Critique my logic/thought patterns a bit here guys.

I’ve got a 2015 T-130SX and it’s been making a noise recently.  Every 1/2 stroke i get what is somewhere between a clunk and a click. I thought it may be the BB so i swapped that the other day. Discovering at the time that the drive-side spacer on the BB was split and leaving about a 2-3mm gap between edges.. So i was hopeful.

Within the diagnosis i’ve also fitted a different crankset, so have tried both a N/W and a standard 2X (but only using the middle ring) along with different pedals and a different seatpost.

If i try to replicate the noise when standing up and not pedalling i cannot make it happen, bouncing on the pedals etc i get nothing… Making me suspect it’s not the seatpost/seat. Anyway….

Finished early and got home, had spare time so thought i’d jump on the Whyte to see if we’d resolved the noise.

First impressions were good, the first 15 mins was silent. It was a longish incline out of the village and i was hopeful. But sadly the sodding noise returned. It seemed to be every 1/2 pedal revolution. So i came home has planned and thought “Right, what can this be”.. First thought was a combination of the N/W chainring and a worn chain. So i set about changing the chain for one in the spares box. It’s done about 1800 miles anyway in varied conditions so was due a change.

After swapping the chain i thought i’d do some quick tests, so i did some runs up a little climb up to the stables by the house, first with the Hope wheel and then with the Whyte/WTB standard wheel. I couldn’t get either to replicate the noise, but i’d also swapped the seatpost…. So back to the other post and i noticed the indexing was completely different on both wheels. That’s not unusual in itself, but i was slightly curious because i couldn’t get the Hope to index all 10 gears fully.

I then realised that the cassette has play in it. The smallest 3 cogs were all over the place. It’s a 20 or so piece SRAM cassette, not a single piece (none are as the last few cogs sort out the spacing etc of course). But this is Ring, spacer, ring, spacer, ring etc… When i’ve been fitting this i think i’ve either got the combination order incorrect or maybe indeed i’ve not fitted the 11>10 spacer on the back. As you may be aware, the 10 speed is a slightly different width to the 11 for the cassette, so if you have an 11 speed compatible freehub, you need a small spacer on the inner side to spacer it out to fit correctly.

Dipped into the spares box and i have a more simplistic 10 speed Shimano unit in there along with a hub spacer… So i’ve stuck that on the Hope hub now and we’ll now see where we are in the noise context when i get out in it in a few days time. Won’t have time or inclination tomorrow, so will be Weds/Thurs depending on weather.
I’ll then also if needed try the WTB/Whyte wheel to compare.

What would help is a check on my logic along with a diagram/order for putting the 10 speed multi piece SRAM back on the bike, along with number of spacers etc… I don’t NEED it on there… But there may come a time when i want it on a bike and it’s no use if it’s not correct. I suspect the cassette is the one that came stock on my Parkwood, but i could swear i’ve used it without issue on other bikes before… Could it be an issue because the chain/mech is Shimano and the cassette is SRAM ?