It was a good design in it's day but let's be honest derailleurs are a poor design from an engineering perspective. A design only embraced by the conditioned masses who know no better.
do we really have to feed the trolls?
Keeps 'em quiet and contented. Less likely to question the status quo I guess
I think it's a miracle they've ever worked. However they seem to be way cheaper than the alternatives
when something like a rohloff/alfine gets light enough (& small enough to fit, sealed, at BB) then, yes, maybe you're right
ton - Member
[url=
ones better[/url]
mmmmmm
Yeah, your right on both counts. The latter because they're built by people gravitating to the the cities in Taiwan and China trying to earn enough money to send back home.... Do they get a fair wage, do they ****?
fair enough.
Odd timing as today I rode a derailuered (and full suss) bike for the first time in 10months as opposed to an alfined HT.
Hated it for the first 10 minutes or so, as I found the steps between the gears way too narrow and pissing about with the front mech frustrated me at the complexity of getting in the area of the gears I wanted.
Then it clicked, it was much faster - more involved but much faster. Ended up battering my time for a a local loop I do (I know, new bike syndrome and all that) mainly down to the higher top speed, but certainly in part at being able to pick a better gear for each hill as opposed to a grind up.
They are cheap and light and it's not that often they break whilst doing a good job... it'll be a long time before they go I think.
Good point Saccades. Every engineering solution has it's weak points and no design is going to be totally satisfactory.
As regards your times, perhaps it's not just about how fast you go but about enjoying the journey? And....doing a lot less cleaning and maintenance at the end of it!!
It's still lighter and cheaper than the alternatives so I think it'll be with us for a while yet.
dérailleurs are rubbish - they wear out all the componemts far too quickly.
It costs me almost as much per mile to run an MTB as a superbike. 10 p per mile in drivetrain wear alone
Alfine is cheaper as well.
Hub £150 other bits up to £250. ( Crankset and shifter) Now price up a complete decent drive train for dérailleurs.
Spot on there TandemJeremy. Particularly relevant if you're comparing one Shimano 'system' to another, despite the fact that they're all probably made in Taiwan. I'm a hypocrite after all....
SGS 501 Alfine £135 from bikecomponents.de plus 10 euros postage. Despite that I ending up buying mine from 18 bikes. £220 built up with DT Swiss 4.2d rim and DT competition spokes. I'll take the last one in stock, thankyou!
As Keith Bontrager said to this argument, dérailleurs have had many years of development and though an inferior system to internal gears have been refined to such a degree that they work as efficiently as they are ever going to. Internal gears have only been around for a short time and so still need a lot of refinement. I think the OP point would receive a different set of answers in say ten years time.
Not for along time IMO. They're cheaper, lighter, offer a better spread and give better weight distribution. Also, I've never really had a problem with bent mech hangers etc. (although it is obviously an issue), and as long as you don't neglect them they last long enough.
Dérailleurs are not cheaper than an alfine
Complete alfine set up of drivetrain amnd rear whell and crankset is about £250. Get a decent rear wheel, cassette, crankset and shifters for that if you can
add to that the longer lasting chain and sprockets
An Alfine can only give you the range you'd get from one of your chainrings on a derailleured setup. How's that going to work for moderately fit somewhat overweight biffers like me somewhere with some steepish ups like the Qs?
It doesn't. Give me derailleurs.
gearbox in the BB has to be best solution, CofG/unsprung mass wise
bottomless pockets and rohloff.
Depends how picky you are with defining [i]decent[/i] TJ. You should be able to get Deore level stuff for that money, and I'd consider Deore to be decent enough.
I have no experience of an alfine though, or any idea what the quality is like.
I must say that in this day and age what with interwebgoogleblogstweets the sheer mechanical crunchiness of a chain being mangled by derailleurs is a refreshing reality check. I hope my car's gearbox doesnt work the same way!
The only solution is singlespeed. £23 for a complete drivetrain (£4 cog, £6 chain and £13 on a Deore chainring), does me a couple of thousand miles on the commute.
</troll>
hub gears OK for commuting and shopping bikes, very old tech 100plus years- weight all wrong still is
bb mounted gears better - might get lighter but still way too heavy
how many bikes in world??? reckon most bikes don't have derailleurs
like my short cage shadow mechs
It costs me almost as much per mile to run an MTB as a superbike. 10 p per mile in drivetrain wear alone
I am genuinely interested in how you worked out the figures, for both, please talk me through it.
G-boxx. the frame will cost a fair few ££ but in teh long run it works out cheaper becuase they come with cranks, shifters etc etc.
or for £700 get a schmidt and have 18 or 20 gears, but you still need a rear mech. I wonder iof you could combine a schimdt and a geared hub?
I don't think the derailleur has had its day by a long way. It may not be perfect but the combination of weight, price, gear spead, ease of use, weight location and durability is well beyond any alternative. Maybe one day, other stuff will surpass it but right now, it's easily king of the hill.
[i]Complete alfine set up of drivetrain amnd rear whell and crankset is about £250. Get a decent rear wheel, cassette, crankset and shifters for that if you can[/i]
Wrong end of the argument TJ, 9.9 out of 10 mountain bikes sold have dérailleurs specced as standard, whereas Alfine and the like are almost always after market devices, contra to your argument, you have to find the equivalent specced Alfine bike for the same money as say a Deore (where I'd put Alfine in the Shimano family) for the same money.
As for dérailleurs being rubbish from an engineering POV, OK, the parallelogram version being going nearly 70 years virtually unchanged, designed for 3 widely spaced gears, it happily copes with up to 11, in mud or whatever. Theres plenty of life left there.
Internal hub gears have their advantages, but IMO they are minimal against a well looked after traditional drive-train, and personally I'd find the additional cost of merely a different way to change gears not really worth it...
At least I haven't been speaking in the wind, people finally spell dérailleurs correctly.
theboatman - MemberIt costs me almost as much per mile to run an MTB as a superbike. 10 p per mile in drivetrain wear alone
I am genuinely interested in how you worked out the figures, for both, please talk me through it.
2000 miles ( on the tandem which wears drivetrains quickly) is a cassette, 4 chains, 4 chainrings £200+ therefore 10+ p per mile.
Solo not far behind that 2000 miles is one cassette, 2 chains, 2 chainrings over a hundred pounds = over 5 p per mile
roughly speaking.
You can hardly claim tandem use as normal though and I reckon I get a lot more life than you're talking about from my drivetrain which I don't change chain or chainrings on so say even at worst estimate, 2000 miles for £30 (cassette) + chain (£15) plus a middle chainring (£20) plus 1/3 of a granny ring (£3) and 1/3 of a big ring (£10) = £78
so 3.9p per mile.
Anyway, the original premise in this thread was that derailleurs are a poor engineering design. Actually, while they may not be an elegant design (bashing/pushing the chain around over teeth) they are a supremely good real world design where they work with high efficiency, little maintenance and low weight. Internal hubs are currently heavy and inefficient in comparison though they should be lower maintenace. They've still got some catching up to do.
TJ - Didn't you have a Rolhoff once upon a time?
sooty - no - I want one but can't afford the outlay.
Got an alfine coming for the solo
Derailleurs are actually a very good, cheap and simple design that work very effectively in horrific conditions over a wide range of gear combinations. That, my friend, is good engineering.
Internal gearing, as yet, cannot really compete on all fronts.
Hmm, lets see, why are matches still in use if 'far superior' lighters(Bic,Zippo) are available? Because of their simplicity and functionality, that's why.
i dont know why no one has put an Alfine or Rholoff system into a BB yet.
the answer i normally get it "it wont fit" but cannondale are using BB30, theres bmx sized standards.
make it bloody fit!
i would put the freewheel mechanism in thier too, so the rear sprocket is a bolt on fixed cog.
now THAT i would buy.
screw in, forget till it explodes, replace.
mechs are beautiful bits of engineering
long may they reign, or until i get my BB gears out at least.
I've never actually owned a superbike however I have had a CBR600F for a number of years - just worked out the cost per mile of that and, including depreciation, it's something like £1.15 a mile so far...
This is the top secret gearbox of Honda's world cup-winning RN-01 DH bike:
[img] 
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Says it all I think. 😉
make it bloody fit!
Make everything smaller, so it'll wear faster? 😛
Olly - Member
i dont know why no one has put an Alfine or Rholoff system into a BB yet.
the answer i normally get it "it wont fit" but cannondale are using BB30, theres bmx sized standards.
make it bloody fit!i would put the freewheel mechanism in thier too, so the rear sprocket is a bolt on fixed cog.
now THAT i would buy.
screw in, forget till it explodes, replace.
There are a couple like that but they are frimly in the downhill freeride camp. I would love one personally.
are the DH ones, not just mechs in boxes, like in the honda.
when i say make it fit, i dont mean make the gears smaller, i mean, make a frame to fit it.
sliding dropouts for tension, like on the orange P7, and a BB that is essentially the size of an Alfine or rholoff hub.
cranks go on the spindle, the chain wheel goes on the sprocket mount, and the whole thing is threaded so it screws into the frame, like a big BB
i dont know why no one has put an Alfine or Rholoff system into a BB yet.
Making small things that last long in harsh conditions is very very expensive, and bordering on impossible. Just look at the number of HTII failures people seem to report (if you believe they are not just a noisy few).
How do you make a bike with a huge mutha of a BB shell, and another shell inside it, without adding to weight, losing lots of ratios, or completely messing up the handling and ground clearance of your bike?
A couple of engineering student mates were on about developing a hydraulic drive train with continuously variable resistance. By changing the flow rate of the fluid (or something), you could have the equivalent of a higher or lower gear. Problem is, hydraulic transmissions are currently about 40% efficient, compared to about 95% for chain drives.
Empire were on about this - make the frame bolt onto the gearbox like the do with motorbikes.
If you can take the cassette, derailleur etc. off the wheel and put it low down in the middle of the bike, that helps suspension performance and handling.
Hydraulic transmission is a nice idea, but as you say inefficient.
When you are the engine you notice these things more. But if you have fossil fuels that you don't mind wasting they're fine.
[img] 
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had a look at this in the shop. it's ****ing heavy!
[url= 
]Here[/url] is the Nicolai one.
You can see it is part of the frame and they use the gboxx idea.
The ground clearance argument about a BB based gearbox is boloney - your BB clearance is not defined by the diameter of the BB shell, it's the diameter of your largest chainring. So long as the BB shell is no larger than whatever chainring you'd chose to drive a hub mounted g-box then it makes no difference, and more significantly makes the weight of the drivetrain unsprung (assuming a the BB shell isn't rigidly attached to the stays)
With a constant chainline you have more ability to control the suspension behaviour under load as the point of force will always be the same and therefore could be compensated for.
Not sure I like the idea of including the freewheel mechanism into the BB shell, as that would mean that when freewheeling down hill it'd be like straddling a chainsaw!
how is putting a geared hub where the BB is, instead of at the back, any heavier at all?
youve just moved it forward, which can only be a good thing anyway?
how is putting a geared hub where the BB is, instead of at the back, any heavier at all?
cos the bb shell is integral to the frame making it bigger is heavier than just a big hub
anyway, the answer is no - they have not had their day, but they are moving into middle age.
Padowan, but if you had something the size of a G-Boxx, for arguments' sake, but centred on the BB, you'd lose any ground clearance advantages?
If you were comparing a standard BB with no chainrings, to a G-Boxx with the input drive at the same point (BB) then yes, the G-Boxx would reduce your ground clearance (between ground and "BB" shell) because it's taking the drive that goes to the hub upwards meaning that the drive sprocket (however big it is) shouldn't protrude below the BB shell.
But I was looking at it from the point of having something like a Alfine or Rolhoff where the input and output shafts are on the same axis, where the drive gears surround the input shaft (BB) and drive a chainring around the same rotational point. In that instance, for a given chainring that becomes your clearance limitation over a hub mounted gearing.
An Alfine can only give you the range you'd get from one of your chainrings on a derailleured setup. How's that going to work for moderately fit somewhat overweight biffers like me somewhere with some steepish ups like the Qs?
Not really true about the Alfine, as you get a lot more gear spread than just one front chainring (on normal setup).
There are a few compromises, in terms of jumps between gears, but the Alfine will cover enough ratio's for most situations.
I'm a biffer too, and the Alfine is great IMHO
My understanding is the alfine is a bit more than a 1x9 but not as much as a 3x9 in terms of gear spread - sort of equivalent to a 11-38 rear casseette