smaller pitch chain systems?

neeb

So Campagnolo have brought out 12 speed and completely undermined the whole point of it IMO by only offering 11-29 cassettes, so in terms of actual commonly usable gears (if you are currently happy with, say, 12-27 or 12-25) it is in fact a downgrade from 11 speed to 10 speed or even 9 speed, with bigger rather than smaller gaps between the cogs... Duh..

Maybe I'm unusual but I like cog gaps to be as small as possible across the range and even find 1 tooth gaps a bit big sometimes (i.e. I sometimes feel I would prefer a gear between two cogs that are only one tooth apart).

So rather than add more giant cogs for those oh-so-common 20km climbs at 25% average gradient I would rather that some thought went into smaller gear gaps. The only way to go smaller than one tooth is to reduce the size of the teeth and use a smaller pitch chain. Despite all of the supposed advances in cycling tech in recent years (at least half of which are pretty pointless) we are still using the same 1/2 inch chain pitch that's been around since god knows when. I assume that smaller pitch chainrings, cassettes and chains could be fitted to current 11 speed drive trains if they were available?

Personally, this would be of much more benefit to my all-round cycling experience than disc brakes, tubeless tyres, 1x and (I despair..) clucth rear mechs.

And before they think of commenting, hipster single-speed fans can just... not.

amrushton

1/8" is a track chain. road chains are normally 3/32". Supposedly there will be a greater choice of cassettes later. They have released the most popular firt

bompington

I assume ½" refers to the length of a link, not the width.

All of which makes me wonder, while manfully attempting to repress the urge to poke fun at someone who feels the need for a 27½ tooth cog:

Are current sizes of chain (pitch and width), chainrings and cogs what they are because of convention, is it ease of manufacture, or is there actual engineering evidence that they are at least close to optimum?

imposter2.0

neeb wrote:

Despite all of the supposed advances in cycling tech in recent years (at least half of which are pretty pointless) we are still using the same 1/2 inch chain pitch that's been around since god knows when. I assume that smaller pitch chainrings, cassettes and chains could be fitted to current 11 speed drive trains if they were available?

In a derailleur/cassette setup, I think the limiting factor is chain width, not pitch. Reducing the pitch won't make any more room on the cassette.

craker

I visited the National Cycle Collection in Llandrinidod Wells at the weekend, there's some fascinating and weird chains in use in bikes of Edwardian vintage. Pretty soon after the war everything looked like it had 1/2" pitch chains, diamond shaped frames and everything you'd expect to see on a modern bike.

Makes you wonder whether a manufacturer with the clout of Shimano could push a new pitch onto the market, it would be incompatible with all their running gear currently on the market. A big gamble with a pretty small marketing opportunity?

imposter2.0

craker wrote:

Makes you wonder whether a manufacturer with the clout of Shimano could push a new pitch onto the market, it would be incompatible with all their running gear currently on the market. A big gamble with a pretty small marketing opportunity?

Shimano already tried that with their 10mm (3/8) pitch track chain in the 70s. ANSI and the Japanese Keirin Assoc pretty much killed it.

keef66

Imposter wrote:

neeb wrote:

Despite all of the supposed advances in cycling tech in recent years (at least half of which are pretty pointless) we are still using the same 1/2 inch chain pitch that's been around since god knows when. I assume that smaller pitch chainrings, cassettes and chains could be fitted to current 11 speed drive trains if they were available?

In a derailleur/cassette setup, I think the limiting factor is chain width, not pitch. Reducing the pitch won't make any more room on the cassette.

He's not after fitting more sprockets on, he wants more teeth on the same sized chainrings / sprockets, so the 1 tooth jumps between them are tinier in terms of effort.

fenix

Hate to say it but riding fixed wheel for a bit would do wonders for your cadence. You just have to get used to a wider range of RPM. Cos you're not gonna get what you want from anyone in the gearing world.

super_davo

Definitely agree with the concept. If you had half the pitch length and diametric pitch on cogs so a 12 became a 24 then you'd have about a 4% difference to the next gear rather than an 8% today. That small difference would help keep you in the power / cadence sweet spot. When you ride on a erg smart trainer at a power threshold you definitely notice the changes in resistance as you change your cadence from 85 - 90 but that's not possible in the real world.

Yes riding a fixed gear trains you to tolerate a much bigger difference in cadence, I ride one for that very reason, but some people don't adapt as well as others.

Flip side is I am sure it would wear faster.

neeb

Yes, if the jump could be half of what it is now that would be massively better, although as you say I think if the pitch was that much less it would wear quite a lot faster.

To clarify in response to some of the above comments - pitch is the distance between one link and the next and it is universally 1/2 an inch and has been for about 100 years, as craker says. The teeth on your chainrings and sprockets are the same 1/2 inch distance apart in order to mesh with the chain obviously. If this distance was less, a one-tooth "gap" between two cogs would represent a smaller change in gearing. Chain width is a different thng and has varied quite a lot. Perhaps modern narrower chains would actually work better with a shorter pitch than older, wider ones?

I knew when I posted this that I'd get comments about trying single speed and how a one-tooth gap on a 1/2 inch chain should be enough for anyone, etc.. ;-) This is of course just failing to make the distinction between usability and optimality - of course 1/2 inch chains (or single speed for that matter) work fine, but that doesn't mean that smaller gaps might not be better.

IMO current 1/2 inch one-tooth-gap gearing is on the too-big-a-jump side of optimal - you can tell that this is the case because more often than not you only shift up or down one gear at a time. If gear gaps were on the too-small-a-jump side of optimal you would find that you were constantly having to shift 2 or more gears at a time. Obviously you do that sometimes (especially on rolling terrain), but for me at least I'm far more often hoping back and forward between two gears trying to find the sweetspot than having to shift several gears at a time.

I don't see why a 3rd party company couldn't make shorter pitch chain systems to fit current groupsets from the main manufacturers. You would just need to make sure the chain width was the same as current 11 (or 12) sp. and fit the chains, cassettes and chainrings as a set. <edit - and jockey wheels too of course!>

cougie

Not single speed ,- go fixed wheel.

Sure someone could make your system but I think you're the first person I've ever heard asking for it. There's no market.

Mind you I also thought SRAM wouldn't make it as a road set..

neeb

cougie wrote:

Not single speed ,- go fixed wheel.

Sure someone could make your system but I think you're the first person I've ever heard asking for it. There's no market.

Mind you I also thought SRAM wouldn't make it as a road set..

Markets seem to be created these days - I'm sure if one of the big three manufacturers decided that this was the next big thing and put all of their marketing might behind it everyone would be "needing" it within a couple of years. There are so many less useful developments that no-one would have thought would sell 10 years ago that are now de rigueur. There wasn't a market for 11 speed, road tubular or electronic gears either...

proto

Back of my mind, I seem to recall Shimano selling a 10mm pitch drive train. I'm old, so I may have made this up.

imposter2.0

proto wrote:

Back of my mind, I seem to recall Shimano selling a 10mm pitch drive train. I'm old, so I may have made this up.

You mean like the one I mentioned earlier in the thread?

neeb

Yup, I read about that. Going from 12mm to 10mm doesn't seem like much of a difference, I wonder if that reflected some technical limitations (chain strength, wear) either generally or at the time.

Matthewfalle

Imposter wrote:

proto wrote:

Back of my mind, I seem to recall Shimano selling a 10mm pitch drive train. I'm old, so I may have made this up.

You mean like the one I mentioned earlier in the thread?

No - a different one. MF said.

cycleclinic

The 1/2" pitch has been around since renolds invented the roller chain in the 1880's. In fact it might have been 1" back then.

The reason why it is still with us it works. Having read this thread I really can't see why shorter pitch chains would be an advantage.

Also the op is in a minority now wanting 1t jumps. Those days are numbered and simply there is not money trying to make groupsets that meet those customers needs. Only smaller niche manufacturers could that but you'll have down tube shifters.

Miche make suitable casettes you can buy friction down tube shifters, and mechs and chainsets from any one will do. The bigger manufacturers have to cater for the market as they see it. No point in making what has gone before, that's how business fail. If you want close gearing stick to record 10 speed.

neeb

thecycleclinic wrote:

The 1/2" pitch has been around since renolds invented the roller chain in the 1880's. In fact it might have been 1" back then.

The reason why it is still with us it works. Having read this thread I really can't see why shorter pitch chains would be an advantage.

Also the op is in a minority now wanting 1t jumps. Those days are numbered and simply there is not money trying to make groupsets that meet those customers needs. Only smaller niche manufacturers could that but you'll have down tube shifters.

Miche make suitable casettes you can buy friction down tube shifters, and mechs and chainsets from any one will do. The bigger manufacturers have to cater for the market as they see it. No point in making what has gone before, that's how business fail. If you want close gearing stick to record 10 speed.

What on earth have downtube shifters got to do with it? You can fit closely spaced cassettes to any system as long as you can make them and the sprocket spacing is the same.

Obviously 1/2" pitch "works", but so would have 1/3" or 2/3". It's entirely a historical accident that we are stuck with it. It's remarkable IMO that despite the many disruptive and often pointless so-called innovations in recent years that have been non-backwards compatible, this very-easy-to-change and fundamental variable has been completely static for more than 100 years. To imply that it must be optimal because it "works" is like saying that single speed/fixed is perfect because it "works".

I assume the fact that you can't see an advantage reflects your personal needs being projected more generally - it's obvious what the advantages are for anyone who is sensitive to gearing.

We are not going to loose 1 tooth jumps at the smaller-cog ends of cassettes any time soon. The pros universally use 11-28 and 53/39 on all but the hilliest stages because they can put out the watts necessary to be using the smaller cogs in that setup (i.e with 1 tooth jumps) 95% of the time. If my FTP was what theirs is I'd be using that setup too - as it is I use 12-27 and 53/36.

If there is a trend towards more widely spaced cassettes there will doubtless in time be a counter trend in the other direction, because the advantages are clear. The whole trend over the last 40 years for increased sprocket numbers (5, 7, 9, 10 11 etc) has been driven primarily by the advantages of closer spacing, not a need for larger sprockets (although the ability of more gears to minimise the trade off between the two has obviously been advantageous).