Viewing 40 posts - 1 through 40 (of 119 total)
  • What is the point of dual chainrings ?
  • scu98rkr
    Free Member

    I get 1*10 lose weight, clutter + simpler.

    But if your going to the effort + weight of having a front derailler you might as well have 3 gears imo.

    I could see the point of compact ie 22+30+38 say to increase clearance.

    But losing the weight of an extra chain ring is pointless while losing its benefits .

    Also the worst place to have extra weight is on the extremities of the bike ie in the rear wheel.

    So by having a compact triple ie 22+30+38 you could probably get away with having 7 or 8 gears on the back 11-30 this should be plenty for most situations and light weight with some clearance.

    ie
    22-30-38 Front
    11-30 rear (8 speed for weight savings)

    thisisnotaspoon
    Free Member

    So you’re argueing for more chainrings as it’s pointless having the dereilieur and not using it, but also getting rid of some gears at the back for the opposite reason?

    My Pitch is a double (22-38) at the moment, which works fine, why would I want to add a 30t ring when it works perfectly well in 38 for all but climbing?

    RestlessNative
    Free Member

    on the flip side what is the point of a big ring unless you only have dull fire roads to ride?

    bjj.andy.w
    Free Member

    Never used my big ring on my mtb so why have something on your bike that you don’t use?

    TandemJeremy
    Free Member

    I run 36 / 22 chain rings on my bikes – gives me gears from 2.5 to 25+ mph – thats enough for me offroad

    kimbers
    Full Member

    well i had 3 chainrings on my bike but rarely used to the big one and often scraped teeth on drop offs and when messing around
    so i got rid of it

    i didnt try to rationalise it with weight or efficiency savings

    my life is better now because of it

    scu98rkr
    Free Member

    Yes, but having a triple opens up a much larger range of gears than a 2*9 or a 2*10.

    And as I say the weight is better in the middle a 1-36 cassette is pretty heavy and is in the wrong place.

    You dont need to lose the gears at the back its just if your weight obsessed like me.

    If just seems a triple + 7-8 gears opens up the largest selection of gears for the lowest weight. Which is what we started with !

    If they can get a 1*10 (9-36) going that is reasonably light I would change to that.

    Murray
    Full Member

    What’s the difference in weight between a 9 and 10 speed XT cassette?

    t-p26
    Free Member

    but having a triple opens up a much larger range of gears than a 2*9 or a 2*10.

    Really? you can use ALL the gears on a 3×8 or 3×9 set up?? Are you running hinged chains?

    jimjam
    Free Member

    What’s the point of dual chainrings?

    I think the better question is what’s the point of a bash ring? And the answer is it replaces a redundant, dangerous and easily damaged large outer ring whilst increasing ground clearance and chain retention.

    sugdenr
    Free Member

    Yes

    (a) I could abandon my perfectly good low normal 2×9 systems (with bash so I dont severely lacerate my leg when I fall off)
    or
    (b)pointlessly upgrade to hugely expensive 10spd system that only comes in traditional rise flavour

    a,b,a,b,a,b..oh what’s it to be

    Sort of weight saving you are talking about is achieved by 1 less cake this week

    *Currrently stockpiling M970 rear mechs in VGC*

    superdan
    Full Member

    I run doubles because everytime I don’t (when zooming around singletrack on demo bikes mostly) I end up taking some teeth off the outer chainring on a rock/log/wall that I am riding over. This is expensive and tedious.

    So yeah, ground clearance+able to run a bash to avoid chainring tattoos.

    duir
    Free Member

    Dual and bash works really well on the new generation of slack bikes with low bottom brackets and prevents chainring damage on rocks. It also really helps to keep the chain on when you are gunning it on descents.

    mrmo
    Free Member

    your more likely to snap a chain shifting on the chainrings than you are on the sprockets.

    It is lighter to have 2 rings than 3

    you can use a shorter rear mech, so no issues about snagging a longer cage can cause

    2 rings looks neater than 3

    better chainline than 3.

    bigger range than 1 ring.

    Sam
    Full Member

    Wider range cassettes when combined with a double give as good a range of gears as ‘old’ (22/32/44-11/32) and you have to shift less at the front. I find them more practical to use, you never have that ‘shift into the granny – immediate twiddling’ moment. I starting using front doubles back in the late 90’s (was it really that long ago?) when Cannondale and Ritchey started doing them.

    Hob-Nob
    Free Member

    What’s the difference in weight between a 9 and 10 speed XT cassette?

    Not a huge amount. ~300g for a 9spd & ~340g for a 10spd.

    You can get an 11-36 10spd cassette for ~200g if you really want, which is lighter than nearly (or possibly all) 9spd full sized cassettes. So weight isn’t really a concern.

    cookeaa
    Full Member

    But if I fitted a big ring where would put my bash ring?

    I think your labouring under the missaprehension that the really tall gearing you would achive with a 44T is actually useful on an MTB,it’s really not that handy to be pushing 104 gear inches, my bike manages 85 gear inches (36-11 with 26″ wheels) and that’s plenty.

    You’re arguing for more Grrrr gears when what most people seem to want now is sensible ratios and a couple of bail out gears ~18 gear inches? can’t quite be done on a 1×10 setup that’s all…

    juan
    Free Member

    can we sjip to the part where njee and I agree to disagree that we don’t do the same sport?

    _tom_
    Free Member

    Someone find the link to alexxx’s thread with the photo of his friends leg after it’d been mauled by the big ring.

    13thfloormonk
    Full Member

    Yes, but having a triple opens up a much larger range of gears than a 2*9 or a 2*10

    This was my argument against 2×10, until I eventually tried it and realised that without being any fitter, I could still climb with the narrower range of gears offered by 2×10, and was descending just as fast on the descents that mattered.

    better chainline than 3

    Also this. I’m changing gears less at the front, spending more time in the ‘big’ 39t ring and bigger sprockets instead of time in a middle 32t ring and smaller sprockets. Like to think it spreads the wear a bit better.

    scruff
    Free Member

    cookeaa –

    http://www.chainreactioncycles.com/Models.aspx?ModelID=17281

    A product for mong bikes.

    andytherocketeer
    Full Member

    Depends what you ride. It’s not all granny ring fire road up, and hardcore rocky or swoopy single track mostly freewheel down.

    I use every gear from 22×32 up to 42×11.

    No 1×10 set up on the market gives me that complete range. A 2×10 setup might (within rounding errors).

    It is lighter to have 2 rings than 3

    True, but I weigh 100kg, my bike weighs quite a few more kg, and 1 chainring weighs a handful of grams. Swap that ring for a bash and the difference is probably so negligible, it’d be like me deciding whether to pack 1 gel or 2.

    Now if I raced, I may view that differently.

    TandemJeremy
    Free Member

    scu98rkr – Member

    Yes, but having a triple opens up a much larger range of gears than a 2*9 or a 2*10.

    Nope – 2 extra high gears compared with a 22 / 36 double – gears that are only needed on the road

    My 36 / 11 top gear can be easily pedalled to 25 mph and spinning like crazy to 30 mph – thats fast enough for me offroad

    RustySpanner
    Full Member

    I like a triple chainring.
    It impresses walkers, dogs and small children and I can’t ride logs or big drops.

    Oh, always give a prime number when asked how many gears your bike has – pointless, but fun.

    randomjeremy
    Free Member

    Double + bash – no chewed ankles from the largely unused big ring, and a granny ring to winch uphill, perfect combination.

    BigJohn
    Full Member

    It’s the fashion. And 42T rings are what you get on Apollos and other Halfords bikes.

    mikewsmith
    Free Member

    Life and bikes is not all about weight, the mud I collect probably makes more difference and the beer I consume.

    Double less grief, less chain needed (a weight saving!!). 22-36 is perfect for me, as said all above no chainring bites, not scrapes better clearance, better chain retention, can run a double chain guide do you want more?

    andytherocketeer
    Full Member

    Oh, always give a prime number when asked

    prime numbers ftw – they are the coolest.

    Best wait for 1×11 then, and not need to lie, assuming you don’t have a legacy 1×7 or an even more legacy 1×5 (had one of them oh and a 1×3 too) or SS.

    willber
    Free Member

    I kinda don’t get the idea of dual ring chain guides. Bash ring and 2 chainrings I get – but you still need the front derailer. So if you’ve got that why bother with the weight of chain device?

    ahwiles
    Free Member

    not having a 42 (or whatever) tooth ‘3rd’ chainring means that i don’t need so much chain.

    so i don’t need such a long rear mech.

    so it doesn’t bounce around as much.

    and the chain is ‘tighter’.

    so i don’t get so much chainsuck.

    what’s the point of that big chainring? what do i get in return for all the extra flap and noise and chainsuck?

    2 extra gears?

    whoopde***kingdo.

    So if you’ve got that why bother with the weight of chain device?

    it stops the chain falling off from the bottom – this can happen if you backpedal into position for a corner – which i do more or less every time i turn left.

    bikewhisperer
    Free Member

    Oh, always give a prime number when asked how many gears your bike has – pointless, but fun.

    My road bike has 3!

    The 44 ring does have it’s uses.. When you use it downhill the chain has more tension so rattles against the stay less.

    I’ve got one bike with a 44/29 FSA chainset that’s Ultra-Guff ™, as the right gear always seems to be cross chained, and the shifting is poo. I’ve got some new 40/29 rings for it that should improve it, but if I was starting from scratch I’d just get a triple.

    TandemJeremy
    Free Member

    bikewhisperer – if yo have a double you can shorten the chain to avoid chain slap 🙂

    ahwiles
    Free Member

    The 44 ring does have it’s uses.. When you use it downhill the chain has more tension so rattles against the stay less.

    but when do you actually use a 44t chainring for riding offroad?

    ime, you need a longer chain to fit a system with a triple, but when you’re in the middle/granny ring (more likely), the chain is slacker than it would be if you only had a double, so it rattles against the stays more

    BigJohn
    Full Member

    prime numbers ftw – they are the coolest.

    No they’re not. 1 (singlespeed) is coolest, and 1 is not prime. It’s a unit.

    chakaping
    Free Member

    I kinda don’t get the idea of dual ring chain guides. Bash ring and 2 chainrings I get – but you still need the front derailer. So if you’ve got that why bother with the weight of chain device?

    Because when I’m shredding the gnar the chain can still fall off despite having a front mech, and a chain device prevents that.

    With regard to the OP, sugdenr and duir explained best.

    I need a granny ring and I need a bigger ring. I need a bash guard too. So a double and bash is a pretty neat solution!

    bikewhisperer
    Free Member

    bikewhisperer – if yo have a double you can shorten the chain to avoid chain slap

    That’s one of the reasons I’ve gone 40 rather than 44 on the double.

    The bike that’s got a triple has a 970 xtr chainset.. The rings are decent, so it doesn’t sound like a bag of spanners if you cross chain it a bit, so you can stay in big more often.

    Another benefit of a triple (specially if it shifts properly) is that you can jump between middle and big quickly on sections with sharp changes down to up.. Quicker than you can grab a handful of rear gears.

    jameso
    Full Member

    So if you’ve got that why bother with the weight of chain device?

    – keeps the chain on on rough pedally descents better than a FD alone, tensions the lower run against chain bounce. A clutch RD would do it better and lighter, but a smashed mech is then much more expensive..

    ime, you need a longer chain to fit a system with a triple, but when you’re in the middle/granny ring (more likely), the chain is slacker than it would be if you only had a double, so it rattles against the stays more…

    Aye. Triples are good for really wide range gradients, proper XC in proper mountains. Seem a bit ott most other places to me, but then again better to have and not need, than need and not have (says a SS rider..ha)

    TandemJeremy
    Free Member

    Aye. Triples are good for really wide range gradients, proper XC in proper mountains

    You want to pedal above 30 mph? braver than me. In the big mountains I amon the brakes not pedalling at 30 mph

    bikewhisperer
    Free Member

    You want to pedal above 30 mph? braver than me. In the big mountains I amon the brakes not pedalling at 30 mph

    Men and boys, Jeremy!

    petefromearth
    Full Member

    I had a double setup a while back that worked a treat. Think it was 38/26 with a normal 9spd cassette. It meant having one ring for uphill, and 1 for the descents, and both with a useful spread of gears.
    Kinda works well for trail centre type riding, whereas I find my flat(ish) local rides are better on a singlespeed
    The ground clearance was a bonus but I can’t say I’ve ever killed a 44t ring by whacking it

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