I cant reinstall my rear cassette!

[Ian H]

It might be as simple as making sure everything is clean so that the cassette slots on fully.

 

[eskimo1986]

This is a 9sp cassette. No spacer required if on an 8/9/10 freehub.
How thick is the spacer you've used? (assume slotted on before cassette).

The spacer was on it before I took the cassette off, and I have tried to install it without the spacer and it's actually worse believe it or not.

 

[eskimo1986]

It might be as simple as making sure everything is clean so that the cassette slots on fully.

Thank you, everything is super clean

 

[eskimo1986]

I would still be looking at either the spacer or a cog fitted the wrong way round.

Believe me, I have checked and double checked and checked again. If I had hair I'd be pulling it out

 

[EckyH]

View attachment 727293
Spacer is there just to show spacer is there...if that makes sense

Thank you.

Could you please verify that the lock nut isn't stopped by that seal (or whatever that disc shaped and seemingly broken entity is) right inside of the outer nut on the axle?

E.

 

[Ajax Bay]

The spacer was on it before I took the cassette off, and I have tried to install it without the spacer and it's actually worse believe it or not.

In what way "worse"? Surely with the spacer absent the cassette will e 1mm further on the splines and lockring will engage at least one more full turn than before.
I enquire again: how thick is that spacer (in image)? 1mm or 1.85mm?
When you serviced and greased the bearings, did you unlock the freehub end locknut, spacer and cone, or leave them be and clean/regrease in situ?
The locknut is a lot further proud (of the freehub threaded edge) than I'd expect - maybe just the image.
What is the distance between the outer edge of the locknut and the edge of the freehub?
With the lockring merely 'fingertight', try installing the wheel. Does the rotor line up properly into/with the pads?

 

[ExBrit]

If you have a caliper measure you can check that the distance between adjacent cogs is consistent. If one is larger, there's your problem.

 

[bikingdad90]

View attachment 727293
Spacer is there just to show spacer is there...if that makes sense

Spacer is incorrectly installed, there is a notch on it which should align with one of the splines and drop the height of it.

The hub should have one slightly bigger spline than all the others to which the cassette should also align with.

 

[T4tomo]

is outer cog on wrong way round so lockring not engaging properly with thread in that cog?

does that spacer is closer to hub if reversed?

that notch is unusual - should it face other way. Normal spacers are notched on inner surface to fit the splines

 

[biketrailerguy]

The 4th smallest cog has no stamp marks on it that I can see - that might indicate it has been fitted in reverse?

I've always assumed the purpose of the different width spline on the hub was to ensure cogs could only be fitted one way - presumably for tooth geometry / topology / shifting purposes?

The hub should have one slightly bigger spline than all the others to which the cassette should also align with.

Am I missing something here, because on the hubs I've messed about with, the odd spline has been narrower than the rest.

 

[bikingdad90]

@biketrailerguy, you are probably correct, I’ve said the inverse:

 

[eskimo1986]

Freehub has moved too close to the outer cog. This results in the 5th cog not locating into the spline for the 9th cog.
Adding the big hammer to this on the 8th cog will result in the 7th cog slotting into the correct place which is why you need a new wheel and hub.

I hope not as this bike is only a month old! Bought brand new.

 

[eskimo1986]

Thank you.

Could you please verify that the lock nut isn't stopped by that seal (or whatever that disc shaped and seemingly broken entity is) right inside of the outer nut on the axle?

E.

Yes, that's exactly what is stopping the lock nut from entering the lock wheel correctly. The disc shaped (broken?) thing is part of the axel which appears to be seized on there as I cannot remove the nut next to it and believe me I've tried

 

[SuffolkBlue]

Am I missing something here, because on the hubs I've messed about with, the odd spline has been narrower than the rest.

The narrow spline is usually an effect of having the wider spline next to it but it doesn't really matter what it is referred to (which is what bikingdad90 has replied) as the cassette/spacer will only go on one way .

@eskimo1986 - just looking at your photo I agree with bikingdad90 and T4tomo, your spacer is not on correctly. Try turning it around and make sure the wider spline is lined up. The spacer should go on very easily.

 

[EckyH]

Yes, that's exactly what is stopping the lock nut from entering the lock wheel correctly. The disc shaped (broken?) thing is part of the axel which appears to be seized on there as I cannot remove the nut next to it and believe me I've tried

Now we have the reason for the engagement problem: the seal is at the wrong place.
It seems to me that it is not deep enough inside the freehub.

Usually the outer nut is locked against the inner nut very tight (not sure whether I wrote that correctly - my English is fairly wobbly. Sorry for that.)
If the hub is a Shimano hub and if you could tell us the model (FH-[0-9][0-9][0-9] for older hub generations - usually it's on the hub body between the flanges) we could find the exploded view of the hub on si.shimano.com.
The exploded view could be helpful to proof that you assembled the hub correctly after you regreased the hub.

E.