Swap out my 3 gear crank to a single crank?

Robbie1220

Hello there. I’m new to mountain biking and trying to pick up on what to do and what not to do. I have been looking at swapping my crank to a single gear crank but would like to hear on wether it’s worth doing or not?

wilberforce

It depends on what current gearing you have and whether or not parts are worn out (I doubt it unless you have bought a used bike).
With 10+ speed cassettes, you can now get a decent range of gears with 1x, and 1x also gives simplicity and weight saving
Any benefit (if any) you will get from 1x also depends on your fitness and the type of riding you do

02gf74

Another benefit of doing away with the front mech is that there no longer is a mud trap at the base of the seat tube.

You don't need a new crank, ditch outer and granny rings, replace middle by a narrow wide.

Search my post about this conversion.

cooldad

Stop using the big and small rings and see.

Robbie1220

Wilberforce wrote:

It depends on what current gearing you have and whether or not parts are worn out (I doubt it unless you have bought a used bike).
With 10+ speed cassettes, you can now get a decent range of gears with 1x, and 1x also gives simplicity and weight saving
Any benefit (if any) you will get from 1x also depends on your fitness and the type of riding you do

No the parts are fine on the gearing. I was thinking about the weight and possible space saving on it? Less bottoming out possibly?

Robbie1220

I’ll give that a try

Robbie1220

02GF74 wrote:

Another benefit of doing away with the front mech is that there no longer is a mud trap at the base of the seat tube.

You don't need a new crank, ditch outer and granny rings, replace middle by a narrow wide.

Search my post about this conversion.

Can you take the gearing apart? Also what is a narrow wide? I’m not sure how to search your post I’m new to the website.

steve_sordy

A "narrow-wide" is a chain ring that has teeth that have alternately a narrow (ie normal) or a wide tooth. By wide, we mean thick as measured across the thickness of the ring. They are designed to fill the narrow and wide gaps in your chain. By so doing it reduces the chances of the chain coming off. Ordinary chain rings are designed to allow the chain to move from one ring to he other, therefore they are designed to lose the chain!

"Can you take the gearing apart?"

Some of the budget end of the market chainsets are riveted together. In which case the whole thing needs to be thrown away if one of the rings get damaged or worn too badly to be of further use. But all the others have chain rings that are bolted on. In which case you can do as many of the posters on your thread have suggested.

02gf74

The teeth on narrow wide chainrings are taller, intention to make it more difficult for the chain to be flung off.


I've ridden maybe 300 miles on nw rings and not had the chain come off once, mind you that is with a clutch rear mech. Clutch mech maintain a higher chain tension.

On my 3 to 1 conversion, it uses nw ring and non clutch mech, when on the smallest 3 sprockets, the chain flops sideways due to lack of tension but even though its not ideal, it has not fallen off.

Re. Cassettes, sram top end 11 speed are CNC from one piece of metal making it impossible to take apart, albeit the 42t alloy sprocket is held on by tabs.

Robbie1220

Right I see, I’ll have a little look at my crank then see if that’s an option with the narrow-wide. Otherwise may look at a new piece and run with that.


I’m assuming the clutch mech’s can also be added to a bike? Want to reduce the chance of the chain coming off not raise it

02gf74

Sram and shimano make Clutch mech for 11 and probably 12 speed. I think shimano did one for 10 speed.

So there will be additional expense of not only the mech but cassette, chain and shifter and possibly freehub too.

JBA

What bike and what chainset is it?

Robbie1220

It’s a GT avalanche and I’m not too sure on the chain set will check when home.

JBA

Which model Avalanche and what year?
These details help getting you a better answer as different models and years have different components.

Robbie1220

Awh my apologies. It is the GT avalanche elite and the 2017 model. Looking on line it has the All-terra T-651 chain set.

billycool

Have a look at this thread as it's similar to what you are discussing:

viewtopic.php?f=10004&t=13093115

The Rookie

The All Terra looks to have bolted chainrings
https://www.cyklonemcik.cz/images/eshop ... -175mm.jpg
But I cant find a view from behind to check, take an Allen key to it and see what happens!

larkim

NW rings are relatively cheap. We swapped to a single NW ring and left the existing non-clutch rear mech in place, and there hasn't been a dropped chain yet, so assuming you can remove the chainrings looks like a simple swap. I think we also had to drop a couple of links from the chain too to keep a decent level of tension (just followed the standard sizing formulas etc). The only issue we had was that getting the old rings off required us to remove the crank temporarily as it wouldn't go over - the BCD on ours was 96mm so I suppose that small diameter was to blame. Don't know what the BCD of the All Terra crankset is, you'd need to measure that before ordering a NW ring to fit.

Not sure my son really noticed the weight advantage, but with an 11-36 cassette and a 30T front he has no issues, and the usual annoyances with maintaining a front mech to avoid rubbing etc have obviously vanished!

Robbie1220

Thanks for the advice guys going to have a go at swapping it all out soon