://www.youtube.com/watch?v=Z97UDBEDFKo&t=15s

My bike had an older 105 rear mech, namely the 105 RD-5701-SS, so, a word of warning to others who might want to try this - the Wolf Tooth Goat Link (WTGL) does not work with old type Shimano 105 rear mechs. It clearly works ok for KK with her Shadow type Ultegra mech and may work with more recent Shadow 105 mechs, but it does not work with the older 105 RD-5701-SS (or longer cage -GS).

The reason is because the WTGL is about 8mm thick and STRAIGHT, you have to adjust the both end stop screws by that much to maintain the same mech movement. The high gear end stop does not cause any issues. It can be adjusted inwards 8 or so mm, no problem. The inward low gear stop, however, has to go right to the limit of its travel and at that point, you run out of cable pull because the ratio of mech travel to cable pull would appear to have reduced at such an extreme angle. If you try to wind the cable tighter to compensate, then the up shifts don't happen.

I'm going to try again with a CRANKED hanger extender (like this https://smile.amazon.co.uk/gp/product/B ... UTF8&psc=1 ) and I'll report my findings.

p.s. I'm getting very good at setting up rear derailleurs...

I have used that derailleur but the GS (11 speed, right?) with a WTGL and an 11-36 derailleur.

I'm sure it would go bigger, not sure about all the way to 40.

[Stevek76]

Its more the stop start rather than the hills, my typical starting gear is more around 40"

[rareposter]

Why are triples out of fashion?

It's less about ratios and more about how much a front mech *really* limits frame design - less so on road bikes but certainly on gravel and MTB, Having a front mech there is a hugely limiting factor in frame design (especially Q-factor), tyre clearance, mud clearance and suspension pivot placement.

Rear mechs can now handle far greater range than previous designs so for most applications of "normal" usage, it's perfectly sensible to dispense with the front mech and shifting arrangement. It also frees up space on the bars to accommodate the control for a dropper post. On a related note, most beginners find it easier to only have one set of gears to think about.

The one downside is that to drop quickly from a high gear into a low gear requires a sweep up 8-9 cogs at the back vs a single shift at the front to go from big ring to small ring but as a general rule that's not a major issue.

[ANTONISH]

A while back just out of interest I made myself an "alpine double" (currently 44/26) with a 12/36 rear cassette.
I used it on a multi day tour and it now resides on my audax bike.
It changes OK but it's a big jump between rings so after a change of ring I'm always having to move up or down the cassette.
My 44/34/24 triple gives me that middle ring which I find so useful.
I like low gears which enables me to climb hills more comfortably - so all in all I prefer a triple.
Sorry to go off topic.

[roubaixtuesday]

Its more the stop start rather than the hills, my typical starting gear is more around 40"

Interesting - at a rough guess I'd typically use my 4th or 5th sprocket - 70-78" looking at a gear calculator. Very different riding styles we have!

[Mick F]

So to return to the OP - a 40t cassette on a road bike. Why? Presumably to compensate for some of the shortcomings in the transmission design.

Exactly.

You've agreed with me.

[biketips666]

Why are triples out of fashion?

In my opinion there are 2 technical factors (amongst many others) that have contributed to this. Firstly the dedicated pursuit of (unnecessary, in my view) indexing of front changes has lead to vastly over complex and finicky front mechs which only work consistently if you stick to exactly the manufacturers inflexible specs and even then only if everything is new, clean and the wind's in the right direction. So getting rid of them is attractive.

I keep hearing this, repeatedly. I don't have a problem with my indexed triple, and it's not using exactly the manufactures specs, either. The chainrings have more or less the same tooth difference as the chainset recommended by the manufacturer, but even then I've run it with a lower than recommended inner. If I change anything (chainring, front derailleur, cable, brifter) it might take a couple of rides to refine it, but once I've set it up it works, and carries on working, reliably, even with worn/dirty stuff. Maybe I'm just a mechanical genius.

[djnotts]

"Lower gearing than that only really needed for laden touring, where a triple comes in. Though even there it's more the lack of readily available (or standard) lower geared chainsets that is the issue rather than the double/triple issue. A double with, say 36/24 and 11-34 would be fine for touring."

Or for the elderly in poor health! My Boardman ASR came with 50/34 and 9 speed 11-32. A Sunrace extender allowed a biggest 40 at rear (and I think would go to 42) with ease. Made all the difference without ditching the top gears.

[biketips666]

Why are triples out of fashion?

Because a modern compact double gives a similar gear range with less complication, due to the much larger range on rear cassette than used to be the case.

Typical off the shelf road bike these days is 50/34 with 11-34, which for an unladen bike is perfect IMO.

50/34 with 11-34 is a range of 454%

my 48/38/26 with 11-34 is a range of 572%

I wouldn't call those "similar".

I've had an even greater range, when the inner was a 24, which worked fine.

Lower gearing than that only really needed for laden touring, where a triple comes in.

I don't tour. But I do cycle, unladen, up hills. I sometimes use the bottom gear. Maybe I'm just not fit enough, but I expect there are plenty of people who would like a wide range of gears. I'm willing to bet good money that a lot of people have been sold doubles, thought they weren't fit enough because bottom gear wasn't low enough, and stopped cycling.

Though even there it's more the lack of readily available (or standard) lower geared chainsets that is the issue rather than the double/triple issue. A double with, say 36/24 and 11-34 would be fine for touring.

Everybody has different ideas about what sort of cycling they want to do, what bike works for them, and what is "fine". What suits you may not suit others.

Triples give another option, namely, a wide range of gears suitable for many different gradients, load carrying ability and physical demands. All on the same bike. I know, it's a crazy idea isn't it, a bike suitable for a wide variety of situations?

[roubaixtuesday]

Triples give another option, namely, a wide range of gears suitable for many different gradients, load carrying ability and physical demands. All on the same bike. I know, it's a crazy idea isn't it, a bike suitable for a wide variety of situations?

Yeah, I agree with all that. Indeed, I gave an example of a bike of mine that has a triple for just those reasons, and said "each to their own"

But I think it's entirely understandable that most road bikes, used for day rides, for most people, a double with modern wide range cassette makes most sense.