Replacement Bolt - Kong Banana

[aricooperdavis]

I'm trying to replace the worn out bottom bobbin of my kong banana with the "special" one that Tony sells. However, in the process of removing the old bobbin I stripped the thread on the bolt and utterly ruined it. So I need a replacement.

I believe it's a stainless (A4?) M7 button head set screw paired with a shoulder nut, however I can't actually find one of these for sale anywhere...

Any ideas gratefully received!

 

[topcat]

When I stripped mine, for exactly the same reason , I was lucky to have a suitable replacement to hand. Only better.
I like the Banana, but the alloy is really soft, the bobbins wear faster than any others I've come across . And the bolts are rubbish too......But both faults are fixable

 

[Cantclimbtom]

My first ever drop of my first ever access job... the Stop (I was issued by the company) self destructed as I loaded it despite seeming OK when I threaded it.

Lucky for me I had a shunt rope. Assuming you don't go caving with a "shunt" rope, if there's even the slightest question of dodginess or cobbling together nuts/etc, I'd bin it and replace with a whole new device.

 

[georgenorth]

I'm trying to replace the worn out bottom bobbin of my kong banana with the "special" one that Tony sells. However, in the process of removing the old bobbin I stripped the thread on the bolt and utterly ruined it. So I need a replacement.

I believe it's a stainless (A4?) M7 button head set screw paired with a shoulder nut, however I can't actually find one of these for sale anywhere...

Any ideas gratefully received!

Can you use a standard hex head bolt instead?

 

[Fjell]

I decided some time ago that the kid’s inheritance could carry a zero repair approach to rope and SRT gear. When it comes to descenders I get a new one when it doesn’t work well, I don’t take it apart any more. This is def how Petzl seem to design their gear now for sure. I would use plenty of loctite red if you do, although that might mean you only do it once.

 

[Chocolate fireguard]

The button head is not important. I think you can use a standard hex head, as georgenorth suggested.
On the face of it the shouldered nut can be replaced by a washer and hex nut, but the dimensions make that difficult (the washer would be 7mm id, about 10mm od and a bit thicker than the swing plate).
There are some thin stainless washers 7mm id, 13mm od and 0.5mm thick on this site.

10/50X M2-M40 Stainless Steel Ultra Thin Flat Washer Ultrathin Shim Plain Gasket | eBay

M15 / M16 / M17 / M18 / M20 / M22 / M25 / M28 /M30 / M35 / M40. M2 / M3 / M4 / M5 / M6 / M8 / M10 / M12 / M13 / M14. There are high quality DIN988 ultra thin flat washer. A2-70/304 stainless steel.

www.ebay.co.uk

If it was mine I would drill or file the hole in the swing plate out to 13mm and use a stack of about half a dozen of those washers instead of the shoulder section of the nut with a decent washer on top of the plate then a nut.
There is very little load on that nut.

 

[aricooperdavis]

Okay, thanks, that seems very achievable. I'll give it a go and update the thread with some photos.

I'm very aware that this DIY approach to PPE is taking on a lot of personal responsibility. I'm comfortable with that, but many will not be (justifiability so).

Loctite at the ready!

 

[pwhole]

Since I bought the special bobbins the Banana has been a pleasure to use - though the bottom bolt did once come unscrewed halfway down Maskhill, which was fun - it literally fell apart at the bottom of Murmuring Churn pitch, but I was taking the rope out at the time, so not under load. Luckily Tony had a spare bolt/nut which turned out to be much better, and has only come unscrewed once! To put folks at ease, I do check this regularly with my spanner. But the bobbins are amazing - I've used them for three years before even rotating them. A lot faster than ally though.

 

[Badlad]

😲 So it fell apart at the bottom of a pitch but since then has only come unscrewed once. Sounds great 💀☠️

 

[aricooperdavis]

To put folks at ease, I do check this regularly with my spanner.

That might be the problem - you'll be breaking your thread locking adhesive!

 

[georgenorth]

😲 So it fell apart at the bottom of a pitch but since then has only come unscrewed once. Sounds great 💀☠️

If only there was some sort of cheap and widely available alternative which doesn’t fall apart. Things would be so much simple-r 😉

 

[pwhole]

The reason it fell apart was because I hadn't put it back together properly, not because it was faulty - I hadn't realised the hex nut had to be screwed in solid first, then the dome nut after, and I was mistakenly screwing them into each other - and the dome nut hadn't fully bedded up to the shoulder, and so wasn't screwed on far enough. I'm not reckless with SRT at all, despite what folks might be thinking, and I seriously doubt it could fall apart under load - the hex nut was still fully engaged, so the bolt and bobbin weren't going anywhere, just the front plate was loose. It sounds a lot worse than it actually was - the nut fell off when I took the rope out. And the stainless bobbins are unbeatable - if Simples came with those, I would maybe get one. But I've stopped using most Petzl ascending/descending gear, as frankly it all just wears out too fast. My last Basic lasted nine months before the teeth were flat- in Derbyshire. Croll wasn't much better.

 

[PeteHall]

Do I recall that you could buy stainless bobbins for a simple or stop, or have I made that up?

 

[mikem]

Can't for the latest version...

 

[andrewmcleod]

The 'new' (2019) Stop has stainless bobbins as standard, I believe, while the Simple has two aluminium bobbins (which are now identical for easier replacement).

 

[Cantclimbtom]

Do I recall that you could buy stainless bobbins for a simple or stop, or have I made that up?

The old stop there was a replacement stainless bobbin available somewhere, not sure that was from Petzl though

 

[PeteHall]

To be honest, I'd forgotten that there was a 'new' Stop. More than happy with my selection of racks

Of relevance to this thread, my Kong rack has extremely soft bars, so presumably similar/ same material as the Banana bobbins?

 

[pwhole]

I think my next descender, when I finally wear out these bobbins, may well be a BMS Micro, though I guess the postage could be steep - I'm so used to not using a handle now, and the speed difference can be amazing. I went down the main Titan Pitch on a dry fat rope a while ago, and could barely move downwards without essentially slackening off the braking krab completely - it took ages. AlexR came down behind me on a Micro Rack in about 1 minute.