42th Middle ring to 40th

[Nigelnaturist]

Would this cause any problems on a Sora triple set up 30-42-52.

 

[Crackle]

You mean changing it to a 40. No but that isn't much of a change and you'll need a specific ramped middle ring or it won't work.

 

[Nigelnaturist]

You mean changing it to a 40. No but that isn't much of a change and you'll need a specific ramped middle ring or it won't work.

Thanks for getting back.
Why wont it work with out a ramped middle ring, did triples and doubles in the past not have ramps, and I have run the same chainset with 30-38-48 without ramps on any of the rings, I mainly just wondered if the extra 2th jump from 40 to 52 would be a problem (guess I should have been clearer), I generally only ride on the middle and outer rings, and with upgrading the rear from 8 to 9sp, I was thinking because I will now have a lot closer grouping on the rear, by dropping a little on the front I could get better gear rangers, current 30-42-52 13/15/17/1921/23/25/28, but looking at 30-40-52 and 13/14/15/16/17/19/21 then either 23/26 or 24/28, depends what rear cogs I have that will fit.
The new cassette is an HG50 13/25.

 

[Crackle]

Have you tried moving from the small to middle without a ramped middle, assuming that your chainset is currently ramped, not all are but the ring spaing is different.

You front derailleur will have a maximum tooth difference which should be specified on the tech. docs but it generally doesn't matter for a middle.

 

[Nigelnaturist]

Have you tried moving from the small to middle without a ramped middle, assuming that your chainset is currently ramped, not all are but the ring spaing is different.

You front derailleur will have a maximum tooth difference which should be specified on the tech. docs but it generally doesn't matter for a middle.

I did when I first started, as I put a 38 and 48 on instead of the 42/52, it worked, I appreciate that the ramps help shift the chain up.
From the top of my head max difference is 22th.

It won't work so well. The changes would be a bit slower etc. It is up to you to decide how important that is.

It really would only be shifting from the small to the middle after a climb I couldn't do on the middle. which around here isn't very often, it depending on the rear but lets say 21/24/28 the only lower gears than the 40x28 would be the 30x24 and 28.

 

[byegad]

It will work without the ramps, but they make for slicker changes. My trikes have a mix of ramped and plain rings over greater ranges than yours, they all change satisfactorily. Changing from ramped to plain middle and outer rings on a 26 39 50 upgraded to 26 40 52 made not a jot of difference to changes on the road, although on the work stand the ramps did seem a lot slicker.

 

[Nigelnaturist]

@Crackle @User and @byegad thanks for the input guys.

 

[HLaB]

Would this cause any problems on a Sora triple set up 30-42-52.

Nope, my sirrus came like that I preferred it, its more usable; on very fast club runs I could spin fast in the middle ring, the 34 on a lot of compacts is too small for my liking and only good as a reserve for hills.

 

[Nigelnaturist]

Nope, my sirrus came like that I preferred it, its more usable; on very fast club runs I could spin fast in the middle ring, the 34 on a lot of compacts is too small for my liking and only good as a reserve for hills.

This is what my thinking is, and switching from 13/15/17/19 to 13/14/15/16/17/19 will make spinning in these gears a little better, with the better stepping, and with it only costing £25 from chainreations for chain and cassette its not to costly.

 

[Crackle]

The spread makes sense, I changed mine for similar reason but unlike you lot I couldn't stop it dropping the chain going from middle to top and had to get a ramped middle.

 

[Nigelnaturist]

The spread makes sense, I changed mine for similar reason but unlike you lot I couldn't stop it dropping the chain going from middle to top and had to get a ramped middle.

It did work, but i did only run it a while when I first started (June 2012) however the inner ring is a really odd B.C.D. and I wanted a lower ring than 30th so I ended up with a touring chainset on for a while (well about 10 months). So I suppose if I got an unramped one it would be a matter of test it and see.
The brifters have arrived not bad since I only won the auction Sat night. So hopefully stuff from chainreactions will arrive tomorrow.