Hub or Derailleur, Which Is Best?

[flecc]

We are looking at the possibility of using the new version of the NuVinci hub which is much lighter and needs less twisting to move through the gears. However after reading Flecc's comments I have some new questions for them!

They'll tell you a very high efficiency figure David, but like every hub gear manufacturer, the figures are simply untrue, no truly independent testing getting remotely near to achieving the quoted figures. The best test is to try an unpowered bike with a derailleur gear and an identical bike with the NuVinci. The pedalling through treacle sensation is immediately unmistakeable. The later somewhat lighter but still very heavy NuVinci is the only one I've tried, but I've obviously missed nothing with the earlier version.

A to B and Velovision have both tested the NuVinci and their impressions exactly match my own, love the concept, hate the drag.

 

[Wisper Bikes]

Thanks Flecc, we are still considering our options, I have only tried an 905Alpino set up with the older version NuVinci. As you know we decided to stick with Alfine8 which was superior in every way. My worry is the possibility of no warranty support from Shimano (sill no response to my request for clarification).

My feeling after being involved in this thread is that for the price of the Alfine8 or NuVinci we can buy a high end cassette and derailleur set up. Maybe this is the best rout forward.

 

[JuicyBike]

Thanks Flecc, we are still considering our options, I have only tried an 905Alpino set up with the older version NuVinci. As you know we decided to stick with Alfine8 which was superior in every way. My worry is the possibility of no warranty support from Shimano (sill no response to my request for clarification).

My feeling after being involved in this thread is that for the price of the Alfine8 or NuVinci we can buy a high end cassette and derailleur set up. Maybe this is the best rout forward.

Definitely David. Far be it from me to teach anyone about eggs etc., but adding a stainless steel chain would ice that derailleur cake!

 

[Wisper Bikes]

Thanks Bob, this really is the beauty of this forum, everyone wants to help!

We wanted to use a carbon belt drive which of course would negate the use of a cassette and derailiure. Does anyone have experience with them?

 

[JuicyBike]

Thanks Bob, this really is the beauty of this forum, everyone wants to help!

We wanted to use a carbon belt drive which of course would negate the use of a cassette and derailiure. Does anyone have experience with them?

Main strength is that they're easier to spell!

 

[Wisper Bikes]

Too many e's and a's for me to possibly get it right Bob even with spell check!

Why derailleur (I think) anyway, why not derailer? There should probably be an accent above the e too!

 

[Scimitar]

Currently I'm using the fairly standard derailleur setup on mine - as dictated by the Chinese hub motor coming with a 5sp freewheel set. My next build will use an SA X-RF5 I picked up for next to nothing as NOS a couple of years ago. I will use this in either a front hub drive arrangement or mount the driving motor above the chainwheel in the diamond.
I grew up using SA hub gears and always had a soft spot for them. I can't recall them ever letting me down, no matter how abused they were. So, I'm hoping this one is as good, even though it's a Sunrace version.
No matter, even as a mantelpiece adornment it looks good

 

[flecc]

Too many e's and a's for me to possibly get it right Bob even with spell check!

Why derailleur (I think) anyway, why not derailer? There should probably be an accent above the e too!

I do have plenty of experience with toothed belt drives in other applications with toothed belts and power, but their only advantage over chain and sprockets is the lack of need for lubrication. They are however much less efficient than chain drive. Don't be fooled by the usual claims to the contrary, it is physically impossible for one of these toothed belt drives to avoid inefficiency by the very nature of the belt structure, it's cords and the body material's relationship to turning corners. The newer makers bluff with talk about the cord material, steel, nylon, carbon or whatever, but that misses the point that the cord has no effect on the efficiency whatsoever.

Why the spelling derailleur? It's French, they invented the modern forms and were responsible for all the early developments.

 

[Wisper Bikes]

Thanks Flecc, I was a little uneasy about belt drives and splitting the rear stays is an issue, the manufacturers blurb seemed quite convincing though. You obviously feel that a lot of the new tech developers seem to be making a lot of claims that cant be substantiated in the real world. It may well be that a decent chain, cassette and derailleur set up is the most sensible if we are looking for both efficiency and strength.

 

[flecc]

It may well be that a decent chain, cassette and derailleur set up is the most sensible if we are looking for both efficiency and strength.

Any hub gear efficiency, including the NuVinci, is measured in isolation without including any chain and sprocket losses. On that basis a derailleur is 100% efficient, no losses whatsoever!

On a previous mention, I can't see Shimano being at all concerned about giving a full hub gear warranty on e-bikes not using crank drives. On average an e-bike rider puts less power through a hub gear on a hub motored bike than an unpowered one, so is less likely to make a warranty claim.
.

 

[Davanti]

Too many e's and a's for me to possibly get it right Bob even with spell check!

Why derailleur (I think) anyway, why not derailer? There should probably be an accent above the e too!

I think it was simply called 'Simplex' gears in my youth. Or am I confused?

 

[flash]

I think it was simply called 'Simplex' gears in my youth. Or am I confused?

Simplex was a manufacturer I started out with Benelux could not afford Campagnola

 

[bode]

Why the spelling derailleur? It's French, they invented the modern forms and were responsible for all the early developments.

The French also came up with the SCART plug, another invention of the devil.

 

[flash]

Efficiency Measurements of Bicycle Transmissions - a neverending Story

If you are really that bothered read this

http://graham.hopto.org/bike/gear_efficiency_report.pdf

 

[Davanti]

Simplex was a manufacturer I started out with Benelux could not afford Campagnola

Of course! It's all coming back now, Nurse.

 

[tillson]

Is there a problem with using an Alfine hub gear unit in conjunction with a crank drive? Unless I've missed the reports somewhere, I'm not aware of a disproportionately large number of failures.

 

[Davanti]

The French also came up with the SCART plug, another invention of the devil.

Wasn't it the French that came up with idea of hanging onions on handlebars to balance a bike fore and aft?

 

[Wisper Bikes]

Is there a problem with using an Alfine hub gear unit in conjunction with a crank drive? Unless I've missed the reports somewhere, I'm not aware of a disproportionately large number of failures.

Hi Tillson, apparently, according to the guys at NuVinci, there is an issue with putting the torque created by a crank driven bike coupled with the torque created by the rider through any of the Shimano hubs in terms of warranty. This only applies to crank driven bikes, hub driven bikes are fine with hub gears.

All the best

David

 

[Wisper Bikes]

It’s my work, he’d say, and I do it for pay
And when it’s over I’d just as soon go on my way
Up to some paradise
Where the trout streams flow and the air is nice

Hi Flash, great song but did he do it?

 

[flecc]

Is there a problem with using an Alfine hub gear unit in conjunction with a crank drive? Unless I've missed the reports somewhere, I'm not aware of a disproportionately large number of failures.

I've never heard of one, and I get plenty of feedback via my website. Nor have A to B, Velovision or the Electric Bike Magazine mentioned any. The editor of the last two, Peter Eland, is a confirmed hub gear fan and never fails to report feedback of failures on any hub gears, he was first in with the failures of the Nexus 8 speed when it was first introduced. That was quickly upgraded and there's been no reports since.

Given NuVinci's entirely spurious efficiency claims, I'm inclined to be suspicious about this report until there is some confirmation from Shimano. Also, having regard to the huge size of the e-bike market in mainland Europe, would that market dominance obsessed company Shimano really want to not take part?