• I'm looking into buying new chainrings for a 130 bcd crankset, looking at some TA Alize inner and outer ones. However, on the internet store it says "The manufacturer recommends a difference of 12 to 16 teeth between the largest and smallest chainrings."

    I was thinking on going 40t on inner and and 50t on outer, but have always thought "the less difference the better". What could be the problems with too little difference?

    Also, anybody have experience with the TA Alize rings?


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  • I think you’ll be fine. Any reason you’re going with that particular combination?

    Years ago, and I’m talking about the 1970s, 10 teeth was the usual difference between chainrings (remember 42-52 chainsets, anyone) but that was because derailleurs couldn’t cope with more, not that we didn’t want a wider range of gears.

    TA rings are fine, I bought some TA replacements for my Campag cranks years ago and they’re still going strong.

  • Thanks! Yes, that was why I was confused about the minimum difference, I can't see their reason for recommending the difference being minimum 12 teeth.

    My rear derailleur is a Shimano DA 7800 so the maximum capacity is 29 teeth and max cog 27. So I've already bought the cassette which is 11-28 which exceeds the max cog of 27, but I seen several people saying that's not a problem. However, since I already exceeded the max cog I didn't wanna push the maximum total capacity to the brink, but to stay under the 29 limit (my understanding of derailleurs and max capacity is limited).

    I have a braze on FD which limit the lower the size on the large chainring to over 50. I figured 50/40 instead of 52/42 since I need ligher gears rather than heavier, but I might be able to go 52/40.

  • In the olden days it was common for doubles to be something like 52/46 or even 48, I bought a 70s group with rings like this, so you can hardly see there's an inner ring. I think some TTers rode them like this. This is with chainrings without pins or ramps or any of that modern shifting help jazz.

    I would go as close ratio as you want, see what happens.

  • My 130 bcd crankset has 48/39. The latter is the smallest generally available for these cranks but ISTR TA make a 38 tooth that fits. (but it might be another brand, I can’t remember) if you want to go lower.

  • In the olden days it was common for doubles to be something like 52/46 or even 48,

    In the even older days (which I'm afraid to say I remember only too well) a 3 tooth difference between chainrings was almost universal.

    As a teenager I was given a TA set which were 48/52 and I (foolishly) thought I was really cool with a big gap between the rings. That was until I looked at a gear table which showed that with a block (cassette) which had 2 tooth differences (normal then) the 3 tooth gap filled in fairly neatly between the gears, but my 4 tooth difference caused a lot of near duplications.

    This so called 'half step' system worked tolerably well but it involved too many double changes, which resulted in the use of straight through blocks (14/18 five speed, say) with 10 tooth differences at the front - the modern arrangement is a development from this.

    If anyone wants to use a 3 tooth difference now, I suggest looking for old TA rings, either for the 'Professionel Adapter' or the 'Criterium' type. These are pretty common at cycle jumbles, work well and were intended for small differences. You would need the old 5 pin cranks for these rings, but they are not rare - you could even use ancient steel cottered cranks.

  • Thanks!

    I ordered a 52/40, we'll see how it works out!


  • I think the minimum difference is 1 tooth.

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Minimum Chainring Difference between inner and outer (TA Alize)?

Posted by Avatar for karldub @karldub