Author Topic: Stiff hinges (Read 11735 times)

quixoticgeek · « **on:** 16 February, 2020, 10:12:11 pm »

The main frame hinge is getting really stiff now.

What have people found most effective to lube this hinge? Would chain lube work? Wd40? Or should I invest in some sort of penetrating oil?

Thanks

J

bludger · « **Reply #1 on:** 16 February, 2020, 10:20:06 pm »

I'd use Boeshield T-9 if you can get it. Great for chains too.

https://boeshield.com/uncategorized/uses-for-boeshield-t-9-around-the-house/

https://boeshield.com/marine/

grams · « **Reply #2 on:** 16 February, 2020, 10:24:36 pm »

A couple of drops of chain oil normally does the job.

I assume you mean Brompton and not knees.

drossall · « **Reply #3 on:** 16 February, 2020, 10:31:50 pm »

Quote from: bludger on 16 February, 2020, 10:20:06 pm

I'd use Boeshield T-9 if you can get it. Great for chains too.

I use white grease, but might try that. As you say, if I can get it.

Ham · « **Reply #4 on:** 17 February, 2020, 10:53:35 am »

You should also carefully examine where the apparent tightness is coming from, and especially if all components are aligned as intended. Sometimes with folders, wear (or, loosness) in one component shows up as tightness in another. Reversing gravity whilst observing the interplay of all components is good for that. (Turn it uʍopǝpᴉsdn and see if it rattles)

quixoticgeek · « **Reply #5 on:** 17 February, 2020, 11:14:49 am »

I put a couple of drops of Chain-L lube on the hinge last night. Will see how it is this afternoon when I ride to the shops.

Thanks all!

J

jiberjaber · « **Reply #6 on:** 17 February, 2020, 12:50:24 pm »

Dental floss and a spray of gt85 sorted mine. I also took the opportunity to take out the bolts and clean and add some light grease.

Much improved!

quixoticgeek · « **Reply #7 on:** 10 May, 2020, 06:38:10 pm »

It doesn't seem to have made a major improvement in hinge performance.

How easy is it to remove the hinge pin and reseat?

J

LittleWheelsandBig · « **Reply #8 on:** 26 May, 2020, 10:50:16 pm »

The hinge pin needs to be drilled to remove the flare and then driven out. A replacement pin is pushed in and flared. You may wish to ream out the hinge. The three pin sizes are nominally 6.0mm, 6.1mm and 6.35mm to compensate for wear.

drossall · « **Reply #9 on:** 27 May, 2020, 08:22:58 am »

My Brompton isn't getting used daily, as it usually would, because of not commuting. I'm finding that the hinges get stiff if not used. I had trouble unfolding it yesterday.

quixoticgeek · « **Reply #10 on:** 27 May, 2020, 12:51:52 pm »

Quote from: LittleWheelsandBig on 26 May, 2020, 10:50:16 pm

The hinge pin needs to be drilled to remove the flare and then driven out. A replacement pin is pushed in and flared. You may wish to ream out the hinge. The three pin sizes are nominally 6.0mm, 6.1mm and 6.35mm to compensate for wear.

I think that may be something I pay someone to do. Mostly so that if it goes wrong, it's their fault not mine...

J

giropaul · « **Reply #11 on:** 27 May, 2020, 06:50:42 pm »

I was about to make some comment about Hinge being a bit stiff, and Bracket’s looking worried.

But I’m probably the only person old enough to find it amusing!

LittleWheelsandBig · « **Reply #12 on:** 28 May, 2020, 11:01:26 pm »

I understand the reference but have never actually heard/ seen them.

Just for completeness, the hinge pins also come in two lengths, one for LWB frame hinges (I have those in all diameters) and another for SWB frame hinges and handlebar stem hinges (ditto). All good fun.

quixoticgeek · « **Reply #13 on:** 20 December, 2021, 09:33:19 pm »

It finally got so bad i took her to the vet. They kept her for over a week as it took them a lot of effort to get the old pin out. They eventually drilled it out

I had forgotten how smooth and free moving the hinge should be. Need to adjust my muscle memory.

J

bhoot · « **Reply #14 on:** 18 December, 2022, 03:13:51 pm »

Just encountered this issue on our two household Bromptons - both B75s, one dates from March 2020 and one from summer 2021, so not very old and not used particularly heavily.

The really odd thing is that both bikes have been from being fine to almost impossible to fold/unfold (main frame hinge only, stem hinge is fine) in about 2 weeks, gradually getting worse. And at exactly the same time. We took them to the Hebrides but most of the time there they stayed indoors folded in their bags as they arrived from the flight, only being unfolded the last day to ride to the airport for our flight home, so they weren't exposed much to salty air or left out in rain. Transit damage while flying seems unlikely - no sign of anything and the chances of that affecting both bikes identically seems very small. The one thing we did which I don't think we have ever done before with previous bikes was to hang them on the sleeper train rather than fold them - we had booked bike spaces so decided to use them. Is there some (apparently unpublished) rule that a Brompton must not be suspended by the front wheel?

We have started trying to free them with a drop of 3 in 1 as we had that available, but no real sign of progress.

LittleWheelsandBig · « **Reply #15 on:** 18 December, 2022, 03:31:49 pm »

Some good lubrication and repeated folding/ unfolding will stop things getting worse and likely improve things a bit but ultimately replacement of the hinge pins was what worked for me.

bhoot · « **Reply #16 on:** 18 December, 2022, 04:10:08 pm »

I am rather surprised if the pin needs to be replaced on a bike which is only 18 months old though, but yes it might come to that.
It also seemed odd that two bikes of different age showed the problem at exactly the same time, which suggested some external factor.

LittleWheelsandBig · « **Reply #17 on:** 18 December, 2022, 06:18:30 pm »

Same time because they were exposed to the same conditions. My guess is corrosion or grit. Try a high quality penetrating lubricant.

jiberjaber · « **Reply #18 on:** 18 December, 2022, 08:15:35 pm »

Dental floss and GT85

rogerzilla · « **Reply #19 on:** 18 December, 2022, 09:03:55 pm »

Wasn't there a punk band called Stiff Little Hinges?

LittleWheelsandBig · « **Reply #20 on:** 18 December, 2022, 10:24:15 pm »

Not sure but I'm certain there was a song called Sticky Hinges