Front rings on mtbs???

[Lovacott]

You actually end up with pretty much the same amount of "usable" gears and no chain-crossing
Pros:-
No front mech or left hand shifter so less to keep on top of.In theory chain should last longer and no chain dropping if you use a narrow/wide(NW) front ring.
Cons:-
Costs more.In some cases a lot more!NW front ring can wear quickly.Ratios are arguably wider but IME you don't notice(or you get used to it).

I'm a newbie to multiple chainrings on the front, but the more I use them, the more I like them.

I do some pretty long climbs and I've learned where to be on the front chainrings before I attack a hill.

If I am hill climbing, I will go small on the front and small on the back just before I start the climb. I then have 6 easier selections on the back which I can make as the climb progresses and I can forget about the front.

When I first started commuting over the hills (shortcut to work), I was losing my chain on the front at least two or three times per commute.

But as I have learned, you should never try to change the front gears down when they are under load when climbing a hill (load tension on the chain causes the chain to snap left when it is forced off the chainring by the derailleur and it will overshoot the lower chainring).

I've been making a mental note of where and when I use each gear and I have to say, that I'm not sure that I could manage with less than the 21 speeds I have got.

There are a couple of hills I do which I couldn't do unless I had the granny gear on the front.

 

[ChrisEyles]

Choice can't be a bad thing - only real way to know for sure which you'll like best is to give them all a go and see!

 

[SkipdiverJohn]

I do some pretty long climbs and I've learned where to be on the front chainrings before I attack a hill.

If I am hill climbing, I will go small on the front and small on the back just before I start the climb. I then have 6 easier selections on the back which I can make as the climb progresses and I can forget about the front.

I use my gears in a very similar way and try to avoid doing double changes involving both front and rear as much as possible, but it's an absolute no-no when climbing a gradient. You lose way too much momentum. My rule of thumb is the front ring is selected for the general riding conditions, then the back gears used progressively. So for me it's:-

Large Ring - flattish decent surfaced tarmac, calm weather or in a tailwind direction.
Middle Ring - gravel and other rougher surfaces such as in woods, more gradients or riding into headwinds.
Small Ring - used well in advance when I know a gradient is coming that can't be climbed just using a brief burst of hard effort. Not necessarily very steep climbs either, but ones that go on for some distance where you cant just use momentum, you just have to grind or spin up them. I prefer spinning on long climbs as it stops my knees from hurting!

 

[Lovacott]

I use my gears in a very similar way and try to avoid doing double changes involving both front and rear as much as possible, but it's an absolute no-no when climbing a gradient.

Looks like you've got this age old problem well sussed.

I learned that lesson the hard way. I'd be hill climbing and lose my chain at the front and get my hands covered in chain oil.

I'd get home and adjust the stop and next day, I wouldn't be able to get into my lower front sprocket. Nothing I did to the mechanics of the bike prevented chain drop.

Fact is, changing down at the front when climbing a hill means that you are trying to force a heavily tensioned chain down to a smaller ring but the level of chain tension stops it from happening until the very last second. Because the chain is forced to snap across under load, it overshoots the smallest ring and gets tangled in the bottom bracket.

You can solve it either with a dogs fang chain catcher you can alter the way you use your gears.

 

[Sniper68]

But as I have learned, you should never try to change the front gears down when they are under load when climbing a hill (load tension on the chain causes the chain to snap left when it is forced off the chainring by the derailleur and it will overshoot the lower chainring).

I've been making a mental note of where and when I use each gear and I have to say, that I'm not sure that I could manage with less than the 21 speeds I have got.

There are a couple of hills I do which I couldn't do unless I had the granny gear on the front.

You seem to be confusing 21 speeds with 21 gears.
Your bike maybe 21 speed but you don't actually have 21 different speeds!Hense me stating usable gears in my last post.Due to duplication of ratios and chain crossing you only actually have 11 or 12 different ratios in reality.

If your bike throws the chain that is due to incorrectly set up gears or trying to change onto the granny when the chain is severely crossed(small cog at the back etc).That is user error!

When you run a 1X set up you still,in effect,have a granny ring.By having larger toothed cassesttes(42,46,50 etc) you can duplicate your current set up by then putting a front ring on that gives you the same ratio(30,32,34t etc).There will always be a small compromise but on a 1X you will still have 11 or 12 usable gears!

I haven't used 7 speed this Century.I used 9-speed for years then went to 10-speed about 10 years ago.I've just gone to 11-speed on my new build.TBH I find the jumps between gears on 10-11 speed much better(closer).My CX bike is 9-speed(compact-34/50) and the gearing is a PITA on the hills around here.

1X is not for everybody but don't write it off because you think you're losing something you have.I doubt I'd ever have it on a Road bike but my next CX/Gravel bike and if I ever build another MTB definitely....I just wouldn't go as big as 50T on the cassette!

 

[Lovacott]

You seem to be confusing 21 speeds with 21 gears.
Your bike maybe 21 speed but you don't actually have 21 different speeds!Hense me stating usable gears in my last post.Due to duplication of ratios and chain crossing you only actually have 11 or 12 different ratios in reality.

True. I have noticed the duplication of gears when I'm riding. I also understand that a cassette set up allows for a few more rings on the back compared to a freewheel which negates the need for multiple rings on the front.

When I was losing the chain on the front lower ring, it was always when I changed down under load (climbing hills mainly). I'd adjust the hard stop a fraction but then the chain wouldn't shift to the lower ring.

Up until I started commuting, I was riding only on the flat along the Tarka Trail near to my home. Once I started to get the hang of the hills, my gear selections became a bit more intelligent (rather than suck it and see). I now don't throw the chain.

When bike shops start getting a bit of stock, I shall start looking at cassette setups which give me a similar range to what I get now.