22 spd MTB

RichMTB

There is a very good reason 95% of bikes run a chain - cassette and deralieur set up - effeciency.

Internal hubs aren't too bads in this regard, but the weight and cost is a big drawback. Belt drives and planetary gear crank sets suffer from poor effeciency and did someone mention CVT its about the most ineffecient drive system ever concieved it works by constantly slipping.

When you are dealing with a vehicle that has (unless your name is Lance) about 0.3 of a horsepower efficiency is king

bomberesque

RichMTB wrote:

There is a very good reason 95% of bikes run a chain - cassette and deralieur set up - effeciency.

I would argue that the real decider is availability but there you go.

Anyone have a link about relative efficiency? I think it's overstated frankly, but I don't know for sure. I've certainly never heard complaints about belt drive efficiency, you got a link for that?

onto cost; an alfine hub is 200 ish Euros. Total what it's replacing and the gap is not what some think it is, especially when you factor that yo're not replacing the chain every 3 months (in fact mine ran a year, albeit on the road, between chains)

as for weight, you're all right that hub drives are currently heavier than a deurallier setup, but let's not forget that this is only the 2nd gen Alfine we're seeing and already they seem to be able to put 11 gears in the same weight as 8 were in before.

is the new alfine smaller gaps or bigger ratio spread and, if the latter, can it replace 3x9? If so then you can add the large ring, granny ring and front deurallier/cable and shifter to the weight calc. It'll still come out in favour of deuralliers for now but this idea has legs, so long as the development is there. In the end it wants to be in the frame not the hub, but one step at a time....

ride_whenever

There is plenty of weight to come off certainly. You could go mental with schlumpf drive, 4 rings, a rohloff and g-boxx. But why would you want to?

pypdjl

Cat With No Tail wrote:

I have to say, Imo the only application I can see for the 11sp Alfine hub at the moment (considering the 8sp one does a perfectly good job, albeit with some large gaps), is going to be the fat bikes, where the extra durability afforded by internals will *sometimes* outweigh such a massive weight penalty

The quoted weights for the 11sp alfine are no different to the current 8sp one, so there is no additional weight penalty.

pypdjl

RichMTB wrote:

Internal hubs aren't too bads in this regard, but the weight and cost is a big drawback.

Cost is hardly an issue compared to replacing chains, cassettes and chainrings...

cat_with_no_tail

pypdjl wrote:

Cat With No Tail wrote:

I have to say, Imo the only application I can see for the 11sp Alfine hub at the moment (considering the 8sp one does a perfectly good job, albeit with some large gaps), is going to be the fat bikes, where the extra durability afforded by internals will *sometimes* outweigh such a massive weight penalty

The quoted weights for the 11sp alfine are no different to the current 8sp one, so there is no additional weight penalty.

My bad, didnt know that. I had assumed that the 11sp one would be heavier.

Goes to show what they say about assumptions is true though :oops:

bomberesque

btw, I'm bored at work so I looked up some ratios for comparison;

Deuralliers;
3x9 (22/32/42 & 11-34) = 590%
2x9 (22/36 & 11-34) = 506%
2x9 (22/32 & 11-34) = 405%
1x9 (32 & 11-34) = 309%

Hub gears
8sp Alfine = 307%
11sp Alfine (apparantly) = 430%
14sp Rolly = 526%

So reasonably the 11sp Alfine could replace a 2x9 setup, meaning;

hub
casette
deurallier
section of chain
granny ring
front deurallier, cable and shifter

I'm going to say 1kg for that lot meaning 5-600 gr additional weight compared to XT, although you still don't get quite the spread you have with a 22/36 2x9 setup

price rumoured to be 400 USD for the hub & shifter, which is quite a lot more than 8sp Alfine (at least more than street), not sure how that would compare to XT MSRP.

supersonic

Atz wrote:

Got to remember that with this new one you'll be swapping it for two mechs, one shifter and a good length of chain so the increase is likely to be 3-400g

Not always though, many will run it single cog, and the Alfine requires a shifter too. Chain difference will be about a foot of chain.

supersonic

pypdjl wrote:

RichMTB wrote:

Internal hubs aren't too bads in this regard, but the weight and cost is a big drawback.

Cost is hardly an issue compared to replacing chains, cassettes and chainrings...

You still have to replace chains, rear cogs and chainrings with a hub gear system!

supersonic

Efficiency - Wiki quotes typically between 82% and 92% - chain drive with mechs is 88 to 99%.

Chaz.Harding

RichMTB wrote:

When you are dealing with a vehicle that has (unless your name is Lance) about 0.3 of a horsepower efficiency is king

I got measured on one of them ''Watt bikes'' - my Horsepower is 1.68, thankyou!!

Not sure about torque, but I read somewhere that a journalist (not specifically a cycling journo) tested a Powertap (or similar) system, and he said his torque was more than a Ford Feista diesel, at somewhere around 80lb/ft...!

I'd be quite interested in my torque reading - I assume it would be quite alot - I like to grind gears, rather than spin 8)

supersonic

Power is a function of torque and revs. Many of us can produce high torques - but can we rev at 8000 rpm lol.

Chaz.Harding

Yup, which is why I'd guess I have alot of torque

You saying you CAN'T spin at 8,000 RPM...? :shock:

supersonic

Well not me pedals -)

RichMTB

I got measured on one of them ''Watt bikes'' - my Horsepower is 1.68, thankyou!!

Thats over 1200watts, if you could sustain that effort you'd be on the top step of the podium at the olympics

biff55

supersonic wrote:

but can we rev at 8000 rpm lol.

with enough sugar and amphetamines , no prob.

Chaz.Harding

RichMTB wrote:

I got measured on one of them ''Watt bikes'' - my Horsepower is 1.68, thankyou!!

Thats over 1200watts, if you could sustain that effort you'd be on the top step of the podium at the olympics

Where did I say I haven't been on the top step of a podium...?

pypdjl

supersonic wrote:

You still have to replace chains, rear cogs and chainrings with a hub gear system!

Yes, well spotted. However you can, of course, run SS chains and steel rings sprockets with big teeth, thus vastly increasing the average lifespan of the components. Then you can also flip the rings/sprocket when they are worn, as they have no shifting ramps. Price of a gusset sprocket ~ 5 quid, price of an XT cassette ...?