Chain Free

link1896

Mr Greenfield
8 hours on Ceramic Speeds 5 axis mill. Sell the BMW to afford the carrot grater.

Err, no idea yet how to achieve synchronised shifts up/down in/out. Sorry, spells prototype with no solution yet.

I smell vapourware.
 
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Nambra

Definitely should have gone to specsavers
How would it go with a full sus mtb... single pivot around the BB centre? Maybe Orange will do one.
 
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stirk

Burner
They forgot how to manage side load in their efforts to try and make the bike look good and light weight, orange give no fucks for their bikes looks or weight so if anyone could pull off such a drive train maybe orange could.
 
Z

Zaf

Guest
They forgot how to manage side load in their efforts to try and make the bike look good and light weight, orange give no fucks for their bikes looks or weight so if anyone could pull off such a drive train maybe orange could.
Why not put the gear plate on the crank and have a single ratio to the rear?

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discofrank

Likes Dirt
gbox wins again, i bet that weighs more than the pinion

ohh i also have less gears and more range...

plus all the roadies i see that have twin rings have 1 tiny and 1 HUGE front ring to what i pressume is to avoid gear overlap
even then, with di2 and etap you can program the shifter to skip to the next lowest / highest gear hell you can do this and only have 1 shifter too !
 

Calvin27

Eats Squid
Every time I have wld dreams to build another franken bike again, I go back to this chart:


Having owned a nuvici and alfine, the rohloff is the only one that shows promise but is still prohibitively expensive and heavy (I'd prefer weight around bb than wheel). Would i give this mince meat plate a shot? Nah custom frame would usually kill it. Unlike the pinion, you can't just hack and existing frame either.
 
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Zaf

Guest
@Calvin27 It's a really interesting blog that (for those who haven't had a look over it http://fahrradzukunft.de) it's worth a read.

For those reading the chart and seeing two graphs per drive assessment, they're the 50W and 200W inputs. So you'll see that across the board with these styles of drive they become more efficient under heavier pedal loads and less when "spinning out".

He does go on to show that the idling power losses in the Pinion gearbox are exacerbated at low watt/high cadence inputs, this chart shows power at different cadences (60, 90 and 120 RPM without a chain attached), this is what's lost through friction seals and bath splashing onto the gears alone.


Be interesting to see what his test bench comes out with on this new Ceramic Speed thing in comparison to the others.
 

Calvin27

Eats Squid
Be interesting to see what his test bench comes out with on this new Ceramic Speed thing in comparison to the others.
I think it will prove the higher efficiency claims. But with all things, for how long? The mechanism looks like it needs to be precise as anything. One of the advantages of gearbox type transmissions is actually the sealed system. 5% might seem like a huge gap, but chuck some mud on there and add a bit of chain stretch within tolerance and it starts to fall fast. I don't know how many times I've taken my clean drivetrain and it's gone to crap within 10 minutes of riding.
 
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