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I'll watch with interest whether gearboxes become common place.
I found this which looks like a good solution though not sure it's rated for offroading.
https://road.cc/content/review/227796-efneo-gtro-3-speed-front-gearbox
I had a Nexus before Alfine came out and it was good but didn't like the extra weight in the back wheel. I the weight is centralised in the BB area I think this would be ideal if they can improve efficiency.
I've bent a hanger precisely once and have yet to break a derailleur, that's with around 6000km of off-road riding a year. A stick or stone being thrown up and messing things up is just one of those things and is simply chance.
I've known (i.e. not "heard of") two Alfine hubs break, one was mine, so they aren't invincible.
The "new" Shimano gearbox looks like it's meant to be compatible with the motor mounting on e-bikes but Alfines aren't huge and a simple threaded shell of the appropriate diameter could be used for something with similar workings. A bit like an extra large EBB.
I've been out riding with someone who broke an Alfine. Luckily it was on a Pugsley so it was possible to swap the wheels around and single-speed it.
I've only been riding once and had to bypass a broken rear mech - and it wasn't mine.
In just over 30 years of MTBing I have killed one rear mech mid-ride and had to replace one mech hanger mid ride (after it did it's job at the very start of a near-2,000m descent in the Alps).
Also, I have three MTBs on 11sp and the same hub standards, and it's really handy to switch wheels between them as required.
[quote=nedrapier]
Obvious solution to the vulnerability of position is for everyone to learn to pedal backwards. Derailleur position is now above the dropout
That's actually not such a stupid idea! Hows about a first stage eicyclic gear that sits in the crank through tube, as the BB is big these days for stiffness that ought to be possible, driving the crank ring backwards with respect to the crank itself?
That would allow the high mount derailleur, and help it stay clear/clean as the chain line would be going backwards up high
maxtorque
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nedrapier wrote:Obvious solution to the vulnerability of position is for everyone to learn to pedal backwards. Derailleur position is now above the dropout
That’s actually not such a stupid idea! Hows about a first stage eicyclic gear that sits in the crank through tube, as the BB is big these days for stiffness that ought to be possible, driving the crank ring backwards with respect to the crank itself?
That would allow the high mount derailleur, and help it stay clear/clean as the chain line would be going backwards up high
I would think that one through a bit more 🙂
Again I think a part of this is how you see your bike. to me its like a landrover – a tool to take me to out of the way places with minimal hassle. To others its like a lancia stratos – a machine to go as fast as possible offroad.
It's how you see biking. MTBing isn't really one sport, it's three or four all using fat tyred bikes. That's why we argue about it so much 🙂
Most MTBing is a pastime not a sport 😉
Edit - I guess you are the second type moley?
Surely to most people it’s a mix of both, depending on the day?
I treat it like a sport. I make myself go out and train to get faster and better.
I also treat it as an outdoor pursuit by getting me out into the hills - but when I do that, I treat it like a sporting/training occasion also. You can do more than one of the categories at a time, but not everyone does 🙂 That's why in the garage I have a long travel bike, a rigid MTB, an XC racey bike and a road bike. And a commuter. And a track bike...
Says more about your riding style and finesse than of the mech tbh.
Which is why you are willing to live with the losses in a epicyclic gearbox.
Apart from a Pinion not being epicyclic, I don't - both my mountain bikes currently run 1x11 though I'd have another Pinion (they're now a bit smaller and lighter and I think they've reduced the Q factor)
Style and lack of finesse may be true but tough to avoid smacking mechs riding through rock trails with gaps barely wider (and sometimes narrower) than the back end of the bike.
A riding buddy had his mech wrap into the spokes yesterday and I've seen a few other mechs and hangers this year on people I've been riding with (though my own has got away with a few scrapes and a manual realignment...).
This piece puts the efficiency losses into perspective -
Less impact than running a dynohub. Less impact than running higher rolling resistance tyres. About the same as carrying 5kg extra weight over 100km. What I did think was interesting is that the noisiest Rohloff gear isn't the least efficient.
https://www.cyclingabout.com/speed-difference-testing-gearbox-systems/
Style and lack of finesse may be true but tough to avoid smacking mechs riding through rock trails with gaps barely wider (and sometimes narrower) than the back end of the bike.
Go over the rocks then 🙂 I tend to see gaps and think 'if I put my wheel in there it'll hit my mech/disc' so I avoid them.
Less impact than running higher rolling resistance tyres.
That's also draggy and annoying on an XC ride.
What I did think was interesting is that the noisiest Rohloff gear isn’t the least efficient.
You are right there though that is interesting. *reads article*
Read it, that is quite interesting. A 7% difference between singlespeed and a Pinion gearbox. For perspective, if you are producing 300W on a long climb that would be a 21W loss. Going from 300W to 320W takes a season's worth of focused training, it's quite a lot of work. Just to offset the losses of a Pinion gearbox.
Although that's comparing SS. It's also very interesting to see that the derailleur test is pretty close to the Rohloff - closer than in other tests I've read IIRC.
I've also read that a dirty chain reduces efficiency, so add to that the theoretical idea that you can fully enclose a chain e.g. with a Heebie Chainglider when using Rohloff, which (if it works) would keep it clean, this might end up without much to choose.
So basically in order to support your argument, you're using an article that essentially says: "No, wait, they are noisy, and less efficient...but not nearly as bad as you think.."
well, that's me convinced 😉
It's horses for courses, as usual. If you keep smacking mechs, hub gears might be worth a look. If you love a nice efficient bike, they may not be.
Plenty of space for both in the world. The question is wether or not this new Shimano job can give the best of both worlds - it might.
Although that’s comparing SS. It’s also very interesting to see that the derailleur test is pretty close to the Rohloff – closer than in other tests I’ve read IIRC.
I’ve also read that a dirty chain reduces efficiency
I noticed that as well. Comparisons between Rohloff used to be with 3x9 (which this still appears to be). Chainline is arguably far worse with 1x in many gears which is interesting given "a derailleur gear with a bad chain line .... may actually be quite a bit less efficient than the Rohloff"
Also "A slightly worn chain tensioner was fitted to the above testing rig and it was determined it lost 2-3 watts using a gear with a straight chain line"
It was filthy out yesterday and my SRAM 1x11 was anything but quiet and smooth.
I’d have another Pinion (they’re now a bit smaller and lighter and I think they’ve reduced the Q factor)
Don’t want to derail this lovely thread but I have one of the newer C.12 gearboxes. It is lighter with reduced Q factor but mine has chunks missing from the surface of the magnesium casing. I can only guess stones from the rear wheel have done this but I don’t really know. My P.12 hasn’t had this problem
It was filthy out yesterday and my SRAM 1×11 was anything but quiet and smooth.
whereas my SRAM 1x12 was perfectly quiet and perfectly smooth (it's only got a 1000 miles on it though, so it should be really)
I can buy the argument that if you keep breaking mechs you'd look for an alternate drivetrain solution, or if you premium utility over everything else. I'd even look at them if you're doing huge annual mileages. Whichever way you frame it though, they (hubs and gearboxes) are all heavier, less efficient, generally noisier, and I think for most folk, 1. they don't regularly break mechs, and 2, mechs are "good enough" for 99% of applications, 3. aren't doing the long long distances that make the return on investment bearable.
With the additional benefits that derailleurs are; easy to look after, (mostly) quiet, cheap, efficient to a point they don't need an article to demonstrate it, and lighter.
I think after 4 pages, with respect to the OP's question, the answer is probably; for most folk, still no.
I think after 4 pages, with respect to the OP’s question, the answer is probably; for most folk, still no.
This basically...
Just had to spend another £90 on another GX 11 speed mech which has bent, in 3 years I have bent and mangled 6 of these and bent 3 mech hangers from riding off road, cant wait for something different.
Crashes, rocks and sticks to go with a rider that enjoys riding more and more technical/chunky terrain and has the occasional crash when he hits a double but forget it hips left and goes straight...
Just had to spend another £90 on another GX 11 speed mech which has bent, in 3 years I have bent and mangled 6 of these
Swap to SLX or XT 11sp shifter and mech next time, that's all you need to change and I've found it's much more tolerant of the odd knock or slight misalignment than Sram GX was.
For those who've never broken a rear mech......
Maybe you haven't, but I'd be careful about trying to extrapolate that experience to others.
Shortly after things went 10s I trashed 3 SRAM mechs in a summer's riding as I liked the shifters and they no longer did the shimano compatible ones, I didn't even ride that much that year, they were just really fragile CNC'd things that bent as soon as you passed a tree stump. Can't recall breaking a shimano mech, but I'm sure a few have died on my bikes in 20 years, just at a more acceptable/forgettable rate than SRAM did! I've just fitted the zee that replaced the last SRAM mech onto a new bike it's still going!
So yea, if you've never trashed a rear mech, get one of the older SRAM ones and go ride Stainburn, it was almost a guarantee! For comparison
It also misses the point. A singlespeed chain is cheap and lasts a good few years, at least double the time of a geared chain, and even then it can be used 2-3x longer again just impossible to swap sprockets or it'll slip. That shimano gearbox, running in a sealed box with an oil bath is probably going to be designed to last years. Given Shimano's reputation for not releasing anything that wasn't upto their standards (even to their detriment when it meant SRAM was releasing stuff that had more appeal on the shop floor). I'd be surprised if they didn't make it last the lifetime of the frame (well, say 4 years of average use before the sort of person who buy expensive frames moves onto the next best thing I'm sure someone will fit it to a hard tail in the Peak district and kill it within a winter).
thisisnotaspoon
Shortly after things went 10s I trashed 3 SRAM mechs
Yeah - the early 10s SRAM mechs were woeful, I went through a few also, they were just crap. And there was a batch of Zees that were crap too, i broke one of those too
Yeah – the early 10s SRAM mechs were woeful, I went through a few also, they were just crap. And there was a batch of Zees that were crap too, i broke one of those too
Thing is SRAM are always simultaneously much better than the previous version, and at the same time utter junk.
It's like their engineers spend 4 years of absolute dedication making a great bit of kit, but do it from scratch and forget every lesson they learnt last time. Either they bend as soon as you look at them, the pivots go sloppy, the jockey wheel seizes, or something else is wrong.
Shimano just quietly keep coming out with slightly refined versions of the last groupset. there are the occasional howlers, which are usually solved with a ....01 version of the component. But how many years have people moaned about SRAM jockey wheels for? I don't care that they're now narrow/wide, just fix the effin' bearing. I don't care that you can machine the entire cassette from a billet of steel, how about steel pins in the pivots so they last more than a few months?
Swap to SLX or XT 11sp shifter and mech next time, that’s all you need to change and I’ve found it’s much more tolerant of the odd knock or slight misalignment than Sram GX was.
I was going to pull the trigger on switching to Shimano, the mech and shifter were the same price as the GX mech, I didnt because the adopters so that i can mount the Shimano shifter to the SRAM MMX weren't available, next time though, it is happening!
I would say the biggest point with a gearbox is moving the weight, obviously a cassette is very central to the wheel but people spend a lot of money to reduce wheel weight. Also suspension may improve if the frame design keeps a fixed chain length and high pivot will suddenly become the norm.
It’s like their engineers spend 4 years of absolute dedication making a great bit of kit, but do it from scratch and forget every lesson they learnt last time. Either they bend as soon as you look at them, the pivots go sloppy, the jockey wheel seizes, or something else is wrong.
Can't remember where I read it (wish i could claim credit) but the best description I read was SRAM is essentially just a continual beta test...
For those who’ve never broken a rear mech……
Maybe you haven’t, but I’d be careful about trying to extrapolate that experience to others.
This is fair comment, but if like me your into the 5th year on a mech, hub gears and gearboxes make no sense whatsoever. But if people can find a system that suits them it's all good.
In 30 odd years of riding off road, in all conditions and in locations all over the world, I’ve never bent or broken a mech. The worst I’ve ever managed is a few scraps on the body. I’ve replaced more jockey wheels than mechs, and I would say my experience is in no way unique amongst the folk I’ve ridden with either. IME they aren’t fragile in a way that makes me want to look for an alternative.
This.
25 years of riding on and off road and I've never trashed a mech but have trashed a mech hanger which was doing its job due to me putting a back wheel in misaligned.
I've worn out a few mechs mind you, the last one cost £25 and 15 minutes in the work stand to replace, lasted about 2k miles on my commuter bike.
And for those reasons I will stick with derailleurs all day long thanks.
Okay, as someone who has ran both a hubgear and a dynamo for over 8 years and 30000+km, I’ll weigh in.
I’ve ran a Alfine 11 in one guise or another since early 2012 and a series of SA hubs long before that.
1. In mechanical form (cables) they are no more reliable than a derailleur, cable tension is critical and more frequent oil changes make-for better performance.
2. They are HEAVY! My alfine 11 gives up over 1100g to a 1×11 XTR drivetrain and its all at the rear. You can feel it, all the time.
3. They are draggy, and you can definitely feel it. This is especially true for the first 1000 miles after servicing.
4. They’re not cheap. Alfine 11, motor, shifter, battery ~ £600. XTR cassette, shifter, mech, hub, £450. You can go a whole lot cheaper and still be significantly lighter.
5. If they get damaged (and they do because they’re easy to abuse) the repair costs can be very high, sometimes requiring the hub to be replaced.
As a test, I’ve just bought a Di2 XTR rear mech and will be swapping my Alfine 11 Di2 and Exposure Revo for a set of CKs and 1*11 Di2 for this winter. That’ll be about 1500-2000km of commuting in shit weather on basically the same bike but with mechs instead of hub gears.
My suspicion is that becase of di2, the bike will behave exactly the same, but will feel much lighter and will require more maintenance.
Bit of feedback here. So, it was a little more complicated than just fitting a Di2 Rear mech. It also needed a new display and battery in order to work with both the Alfine and XTR M9150 RD. Also, I had to swap cranksets as the chainline for the Alfine is totally wrong for 1*.
Anyway - I've now been riding the derailleur equipped bike for over a week and about 200km. It's so much lighter - almost 1.2kg, the bike is so much more lively that I almost fell off the thing when I went to pedal out of the saddle for the first time. The bike also maintains speed much better than the Alfine, even when the Alfine is in gear 5-6 (1:1) and so I have to pedal less. On a 54km round trip commute, I'm about 2-3kph faster with the derailleur than the hub gear, I also have less fear of changing gear (You have to back off on the Alfine), but I do miss being also to shift gear while stationary - it's surprisingly handy on a commute.
I'm going to run it like this until Christmas and then change back for January and see how it feels going the other way.
On a 54km round trip commute, I’m about 2-3kph faster with the derailleur than the hub gear,
Blimey. Not an insignificant amount, that!
Be interesting to see how it goes once you swap back.
Umm...
Skip to 18:00 if you don’t want to hear about the new Deviate Highlander, their new HSP 140mm 29er with a conventional gear setup
I think McTrail rider had got used to the mech-free benefits of the Deviate Guide.
In certain applications yes... Starling Spur moves the idea on a few notches.
high pivot rear axle path, no chain growth, perfect chainline all the time, no mech to hit off and a v light/strong rear wheel allowing far superior suspension performance. And silent. If you have every ridden a full sus dh without a chain you will know how good the bike suddenly feels. This rides like that all the time!!
That Effigear is a lovely mechanical solution but all those gears meshed all the time?
Another vote for "Gearboxes sound great, but I don't actually break derailleurs".
That Effigear is a lovely mechanical solution but all those gears meshed all the time?
It's how motorbike gearboxes have worked for many, many years.
Yes, but 745.7 Watts are equal to ONE HORSEPOWER
And I don’t have 745 Watts. So losses are A Thing for bicycles in a way motorbikes don’t need to worry about.
Edit: the effigear *does* look pretty, though. I agree there.
That Effigear is a lovely mechanical solution but all those gears meshed all the time?
But only one is coupled to the input shaft at any one point (otherwise it would only have a single ratio) - I've probably missed your point though?
It does look like a good, relatively simple (read serviceable) solution though.
Its a "constant mesh" gearbox I think. So all gears are meshed at all times but only the gear pair you are using are fixed on the shafts - the rest are freely rotating. so you are turning every pair of gears all the time. They will be under no load so drag will be small but it will still be there
Ah yes, I see your point - if the sprockets are fixed on the output shaft they will spin the unused input gears (it would be possible, I guess, to only couple the selected sproket on the output shaft too, but more mechanically complicated).
FWIW the situation is similar in a derailleur system in that you spin all the chainrings and the whole cassette all of the time.
I really wish they would come up with something better.
Replacing a chain every 500 miles then replacing the entire group set after 2000 miles is pathetic considering the 0.2 horsepower I'm putting through it.
For E Bike's they only last half that and cost twice as much! 4X more maintenance, or is that 6 to 8X more in time terms given the higher speeds ?!!
The benefits of gearboxes are good, lower unsprung weight, durability, maintenance etc.
The biggest thing holding them back, is lack of demand.
Imagine a buyer speccing 2021 bikes at a big manufacturer, they have a choice between a frame than can be used across multiple models, with various spec of drive train from multiple manufacturers (for which they probably get a massive discount), priced from £2000 to £6000 (for a typical FS bike), and that is 99% guaranteed to sell well.
Or, they could build a brand new frame which will only take a single, specific drive train from a single manufacturer, which due to the cost can only be specced on a £5000 bike, which might sell well, but might not.
That's a big old risk. It needs one of the big players (shimano or sram) to build one, but they'll still be low in demand, due to the frames needing to built specifically for them, and the cost.
Meanwhile the derailleur continues to be refined and refined with smoother shifting, more range etc. And for the vast majority of people, the durability isn't an issue.
If gearboxes take off, I reckon it'll be start with an ebike specific one. As the motors get smaller, there'll be more space free for a gearbox, maybe attached directly to the output of the motor in some way.
They will be under no load so drag will be small but it will still be there
This
FWIW the situation is similar in a derailleur system in that you spin all the chainrings and the whole cassette all of the time.
Well no. When gears mesh, the teeth slide over each other as each tooth engages then disengages. This is what causes the drag. The extra sprockets on a derailleur system are just spinning in air not touching anything. As TJ says the drag will be small but you're multiplying it by however many cogs there are. It's a lovely solution but I think it's going to be a bit draggy. This may not matter to you, of course.
Replacing a chain every 500 miles then replacing the entire group set after 2000 miles
Putoline. Seriously. Give it a try. I used to hate grinding my drivetrain away on wet rides, but there's no grinding with Putoline. And you don't have to clean it. One of the best £20s I ever spent.