Jockey wheels maintenance?

[IonutF]

question for the ones more experienced, please

my NX derailleur has the upper pulley with 12 teeth, while the lower one with 14 teeth and I am planning to change these with some color ones.
Asking a bike shop around my area, where I found colored ones, but not with 14t, the bike mechanic there said that it works even if I mount 12T pulley instead of 14T one....does this make sense?

 

[KeithO]

I’m not qualified enough to answer that but be interested to see what the experts say

 

[Gary]

question for the ones more experienced, please

my NX derailleur has the upper pulley with 12 teeth, while the lower one with 14 teeth and I am planning to change these with some color ones.
Asking a bike shop around my area, where I found colored ones, but not with 14t, the bike mechanic there said that it works even if I mount 12T pulley instead of 14T one....does this make sense?

Yes. it'll "work" just not exactly how it was designed to.
The bottom jockey just tensions the chain. and because it's under more tension wears quicker. part of the reason it was designed with more teeth. more teeth also take up slightly more slack which matters across wide ratio cassettes

 

[Mikerb]

it would result in less chain wrap on the lower pulley wheel and the smaller wheel would sit away from the guard rail of the lower cage. I suspect the chain would also be a little slacker.
Not a good idea I don't reckon!

 

[IonutF]

Thank you guys for your inputs, all make sense, hence, will continue searching for 14t & 12t colored pulleys.
Luckly the stock ones are 3 months old, so I have time to find propet setup

 

[Apples]

I fitted Hopes to my Levo on Oct and ride it in shitty conditions , clean down after every ride . But last week realised the jockeys were near solid ! Took out and removed the covers , loads of mud gets in , cleaned , greased and put back on .
LBS said they are a bit known to do this if you ride in slop in the British Winter . So I will now do mine every three months now .