The QUICK question thread.....

[crash3]

First proper ride on the new bike yesterday, when pedalling in the lower gears (and not changing gears) heard what sounds like that chain grinding noise you get when you try to change gear under load. I noticed this after about 1 min of riding. Noise is loudest at lowest gear, proportionally quieter with every gear up.

Went to adjust rear derailleur this morning, alignment looked fine at both largest and smallest cogs. Found noise still while pedalling on my 'bike stand', but noise is actually coming from the bottom bracket/chain-ring area. Blew this area with compressed air to clear any potential grit & dirt, nothing much came out. Noise persisted during today's ride.

My suspicion is this noise is from the large angle at which the chain is approaching/departing the chainring, as the noise seems proportional to whatever angle this is, and the fix is going to be a chain-guide/bash guard.
Any other ideas?

 

[creaky]

Chain routing through the RD all good (gotta ask).
Have you got the correct offset chainring for your frame (e.g. boost w/- non-boost)?
Put up photos of the chainline from behind with in the smallest and largest cogs.
You don't have the narrow chain holes running on the wide chainring teeth?

 

[crash3]

Chain routing through the RD all good (gotta ask).
Have you got the correct offset chainring for your frame (e.g. boost w/- non-boost)?
Put up photos of the chainline from behind with in the smallest and largest cogs.
You don't have the narrow chain holes running on the wide chainring teeth?

RD = rear derailleur? If so then yes. I have made that mistake before, but It's a brand-new bike I unboxed and assembled Tues night, didn't touch the drivetrain other than fitting pedals and lubing chain before riding. Assembly was just pedals, seat post, handlebars and front wheel, other than that it was ready to go. I did check the alignment before riding but it looked fine. Will chuck up some photos from the rear tonight.

I hadn't checked (or considered this as a potential issue) your last point, but I will when I get home. But as it was a new bike and the drivetrain was pre-assembled, chances are that would be correct.

 

[shiny]

External routed dropper post. When I sit it sinks.

was thinking cable tension. Fresh cable. Same result. As soon as there is tension on the connector it sinks. Worth pulling apart and checking internal string bit? Thinking the cartridge had finally died. 8yr old post.

 

[pink poodle]

External routed dropper post. When I sit it sinks.

was thinking cable tension. Fresh cable. Same result. As soon as there is tension on the connector it sinks. Worth pulling apart and checking internal string bit? Thinking the has cartridge finally died. 8yr old post.

Time for a new bike.

 

[shiny]

Time for a new bike.

I wish. Loathed to spend any more on this one as want a shiny new one but got to keep it running. Might have to see if there is anything in farcebook I can grab cheap.

 

[creaky]

External routed dropper post. When I sit it sinks.

was thinking cable tension. Fresh cable. Same result. As soon as there is tension on the connector it sinks. Worth pulling apart and checking internal string bit? Thinking the cartridge had finally died. 8yr old post.

Which post? Some are serviceable, some aren’t.

 

[shiny]

Which post? Some are serviceable, some aren’t.

KS LEV. Just serviced it and the string bit snapped when re-connecting to little claw bit. Doh. No riding this weekend.

 

[creaky]

KS LEV. Just serviced it and the string bit snapped when re-connecting to little claw bit. Doh. No riding this weekend.

PM @Nerf Herder and see what the options/costs would be for a fix, then decide if it’s new bike day or not.

 

[shiny]

PM @Nerf Herder and see what the options/costs would be for a fix, then decide if it’s new bike day or not.

Bought a second hand one off a local bloke this arvo. Wouldn’t budge on price but will keep the bike going for a bit longer.

 

[Freediver]

KS LEV. Just serviced it and the string bit snapped when re-connecting to little claw bit. Doh. No riding this weekend.

Snapped or pulled the little barbell bit of the end. I'm pretty sure its spectra and even when it's that skinny it's got a pretty good breaking strain.

 

[shiny]

Snapped or pulled the little barbell bit of the end. I'm pretty sure its spectra and even when it's that skinny it's got a pretty good breaking strain.

Hmmm..well the barbell barrel thing did fly across the shed never to be seen again. Didn’t bother to check the length of the cord after as had enough and called it quits.

 

[crash3]

Chain routing through the RD all good (gotta ask).
Have you got the correct offset chainring for your frame (e.g. boost w/- non-boost)?
Put up photos of the chainline from behind with in the smallest and largest cogs.
You don't have the narrow chain holes running on the wide chainring teeth?

RD alignment on biggest cog:

Chain coming off chainring (biggest cog):

 

[pink poodle]

That looks like a lot of angle off the front ring.

 

[Minlak]

That looks like a lot of angle off the front ring.

I would be dropping that spacer in the BB

 

[creaky]

Chain coming off chainring (biggest cog):

It does look like a sharp angle from the chainring to the granny in the 2nd photo. Can't see the full top chain line in the first photo though.

 

[creaky]

I would be dropping that spacer in the BB

Don't drop it ... move it to the other side.

 

[crash3]

That looks like a lot of angle off the front ring.

Yeah I thought so too. Reckon that's where my noise is coming from.

Don't drop it ... move it to the other side.

I'll get around it on the weekend.

Thanks for the advice all.

 

[pink poodle]

Definitely a source of some noise. A crunchy grindy sound as the links wrestle their way onto the ring.

 

[crash3]

Definitely a source of some noise. A crunchy grindy sound as the links wrestle their way onto the ring.

Yeah that's it. Decreases in volume every cog I jump closer to the centre. Haven't gotten to the smallest cogs yet so don't know if it does it there, but it's safe to say I'll be using the lowest more than the highest so should set the bike up to suit.