Here's one for you - why are chains on the right?

[Ray Luxury-Yacht]

I guess this possibly applies to some motorbikes too.

I was idly wondering why all bicycles have the chain and drive-gear on the right hand side.

After a Google round, I am none the wiser. There are many theories from 'keeping the component away from the kerb' and 'the threads on the pedals and bottom bracket' to 'this is just the agreed convention.'

I'm not suggesting this is a problem of course - any standardisation is generally good. However, I wonder if any of you serious bicycle anoraks had a more definitive answer than I have managed to find on Google?!

Be interested to hear ideas and opinions!

Edited by Ray Luxury-Yacht on Thursday 18th September 21:32

[sherbertdip]

Because in the day of screw on cassettes and gears they were RH thread, so the chain has to be on the RHS. If the gear/cassette was on the LHS of the wheel it would be unscrewed.





Maybe......

[Gizmoish]

Tandem f-r cranks are LHS. You're right though, there must be a reason.

[Watchman]

I've just replaced a square taper BB. The threads are such that forward pedalling would undo both sides. I thought that rather odd.

Edited by Watchman on Thursday 18th September 21:31

[D1bram]

funny enough, most motorbikes have them on the left. (I had to think about that despite owning a number of bikes over the years!)

[Dammit]

Watchman said:

I've just replaced a square taper BB. The threads are such that forward pedalling would undo both sides. I thought that rather odd.

Edited by Watchman on Thursday 18th September 21:31

That'd be an Italian BB (not a joke, this is actually true).

[Efbe]

D1bram said:

funny enough, most motorbikes have them on the left. (I had to think about that despite owning a number of bikes over the years!)

yes all of mine have been.

strange

[deadtom]

Most people are right handed so the right hand side is often preferred, so that's how it started and that's how it's stayed [citation needed]

it's probably worth mentioning however that a lot of BMX bikes are left hand drive to make it easier to do grinds and stalls and whatnot on the right hand side of the bike without smashing the chain and sprockets

[deadtom]

Dammit said:

That'd be an Italian BB (not a joke, this is actually true).

surprisingly it is actually the british BB threading that has standard thread on the LHS and opposite thread on the RHS, so does indeed unscrew in the same direction as you pedal.

The Italians are much more sensible(!) and have standard threads on both sides (I think; Italian threads are a road thing and therefore not my area of expertise)

[Watchman]

deadtom said:

Dammit said:

That'd be an Italian BB (not a joke, this is actually true).

surprisingly it is actually the british BB threading that has standard thread on the LHS and opposite thread on the RHS, so does indeed unscrew in the same direction as you pedal.

The Italians are much more sensible(!) and have standard threads on both sides (I think; Italian threads are a road thing and therefore not my area of expertise)

Deadtom is correct. It is indeed a British BB. Shimano UN55.

[Soop Dogg]

Yep - BB has the reverse thread on the right hand side.

Whereas pedals have the reverse thread on the left.

[Dammit]

Wrong way round- if it's Italian then it's slowly backing itself out - have a read: http://en.wikipedia.org/wiki/Precession_(mechanica...

Edited by Dammit on Friday 19th September 10:02

Edited by Dammit on Friday 19th September 10:04

[BMWBen]

Watchman said:

deadtom said:

Dammit said:

That'd be an Italian BB (not a joke, this is actually true).

surprisingly it is actually the british BB threading that has standard thread on the LHS and opposite thread on the RHS, so does indeed unscrew in the same direction as you pedal.

The Italians are much more sensible(!) and have standard threads on both sides (I think; Italian threads are a road thing and therefore not my area of expertise)

Deadtom is correct. It is indeed a British BB. Shimano UN55.

I'm with dammit - unscrewing in the same direction as you pedal means it tightens as you pedal! Yay for engineering!

[Watchman]

That is rather clever. And I particularly love the fact the the British BB has the threads cut in the direction that means they won't undo, which is contrary to most people's (including mine) instincts. Yay - indeed - for (British) engineering.

[TedMaul]

If most folks are right handed, their right leg is strongest and hence it may be more efficient to put that power through the cranks having the power side on the right side.

Maybe whomever designed the Rover Safety Bicycle tossed a coin and everyone else said fk and copied them

[Dr Jekyll]

D1bram said:

funny enough, most motorbikes have them on the left. (I had to think about that despite owning a number of bikes over the years!)

Didn't old British bikes have them on the left? Chain drive BMWs still do.

I thought British bikes were initially developed from pedal bikes so continued to have the chain on the right. Then Japanese manufacturers started from scratch and picked the other side.