In the lower down the cassette gears (might just be one in particular) I get a weird feeling on pedalling. It's a Hope Pro II rear hub and it almost feels like a biopace ring or something. It's not jumping, just a sort of lump as though it's suddenly gone into an easier gear for a small part of the pedal stroke. Any ideas before I whip the cassette off?
'tis called the 'dropping in' effect.
Rickos, it makes no sense. Unless your chainring chnges to biopace when in that sprocket.
DROPPIN' IN!
I was just riding along the old railway line though, so no radness. All I can think of is that the sprocket is cutting through the freehub body to give the 'easy for a split second' feeling.
Tighten up your ring. You lockring that is!
Again? Sheesh...
No noise up front at all then, like from the chain rubbing the front mech guide plate because of a wonky chain ring or worn and not a warped rotor?
You'd notice a warped one of them more under less torque. Maybe, i'm makiing it all up really. Just some ideas.
xx
Check you haven't got a stiff link in your chain.
This has come on since I put the cassette back on after being SS for a short while. Did it with an old set of cranks and a brand new set of SLX and pretty sure there's no stiff link (and wouldn't I be able to feel that in all gears?).
Thinking about this overnight the stiff link might make sense on what I'm feeling at the pedals, but no idea how it got there as I've not split this chain for ages and it's got a SRAM connector for taking off and on again.
If your lad was older I'd have suggested that you should look for lego 'modifications' placed in hard to reach locations, after some mechanicing by 'daddy's little helper' 🙂
Stiff links do tend to be more noticable on the smaller gears, they have to turn through a tighter angle to follow the size of the sprocket.Check it by pedalling backwards in a small gear and look for the mech cage suddenly jumping as the stiff link goes around the sprocket or over the jockey wheel.