The timeless appeal of 7-speed gearing

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Samuel D
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The timeless appeal of 7-speed gearing

Postby Samuel D » 31 Jan 2018, 6:26pm

Inspired by Manc33’s epic posts on the minutiae of gearing (latest example), I considered the following scheme.

But first, a quote from Sheldon Brown:

“Seven sprockets enough? More sprockets must be better, right? Not necessarily! The trend toward more sprockets is driven largely by spec hype. Two chainwheels and 7 sprockets can provide everything most cyclists need. Still not enough? A third chainwheel adds much more than an 8th, 9th or 10th sprocket.”

Today I think you could add 11th sprocket to that without changing much. To the minimal extent that 11-speed changes the game, you must counter with the downsides of the Herculean effort that made it workable:

  • expensive chains with counterbored side plates
  • still-narrower sprockets and pitch
  • a new shift ratio, front and rear, incompatible with old gear (i.e. low-cost gear) still on the market
  • new rear hubs (old ones being incompatible)
  • even more extreme dishing of the rear wheel, sometimes ameliorated with asymmetric rear rims or wider OLN distances in the case of disc brakes
  • expensive, short-lived, polymer-coated cables (and other friction-reducing doodahs such as ferrules with tongues)
  • STI lock-in (no indexed down-tube shifters)
  • and no doubt others.
For me, 11-speed jumped the shark, as they say. The main thing going for it is smooth and quiet shifting under load when it’s new and fresh, something that doesn’t matter in the least to me but renders bicycle reviewers ecstatic. All I care is that the shift is reliable and immediate. Let it clunk! For that matter, it’s vanishingly rare that a shift of mine must be performed under load.

So, seven speed.

Shimano 7-speed cassettes have among the most rational tooth-counts of any they have made. You can get almost any largest sprocket you desire without having to waste gears on 11T and 12T cogs at the other end. Here are some varieties of the CS-HG50-7 in ascending largest sprocket:

13–26 (13, 15, 17, 19, 21, 23, 26)
12–28 (12, 14, 16, 18, 21, 24, 28)
13–28 (13, 15, 17, 19, 21, 24, 28)
13–30 (13, 15, 17, 20, 23, 26, 30)
14–32 (14, 16, 18, 21, 24, 28, 32)
13–34 (13, 15, 17, 20, 24, 29, 34)

Although these cassettes may have been taken for granted when they came out, they are refreshingly practical when compared to today’s plethora of touring cassettes … all starting at 11T. Look at the relatively close ratios on the 14–32T despite its mere 7 sprockets.

I can think of some notable benefits to 7-speed over even 8-speed:

  • even greater sprocket pitch but the same derailleur shift ratio, a combination that provides greater wear tolerance in cables, shifters, and derailleurs
  • slightly more cable pull per shift than 8-speed, which itself has more than the new 11-speed pull, never mind 9- or 10-speed shifters with their proportionally shorter pulls
  • less flange offset on the rear hub, allowing less dish and higher spoke tension on the left side
  • better chain angle because the cassette is narrower
  • more heel clearance with the narrower OLN distance
  • potentially narrower Q-factor and better pedal clearance in corners.
So how about jumping off the bandwagon at 7-speed and staying put for the rest of your days?

To make this work you would need:

  • a frame with 126 mm spacing. That means an old one or a custom-made one if you don’t already have one. You may have other reasons to order a custom frame anyway (I do)
  • a hoard of cassettes in the flavours you’re likely to want. I have settled on the 13–26T in 8-speed so the same in 7-speed (which is only missing the 14T) sounds like a good option to me. These are still pretty cheap, because Shimano still makes them. That won’t last forever, hence this stash
  • shifters. This isn’t a problem if you have freed yourself from the tyranny of STIs. There are many NOS indexed down-tube shifters on eBay. No doubt bar-end shifters are also available. These are durable, so a pair a decade should do. Besides, friction shifters are an option. STI shifters may also be viable
  • a couple of 126 mm hubs and preferably some spare cones. NOS Shimano 126 mm hubs on eBay are still nearly as cheap as new 130 mm hubs, so this doesn’t pose a large problem.
For the foreseeable future you will be able to buy:

  • chains. They are identical to “8-speed” chains that are still widely available, but 9- and even 10-speed chains are likely to work also
  • derailleurs. Anything works at the front, and any 7-, 8-, 9-, or 10-speed road derailleur (and many MTB ones too) work at the back. Thus compatible derailleurs are also likely to be available for a long time to come.
None of this would work on a commercial scale, but I see no reason it couldn’t be economically made to work if you’re an individual cyclist with a penchant for steel frames.

Why not 5- or 6-speed while we’re at it? Maybe, but parts availability does not make this an economical exercise and Shimano’s freehub design has advantages. Besides, at those sprocket-counts you may start to feel the lack of ratios by comparison to modern standards (although that hasn’t prevented a revival of fixed-gear bicycles).

Have I missed anything important?

brynpoeth
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Re: The timeless appeal of 7-speed gearing

Postby brynpoeth » 31 Jan 2018, 6:32pm

Sounds like you started cycling when 7-speed was the norm or latest, right?
I started in 1973 so I think 5 speeds are plenty
I do remember getting a Suntour block with a 34T bottom sprocket in 1974, +1
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andrew_s
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Re: The timeless appeal of 7-speed gearing

Postby andrew_s » 31 Jan 2018, 6:40pm

I've taken a similar view, though I settled on 8 speed, which is almost equally cheap for consumables, and allows a choice of decent bar end shifters or Campag Ergo ( I've older 10 sp Chorus & Record in my parts box that are ideal for Shimano 8 speed).

The big step in faster transmission wear wasn't 7 to 8, but the change to Hyperglide and butchered sprocket teeth.

neilob
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Re: The timeless appeal of 7-speed gearing

Postby neilob » 31 Jan 2018, 6:47pm

Plus 4s are pretty good too.
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Samuel D
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Re: The timeless appeal of 7-speed gearing

Postby Samuel D » 31 Jan 2018, 6:51pm

brynpoeth wrote:Sounds like you started cycling when 7-speed was the norm or latest, right?

Even later! 9-speed had arrived by the time I got into cycling in a big way in my late teens, although I had an 8-speed bicycle. I got another 8-speed when I got back into cycling a few years ago. I’m thirty-six (going on twenty).

I have peers who genuinely think 11-speed (or Di2 for that matter) gives them a meaningful advantage on the road. They don’t think about this stuff in technical terms (and that’s fine) and couldn’t tell you how many teeth their sprockets have, other than maybe the extremes. Using 7-speed, or worse 5-speed, tends to go along with a contrarian or at least geeky nature in 2018. But as I posit above, it shouldn’t. There are good technical reasons for preferring the old stuff. Sheldon Brown clearly did.

There are some technical reasons for preferring more gears too, I accept. It’s just that the cost in dollars and other aspects of performance is high. And:

Going from a single speed to 2 speeds adds a great deal of utility. From 2 to 3 gears is significant too. By the time you go from 10 to 11 the increased usefulness is lost in the noise, and yet for that marginal gain a huge design effort at great expense was required. I won’t pay for that near-pointless effort if I can avoid it.

neilob wrote:Plus 4s are pretty good too.

What’s functionally or economically good about them? That’s all I’m interested in.

recumbentpanda
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Re: The timeless appeal of 7-speed gearing

Postby recumbentpanda » 31 Jan 2018, 6:56pm

I did most of my heavy duty long distance touring in my youth on 5 speed. That’s as in actual 5 speed with a single front chainwheel. I’m older now, but here’s a thing: I run 9 speed on my main bikes, with trigger shift. Almost every time I shift I find myself making a ‘double click’! The only single clicks are to fine tune cadence.

JakobW
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Re: The timeless appeal of 7-speed gearing

Postby JakobW » 31 Jan 2018, 6:58pm

Aren't there 7-speed hubs with 130mm spacing? But otherwise I can't find much to disagree with; indeed, I have the faintly quixotic desire to try 7s half-step-plus-granny once my current transmission wears out. Given the kind of riding I do, I can't see there being much of a downside.

Brucey
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Re: The timeless appeal of 7-speed gearing

Postby Brucey » 31 Jan 2018, 7:15pm

JakobW wrote:Aren't there 7-speed hubs with 130mm spacing?....


better yet there are 7s hubs at 135mm spacing.

The wheel dish is the most important thing IMHO. Starting with a 7s/135mm hub you can have a virtually dishless rear wheel. It is also easy enough to fit 8 sprockets from a 9s cassette to a 7s freehub body. This means you get to chuck a (useless, dish-causing) 11T or 12T sprocket in the bin.

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scottg
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Re: The timeless appeal of 7-speed gearing

Postby scottg » 31 Jan 2018, 7:17pm

I have a 126 spaced frame, found a newish Shimano 600 7 speed hub.
Put a 10s speed cassette on it, left off the 11t spacer cog. (11-28)
The 12t cog had the corrugations to engage the lock ring, very convenient.
Shimano still makes 10s down tube shifters, all is happy.

For a really low dish wheel, 135oln 7s mtb hubs were made for a short while.
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Re: The timeless appeal of 7-speed gearing

Postby gregoryoftours » 31 Jan 2018, 7:54pm

For me riding flat bars 9sp is the sweet spot. Of course it doesn't last as long but I like the shifting and I also prefer the shifting feel, ergonomics and adjustability of later higher end Shimano 9sp trigger shifters, plus the 2 way release function. Thumb shifters are good and really reliable but for enjoyment of using day to day it's 9sp trigger for me. I wish that nice Shimano compatible 9sp thumb shifters existed, not just those custom adapted road bar end shifters

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robc02
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Re: The timeless appeal of 7-speed gearing

Postby robc02 » 31 Jan 2018, 8:24pm

I started cycling when 5 speed was the norm and most "serious" cyclists had a double chainring - apart from time triallists, some of whom thought the additional weight of the large (17 or 18T) sprocket an extravagance, so removed it!
When Suntour/Maillard brought out their narrow spaced freewheels I gladly used a six speed (in the space of a conventional 5). When I bought a frame with 126mm spacing I took the opportunity to stay with six speed and respace the wider hub to reduce the wheel dish. It took me several years to finally move to seven speed, and that was due to deciding to concentrate on hilly timetrials where the chance to have a wider gear spread while retaining small steps between gears was beneficial.
I used Maillard freewheels where every cog could be chosen individually (I had a box of them covering most options from 13T to 28T). This flexibility was very appealing and I was very happy with it. Would I be now? - Probably, for most of my riding, but only if I could choose the sprocket sizes as I did before. I'm not sure I would be happy with predetermined "standard" cassettes. (I know you can mix and match to a degree, but it's more hassle than being invited to buy individual cogs).
I haven't raced for a couple of years now, but I still like to ride quite hard at times and would be reluctant to give up my close ratios. 9/10 speed allows me to have them and still have some low gears for the hillier area in which I now live. I don't think I'll be giving up that luxury!

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robgul
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Re: The timeless appeal of 7-speed gearing

Postby robgul » 31 Jan 2018, 8:46pm

Having started out with a 4 speed Cyclo-Benelux derailleur way back when I've failed to grasp the need for ever more sprockets and chainwheels - my Galaxy tourer from 1975 has 3 x 7 - both my 2014 Van Nic machines (tourer and road) have the extravagance of 3 x 8 - they all do the job just fine (with sturdy chains that last longer)

... did anyone mention bar-end shifters? - guess what, that's what I use ... and set to friction.

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Re: The timeless appeal of 7-speed gearing

Postby mercalia » 31 Jan 2018, 9:00pm

7 speed is ok - you need 2-3 in the middle 2 low ones and 2 high ones. 8 speed is next best thing - 4 in the middle, 2 low and 2 high

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horizon
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Re: The timeless appeal of 7-speed gearing

Postby horizon » 31 Jan 2018, 9:10pm

scottg wrote:
For a really low dish wheel, 135oln 7s mtb hubs were made for a short while.


Both my MTBs are 135 OLN and seven speed. Or at least I thought so! Should I check? :shock:
I have two doctors, my left leg and my right leg. (G. M. Trevelyan)
PS I always wondered why the YHA HQ was called Trevelyan House. :)

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horizon
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Re: The timeless appeal of 7-speed gearing

Postby horizon » 31 Jan 2018, 9:17pm

To make this work you would need: a frame with 126 mm spacing



I don't understand this (see previous post).
I have two doctors, my left leg and my right leg. (G. M. Trevelyan)
PS I always wondered why the YHA HQ was called Trevelyan House. :)