Setting chain length with a mid-length rear derailleur cage

[Woz]

I remember back in the 1990s, it wasn't that uncommon to see people on MTBs using a short cage road mech with a close ratio road cassette!

Mmmmh. Yum Yum. A time when people optimised the gearing for the riding. All terribly old fashioned now since you
are supposed to buy a new bloody groupset because of a wanted 2 extra teeth on a sprocket, or an extra sprocket, or god forbid a front chain-ring with 4 more teeth. Just how many expensive cassettes are getting thrown away out there just because the 17T is worn and slips? How many people got road compact set-ups just to find they are shit in flat areas, how many people ride with a triple when the granny sees no real world action? How many MTB commuters in the city are dragging around a 34T with no use? World gone mad. I need to lie down and have more wine before ranting on that Ebay will be full of only FDs and left hand shifters soon.

I'm puzzled about this - did Shimano change cage lengths over the years?

Off to the shed to measure...

Don't bother. They have fiddled and farted around with all sorts and created utter confusion of what actually
constitutes a short-cage (SS) mid-cage (GS) and long-cage (SGS). Don't get me started in trying to find
equivalence between road and MTB through the years.

 

[legrandefromage]

All my drive trains are designed to go 'big big' as I pretty much ride 1x setups with the middle and granny rings redundant for where I live.

I first hit upon using a road cage on my MTB mechs sometime in the early 1990's as I'd either seen someone else do it or it was in a magazine - I'm not so brainy as to come up with that independently but may have actually done so when I got given a broken 600 road mech and really liked the cage.

For where I live 30t is about as big as I need to go, even for what passes for hills around here. when I am out on my rides, there will often be someone spinning out with their 1x as their chainring is something daft like a 32t or a 36t. It just doesnt work for my local area.

I have 44, 46 and 48t on all the MTBs for home and the road bikes are between 48t and 53t depending on the knees

When I do escape to the lumpy bits, its a 40 or a 42t up front and maybe a 36t or 34t at the back but still the option to go middle ring or granny depending on the knackered old retro bicycle for the day.

and ebay is awash with left hand shifters and front mechs which is a bit sad

 

[d8mok]

Re:

So why not just go to a 1x set up ?

You do realise you can mirror the ratio of big /big by using a more appropriate set of gears such as middle and 24T etc.

It’s like these grannies you see and hear driving around in 2nd gear as that’s all they need according to them.. Set off from standstill -2nd gear and loads of clutch , doing 43mph in a 60 - that’ll be 2nd gear too ......

Just because it can be done doesn’t mean there isn’t a better way of doing it. But you stick to it and keep beating all those spinning out on a 36T

 

[legrandefromage]

I don't want a 1x set up, my bikes are 20 to 30 years or more old, it's how they were designed.

How many land rover owners actually use their high/ low range gearbox? Doesn't mean it should be removed, its just there.

 

[d8mok]

Re:

But said land rovers don’t use the wrong gearbox whilst driving along on the roads and if they do well ....


I’ve got a 22 year old bike here which is 1x which I built in 1999 so it existed. Running a 44 front spaced correctly.

It’s nothing to do with chainring size it’s about chain line. Running a triple and using big/big isn’t right. But you can do as you please of course. But it doesn’t make it correct.

 

[trailwright]

Ah, those hazy days of '89, when real men had 28-38-48 up front, and 12-28 out back, and legs to match.

 

[d8mok]

Re:

Real men have a 30T front oval , and a 10-52 at the back

 

[hookooekoo]

Re: Re:

Why would you use the granny ring with smallest cogs and why on earth would you be anywhere near using the big/big ?

Cross chaining and the fact that ratios will be doubled up by using better combos

I think you are trying to solve a problem that doesn’t (shouldn’t) exist

You are absolutely right when you say that those combinations should be avoided. Although my experience of shifting from granny ring to middle ring on early 1990s Shimano chainrings is that you should try to avoid it when on a technical section of trail, because there might be quite a bit of grinding and scraping before the chain hooks onto the middle ring. That means there might be short periods of time when I want to use combinations that sub optimal. Later Shimano chainrings were, in my opinion, much better, as they had little hooks at several places, rather than just a few half height teeth as found on early 1990s chainrings.

By the way, may I ask your opinion of the modern 1 x 10, 1 x 11, and 1 x 12 setups? I'm guessing you think it's a regression in design due to the extreme chain lines.

I think the 1x systems are great. Chain lines aren’t bad at all as the front chainring is designed to be central mostly for the system. Wouldn’t use anything else on a bike I intend to ride properly

If money was no object, I think I'd go down the Rohloff + Belt Drive route. There's a lot to be said for having a gear system that isn't exposed to mud and water, and a belt that never needs lubing, doesn't get stiff links, and can be cleaned in seconds with a quick blast from a garden hose.

 

[hookooekoo]

Just how many expensive cassettes are getting thrown away out there just because the 17T is worn and slips?

I'm not sure that I ever saw a bike shop selling individual Shimano Hyperglide sprockets, although some of the better shops could probably have ordered them if you asked. Anyway, it's the same with pretty much everything now isn't it? One bit breaks, so you bin the whole product due to lack of spares or a design that was never intended to be serviceable. It's great for the economies of countries that make this stuff, but not so great for the environment.

As an aside, realising that I spent most of the time in just a few gears was one factor that got me interested in single speed and fixed wheel bikes.

 

[hamster]

Re: Re:

Real men have a 30T front oval , and a 10-52 at the back

Holy crap, 30T driving a 52? :shock:
That's a 17" gear on a 29er - I don't even need that on a tourer with 4 panniers!
What do you use it for, rock climbing? :?