Author Topic: grumble grumble clank grumble grumble....  (Read 1239 times)

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
grumble grumble clank grumble grumble....
« on: July 16, 2018, 10:37:29 pm »
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_853green

The 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?
Regards,

Joergen

JonB

  • Granny Ring ... Yes Please!
Re: grumble grumble clank grumble grumble....
« Reply #1 on: July 17, 2018, 07:43:09 am »
I'm sure that someone with more knowledge will be along soon but it does sound like a chainline issue although I wonder whether the big clunk you describe could be something like a loose crank bolt or the bottom bracket not being sufficiently tight. Re the frame, I don't think frame's have set chainline's although there are tolerances beyond which your crank will be hitting the chainstay.  You know what the rear chainline is for the Surly hub so I'd be inclined to use that as your reference point (without spacers), then look up what the specified chainline for your crankset is with it's recommended bottom bracket (velodrome shop are quite good for this), then determine what your bottom bracket needs to move out by for a 53.5 chainline (remember that a wider axle will only shift it half the amount that it's wider by because the extra width is over both sides). 

Rather than listen to my ramblings you're probably better off reading Rogerzilla's excellent thread here https://yacf.co.uk/forum/index.php?topic=104960.0

Good luck, I feel your pain as currently trying to sort out chainline on a new project :-\

Re: grumble grumble clank grumble grumble....
« Reply #2 on: July 17, 2018, 08:00:39 am »
It's not the hub bearings, is it?

Torslanda

  • Professional Gobshite
  • Just a tart for retro kit . . .
    • John's Bikes
Re: grumble grumble clank grumble grumble....
« Reply #3 on: July 17, 2018, 08:05:03 am »
Probably....
VELOMANCER

Well that's the more blunt way of putting it but as usual he's dead right.

Re: grumble grumble clank grumble grumble....
« Reply #4 on: July 17, 2018, 08:22:33 am »
sound like the bottom bracket. Is there any play in your crank arms?

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: grumble grumble clank grumble grumble....
« Reply #5 on: July 17, 2018, 08:36:56 am »
Bike has only done 1400km from new, I've changed the BB quite a few times (I've pretty much got a full range of UN55 BB lengths).  There is no play in the BB/crank arms when I stomp up a hill for example or when on the ground in the house just now.... 

I've not extracted the hub bearings to take a look at them but the wheel feels fine (relative to bearings)...

Going to have a read through Rogerzilla's post over my coffee this morning and revisit the crank end chainline again....  :thumbsup:
Regards,

Joergen

Re: grumble grumble clank grumble grumble....
« Reply #6 on: July 17, 2018, 10:08:11 am »
Old chain on new sprocket, or vv?

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: grumble grumble clank grumble grumble....
« Reply #7 on: July 17, 2018, 11:04:32 am »
Everything on the drive train was within 60km of each other...

Anyhow... success!

I did a whole load of measuring and made sure I wrote stuff down this time... as a result put the 127mm BB back on. Based on that I did a mixture of trying different combinations of spacers and sprocket orientation till I got it quiet.

So in the end I am sort of almost back to where I was though this time, there are 2x1mm spacers on the BB and the sprocket is flat side out...

There's a slight tick as the chain joiner rotates past the sprocket, which I think is a stiff link from chain fettling. I expect to that to calm down but will keep an eye on it...

I found that also observing where the teeth were on the chainring (1/8) and sprocket (3/32) relative to the chain helped zero in on adjustments - the more central the quieter obviously, and slightly adjusting the crank bolt (its a self extracting one) to check potential adjustment requirements.

This simple fixed gear isn't as simple as it first seems - I've spent longer fettling with this bike than any other one I have ever owned!

Might take it for a spin to enjoy the zen and a coffee to celebrate!   :thumbsup:
Regards,

Joergen

JonB

  • Granny Ring ... Yes Please!
Re: grumble grumble clank grumble grumble....
« Reply #8 on: July 17, 2018, 11:24:19 am »
Good stuff, well done :thumbsup:

I found that also observing where the teeth were on the chainring (1/8) and sprocket (3/32)

When I first tried fixed I mixed up the drivechain a bit with a 3/32 inner road chainring but pretty sure things got smoother and quieter when I used 1/8 all round ... one for the future maybe as it sounds like you've cracked it so no need to mess around at the moment :hand:

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: grumble grumble clank grumble grumble....
« Reply #9 on: July 17, 2018, 11:36:55 am »
Good stuff, well done :thumbsup:

I found that also observing where the teeth were on the chainring (1/8) and sprocket (3/32)

When I first tried fixed I mixed up the drivechain a bit with a 3/32 inner road chainring but pretty sure things got smoother and quieter when I used 1/8 all round ... one for the future maybe as it sounds like you've cracked it so no need to mess around at the moment :hand:

I've got a 1/8 sprocket, but I snapped my chain whip and the replacement I noticed is 3/32 so didn't want to try that as I have no way at the moment of getting it off again! :)  New 1/8 chain whip is on the cards though :)
Regards,

Joergen

LittleWheelsandBig

  • Whimsy Rider
Re: grumble grumble clank grumble grumble....
« Reply #10 on: July 17, 2018, 11:43:36 am »
Usually it is very easy to repair chain whips.
Wheel meet again, don't know where, don't know when...

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: grumble grumble clank grumble grumble....
« Reply #11 on: July 17, 2018, 12:45:51 pm »
Usually it is very easy to repair chain whips.
Not this one I'm afraid, I can't get a tool in close enough to fit a new chain to the body.

In other new, it's noisy again after 10km. Checked the chain tightness and that's ok. It's not as noisy but enough to know it's there. Think something's snugged up with riding and changed the parameters! Trouble is, is it the sprocket or the BB!.

My digital calipers are broken so hard to check accurately, will ponder some more over my coffee and see how annoying I find it on the way home!
Regards,

Joergen

Re: grumble grumble clank grumble grumble....
« Reply #12 on: July 17, 2018, 12:50:11 pm »
Either switch to a 3/32" drivetrain and use an 8 speed chain or get some louder music. :thumbsup:

LittleWheelsandBig

  • Whimsy Rider
Re: grumble grumble clank grumble grumble....
« Reply #13 on: July 17, 2018, 12:59:02 pm »
You don't use a chain tool to put a new chain on a chain whip. You use a hammer to drive the rivet through the chain whip, ideally on an anvil with a small hole to allow the rivet to be laterally centred within the chain. Otherwise you can use a single speed chain link with circlip to connect a narrow chain to the tool.
Wheel meet again, don't know where, don't know when...

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: grumble grumble clank grumble grumble....
« Reply #14 on: July 17, 2018, 12:59:11 pm »
Either switch to a 3/32" drivetrain and use an 8 speed chain or get some louder music.
Left the headphones at home... ;)

I am amazed at how I tolerant this is to changes in the various parameters...  Need a bigger hammer I expect :)
Regards,

Joergen

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: grumble grumble clank grumble grumble....
« Reply #15 on: July 17, 2018, 04:28:55 pm »
Bit of research shows that the Miche Primato Advanced crankset and BB length 107mm gives 42.5mm chainline (why I couldn't find this when I first built up the bike last year I don't know!)

https://www.miche.it/en/products/pista/guarniture/primato-advanced.html
Under "Tabelle tecnicheis" a PDF drawing showing Chainline, Q and BCD etc. just in case anyone else is searching for this info in the future.

Calculating that up for a 127mm BB gives a chainline of 52.5mm - so all should be OK with just 1 mm spacer in theory (currently 2 fitted at the moment). 

I've measured the current chainline and its now showing 54.25mm! 

I blame the dodgy analog scale on my broken digital calipers!  How it was silent for the first 10km then started getting noisy I have no idea!  I had assumed from my post ride measure that during the ride the torque had tightened up on the BB to move in 0.5ish mm but on a remeasure as I write I get something similar to the calculated plus my spacers  ???

I'll probably take out the 1mm spacer and buy some 0.6 chain ring spacers just in case I need to fettle some more.

Anyway - more fettling!  :facepalm:
Regards,

Joergen

Re: grumble grumble clank grumble grumble....
« Reply #16 on: July 17, 2018, 05:30:45 pm »
Maybe less coffee?
L'enfer, c'est les autos.

Re: grumble grumble clank grumble grumble....
« Reply #17 on: July 17, 2018, 09:19:13 pm »
A thought re chain line, instead of trying to measure same by calculation, as described in this forum try checking chainring/ sprocket alignment with a straight edge making due allowance for 3/32 to 1/8 sprocket chainring difference!
Boots an Spurs

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: grumble grumble clank grumble grumble....
« Reply #18 on: July 18, 2018, 08:55:52 am »
A thought re chain line, instead of trying to measure same by calculation, as described in this forum try checking chainring/ sprocket alignment with a straight edge making due allowance for 3/32 to 1/8 sprocket chainring difference!

I've done that and its broadly in line but not quite, it's a bit tricky getting my straight edge (18inch square) to project far enough into the drop out area to measure the difference however, its either fouled by the seat stay or the spokes!  It looks about as much in line as using mk 1 eyeball on the actual fitted chain.  I've got a 1/8 18t and a suitable chain whip on the way to try that plus some 0.6mm spacers, that should give me more of a fighting chance :)
Regards,

Joergen

JonB

  • Granny Ring ... Yes Please!
Re: grumble grumble clank grumble grumble....
« Reply #19 on: July 18, 2018, 01:40:53 pm »
I've got a 1/8 18t and a suitable chain whip on the way to try that plus some 0.6mm spacers, that should give me more of a fighting chance :)

I'm a big fan of a vice for removing cogs, wrap an old bit of chain around the cog clamp up and use the wheel as the lever. Relies on having a fairly chunky vice secured to a solid bench but has worked well so far which is a good job because the chain whip I bought is rubbish and is only any good for lock ring removal/fiting

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: grumble grumble clank grumble grumble....
« Reply #20 on: July 18, 2018, 01:58:20 pm »
I've got a 1/8 18t and a suitable chain whip on the way to try that plus some 0.6mm spacers, that should give me more of a fighting chance :)

I'm a big fan of a vice for removing cogs, wrap an old bit of chain around the cog clamp up and use the wheel as the lever. Relies on having a fairly chunky vice secured to a solid bench but has worked well so far which is a good job because the chain whip I bought is rubbish and is only any good for lock ring removal/fiting

That's a good option, will keep that for future reference - My big vice is down the end of the garden so not where I usually maintain the bikes, but this tip might have prevented me snapping the whip at the weekend.   :thumbsup:
Regards,

Joergen

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: grumble grumble clank grumble grumble....
« Reply #21 on: July 24, 2018, 08:51:36 pm »
So some sort of success... after lots of combinations, I think this is as good as it will get, sounds slightly quieter than the video portrays

https://youtu.be/p4myycg075I

Ended up with a 118mm BB 1 mm spacer and chainring spacer circa 1.5mm.
Regards,

Joergen