http://www.dynamicbicycles.com/bicycles/switchbackelite8.php

The benefits…maybe?
http://www.dynamicbicycles.com/chainless-technology/shaft_v_chain.php

more like the past. Been about for yonks…

Will allways be less efficient than a chain. turn the drive thru a right angle twice

easy-to-read gear indicator

Have to get me one of them then!

I used to have a motorbike with shaft drive and that was quite good.

I quite like the look of this though: Not shaft but v belt.

http://www.milkbikes.com/bikes/adl-all-day-long/

Aye, for the sort of bike that can take 1200cc and still only make 100bhp, shaft drive probably doesn’t seem too stupid.

Always think you can tell a lot about this sort of product by the test bike it’s bolted to.

The Cardiff version of Boris bikes are shaft drive.

I had a good look at that Milk bike at the Bristol Bespoke bike show. And I liked it.

that japanese no brand shop(?) used to sell shaft drive bikes about 20yrs ago.

2wheel drive is the future(also done many years ago)

i seem to rememberer a 2 wheel drive full sus one from a few yeas ago

Chains cost 5 quid, last a long time and don’t lose much power at all.

Why would anyone want to fix that?

Chains cost 5 quid

Do they?

I should think that chains cost less than £5, what they sell for is something else entirely!

whoever built that milk needs a stern talking too. the routing of that alfine cable blows goats. they put that out to promote sales? 😯

Del please think before typing?

Shame the frame looks a bit duff…but they had to make a proprietry frame for hopefully obvious reasons.

Does anyone have figures for the loss in efficiency? Thought not.

i looked at the picture and thought ‘the way they routed that cable looks crap’.
they could have played around with the non-turn washers and routed it much more neatly. if you’re looking to put something in the public domain to promote sales, to my mind, it makes sense to get it right.
shame because the rest of the bike looks quite nice.

This thread needs more Issac Hayes.

Damn right!

1896 first shaft drive….up there with rubber band drive,ineffiecent for amount of torque you will ever put thru,good ol filthy dirty nasty chain 98.5 percent effiencent.

I quite like the idea and looked into but it is inefficient and potentially fragile (if you want light weight) and there is a problem with frame flex and keeping the gears meshed correctly. There are ways around it butwill add complexity, cost, weight etc and it will be harder to fix out on a ride.

I don’t get belt drive either. Every situation I have had belt in I hate them (racing RC cars, engine timing belts etc etc

mental as #%¥*

Done to death in motorcycling….the figures speak for themselves, a shaft drive set-up loses significantly more forces through that arrangement than a chain and sprocket system, which i believe only loses around 5% of the energy put in at the engine or pedals.

Done to death in motorcycling….the figures speak for themselves, a shaft drive set-up loses significantly more forces through that arrangement than a chain and sprocket system, which i believe only loses around 5% of the energy put in at the engine or pedals.

Without the normal STW sarcasm, I’d genuinely like to read studies that compare chains and shafts. I’d have thought a lightweight ‘cable’ drive, rather than solid shaft, as used on motorcycles, would be a very good alternative to the chain.

Ignoring that metals have gone up in price significantly over the past few years, I would have thought a small transfer box/diff at the BB & hub, which would then slide on a splined hub that provides the gear ratios, would be an easy proposition for a progressive engineering company. In my head its made of Ti, fully sealed, which would then reduce the need for masses of heavy lubericating oil.

Del, what’s wrong with the cable routing?

untidy for one thing, but also hangs down from the open end at the hub, which will allow water to gather, and the cable to become contaminated.
to be fair, you’ll see it on a lot of alfine installs, but it doesn’t take much effort to do it right.
all, obviously, IMO. YMMV, etc. etc.

http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=10063
I haven’t got my copy with me.I seem to recall a clean chain losing about 3%.small sprockets are quite inefficient though.small is smaller than 16.anyway.shaft drive loses much more, 15%?plus the machining has to be more precise.
now,cable drive…
it’s all there.you can find it on amazon.best cycling book ever.

mildred – Member

I’d have thought a lightweight ‘cable’ drive, rather than solid shaft, as used on motorcycles, would be a very good alternative to the chain.

I believe the issue really is the bevel gears – you need to turn the drive thru a right angle twice – to keep it compact and light they need to be small and this is where the power gets lost.

They reckon it’s as inefficient as a dirty chain with an acute chain line. But they’re using Alfine, so if you were comparing like with like you’d have to compare direct chain lines that you’d get with a chain drive Alfine. Belt drive ftw, like I said.