..you have nothing to lose but your chains..

[mrcharly-YHT]

Think a chain looks better anyway 

I agree with you there. Until the chain, sprockets, etc get covered in thick black greasy grundge.

[Euan Uzami]

But the dirtier it gets the more satisfying it is to clean it

The belt is in no way any more immune from dirt than a chain, it's just black to start off with :-/

[Chris N]

Belts don't need oil (which attracts dirt) and they don't wear or stretch as much as a chain.  The sprockets, rings, gearing options and frame designs are restrictive.

Chains are more easily fitted and modified, plus the technology is mature (in this application) but do need protection or regular maintenance.  They're probably lighter once you take into account a multiple geared set up too.

[AndyK]

Timing belts replaced timing chains in Internal Combustion Engines years ago.

complete bollocks. The last two cars
I've had have got chains, and no they're not that old.
The only difference is that the chain doesn't need replacing every 60k miles.

I worked in Ford Dagenham for twenty years. Cars have had timing belts for at least 25 years.

Some may have, fords for example.
Certainly not all.
Mercs, bmw have chains, and ime apparently also my Toyota.
My cars definitely got a chain I'll tell you that for a fact.
In fact, the need for a costly operation at 60k miles on pain of the possibility of the engine exploding is imho a very good reason to opt for a car with a chain as opposed to a belt.

A snapped timing belt would only cause damage on an interference engine. The majority of engines are non-interference, so a snapped belt will simply cause the engine to stop.

[Asterix, the former Gaul.]

My understanding is that modern engines are

a) non-interference (therefore belt failure not an engine wrecker)
b) chain equipped (therefore more longevity)

However, the comparison bicycle drive belts with car timing belts is not a valid one.  My car runs at thousands of rpm for tens of thousands of miles using huge amounts of power.  My legs run at tens of rpm for relatively few miles and their power is feeble (I admit it).

What is more, car timing chains are protected from the elements and probably superbly lubricated all the time.  Bicycle chains are inadequately lubricated and thanks to oil, pick up all the crud going.  They live in total squalor.

Anyway, I have now been out for several spins on the new machine and can say it is a great ride.  My only criticism being that the straight handle bars are too wide.  I must find my pipe cutter.

[inc]

Diesels are mostly interference engines, last year diesel car sales exceeded petrol in the UK and if you include commercial; vehicles I can't see that the majority  of vehicles have non-interference engines.

[mzjo]

Diesels are mostly interference engines, last year diesel car sales exceeded petrol in the UK and if you include commercial; vehicles I can't see that the majority  of vehicles have non-interference engines.

1. The internal combustion engine is an evolutionary dead-end.
2. This is a cycling forum
Therefore the more engines that break their belts, die and persuade people that there might be a better way is probably in all our interests.

[clarion]

*wonders*

How easy would it be to fit a Gates Drive sprocket to a Sturmey Archer S3X?

[LittleWheelsandBig]

Seriously not cheap.

[PaulF]

*wonders*

How easy would it be to fit a Gates Drive sprocket to a Sturmey Archer S3X?

The guy who won this years Tour Divide did it with a Gates/Rohloff combination so I guess it's possible.

[mark]

A snapped timing belt would only cause damage on an interference engine. The majority of engines are non-interference, so a snapped belt will simply cause the engine to stop.

My understanding is that the majority of engines today are interference. Crevice-free combustion chambers (no relief cut into piston tops for valve clearance) for the cleanest and most efficient combustion, and high valve lift and/or duration for better breathing. I also understand that car makers are going back to timing chains to reduce vehicle maintenance costs. My '95 Honda had a timing belt, my 2006 Honda has a timing chain.

back to the subject, a belt drive sounds interesting, but a chain drive with hub gears and a lightweight chain case fully enclosing the drive train would seem to offer the low maintenance of a belt drive/hub gear combo at a lower cost. The chain drive would be at least as efficient, too.

[Graymee]

This might be of interest.

http://forum.ctc.org.uk/viewtopic.php?f=5&t=62174&hilit=belt+drive

[TimO]

This might be of interest.

http://forum.ctc.org.uk/viewtopic.php?f=5&t=62174&hilit=belt+drive

... Seatstay break was put in by me with a hacksaw & I tigged an ally piece to one side with c/sunk M8 for bolting together. ...

I don't think I'm about to hacksaw a brand new frame in two, so I can bolt it together after fitting the belt!

[Bledlow]

Timing belts replaced timing chains in Internal Combustion Engines years ago.

complete bollocks. The last two cars
I've had have got chains, and no they're not that old.
The only difference is that the chain doesn't need replacing every 60k miles.

Just noticed this. When we last bought a new car, in 2006, it had a timing chain, not a belt, & according to the list on Honest John, the number of models with chains has been increasing for several years. check new Micras, Almeras, Minis, Yaris - loads 'n loads of 'em.

[Cudzoziemiec]

Desmodromics are clearly what we want. I'm sure Sturmey are working on a Desmo-hub right now.