Forum menu
What is the point o...
 

[Closed] What is the point of dual chainrings ?

Posts: 41395
Free Member
 

I tried a double, looked well 'ard but I was shifting a the front more (on a 36) which I found a PITA...and otherwise I found no benefit.


 
Posted : 24/01/2012 7:31 pm
Posts: 66111
Full Member
 

scu98rkr - Member

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

It [i]really[/i] doesn't. IIRC I lost the top 2-and-a-half gears. You know, those ones you never use offroad unless you're riding something gobsmackingly dull.


 
Posted : 24/01/2012 7:32 pm
Posts: 8859
Free Member
 

In addition to the usual reasons, anyone who rides leftie usually ends up with loads of chain ring wounds, as their right legs (chain ring side) is the one they put down first, kick off with and balance with. Getting rid of the big ring pretty much eliminates bloodied leg. If you're right foot forward it's not such as big an issue.


 
Posted : 24/01/2012 7:33 pm
Posts: 0
Free Member
 

I use the big ring off road all the time, even on technical stuff.

You guys really need to MTFU.


 
Posted : 24/01/2012 7:37 pm
Posts: 66111
Full Member
 

glenh - Member

I use the big ring off road all the time,

Do you use those top 2 gears? Those are the only 2 not replicated on a 36T "middle"


 
Posted : 24/01/2012 7:37 pm
Posts: 71
Free Member
 

Here we go Juan, feel free to get involved...

I always found a 22t too small to be of use and a 44t too big. So something in the middle was perfect. 28/40 was nice.

Did it originally by just taking off the granny - forces one to MTFU in races a bit, still had a 1:1 bottom gear.

Not for everyone though, some folk enjoy/need a 22 etc etc. 1x10 now, and that's even better.


 
Posted : 24/01/2012 7:40 pm
 Spin
Posts: 7808
Free Member
 

Can't be arsed reading the whole thread but here's my 2 cents.

I ride double and bash (22/32 I think) so no weight saving over a triple. I find it gives the right ratios for riding in yer actual mountains i.e. a tiny gear for massive ascents and something big enough for the kind of downs you find in the big hills - mainly techy and so not too fast. No need for a big un as you won't be bombing it and you can freewheel if you need to. Judging from the state of the bash ring it's doing it's job. Never once wished for the big ring since I got rid of it.

Horses for Courses innit?


 
Posted : 24/01/2012 7:48 pm
 DezB
Posts: 54367
Free Member
 

I use the big ring on bumpy fast stuff. Tensions the chain and stops it jumping off. Sorry to not follow fashion, but I'm not changing my setup until I [i]need to[/i].

(excuse me while I fit this 50mm stem, 750mm bars and flat pedals to my new frame I had to buy cos everyone said I needed a tapered steerer. And now my new front wheel, oh, and forks because I must use a 15mm dropout fork of course. Then I just have to get this 10 speed rear mech on. F-me, you lot must have money to burn staying with the trends)


 
Posted : 24/01/2012 7:54 pm
Posts: 8859
Free Member
 

DebZ having a moment there :wink:[img] [/img]


 
Posted : 24/01/2012 8:03 pm
Posts: 2
Free Member
Topic starter
 

I think alot of you are missing my point.

Im not asking what the advantage of smaller front chain rings are. I agree with all of them. I also agree we could probably get away with a smaller range of gears.

Im asking what the advantage of a double.

If you have a front gear mech why not stick in a third chain ring .

Say this XT model

http://www.chainreactioncycles.com/Models.aspx?ModelID=67200

it has a 28-4O T model why not just bung in a 22 tooth ring as well.

it would hardly weigh anything.


 
Posted : 24/01/2012 8:04 pm
Posts: 0
Free Member
 

Im asking what the advantage of a double.

Chain doesn't come off as much. End of.


 
Posted : 24/01/2012 8:08 pm
Posts: 66111
Full Member
 

scu98rkr - Member

If you have a front gear mech why not stick in a third chain ring .

This has been answered 😕 it adds almost nothing, it takes away ground clearance, sometimes adds weight, and assuming you're going up gears also requires more chain, which means more chainslapping and less good chain control in general in the lower gears- ie worse shifting, more noise, more dropped chains. And another part to buy and maintain. In theory a double can give you better chainline too though in practice I'm not sure how often this happens.


 
Posted : 24/01/2012 8:09 pm
Posts: 3225
Free Member
 

With Kudos100. Only reason I have just changed is for the chain device.

Bashguard is required to allow the screws to tighten, I personally cannot remember the last time I hit my big chainrng on an obstacle.


 
Posted : 24/01/2012 8:26 pm
Posts: 2
Free Member
Topic starter
 

This has been answered it adds almost nothing, it takes away ground clearance, sometimes adds weight, and assuming you're going up gears also requires more chain, which means more chainslapping and less good chain control in general in the lower gears- ie worse shifting, more noise, more dropped chains. And another part to buy and maintain. In theory a double can give you better chainline too though in practice I'm not sure how often this happens

im not on about adding a big chainring im on about adding a small one.

ok chainline and q factor are valid oints.


 
Posted : 24/01/2012 8:28 pm
Posts: 8859
Free Member
 

Bashguard is required to allow the screws to tighten,

EH?


 
Posted : 24/01/2012 8:31 pm
Posts: 0
Free Member
 

im not on about adding a big chainring im on about adding a small one.

smaller than a 26t?

eh?

😕


 
Posted : 24/01/2012 8:33 pm
Posts: 40432
Free Member
 

You know, those ones you never use offroad unless you're riding something gobsmackingly dull.

I get mildly annoyed when people say this about having a big ring.

Sometimes I have to ride open fast bits or even tarmac before or after the sort of techy gnar shreddage that I presume makes up 100% of your riding.

I make do with the 36t ring on my double and bash, but I'll admit I would like my old 44t big ring from time to time.


 
Posted : 24/01/2012 8:34 pm
 DezB
Posts: 54367
Free Member
 

[i]DebZ having a moment there[/i]

😆


 
Posted : 24/01/2012 8:56 pm
Posts: 0
Free Member
 

bash ring, less chain, short cage 🙂


 
Posted : 24/01/2012 9:00 pm
Posts: 2
Free Member
Topic starter
 

yeah then u would nt need a silly heavy 1O seed cassette out the back and 8 seed or something would do saving weight escially out the back. and meaning u dont damage your hubs so easy


 
Posted : 24/01/2012 9:03 pm
Posts: 1
Free Member
 

I took my big ring off as it only used to rip my kecks or my leg. Also, if I twonked it into a rock or log it would bend and could spoil my flow by making me stop to sort it out.

Now all my mountain bikes have bash rings and 2 rings.

I hardly ever used my big ring anyway. it ain't that flat where I go.


 
Posted : 24/01/2012 9:06 pm
Posts: 66111
Full Member
 

superfli - Member

Bashguard is required to allow the screws to tighten

What?


 
Posted : 24/01/2012 9:21 pm
 Spin
Posts: 7808
Free Member
 

8 seed or something

This idea is growing on me...


 
Posted : 24/01/2012 9:21 pm
Posts: 66111
Full Member
 

Apologies Chakaping- should have said "Never need" rather than "never use".


 
Posted : 24/01/2012 9:22 pm
Posts: 0
Free Member
 

As someone who has always had a triple. I do find myself thinking, what is the point of the big chain ring? When i'm going fast enough to spinout on the middle ring, i'm happy at that speed, no need to go any faster. I usually just glide and let gravity do it's work.


 
Posted : 24/01/2012 9:47 pm
Posts: 0
Free Member
 

I cannot see the point in triple chainsets anymore. I never use the granny ring on the one MTB that still has one (the other two are SS so it is untlerly pointless. Even in Wales I was always in the middle ring up the steep gradients.

2x9 or 2x10 with 22/38T matched to 11-32 casstte is all you will ever need. If you need a lower gear than 22/32 you are not trying hard enough and it will be quicker to get of and pick up the bike and walk.


 
Posted : 24/01/2012 9:59 pm
Posts: 66111
Full Member
 

I do think triples have their place tbh... But I see it as being the same as single ring- something that a minority of people will benefit from. The default ought to be doubles for mountain bikes IMO.


 
Posted : 24/01/2012 10:04 pm
Posts: 3225
Free Member
 

I couldn't tighten the middle ring screws without some sort of spacer. So bash ring filled the gap.


 
Posted : 24/01/2012 10:19 pm
Posts: 0
Free Member
 

"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"

22-34T is an extra gear over 22-30T, I use this bottom gear a fair bit on steep(er) hills, either at the end of a longer ride when I'm on my arse, when its really really steep and/or when I want to be able to spin fairly fast (rather than grind away) over the rough
Re: its quicker to walk, spinning quite fast in 22-34T is faster than walking IME, plus I went for a bike ride, not a walk with my bike
Only times I've really really wanted higher than a 32T chainring on FS bike has been on road downs (good bits but still). I'd like a 36T so I'm not using the smallest end of the casette so often and spinny, but I don't really want the 14T jump between 22>36T tbh, I'd be losing 32-34T which is quite useful for up-down-up-down-up-down trails where I'm up and down the casette

"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 "
Yes, but how much does an XX 10spd 11-36T casette cost?

"you use it downhill the chain has more tension so rattles against the stay less"
I used to do this, I often found I ended up with the chain halfway (or further) up the casette, the chainline then not only was less efficient, it very often pulled the chain off the big chainring over the rough.
I found within 6 months of fitting new outer chainrings (which I stopped using since shimano figured how to make (middle) chainrings that aren't made of cheese (since SLX came out) I'd worn the teeth so badly the chain wouldn't stay on it.
2*9 + medium cage mech + shorter chain suprised me how much less my chain falls from middle to granny ring (And then off and jamming against a frame pivot). Its pretty much never now

Mech hitting chainstay? A Shadow mech gets round that IME
(Or chain slapping chainstay?)

"Bashguard is required to allow the screws to tighten"
Not if you use short ones?


 
Posted : 24/01/2012 10:22 pm
Posts: 15458
Full Member
 

"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"

Yep 8 speed 11-30 here with a 22/36 double as quite honestly your proposed triple would be pretty pointless
the whole reason for a double with 14T difference between granny and big ring is that the granny is really just the winching gear...

80%+ of your riding will be done in the bigger ring don't think of it as a double think of it as a 1xn drivetrain with an emergency bailout granny ring...

Triples are toss

I'm waiting for Hope to pull their finger out and deliver the promised 9-36 cassette that's when 1x10 really starts to look like a goer to me, as discussed elsewhere today then you can run a smaller ring (30 or 29T) have a ~22" climbing gear and still get the same Grrrr gear as an 36-11 (~85") no duplication and one less shifter to clutter the bars, win/win I reckon... Now lets see it in the shops please...


 
Posted : 24/01/2012 11:58 pm
 dyl
Posts: 0
Free Member
 

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

I suppose some people live in houses that are already off-road so they don't have to cycle along roads to get there, but I unfortunately do live on a road, so I have to cycle along it to get to the off-road.

HTH 🙂


 
Posted : 25/01/2012 4:40 pm
Posts: 71
Free Member
 

it has a 28-4O T model why not just bung in a 22 tooth ring as well.

Because not everyone finds any use in a 22. By having 2 the chainline is far better too, so you can use the full cassette in both rings, so don't have to worry so much about 'big/big' and what not.


 
Posted : 25/01/2012 4:46 pm
Posts: 57389
Full Member
 

Surely a big ring is the purest possible indication of being gay?


 
Posted : 25/01/2012 4:58 pm
Posts: 0
Free Member
 

scu98rkr- if you that concerned with weight ride a singlespeed and pedal your ass of to keep up with you mates 😀


 
Posted : 25/01/2012 5:18 pm
Posts: 1617
Free Member
 

One set of reasons for a triple:

If you do a fair bit of road/cycle path to get to and from trails (ie don't use your car to transport you to trails) then you can stomp along in the big ring and smallest 2 sprockets with a nice straight chain and not putting wear on your middle chainring you use out on the trails.

One of the points of having 3 rings up front is straighter chain. You are not supposed to use the whole spread of the cassette with a single ring up front so using a triple correctly maximises drivetrain life due to less use of each chainring and less sideways articulation of the chain.

But yes the negatives are reduces ground clearance, nasty cuts, a bit of weight and a lot of people don't need the large ring.

I actually went one worse that 22-32-44 on a 9 speed 11-32 cassette and went 10 speed 24-32-42 cranks. I get even more duplicate ratios and I lose the top most gears but I get a little bit better clearance than a large 44T, I never used 22-32 as it's just too spinny and in return I get much better shifting up front, especially when mud takes hold so I am actually more likely to use the front shifting on a ride and not be scared to shift from the one I am in. Yes some people will claim their gear set up is amazing and they have no shifting problems but I'm not that good setting up gears and when caked in mud even the best set up gears struggle.


 
Posted : 25/01/2012 5:38 pm
Posts: 71
Free Member
 

you can stomp along in the big ring and smallest 2 sprockets with a nice straight chain and not putting wear on your middle chainring you use out on the trails.

You could have a double with a 42t outer though, and the chainline would be better for the usable gears, and as you say you don't have the uber-spinny gears like 22-32.


 
Posted : 25/01/2012 5:43 pm
Posts: 0
Free Member
 

It sounds like a bunch of people have ended up with front shifting issues that have made them not use the front gears enough, and then abandon the 44 as they don't use it.. From spending years as a shop mechanic fixing gears and brakes, it comes as no surprise to me. Front mechs are only generally ever set up wrongly from the factory.. Too high, wonky or bent.. and generally cheap, as nobody cares what's written on their *front* mech when they see the bike on display.. and most of them aren't fixed up before the bike leaves the shop (well I always did, but it's quite time consuming on a PDI on a busy saturday).

Expensive bits (ie, at least XT mechs, good cables and decent chainrings) set up and working properly are so much better to use, work quickly, and don't tend to drop the chain or grind through changes, no matter how muddy it is. I guess that not a large proportion of people ever get to use something like that.. so they never learn to use the front gears properly.


 
Posted : 25/01/2012 6:21 pm
Posts: 21016
Full Member
 

I think you need a degree of mechanical sympathy to get a triple to work well.

And a good read of either Richard's Bicycle Book or Sheldon's website.
🙂

I also think growing up using friction shifters gives you a better idea of how things work properly, learning how to trim, how not to stress the chain etc.

Sadly, many people have no patience and can't be bothered to learn anything anymore - seems like 2*10 is perfect for the 'can't be arsed to read the manual' crowd.


 
Posted : 25/01/2012 7:05 pm
Posts: 1617
Free Member
 

njee20 - Member

You could have a double with a 42t outer though, and the chainline would be better for the usable gears, and as you say you don't have the uber-spinny gears like 22-32.

But not all of us want to go out and spend £ on a specific double crank set with better offset. Most people switching to double will be doing so by just ditching the outer ring. The only double specific cranks I have seen are top end ones. The SLX 22-36-bash does not count as it's basically a triple set up with steel pedal inserts.

As for the 'spinny' 22 - unfortunately some of us need something lower than a 28 up front and don't want to upgrade to a 10 speed rear to get the 36T which is probably quite heavy.


 
Posted : 25/01/2012 7:13 pm
Posts: 66111
Full Member
 

You can build an 11-36 9-speed cassette, incidentally, but it works out very heavy- take a 12-36 and replace the little ring.


 
Posted : 25/01/2012 7:36 pm
Posts: 15458
Full Member
 

I think you need a degree of mechanical sympathy to get a triple to work well.

And a good read of either Richard's Bicycle Book or Sheldon's website.

I also think growing up using friction shifters gives you a better idea of how things work properly, learning how to trim, how not to stress the chain etc.

Sadly, many people have no patience and can't be bothered to learn anything anymore - seems like 2*10 is perfect for the 'can't be arsed to read the manual' crowd.

You what?

How have you infered a lack of "Mechanical Sympathy" or inability to maintain/operate a bike properly from removal of a chainring?

I think the primary problem with this thread is just a lack of empathy if anything, a simple appreciation that people like different flavours of MTBing, and maybe lack any real sympathy for others take on the sport.

To suggest I and other who have chosen to varied the rings on our bikes from the shop bought standard, because we are mechanically inept strikes me as a bit cheeky TBH.

"Can't be arsed to read the manual crowd?" Who are they exactly?
I know the only reason I have a 2xn drivetrain is because I can be arsed, not only to understand how my bikes work, but to experiment with their configuration to try and make it fit my needs better and not accept the broad spectrum toss that comes fitted as standard to accomodate dusty old giffers who think bicycle technology reached it's apex with friction shifters...


 
Posted : 26/01/2012 10:59 am
Posts: 71
Free Member
 

But not all of us want to go out and spend £ on a specific double crank set with better offset. Most people switching to double will be doing so by just ditching the outer ring

Don't need a special chainset - just use the inner and middle ring positions on a triple. I've done 30/42 and 28/40 like that.


 
Posted : 26/01/2012 11:08 am
Posts: 0
Free Member
 

I use a 2x9 as it suits my needs. I have the 36 ring for flat and downhill that allows me to pedal up to 25 mph easily and 30 mph spinning away like a lib dem spokesman.

I have a 22 ring for hillclimbing.

I simply shift into the granny ring at the bottom of a climb and use a range of gears 1-6 or so . this gives a range of low and importantly close gears for hillclimbing.

I will only shift the front a couple of times each ride.

Simple, elegant and gives the right range of gears for me, my riding style and where I live.

I simply have no need for a gear that can be pedalled up to 35+mph. 25+ does me fine. Its a mountainbike after all


 
Posted : 26/01/2012 11:13 am
 D0NK
Posts: 10677
Full Member
 

I tried running triple and a close ratio road cassette, rubbish, pretty much everytime I changed gear offroad I'd move 2 at a time anyway and I had to switch chainrings a lot more often. I run 22/32 11-32 mostly now, slightly undergeared for downhill fireroads but as I only ride those once in a while it's fine.
22/36 11-32 has more top end but I like a 1:1 available in middle ring, lots of climbs seem to be just a bit too steep/long for 36/32 so too much use of the granny, wouldn't mind 24/36 11-36 10spd but CBA with the cost and effort at the moment (and I like my RR dérailleurs too)


 
Posted : 26/01/2012 11:15 am
Posts: 71
Free Member
 

I tried running triple and a close ratio road cassette, rubbish, pretty much everytime I changed gear offroad I'd move 2 at a time anyway and I had to switch chainrings a lot more often

+1, couldn't get on with that either.


 
Posted : 26/01/2012 11:18 am
Page 2 / 3