Shimano have just filed a patent for a front chainring that moves side to side so good chainline is maintained through the whole range of the rear cassette.

I think this is going to solve the a significant problem with 1x setups and make them more attractive than 2x for many people who hadn’t already made the switch. Frames designs are probably going to need to be adjusted to clear the chainring though.

I am really pissed off because I had a very similar same idea about a year ago but didn’t file anything of course.

patent document here

wow good spot! Everyone’s new 2018 bike is already out of date!

Lots of people have had the idea. I’ve posted something similar on here as well.

Do people have problems due to chainline? I don’t

Patent application submitted end of 2015 according to Bike Radar. They filed one for a electronic dropper using the Di2 battery several years ago which hasn’t materialised yet. Whether either will – who knows?

The patent isn’t for the idea you claim to share, is is for keeping the sliding mechanism that moves the ring mostly inside the crank/BB axle to keep moving parts other than the ring itself away from all the shit mountain biking throws at drivetrains.

Mackem – Member

Do people have problems due to chainline? I don’t

Me neither. People with shimano sometimes complain of the chain dropping when backpedalling but as far as I can see the answer to that is the same as the answer to all other 1x problems- buy SRAM.

OTOH lots of people who’ve not used 1x expect chainline to be an issue so maybe it’s just catering to that perceived issue rather than a real one?

If the response to GX 12 speed is messing about with chainline they’ve pretty much given up

It seems rather complicated and I don’t know how the extra weight would compare to a double ring and a front mech.

A 2x set up wouldn’t offer a perfect chainline every ratio but it’d be better than a single (and I’m not sure that this is a massive issue anyway).

More to the point it looks expensive and prone to wear, so lots of extra dollars for Shimano (in initial purchases and spares) which of course is what drives this sort of ‘innovation‘.

I’m happily running a cable operated 3×9 system which continues to work well and threatens to do so for some time to come – so not great from Shimano’s point of view.

It’s only an application, so if someone did document what they’re claiming (not necessarily the pretty pictures) it may not get granted. (But I’m sure they’ve done their homework.)

Northwind – Bike Radar’s article shows both SRAM and Shimano having submitted patent applications for systems that allow a floating chainline. So – should SRAM give up too?

And the back-pedalling issue is resolved by using the 11-46 cassette option. I’ve not come across any issues with people using that.

Even if you don’t have problems with shifting and chain drop; the skewed chainline does increase drivetrain friction and wear. I would rather carry an extra 100g or so rather than lose an extra 2% of my power due to a very skewed chainline, life of the mechanism should not be a problem as long as the design keeps the crap off the moving parts – making sure that the design does not allow stiction to stop the chainring from moving with the chainline is probably the more challenging bit.

I see now that Shimano have just filed for a particular embodiment rather than for the general concept and that SRAM have a rather different embodiment. Also Wolftooth and Eko Sport may also have similar patents, although I haven’t managed to find the images for those yet. Maybe my embodiment remains uninfringed, but I really need to concentrate on the patent I already have filed before I throw money/time at anything else 😮

OTOH lots of people who’ve not used 1x expect chainline to be an issue so maybe it’s just catering to that perceived issue rather than a real one?

This, I think. I have never found chainline to be a problem on any bike I’ve ever ridden unless it’s actually been fouling on the frame or the wheel/tyre. Personally, I bury the concept of ‘crosschaining’ in the same Room 101 that I’d place solvent filled jars with chains, three-chain rotation methods and all the other stuff that might have been important on seventies bikes but really doesn’t matter anymore.

Even if you don’t have problems with shifting and chain drop; the skewed chainline does increase drivetrain friction and wear. I would rather carry an extra 100g or so rather than lose an extra 2% of my power due to a very skewed chainline,

Is it 2%? Does this reduce that 2% to zero or 1.25%?

A lot of opinions out there and not much to go on.

So much for those ‘simple’ 1x set ups eh.

I would rather carry an extra 100g or so rather than lose an extra 2% of my power due to a very skewed chainline,

You’ll lose some power at the place the chainring pivots instead.

A while back I looked at the chain angles and totted up the loss of force compared to a straight CL, just as a components of a force diagram not inc added friction in the chain. It wasn’t a lot, less than my dynamo hub that pulls 3W at 16-18mph, ~2% of my power much of the time – makes no actual difference unless TTing on a very smooth flat road.

On the upside, it offers more opportunities for the joy of hunting down a ‘mystery creak’ from your crank/bb area.

the answer to that is the same as the answer to all other 1x problems- buy SRAM

Weird. My Shimano 1×10 has been flawless while my SRAM 1×10 destroyed itself once (blown clutch followed by mech jumping into rear wheel) and the replacement clutch is on the way out as well. Can’t wait to replace it with Shimano next time that happens.

Oh yeah, 10 speed you want Shimano- my Saint/XT with radcage is superb. But Shimano are just nowhere for 11 speed.

yep nearing 4000km on Gx 11Sp, mates have been near 2 XT cassettes in that time

My guess is that if this ever surfaces, it’ll sink without a trace. Remember Truvaiv Hammerscmidt cranks…?

I can’t imagine the extra cost, complexity and wear will ever be worth the bother.

Shimano also have a patent for a 14 speed cassette they’ve been sitting on for donkeys years.

yep nearing 4000km on Gx 11Sp, mates have been near 2 XT cassettes in that time

That’s all down to cleaning, maintainence and riding conditions (and how accurate everyone’s mileage records are….) I’ve had as high as 3500 MILES out of a Shimano cassette, and as low as 900.

Northwind – Member 
Me neither. People with shimano sometimes complain of the chain dropping when backpedalling but as far as I can see the answer to that is the same as the answer to all other 1x problems- buy SRAM.

I never even have backpedal problem with Shimano (though I only have Shimano cassette. SRAM generally, I just don’t do XD stuff is all).

Chainlines I have no issue with on 1x. People fuss about getting the right chainline down to a mm. Don’t really get it. Shifts okay? Pedals okay? Good enough.

The stuff about it being for wider range cassettes I don’t get as the cassette width across the hub is still the same.

mikewsmith – Member 
yep nearing 4000km on Gx 11Sp, mates have been near 2 XT cassettes in that time

Knocking on 4000km on one XT cassette, and same chain on it too.

A lot of people go through cassettes because they do the Park Tools Chain Checker frequent chain replacement and after one or two they find they can’t run the cassette with a new chain so replace that. Thinking they’ve “saved” the cassette in the process. I concluded otherwise. Treat it right, and just run on and on, and one chain and cassette outlasts multiple chains on one cassette.

PeterPoddy – Member

That’s all down to cleaning, maintainence and riding conditions

Nah, don’t think it is, going from Shimano 10 to a SRAM 11 speed cassette (and Shimano shifting, because I’m an idiot) the price of the 11 speed cassette almost made my cry but it’s already well outlasted a 10 speed XT cassette and looks set to outlast at least one more. Don’t know why but SRAM claim long life and it seems to be true. Better mud clearance? I dunno.

deadkenny – Member

Chainlines I have no issue with on 1x. People fuss about getting the right chainline down to a mm. Don’t really get it. Shifts okay? Pedals okay? Good enough.

Yep. I’ve got a total mashup on my fatbike- it’s a 197 rear but I use 170 cranks, with a flipped over chainring to push the chainline outwards, lots of people asked how the chainline is, I say fine, they say is it correct, I say I have no idea but it’s fine.

I suspect for 1x, “correct” chainline is actually off to the left somewhere since you probably spend more time in teh lower gears and apply most stress there, rather than bang in the middle where most folks want it. But it’s all pretty much within the range of a double or triple anyway

derailleur based gearing is just fundamentally a pretty horrible bit of engineering. Its all exposed to filth and damage and changing gear relies on physically forcing the chain to move between sprockets, grinding over teeth in the process and stressing the chain.

All the various things like shaped teeth and floating pulleys and so on are attempts to mitigate that horribleness. However in the real world it kind of works in a brutal fashion, you have just have to accept all the limitations.

A 1x setup has compromises in the chainline but gains in not having to heave the chain over big gaps in the chainrings. FWIW I swapped out the alloy ring on my GX transmission for a steel ring straight away, a few 10s of grams more but hopefully a longer lifespan.

There’s always hub gearing….

Well I’ve just gone 11 speed with a Sunrace cassette, any views on how they wear? (KMC chain if it’s relevant.)

Instead of sliding the chainring from side to side, what if we used an entirely separate chainring next to the main one? You could even make it a different size to work better with the expected overall gearing, ie: a smaller one for higher up the cassette and low gears, and a bigger one for going faster on the outside.

You’d need some kind of device for the front though to move the chain between them, but I don’t think that would be too big of a technical challenge to overcome…

An added benefit might be possible use of smaller cassettes, shorter chains and mech cages, and potentially even an increased range of gears, definitely seems worth exploring the idea!

😀

Seriously though, sounds like a lot of faff, mechanical complexity, and potentially weight to overcome a not-very-big problem, I’m also pretty sure I’ve seen some photos or drawings of a sliding front chainring concept from some time last century, so definitely not a new idea in general.

Given that the chain line is at it’s worst when in the largest rear sprocket then to improve it you would need to slide the chainring further in towards the frame to improve it but all the 1X systems that I’ve seen run the chainring very close to the frame anyway so I don’t see that it would make much difference .

When Shimano produce a gearbox all of this will be irrelevant. 😀

sillyoldman – Member

And the back-pedalling issue is resolved by using the 11-46 cassette option. I’ve not come across any issues with people using that.

Mine has done it a couple of times, when doing maintenance. It’s never been a problem out riding tho.

joemmo – Member 
but gains in not having to heave the chain over big gaps in the chainrings

I’ve been convinced that a lot of chain wear and damage comes from the brute force of a front mech. Whack the chain to knock it down a gear and jam the mech against the chain to force it up a ramp to go up a gear, squashing the chain plates in the process.

That’s when they don’t screw up and knock a chain too far jamming it between cage and chainring. Plus damage to chain and frame with chainsuck, though that’s been cured mainly by narrow wide chainrings.

Rear mech is quite elegant in shifting, front mechs are plain horrible.

Both of my XT setups will drop two chainrings when backpedalling, much to my annoyance.

Oh and this:

Rear mech is quite elegant in shifting, front mechs are plain horrible.

I presume it’s needed when they introduce their 14 speed cassette

https://www.google.com/patents/US5954604

“Rear mech is quite elegant in shifting, front mechs are plain horrible”

not really, they both do essentially the same thing – forcing the chain off one sprocket on to another. The rear mech just has the luxury of doing it at the point where the chain isn’t under as much tension under power.

Ramsey Neil – Member

Given that the chain line is at it’s worst when in the largest rear sprocket then to improve it you would need to slide the chainring further in towards the frame to improve it but all the 1X systems that I’ve seen run the chainring very close to the frame anyway so I don’t see that it would make much difference .

Good point this

Will they owe Trivelox some royalties?

I did mention that frames would need a redesign to clear the chainring 😉

Good point the TriVelox system has been around for a bit over 20 years now.

2% extra inefficiency for a skewed chain line I pulled out of the air but should be in line with data I saw from FrictionFacts some other HPV publication I once saw.

20? 80!

[video]http://www.youtube.com/watch?v=qNDKSXE2tLc[/video]

I’m really beginning to think 1x threads should be filed away with ‘should I wear a helmet?’ and ‘what wheel size is best?’ threads.

That Trivelox is awesome!

The British cyclist expected his or her chain to last not just for years but for decades – and as any modern cyclist knows, this is not the way of the derailleur.

TriVelox responded to this challenge with a gear system in which the chain ran in a straight line through a fixed ‘derailleur’ arm. You changed gear, not by moving the derailleur and bending the chain, but by sliding the freewheel block sideways on the hub. And it worked, Walter Greaves rode a TriVelox system for 45,383 miles in a single year and used only two chains and two sets of sprockets. Try getting 23,000 miles out of a single chain on a modern bicycle!

However the Trivelox system also had its down sides, it was humungously heavy and it required a very wide rear axle to accommodate the sliding freewheel block. As far as I am aware it never developed beyond a three-speed system because this would have required and even wider hub.

Ha! No vision. I’m looking forward to SRAM DodecaVelox SuperBooostX hub spacing.

It defintely had some advantages:

http://www.disraeligears.co.uk/Site/TriVelox_derailleurs.html

The British cyclist expected his or her chain to last not just for years but for decades – and as any modern cyclist knows, this is not the way of the derailleur.

TriVelox responded to this challenge with a gear system in which the chain ran in a straight line through a fixed ‘derailleur’ arm. You changed gear, not by moving the derailleur and bending the chain, but by sliding the freewheel block sideways on the hub. And it worked, Walter Greaves rode a TriVelox system for 45,383 miles in a single year and used only two chains and two sets of sprockets. Try getting 23,000 miles out of a single chain on a modern bicycle!

However the Trivelox system also had its down sides, it was humungously heavy and it required a very wide rear axle to accommodate the sliding freewheel block. As far as I am aware it never developed beyond a three-speed system because this would have required and even wider hub.

Ha! No vision. I’m looking forward to SRAM DodecaVelox gears on HyperBooostX hub spacing.