Chainring

[beetlejuice]

Hi all,

I'm changing my 2x9 setup on my Defy 3 to a 1 x 9 using a 44 front chainring.

Does anyone know if I just remove both current chainrings and replace with a single 44t on the existing crank arms (in the outside position) if this will increase wear on the chain due to alignment or is it better to replace the whole crankset to have a more central chain line?

Plus is there a particular chainring/crank i should be looking at that will be compatible with the existing 9 speed KMC chain?

Lastly, anyone any ideas/tips how to remove a seized in BB? I've got the correct removal tool but it's just not budging

Thanks

 

[si_c]

It'll work, particularly if you don't need to use the lower gears particularly, but of course you'd be better off with a dedicated 1x chainset. Also make sure you get a narrow/wide chainring for the front.

 

[beetlejuice]

[QUOTE 5148587, member: 43827"]Which type of BB is it?[/QUOTE] it's a FSA sealed cartridge

Also make sure you get a narrow/wide chainring for the front.

- narrow/wide chainring? Why - is there a benefit of having this?

Thanks

 

[si_c]

- narrow/wide chainring? Why - is there a benefit of having this?

Most chainrings for geared bikes have ramped and profiled teeth that make shifting gears smoother. When on a single chainring setup this is redundant but also increases the likelihood that the chain will come off. A narrow/wide chainring has alternating narrow and wide teeth to match the inner profile of the chain, meaning that the chain meshes with the teeth better - reducing the likelihood of your chain coming off.

It doesn't reduce the likelihood entirely - on an MTB setup you will want to combine a narrow/wide chainring with a clutched derailleur - but on a road bike it is less likely you will be hitting bumps which will cause the chain to come off.

 

[Ajax Bay]

Does anyone know if I just remove both current chainrings and replace with a single 44t on the existing crank arms (in the outside position) if this will increase wear on the chain due to alignment

The difference in chainline moving from a double to just using the outer chain ring position is not much and will work perfectly well. Let's face it, a rider can cycle perfectly well in large/large and the efficiency loss is much less than generally thought (I have posted a link to the research on here but no time to find it now) maybe 0.5% loss for a 2.5 degree chain angle. I'd just go for it but put the chain through the FD fixed in position by upper and lower limit screws - reduces risk of dropping chain.
New single speed chainset and almost certainly BB implies rather more expenditure, which the OP may choose to incur, once they're content with the set up (using current crank set/BB).
Google narrow/wide chain ring to find out the benefits - designed to keep the chain more secure.
Assume a 44/32 ratio will get you up all the hills you visit.

 

[beetlejuice]

Cheers everyone, very helpful as always