[Closed] Gearbox Fans/Haters: What if...

Weight and "feel" (drag and take-up) are the biggest things for me. Shifting I can live with provided it is reliable. We have alfine 8 and a few sturmey / Sachs 3 hubs knocking around.

The 3 speeds feel least draggy and closest to the take-up of a regular hub (but have to live with tick-tick-tick as you pedal along). The alfine is quiet but I really dislike that mushy feeling as the clutches engage (have done the Fred Whitton route on Alfine) .
I can see why take up isn't an issue on the tandem, but for my favourite techy climby pedal clocking singletrack I want something that feels as direct as a singlespeed with a Hope hub.

I'm just at the point of making a new mtb frame for Alps in summer. My original e-stay from 2011 is now my commuter and surprisingly still hasn't cracked - a variation on that design would work well with Pinion. Hmmm.....

The PO asked:

IF there was a gearbox drivetrain that:
- Weighed less than a derailleur system
- Shifted as well as (or nearly as well as) a derailleur system
- Had a decent trigger shifter
- Fitted on your current bike

Would you buy it? How much efficiency would you give up? How much shift quality would you give up?

I answered 3 % - as a guess.
Funny that somebody posts this:

They aren't aimed at road race bikes though are they so that's a pointless argument.

I'am not a gear box hater at all.
But I stated my opinion and think it's not pointless at all.

Road and MTB:

Gear-box bikes might have a big future if somebody is able to win a race on them. Right now gear box bikes are niche products.

MTB: there are fantastic new bike designs out there - using gear boxes. But to be commercially a bigger success they need to win a race.

My guess, mtb: 3 % less efficiency will be tolerable if there are other advantages (there are quite some!)

But only if this stays true:

Weighed less than a derailleur system

IHG bikes are only niche in the UK. they are mainstream in most of europe

they are mainstream in most of europe

O.k. - if we don't talk about bikes for sport.

As soon as we talk about "sport" (not only racing):
weight and efficiency will be key. Most mtb bikers do biking as a "sport" and bike in a group.
More than 3 % loss in efficiency might take the fun away from them. This might mean starting to struggle to keep up with the group.

Average power rating of a trained biker is quite low. A three percent difference will be felt right away.
I guess at least...

Might be wrong so.
😉

What would make you buy one? The cash in the bank to be able to afford one....

Massive fan of gearbox systems.

It's all about feel. If you 'feel' that an IHG is draggy, and it's going to annoy you, then it's going to spoil your ride regardless of anything else. Nothing to do with actual wattages or times. If however you don't care, then crack on and enjoy the benefits. Choice is good in this situation.

I reckon 3% is about the same as the difference between using draggy tyres and quick ones. And that's often discussed as something people notice and affects their riding experience.

I have a bike with a Pinion gearbox. I had a demo ride on a hardtail with a gearbox before eventually buying a full suspension bike so to answer one of the questions 'what would persuade me to buy' I'd say simply a demo. The chance to try it out and find that I liked it. A lot.

A Rohloff hub was an alternative but all that weight out back isn't ideal on a MTB so my only hesitation in going Pinion was the price.

Most mtb bikers do biking as a "sport" and bike in a group.

That's me. I'm not the fastest nor the slowest on my average ride and that is no different whether I am on my gearbox bike or 1 X 10.

I should have a second gearbox by the end of the month, a hardtail. I'm thinking of singlespeeding my 1 X 10 so I may be derailleur free by Feb.

I reckon 3% is about the same as the difference between using draggy tyres and quick ones. And that's often discussed as something people notice and affects their riding experience.

Good point. One reason why mtb bikers started to put "fast" tyres onto the back and "grippy" ones onto the front.

@Rubber_Buccaneer

I have a bike with a Pinion gearbox.

great input. Means the Pinion is already very close to the efficiency of an convential 1x11 system or similar?
Is there literature about it? Maybe the Pinion is in that 3 % range already?

@JonEdwards

I happened to bump into Ben Jones from Deviate a few weeks back on my local trails and had a good look at the bike. Looks very well sorted. Barring cost (at the mo) I'd love one, and a much more interesting way to spend £5k than a blinged Santa Cruz or an HB160.

They put that much thinking into the engineering of the suspension together with the gear box - just GREAT.
Hope they succeed.

What would be great: if a professional biker starts biking the Deviate bike and starts getting into the top three of some races.
This would definitely push the product.

I reckon 3% is about the same as the difference between using draggy tyres and quick ones

I think you'll find tyres can often be bigger variation and impact than 3%.

Even on the road the difference between a fast tyre like a Conti 4000sII (~11W per tyre) and a cheaper but still fastish Michelin Lition (17W per tyre) means you're talking 12W difference between tyres, at 100W pootling output that's >10% right there, at 200W it's still over 5%.

Taking a 'slow' road tyre at over 20W per tyres means you could be giving up over 20W just in tyre choice alone, and for most people punting out 200-250W for any length of time is a hard effort, and the differences in MTB tyres can be even more extreme than the road examples too so drivetrain losses that small wouldn't be much to worry about for general use.

It's all about feel. If you 'feel' that an IHG is draggy, and it's going to annoy you

This is chicken and egg though, you adapt to what you're used to. If you spend a lot of time on fixed or SS then it's noticeably 'draggy' when you jump back on a geared bike.

If history had been different and we'd all grown up on draggy IGHs and gearboxes and then someone invented the derailleur would we find people jumping ship due to the performance increases of a free-running but niche and expensive derailleur system? For racing undoubtedly yes, but in the general sector, if it meant suddenly being saddled with increased maintenance, vulnerable mechs, custom frames and increased cost? I'm not so sure....

I have SS bikes, dedangler bikes and IGHs, I like them for different things and I am genuinely considering a Pinion machine in the future (I'd buy one right now if I had the spare £) as I'm already sold on a lot of the aspects, but you won't find me racing on one at the moment.

It's a case of what's important to you. On my commuter or on a tourer or bikepacking bike, or even a bad weather MTB, the drag and weight are a non-issue for me. But for fast road riding and racing it's still an issue, ie: it's very person/use specific as to what is an isn't an issue.

The pinion gearbox should not have the drag of IGHs as its just two meshing cogs and some shafts turning not the highly loaded epicyclics of the IGH

On the backpeddalling twospeed this is the system. Its not an IGH its a weird system with two freewheels and a ridiculous chain path

[img] [/img]
By Hirsutism - Own work, CC BY-SA 3.0,

https://en.wikipedia.org/wiki/Retro-direct

Its not an IGH its a weird system with two freewheels and a ridiculous chain path

And they're also ridiculously good fun, easy to knock up and bodge together. Use the retro/reverse gear as the overdrive/higher gear as it's a lot easier to pedal backwards cruising than it is trying to winch uphill, legs don't work right backwards!

@Tj and drag of 11s Vs 8s...

Just as another data point...there is a noticeable difference on my 11s versus my 8s hubs too when freewheeling it in the stand, but out on the trail it's not noticeably different. The mushy clutch engagement however is more noticeable on the 11s though in certain gears, 2 being the worst IME, I actually try to skip 2 on the 11s as much as possible as it [i]really [/i]annoys me!

the Pinion is already very close to the efficiency of an convential 1x11 system or similar?
Is there literature about it? Maybe the Pinion is in that 3 % range already?

I think it is close. Freshly prepared bike rolling out of the shed maybe the pinion has a little more drag, half an hour later in current muddy conditions on the South Downs maybe the derailleur has a little more drag or perhaps it's just evened things up. Overall other factors have a bigger impact, choice of tyres, pressure, etc.

Ta amedias. I guess its the better seals?

found some stuff, research about efficiency Pinion:

http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2669549

ASME 2017 International Mechanical Engineering Congress and Exposition
Volume 12: Transportation Systems
Tampa, Florida, USA, November 3–9, 2017
Conference Sponsors: ASME
ISBN: 978-0-7918-5847-9
Copyright © 2017 by ASME

Results indicate these transmissions are comparable to many modern multispeed geared bicycle hubs, ranging from 91.6–94.95%. Single-speed and derailleur systems can obtain higher efficiencies. However, the Pinion transmission provides enhanced reliability, reduced maintenance and relocates the majority of the drive weight to the middle of the bicycle. A repeatability study was conducted on the P1.12 transmission.

Pinion reaches 95% efficiency! That is very high!

@Rubber_Buccaneer :
no wonder that you are happy with your bike!

Maybe somebody is able to find some results for convential 1x11:
remember having read something about 97%.
Possible that this number is correct? (all new, clean, shiny, lubricated)

If so:
The Pinion is maybe in the range of 2 % of such an convential drive train.

Guess much better: when you are stuck in the mud and your 1x11 isn't "clean"...

@Rubber_Buccaneer:

haha - your post was quicker:

I think it is close. Freshly prepared bike rolling out of the shed maybe the pinion has a little more drag, half an hour later in current muddy conditions on the South Downs maybe the derailleur has a little more drag or perhaps it's just evened things up

Your sensors are damned good!!!
ASME 2017 paper, above: exactly right!
😯

Deviate:

with above efficiency information plus the great Deviate suspension design...

very possible that they are able to win some races soon!

Hopefully they find an excellent professional biker.
😉

andreasrhoen - What would be great: if a professional biker starts biking the Deviate bike and starts getting into the top three of some races.
This would definitely push the product.

Its a long time since race results meant guaranteed sales.

sjshaw672 - IF there was a gearbox drivetrain that:
- Weighed less than a derailleur system
- Shifted as well as (or nearly as well as) a derailleur system

We've just had 500 internal gear bikes with drum brakes appear in Sheffield for almost free (OFO dockless bikes, look them up). I think this and time will have as much if not more effect on people taking up gearbox bikes than a lot of the stuff written above. People need to get used to bikes not having "visible" gears and then they become less the norm.

As a way of changing gear on a mountain bike my impression of the (admittedly) few rides is that they are heavy draggy and expensive. I'm not a destroyer of kit (I've never smashed a mech) so the saving in rings and chains and so on isnt something that I worry about or are particularly interested in.

I'm all for the idea of options and choice, but I'm not in a rush to buy one

I think efficiency would have to be within 0.1s of a %, and weight within 100s of g for me to really want one on a do everything bike.

I can't see me having a "gloopy weather bike" - at least not one that's not just a single speed.

An enclosed chain case would appeal to me, and might get me to consider a gearbox (as after the first couple of muddy puddles, the efficiency of the chain would still be high, negating the reduced efficiency of the gearbox), and I would be OK with that for the couple of times a year my drivetrain doesn't get covered in shite.

philjunior - I think efficiency would have to be within 0.1s of a %, and weight within 100s of g for me to really want one on a do everything bike.

Thinking about the Pinion numbers,

If they are correct so:

Wouldn't be surprised if SRAM or Shimano will try to buy them soon.
If they don't sell ... SRAM or Shimano might try to copy & start a nice mass production?

If so: Cost would come down and people would buy these kind of high technology bikes.

@thepodge:

Its a long time since race results meant guaranteed sales.

Some interesting posts above - good discussion chaps!

I like the idea of a gear box - less maintenance, less prone to damage etc.

They seem fairly efficient at the moment looking at the data provided in the posts above.

I think what it needs is a manufacturer to jump on board with it and be able to get the prices lower. At the moment it looks to be around £6k for a carbon full susser.

Didn't I see a post a while back that Sick were producing a gear box frame? Anyone have details on that?

thepodge - Member
philjunior - I think efficiency would have to be within 0.1s of a %, and weight within 100s of g for me to really want one on a do everything bike.

Of what though? XTR or Alivio?

Out of the box they're probably identical, infact apart from the mech going a bit sloppy I bet they're the same for the life of the parts.

The pinion is 95% efficient, a derailleur is 99% (+/- 1% depending on chain lube, jockey wheels etc).

If a hypothetical system carried no weight penalty, was as efficient, etc, then why not. But nothing comes close to a derailleur (yet).

What wattage was the pinion efficiency test 95 ? For example a rohloff is 96% on paper if your putting out a constant 200w. Drops to 92 at 50w though.

Derailleur systems between 93-98% depending on gear and power used for test.

has anyone mentioned the url for this thread yet?

[url= http://singletrackworld.com/forum/topic/gearbox-fanshaters-what-if ]http://singletrackworld.com/forum/topic/gearbox-fanshaters-what-if[/url]

unfortunate '/' removal.

as you were.

dirkpitt74 - I think what it needs is a manufacturer to jump on board with it and be able to get the prices lower. At the moment it looks to be around £6k for a carbon full susser.

That's not just down to the gearbox though, carbon tax, aspiration tax, niche tax, low volume tax, they all add up.

If someone wanted then they could realistically get an alu frame full suspension gearbox frame at a competitive price. I think Sick could be the ones to do that.

trail_rat - Member

What wattage was the pinion efficiency test 95 ? For example a rohloff is 96% on paper if your putting out a constant 200w. Drops to 92 at 50w though.

Thats interesting - presumably part of why we don't feel the drag so much on the tandem

Ref: Wattage of tests, the only tests I've seen were the ones that produced this graph:

[img] [/img]

Which shows output for both 50W and 200W for various drive options.
Efficiency doesn't just vary by input power, but by the specific gear too, this affects epicyclic IGH's and Alfines specifically worse than the Pinion.

While the 'Hoff is spiky, it's actually over a small range so pretty small actual variations between gears. The Pinion is reasonably flat too, the 8s Alfine especially though is massively variable!

Basically, if you're spinning around in 4th* on an A8 at lower power you're gonna feel it! the worst gears on the A11 are at the end where you're more likely to be putting out more power so although they are 'worse' they're not as bad in reality.

*It's an annoying quirk of the 8s really that right in the middle or the normal 'pootling' range is the least efficient gear. It really is worth while paying proper attention to your ratios to make sure you spend the bulk of your time in the right gear.

Imagine the difference in perception between two riders, one who spends 90% of his city commute in 4th, and one who spends it in 5th. a few teeth on the chainring could totally alter your perception of the hub.

** Also worth noting I think the Inter8 on that graph is actually a Nexus, not an Alfine, same gearing but plain bushes not bearings on various bits so an A8 will be marginally better than the N8 on that graph.

Has someone intergated a gearbox with an electric motor yet?

That would be awesome on an ebike

Has someone intergated a gearbox with an electric motor yet?

Alfine Di2 + Electric assist has been done a lot, we have it (at Bike Charity) on a Larry V Harry cargo bike, auto shifting + e-Assist, just pedal and go, it's ace! It even auto shifts back to a predefined 'starting' gear when you stop.

Just been looking at the Pinion site - not worked it out properly but the all-in numbers (inc steel frame hardware etc) look a bit heavy at the moment (crank arms look a bit of a lump compared to HT2). Suppose there are some small savings to be salvaged with a light rear hub etc.

We had a day biking in Copenhagen last year (belt drive Biomega with Alfine). In an urban setting I really ended up driving it like a car - shift to low gear at the lights, then set off sat down and quickly shifting up through gears.

@amedias:

great information!

Most surprising: Speedhub - Rohloff

mtb & Speedhub: are there still brands offering the speedhub on an mtb? I guess not. Too much weight for the rear hub / suspension problems?

but for those where this weight issue is no problem: looks like the Rohloff is as efficient as an conventional drive train. (Without having the maintenance hassle.)

Pinion: they put the additional mass into the correct location.
neat.

I keep threatening to start a dedicated thread or a blog about this but still not got round to it. Seems to align with a few discussions on this thread though.
Interesting to hear the 'mushy clutch' comments on the Alfine. I wonder if that's the actual cause of the flexy feeling when I try to wheelie or sprint - I'd assumed it was twist in the frame - it's probably a combination of both.

Anyway, enough ponderings. Want a low CoM, low unsprung mass, "gearbox bike"? Build one yourself. I give you [i]Alfino Bombino[/i]:

[img] [/img]

andreasrhoen

the consensus is that the rohloff is almost as efficient as a dérailleur once run in and assuming a worn / dirty / averagely maintained drivetrain ( Ie halfway thru a muddy ride) but a brand new properly lubed dérailleur drivetrain is better

are there still brands offering the speedhub on an mtb

Yes there are, not many in the UK, more in Germany (unsuprisingly), mostly hardtails mind...

Interesting to hear the 'mushy clutch' comments on the Alfine. I wonder if that's the actual cause of the flexy feeling when I try to wheelie or sprint

I wouldn't be at all suprised, I can wheelie with the best of them, but on the Alfine it is much harder work to micro-ratchet and control, you basically end up doing a lot of manualling with occasional pwoer application instead, less control from drive and more from weight shift if that makes sense?

Try doing any kind of trials with one! even if you ignore the weight, and torque implications, just trying any kind of pedal lunges/back hops, gaps or ratchety control moves is a flippin nightmare!

For clarity, I'm not really putting this as a downside for IGH, as it's not it's intended use, but it is comical just how awful my Alfine feels for that kind of stuff.

Sick just announced they now need to get stuff made abroad to make a living.

Paul@RTW - Anyway, enough ponderings. Want a low CoM, low unsprung mass, "gearbox bike"? Build one yourself. I give you Alfino Bombino:

More info please.

the rohloff is almost as efficient as a dérailleur once run in and assuming a worn / dirty / averagely maintained drivetrain

I have to express my scepticism there.

More info please.

I will get round to writing about it in more detail at some point but in summary, I got bored of waiting for a usable gear box type trail bike so decided to build my own. Without getting away from the OP's theme too much, the intention was getting the mass central and low and the unsprung mass as low as possible. So it wasn't about creating a gear box bike as such or even using an Alfine instead of derailleurs, more, how do you get this hunk of gubbins off the rear wheel. So it's an Alfine, sandwiched between your ankles, driving the rear wheel. Frame is made using the cold cure carbon composite wrapped foam method(as has been described on here by various others).

OK new thread on the Bombino please with lots of pictures! Lots of interesting stuff just from that one photo. 29er? How short is the back end? Funnily enough I was doodling a frame yesterday with a skewed parallelogram back end to keep short stays and a rearward axle path......

Welcome to the STW club of backyard framebuilders 🙂

Welcome to the STW club of backyard framebuilders

I thank you. I have been here a while, popping up on threads here and there, I've just never really flashed any of my wares before. I will sort some more info out asap.

So that graph shows the epicyclic Rohloff to be more efficient than the Pinion?
I'm in the market for a new hardtail to commute on this year, currently using a Chinese carbon 26" frame with a Rohloff.
It'll be either a 29er with the Rohloff rebuilt into a bigger rim or a gearbox bike probably Pinion.
That Olson websites not good.

Anyone seen or tried the "French Pinion"?

Looks to be lighter and has a rather nice one piece fixed rear hub.
https://www.effigear.com/gearbox

Rather nice full bikes
https://www.cavalerie-bikes.com/copie-de-page-d-acceuil