As per the title that's what my fixed sounds like at the moment, I've managed to quieten it down a bit but there is still a distinct unhappiness from the drive train.
Bit of a long story to set the context....
I dug it out of storage a couple of weeks ago and geared it down to 62inch with a Surly 19t 3/32 on the back and a velosolo 44t 1/8 on the front... this was with the sprocket 'flat side out' and a 1mm cassette spacer fitted.. it was super silent in that configuration but unenjoyable downhill....
So I decided to step it up to 64-ish inches with a Planet X 18t 3/32 sprocket on the back. This was when it started to get noisy... sort of like a bike which is just on the cusp of wanting to change gear (grumbling).
I played around with the angle of the hub and also spacers and could get it a little quieter but not silent like I had enjoyed with the 19t on. I put up with this for another ride out and decided I really enjoyed the silent version. The Surly hub I have fitted has a specified chainline of 53.5 and with the near silent (but not quite!) configuration I now had was using 2x 1mm spacers and the sprocket flat facing outwards After a bit of measuring and knowing the BB was 127mm length I deduced that I needed a BB length of around 112mm so fitting a 110mm BB and the 2x1mm spacers on the BB should give me a chainline that would allow the sprocket to be fitted by itself and the correct way round. Upon trying this however I ran into a problem that the left crank arm jammed on to the BB shel when tightened up...
So plan B - fit 113mm BB, which is what is currently fitted and then use one 1mm spacer and the cassette the right way round... should have worked but didn't... chain was trying to come off the front chainring every now and again... removing the spacer reduced the desire of the chain to come off but didn't remove it.
Convinced it might be something else, I bought a new sprocket 18t (3/32) but this made no difference so I think bought a 17t (1/8) sprocket, new 1/8 chain and also a new chainring (miche 46t 1/8).
At the moment I have the new chain fitted and 46t x 18t - there is still some grumble from the drive train (worse when the chain is tight, so its a little slack at the moment) and every now and again under power, there is a big clank a bit like a chain slip.....
I'm at my wits end trying to diagnose this.. I am sure it's still related to chain line... there's no stated chainline for the frame (All City Natureboy) and when I asked them they were just very vague about it...
https://allcitycycles.com/bikes/archive/nature_boy_853greenThe frame has axle-adjusters inboard on both sides of the rear drop out, the wheel is centred in the frame, sighting the sprocket and chainring sort of looks inline and measuring where the sprocket teeth are (Hub OLN/2 minus distance from teeth to inside of drop out) gives the stated Surly chain line for the hub. Measuring the chainline for the chainring is a bit harder but seems to be about the same now...
So a bit of a plea for ideas / methodology to finally get this machine running silent...
last thing I want to do is revert to the 127mm BB and 19t /44t config but happy to do so if needs be to get some measurements....
TIA!
TL;DR:
Fixed is noisy, help me diagnose and make it silent again! Possibly chainline?