The creaking.

[Kell]

Just so you can see what I'm on about, I've video'd me pedalling about in our work car park.

As you can hear, it creaks really badly when pedalling hard. And at the end, you can hear when I'm sat down but pressing on the pedal.

Any ideas.

View: https://youtu.be/0RYbrBmqh0U

 

[Yellow Saddle]

That squirty creak sounds a lot like Shimano SPDs on some shoes. Can you replicate the creak using ordinary shoes?

 

[srw]

It's a Brompton. All Bromptons creak.

 

[Fab Foodie]

It's a Brompton. All Bromptons creak.

It's why London's so noisy ....

 

[shouldbeinbed]

Just listening to the noise, it sounds saddle &/or seatpost to me but at the end when you're rocking on the pedal seems to belie that. its not SPD related is it? sounds too loud for that tho.

My Birdy seatpost can creak like a 4 mast sailing ship in a hurricane when I'm honking on it.


Edit; is the back end all bolted nice and tightly together, v unlikely but could it be some flex at the rear axle????


The only other suggestion is a trapped hamster

 

[12boy]

Sure sounds like a suspension block to me. The force of pedaling compresses the block more than bumps in the road. I have had to really tighten this down after greasing the shaft. With mine, the noise increased with with the force of pedaling so that on level ground not as much as going up a steep hill. Do you have a Brooks saddle? They, too, can creak under the same conditions,, more when pedaling hard than just sitting there or pedaling easy.

 

[Kell]

With the suspension block. I removed it entirely last weekend and greased the contact patch with the frame. This has not really solved anything.

Other than when I got caught in the rain, the creaking disappeared entirely.

I don't think it's pedal related, but it is worse when I press down on the left pedal.

However, as they're spd's I unclipped the left one and pedalled only with the right and the creaking was just as bad.

It disappears when I stand up and pedal.

And it doesn't happen if I sit down and freewheel.

I can't replicate it by not peddling and bouncing up and down on the bike.

It's worse when pressing on. Which for me is pretty much all the time.

I don't think it's the seat post clamp as I've tried it tighter and looser and it makes no odds.

And I've greased the seat post rails where they fit into the pentaclip and that's not made any difference.

My theory is that it's the rocking motion of pedalling which is causing the problem. Could it be a torsional force on the rear swing arm joint?

 

[12boy]

Were it the rear arm joint, the pedal or the BB it would squeak when standing because standing is when most torque is applied. Being a bit neurotic, BTW,I drilled a very small hole in the top of the joint, making sure to keep the metal caused by drilling out of the hole, and injected some oil in the hole to better lube the bushings therein. Since I wax my chains I had some wax available which I warmed to be malleable and worked into the hole after oiling. If I have to have the joint rebuilt I will put a Zerk fitting in there so I can shoot it full of grease. What kind of saddle are you using? If it is a Brooks switch out to a regular one and see if that does it. If not I would tighten the suspension bolt a bit more. You can check the suspension by using the brakes to prevent the bike from moving and putting your weight on one pedal. When you do this you can see the block compress.

 

[Rohloff_Brompton_Rider]

Another vote for the saddle. Possibly a rear frame hinge squeak, might be worth trying to get some thin oil in there, it might help if it is worn.

 

[Kell]

I'm hoping that loosening and tightening the rear frame might have cured it.

Seems to have gone on a quick test ride. But I'll see tomorrow when I use it in anger.

 

[srw]

I'm hoping that loosening and tightening the rear frame might have cured it.

Seems to have gone on a quick test ride. But I'll see tomorrow when I use it in anger.

Beware - the rear frame can come undone. Keep checking it, and if necessary add some threadlock.

 

[Kell]

Well I've done about 10 miles this morning and the creaking has completely gone.

Just the tick-tick-ticking of the SA hub (and my wheezing) as I barrelled along this morning.

In fairness to everyone else's comments, I tried everything else before finally deciding on doing something with the hinge. Took the suspension block apart and greased it inside and out, front and back, regreased the seat rails, checked the seat post clamp, oiled the spds and added a few more drops of oil to the rear hub.

Part of the reason for doing everything else first was because when I first tried attacking the bolts for the swingarm, a 4mm allen key wouldn't fit, and a 3mm allen key was too loose. I thought they'd used a weird size that I didn't have.

Once everything else didn't work, I tried again. The 4mm allen key just needed a bit of persuading to go in.

It was a little loose on the drive side - handily, as you can't access this without removing the front ring.

For such a vital part, I'm surprised that it's held on by such a small bolt.

I did put some copper slip on the bolt before refitting.

 

[12boy]

By simply tightening the bolt that goes into the hinge you removed the creaking? If so that is very good to know.

 

[jonny jeez]

Saddle

Seat post

Shoes

Pedals

Bars

these might all be sorted with adjustment and liberally lubing.

also from my experience, check that the wheels are seated properly and that the skewers are actually tightening and not just getting tight. Place some grease on the skewer roller (at the hinge of the thumb lever) to ensure the lever is actually tightening the wheel. if this is not seated correctly it will creak as you put pressure on the crank arms.

PS cant watch the video, am at work.

EDIT...damn, too slow!

 

[Kell]

It certainly seems that way in the short term.

I'll let you know whether this cures it long term.

From reading elsewhere on the interwebs, this is quite a delicate hinge and Brompton reckon it needs replacing every two years. But surely that's mileage and weight (of rider) dependent, as well as your style of riding.

So far since August last year, I've done around 1,800 miles and I weigh in at a not insubstantial 16 stone.

I do get out the saddle quite a lot when I ride though, maybe I'm too aggressive and should not cycle in lycra, but pootle about in my tweeds.