Mystery creak

[Tcc]

I have a 1970 Holdsworth and it has a mystery creak from the Chainset area but only when the chain is on the smaller chainring.
I have regreased the bottom bracket and dismantled the Chainset and put copper grease between all the bolts and chainrings.
It’s a new chain but the gears run and change smoothly with nothing catching.
The bike is all Original Campag record
Any help gratefully received!

[Jdsk]

As previously identified many times... creaks can come from surprisingly far away. So don't narrow down the investigation too early.

Is it once per turn of the crank?

Can you reproduce it with the bike on a stand?

Good luck.

Jonathan

[Tcc]

Thanks Jonathan
Yes it’s once per turn and only when I ride the bike and press hard - nothing noticeable when on the stand.
The fact that it’s only when the small chainring is engaged is making me think chainring or chain
Regards
Tim

[mig]

alot more torque is forced through the bike when on the small chainring - especially when climbing. you also sit forcefully on the saddle. i wouldn't be surprised if it was in the seat area.

or either knee.

[Jupestar]

Fron what you have said so far I would double and triple checking the chainrinig bolts are really tight and installed correctly/.

Is it when you push hard on either leg or just one side? Is the creak at a consistent spot on the pedal rotation?

If you change the rear cog, does the creak still occur in the same place in the pedal rotation?

[Tcc]

Many thanks for all those ideas - I’ll report back!

[slowster]

Firstly, if you have not already done so, you should try to systematically isolate different potential causes when riding. For example, see if the creak disappears when you ride out of the saddle, which would narrow down the likely cause to the saddle (especially rails/clamp interface) or seatpost/seatclamp/seat tube.

Secondly, there have been a few similar threads over the years where location of the creak was eventually found to be the rear wheel, and I would check for this especially, given that the fact that it occurs in the small ring is when the most torque is transmitted through the chain to the rear sprockets, freewheel/freehub and axle. For example, I would suggest checking that the rear quick release is clamped sufficiently tight and that the axle is not moving slightly in the dropout.

[Tcc]

Thanks again
Just put a different chain on with no difference
It’s both sides, same spot and when I stand up too
Will investigate the rear wheel
Thanks again

[roubaixtuesday]

+1 for quick release on rear wheel. And greasing the dropouts is more reliable than tightening to eliminate it. I had one of these a couple of weeks ago after spending hours looking for the cause.

Also saddle rails is a common one - does it happen out of the saddle?

Other suggestions:
try putting the front wheel between your knees and apply twisting force to the bars in all three axes, to see if you can replicate
Pedal bearings/cleats
Fixings to the frame can cause these - racks, bottle cages etc. Tighten them

Good luck, can be extremely difficult, and of course a new one normally promptly appears!

[rjb]

I was given a bike by a frustrated owner who couldn't sort a creaking chainset. He had even renewed the bottom bracket with no improvement.
Tuned out to be the seatpin, stuck in the seat tube. Penetrating oil released it. It could be something simple like the saddle rail moving in the plastic saddle. Squirt of furniture polish cured that one.
Keep looking you'll find and cure it eventually.

[al_yrpal]

I had one for months and fixed it by tightening screws on the pedals.

Al

[pwa]

alot more torque is forced through the bike when on the small chainring - especially when climbing. you also sit forcefully on the saddle. i wouldn't be surprised if it was in the seat area.

or either knee.

I had a similar creak that I thought was coming from the bottom bracket area, but which turned out to be the seat post needing one more turn of the allen key. It creaked in time with rotations of the cranks because it was generated by my bottom moving in time with the cranks.

[Phileas]

I also have a creak that might seem as though it could be from the crank but in fact is seatpost related.

At first thought it couldn’t be because the creak is just as bad when out of the saddle. But I recently raised my Carradice SQR bracket and it got worse which is what made me focus on the seatpost. If I leave the bag off, the creak mostly goes away, so it seems like the swinging weight of the seatpost bag is sufficient.

The creak is also considerably worse when the bike is warm after being in a hot bike shed all day.

[richardfm]

I'm trying to chase down a similar creak. I thought I had found when it appeared to go when I was out of the saddle. I tightened the seat post and the saddle and thought I had cured it, then it came back. I'll go back to the seat post/saddle and also consider some of the suggestions here.

[ihc]

I'd suggest removing the pedals, clean and regrease all the threads and then reassemble everything at a decent torque. I have had a similar creak to the one you describe several times and it has always been the pedals.