Why no 50/36 compacts?

neeb
neeb Posts: 4,470
edited March 2010 in Road buying advice
Until a year or two ago Campagnolo were offering 50/36 chainrings as an option on their compact cranks, as an alternative to 50/34, which now seems to be the only option offered by the major manufacturers. The problem with 50/34 is the big jump between the two rings, which is a little disconcerting, especially when shifting to the small ring. With 50/36 on the other hand, the difference in the actual gear (gain ratio, gear inches or whatever) between the big ring and the small ring is nearly the same as with a 53/39, and much more comfortable. The percentage increase going from the small ring to the the big ring is 35.9% for 53/39, 38.9% for 50/36, but 47.1% for 50/34.

I have been running a 50/36 with an 11-23 cassette for 2 or 3 years. Actually, this is practically identical in all respects to the “standard” 53/39 setup with a 12-25 cassette. Not only is the total range of gears practically the same, the range on any given chainring is too, so you will spend the same percentage of time on each ring and use the gears in exactly the same way (yes, the top gear is actually very slightly higher, but not by a meaningful amount and this is the biggest difference!). The advantage of the 50/36, 11-23 setup over 53/39, 12-25 is the extra flexibility for adding lower gears if you need them, by swapping the cassette or temporarily using a 34 ring. There is also a slight weight advantage, because you are using smaller cogs, smaller rings and less chain. But I’ll get on to that in a minute...

Because the 50/36 combination seems to be no longer supported by Campagnolo, I have decided in the end to go for a standard double with the new 11sp groupset I am getting (53/39 with 12-25 cassette). I don’t want the hassle of having to look for 3rd party, possibly inferior chainrings. It’ll just mean that if I go to the mountains I’ll have to slap on a 12-27 cassette instead of a cheaper 34T front ring. Also, it seems that with 11sp the weight advantage of using a 11-23 cassette instead of 12-25 is effectively absent – about 6g rather than 20-30g with 10 speed! (weight differences due to the rings and chain are tiny). There is also the advantage of possibly less wear, as well as the cool factor – let’s face it, a standard double just looks a little more macho :-)

I do think that the 50/36 combination is possibly ideal though, and wonder why it isn’t being marketed by the big three. 50/36 could potentially replace both standard and compact cranks and become a new universal standard. Although it seems as if 50/34 is being specced on a majority of new bikes these days, I'd prefer not to use it myself as a normal setup due to the jump between the rings.

Comments

  • Anonymous
    Anonymous Posts: 79,667
    You can always get new chainrings.

    SRAM offer a 50 36 now anyway...
  • I've had both and can safely say I noticed bugger all difference between 50/36 and 50/34.
  • Smokin Joe
    Smokin Joe Posts: 2,706
    I hate 50/34 for the reasons in the OP. My Mirage chainset on the winter hack came with 48/34 and I bought a TA 36t ring to swap with the 34 on my best bike to give 50/34.

    Next time I need a chainset I will probably go with Stronglight as they offer all the options off the shelf.
  • Anonymous
    Anonymous Posts: 79,667
    Smokin Joe wrote:
    I hate 50/34 for the reasons in the OP. My Mirage chainset on the winter hack came with 48/34 and I bought a TA 36t ring to swap with the 34 on my best bike to give 50/34.

    Next time I need a chainset I will probably go with Stronglight as they offer all the options off the shelf.

    I have Stronglight CT2s on one bike, 52/37. Brilliant!
  • Stop crying about the gap. learn to shift properly or leanr to spin/grind a bit

    if you shift to a smaller cog on the back just before going to 34 and vice versa then the gap is tiny. sometimes I shift twice on the back while changing but it is usually not needed.
  • neeb
    neeb Posts: 4,470
    Stop crying about the gap. learn to shift properly or leanr to spin/grind a bit

    if you shift to a smaller cog on the back just before going to 34 and vice versa then the gap is tiny. sometimes I shift twice on the back while changing but it is usually not needed.

    Yeah, I know how to shift properly and I do exactly what you are saying when I'm using a 50/34. Point is that with a 50/36 you don't have to, or it's less of an issue.
  • maddog 2
    maddog 2 Posts: 8,114
    am I missing something...

    just buy a 36 ring.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • neeb
    neeb Posts: 4,470
    am I missing something...

    just buy a 36 ring.
    I have never seen a Campagnolo 11 speed 36T ring, or any evidence that they exist. There are the TA Nerius rings, which I considered, but I'd rather use Campag rings if possible, you never know how well 3rd party rings are going to work as regards shifting performance or durability.

    Yes, I know some people say the 10sp rings work with an 11speed chain, but then others claim that the chain can occasionally jam hard between the rings...

    Good for SRAM for introducing a 36 option though, I didn't know that.
  • mrushton
    mrushton Posts: 5,182
    It's a 36 tooth ring (campag or compatible) you require. Doesn't matter whether it's 9/10/11 speed as long as it's the right BCD and has the offset bolt. Campag rings are expensive. I'm of the opinion that most of s could mange on 48/36 0r 48/34 and use a suitable cassette for the terrain.
    M.Rushton
  • Smokin Joe
    Smokin Joe Posts: 2,706
    neeb wrote:
    am I missing something...

    just buy a 36 ring.
    There are the TA Nerius rings, which I considered, but I'd rather use Campag rings if possible, you never know how well 3rd party rings are going to work as regards shifting performance or durability.
    .
    The TA ring I bought shifts exactly the same as the Campag it replaced.
  • neeb
    neeb Posts: 4,470
    Good to know that the TA rings work.
    It's a 36 tooth ring (campag or compatible) you require. Doesn't matter whether it's 9/10/11 speed as long as it's the right BCD and has the offset bolt.
    The story I heard was that it's possible (not likely, but it can happen) for the slightly narrower 11sp chain to get stuck between 10sp chainrings and jam solid. If you look closely at the Nerius 11sp inner ring, the teeth are slightly offset towards the larger ring in relation to the part of the ring that's attached to the crank arm. Similarly the campag 11sp outer ring has a moulded profile that I am guessing brings the outer teeth a tad closer to the inner ring. In both cases, the rings seem to be designed so that when they are mounted to the crank arm, the gap between the teeth of the inner and outer rings is fractionally narrower than the gap between the mounting points of the rings. I am guessing campag did it this way because it was cheaper to redesign the rings for the narrower 11sp chains than to remould the crankarm (which also means that the crankarms at least are 100% interchangeable between 10 & 11sp).

    But then I've also heard plenty people say that 10sp chainrings are fine with 11sp chains. It could be one of those situations where it works 99.9% of the time...
  • Stevo_666
    Stevo_666 Posts: 59,829
    As mentioned above - SRMA do one. The Truvativ crank on my Hybrid is a 50/36.
    "I spent most of my money on birds, booze and fast cars: the rest of it I just squandered." [George Best]
  • rickhotrod
    rickhotrod Posts: 181
    With an 11 speed 50/36 11-23 combination, you need to make 4 rear shifts when you do a front shift. ie. 50/19 to 36/15 and vice-versa.
  • freehub
    freehub Posts: 4,257
    What's wrong exactly with the jump between 50-34? Never had a problem here, seems to work, I have 50/36 on my commuter and also notice not much diffo, I might be able to get an extra couple of mph in the little ring when spinning furiously but then I'd be in little/little.

    I love my 50/32 goes everywhere, on hills I use like 34-21 or 23 everywhere, it's got a 25 ring like. Using a 36 would give me no benefit.
  • maddog 2
    maddog 2 Posts: 8,114
    couldn't comment on the 11-speed thing but 8/9/10 is all interchangeable in my experience.

    As for shifting, the small ring is much less important for shifting than the big one IMO. Dropping down onto the small ring it is pretty straightforward and shifting back up onto the big ring has much more to do with the shape of the big ring (contours, tooth design etc.) than the shape of the teeth on the small ring, in my experience.

    In other words, I've run small rings with not cutouts or fancy teeth design at all and the shifting is spot on
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • Chris James
    Chris James Posts: 1,040
    mrushton wrote:
    I'm of the opinion that most of s could mange on 48/36 ... and use a suitable cassette for the terrain.

    My mate has just specced exactly this on his new bike. Very sensible for general riding, and he is definitely no slouch.
  • neeb
    neeb Posts: 4,470
    What's wrong exactly with the jump between 50-34? Never had a problem here, seems to work, I have 50/36 on my commuter and also notice not much diffo, I might be able to get an extra couple of mph in the little ring when spinning furiously but then I'd be in little/little.

    I love my 50/32 goes everywhere, on hills I use like 34-21 or 23 everywhere, it's got a 25 ring like. Using a 36 would give me no benefit.
    Nothing wrong with 50/34 as such, it's just that compared with a 50/36 there is effectively an extra gear's difference when you swap between the rings. A lot of people, myself included, find this gap just a little more than is ideally comfortable. It just takes a tad more faffing when you are changing down if you are to avoid the gearing getting outside of your upper cadence limit and feeling like your chain has just fallen off... :wink: Personally I find that a 36 instead of 34 makes all the difference, but I guess it will depend on natural cadence, preferred shifting habits etc.

    A lot of people say that they really notice the difference between a 53/39 and a 50/34 in this respect. According to the numbers, it should be the case that a 50/36 feels like a 53/39 rather than a 50/34, if appropriate sprockets are fitted.
  • redddraggon
    redddraggon Posts: 10,862
    neeb wrote:
    What's wrong exactly with the jump between 50-34? Never had a problem here, seems to work, I have 50/36 on my commuter and also notice not much diffo, I might be able to get an extra couple of mph in the little ring when spinning furiously but then I'd be in little/little.

    I love my 50/32 goes everywhere, on hills I use like 34-21 or 23 everywhere, it's got a 25 ring like. Using a 36 would give me no benefit.
    Nothing wrong with 50/34 as such, it's just that compared with a 50/36 there is effectively an extra gear's difference when you swap between the rings. A lot of people, myself included, find this gap just a little more than is ideally comfortable. It just takes a tad more faffing when you are changing down if you are to avoid the gearing getting outside of your upper cadence limit and feeling like your chain has just fallen off... :wink: Personally I find that a 36 instead of 34 makes all the difference, but I guess it will depend on natural cadence, preferred shifting habits etc.

    A lot of people say that they really notice the difference between a 53/39 and a 50/34 in this respect. According to the numbers, it should be the case that a 50/36 feels like a 53/39 rather than a 50/34, if appropriate sprockets are fitted.

    Will doesn't know about the gap between 50 and 34, because he can do everything in the 50T ring.
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  • Mossrider
    Mossrider Posts: 226
    I'm with you on this Neeb, I also ride 50/36 with a 11/23 cassette (in hilly West Yorkshire) keeping a 12/25 for sportives / Alpine trips etc. It gives the perfect range with the minimum faffing. I'm always afraid if I drop to a 34 I'll just get lazy on the hills....

    Come on campag, re-introduce the 50/36,