chain angle and efficiency

I have a 3x8 setup which is designed to let me ride almost 100% of the time in the middle ring. I like this.

However, the angle of the chain when using middle ring and the upper half of the cassette seems a bit extreme, is this ever a problem?

Will the chain wear faster? Will I lose some energy to friction?

Re:

Yes and yes, but both so little you won't really notice it.

Re:

You raise some interesting questions. A few years ago with the advent of the '10 speed racer' having a 2 x 5 design, instead of the supposed
10 different speeds,in many cases you had in fact only 6 speeds due to the duplication of gear ratios.
It would be worth a bit of research on your part to make a list of the gear ratios available with each of the front rings that you have. I am sure
that you will find near duplication of many of the alternate combinations. This means that you don't really have 24 different speeds at all !
I would suggest that the sensible use of a 3 x 8 set up would be the use of the 4 largest sprockets with the inner chainring, the 4 middle
sprockets with the middle chainring and the 4 smallest sprockets with the outer chainring. This will give you 12 speeds ( there may still be
some duplication ) with a minimum of wear to the chain, chainrings, front mech cage and lower jockey wheel.
Finally you should check your chain line to make sure that there is no side to side chain deflection when it runs from the middle chainring
to the middle sprocket

Re:

Are you sure the bottom bracket axle is the correct length for the chainset that's fitted?

Re:

This is the problem with a 3 ring trick - there's a very fine optimum chain line and when the chain has to work harder and bend out of line across the far ends of the gears, it is inevitably going to be less efficient, possibly cause chain suck, etc and cause wear to the whole drivetrain. Really, there's only a few gears that you ever use most of the time. Bitd, it was 3 rings but all those gears choices were unnecessary really. I'm now on just one and life is a lot easier. When on the middle ring, the chain should ideally be running in an optimum straight line from the cassette. Why not try a wide range 8speed with either 34 or 36 to 12 teeth on a single ring?

Re: Re:

groovyblueshed":o89wkkcs said:

This is the problem with a 3 ring trick - there's a very fine optimum chain line and when the chain has to work harder and bend out of line across the far ends of the gears, it is inevitably going to be less efficient, possibly cause chain suck, etc and cause wear to the whole drivetrain. Really, there's only a few gears that you ever use most of the time. Bitd, it was 3 rings but all those gears choices were unnecessary really. I'm now on just one and life is a lot easier. When on the middle ring, the chain should ideally be running in an optimum straight line from the cassette. Why not try a wide range 8speed with either 34 or 36 to 12 teeth on a single ring?

Click to expand...

Thanks. At the moment I've got an 11-34 8 speed cassette with a 30 t front middle ring (and outer and inner rings there just in case, because weight is not a problem). I'm planning to break a Deore 9 speed 12-36 cassette to make my own custom 11-36 8 speed cassette, which should give me a de facto 1x8 set up which I can use on all possible off road gradients.

Re: Re:

ultrazenith":381u4uio said:

groovyblueshed":381u4uio said:

This is the problem with a 3 ring trick - there's a very fine optimum chain line and when the chain has to work harder and bend out of line across the far ends of the gears, it is inevitably going to be less efficient, possibly cause chain suck, etc and cause wear to the whole drivetrain. Really, there's only a few gears that you ever use most of the time. Bitd, it was 3 rings but all those gears choices were unnecessary really. I'm now on just one and life is a lot easier. When on the middle ring, the chain should ideally be running in an optimum straight line from the cassette. Why not try a wide range 8speed with either 34 or 36 to 12 teeth on a single ring?

Click to expand...

Thanks. At the moment I've got an 11-34 8 speed cassette with a 30 t front middle ring (and outer and inner rings there just in case, because weight is not a problem). I'm planning to break a Deore 9 speed 12-36 cassette to make my own custom 11-36 8 speed cassette, which should give me a de facto 1x8 set up which I can use on all possible off road gradients.

Click to expand...

Yeah! This is a project I'm looking into too. My old Clockwork has quite a tight chain line. With 2 or 3 rings it was a right chore having to keep it in tune regularly. After various trials, I've gone back to a 7speed which now properly syncs with old indexed 7speed thumbies. Obviously, 1x7 is limited but it covers most of my current riding apart from long steep or technical climbs where I might run out of grunt. The custom cassette could well be the way forward...