Mechanics and Fixing Any Questions Answered

Ah shucks. It's only been on the bike for a half a year, guess doing big miles is costly! Shame everything is out of stock at the moment! Might look at a cheaper chainset option

Is there a "it'll do" repair for a partially mangled thread. I've just got a bike where the pedal was put in diagonally (on the DS surprisingly). The inner 3-4 threads or intact but one side of the outer few threads is mangled. I can tighten it down and I think it will be fine, but is there anything I could add to give a bit of contact and fill the gap between the threaded section of the pedal axle and the mangled part of the crank thread. I could just add loads of threadlock, but is there something I could leave mostly harden off and then wind the pedal into?

Buy lots of cheap chains and change them more often.

Can try threading the pedal in from the reverse of the crank to clean things up, otherwise a helicoil fix.

It's a bodgy old hack, but I've seen this work before:

1. Cover the pedal thread in grease. Lots of grease. This cannot be emphasised enough.
   
2. Smear JB Weld (the proper kind, not the quick-setting kind) on the inside of the crank threads.
   
3. Thread the pedal in from the back of the cranks.
   
4. Smear the excess JB Weld which gets pushed out around the face of the crank and scrape off any excess.
   
5. Wait for the JB Weld to set (24 hours to be on the safe side)
   
6. Hope you added enough grease so that the JB Weld doesn't stick to the pedal.
   
   

JB Weld is amazing stuff. Part of the engine block on my old race car was held together using it, after I cracked it overtightening a tapered oil pressure sender fitting. If you don't add enough grease to the pedal threads, and the JB Weld bonds the pedal to the crank, it's never coming out again without copious amounts of drilling.

The other option is to build up the damaged thread with JB Weld or (if you have an AC TIG welder) with weld, and then retap it from the back, but that requires a 9/16" tap. And possibly an AC TIG welder.

Yes this is the kind of thing that I was wondering about. It's a bit awkward because the thread is knackered only on one side of the outer end, so the area that needs fixing/gap filling is a sort of rounded wedge. Also, I have wound the pedal in from the back, but the axle doesn't reach all the way through to the outer face, which is the questionable bit. In the above method is it possible to let the JB weld semi-harden, "tap" it with the pedal and then remove the pedal again to allow it to fully harden?

Question:

Where can I get Ridea 3D24 5-bolt Spider only? Can't find anything on the usual places

Appreciated the help

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Got any look pedals, the ones I've seen tend to have a lot of thread.

In the above method is it possible to let the JB weld semi-harden, "tap" it with the pedal and then remove the pedal again to allow it to fully harden?

Not really, no. If it's not set the threads won't be strong enough to last. If it is set, you ain't never getting that pedal off again. There may be a Goldilocks point in between the two, but I wouldn't want to find out what it is. I don't own enough cranks or pedals.

This JB Weld trick sounds like a proper evil genius hack if it works.

A less genius approach would be to simply araldite (epoxy) a pedal into the crank, preferably a pedal that is easily serviceable. Clean the crank and pedal threads first. Obviously it's never coming out again but should still be serviceable.

JB Weld is basically epoxy with very fine bits of steel in it. When it sets it has similar properties to steel, but with a lower melting point.

It's very handy stuff. Just don't buy too much of it - it's a favourite with underworld armourers for making very illegal soft-nosed bullets.

I wondered about epoxy, but since it's coming down to a feather edge, my feeling is that it would be too brittle. I wondered about isopon (or even the two-part wood filler that smells the same), since it's really tough but doesn't seem to set quite as crispy as epoxy.

@Brommers interesting! Every day is a school day. Makes sense.

@ffm

feather edge

...do you mean that it's a thin layer of epoxy? If so I don't think that's a problem. Epoxy is used in laminates and the thicknesses are very low. A thin wafer of epoxy resin by itself would not be strong, but luckily in this application it would holding together a nice metal sandwich. You know, a sort of spiral sandwich.

I think what is most important is the size of the surface area available for the epoxy to grab onto. Should be heaps here.

As @Brommers said, if the epoxy (or JB Weld) cures with the pedal in the crank, it's never coming loose.

do you mean that it's a thin layer of epoxy?

Not just thin, but reducing in thickness down to nothing. This is because the mangling of the thread only on one side at one end effectively makes the hole tapered. I don't really want to glue a pedal in there, what I want to do is provide support where the thread is mashed in order to stop any flex of the joint, which would increase strain on the intact threads and increase their chance of failure. I worry that very thin epoxy would crack and flake out with any movement and so not do that job (plus, I don't want to glue the pedal in).

I’d definitely just find a scrap pedal with a long thread and go at it from behind. You only need to clean up those outside threads enough to get the pedal started and the rest of the good threads will hold it once it’s in straight

Ok fair. I appreciate that gluing a pedal in is not the ideal option.

And I would agree that building threads from pure epoxy resin could just result in little thread-shaped shards of epoxy on the floor (as opposed to JB Weld which sounds more suited).

FWIW I would also start by screwing a pedal from behind as @PhilDAS and a few others have mentioned - provided you can find one with a long enough threaded axle.

I have a 20" QR wheelset on the way.

Found out fork requires thru-axle (rear is QR).

Do I have any options for these to work with one another? Is there an adapter to let the QR wheels work in the thru-axle fork?

What hubs are the wheels built around? A lot of hubs now come with changeable end caps that allow you to fit the wheel to different axle types.

@andyp,

Can disregard... I thought they were still enroute. As luck would have it, shop was able to get my message in time so paused/cancelled order. They're sourcing a thru-axle hub to fit as appropriate.

Another tool identification question. My guess is that this is for facing brake mount? But Googling the markings on it (Silva 717 HS/C1 5/93) doesn't give me anything useful. Looks like it needs some parts.
(Sorry about the filthy hands and other flesh on display)

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Have you bought a job lot of mystery bicycle tools?

Could well be. If it is, there's a lot of bits missing though.

Yeah, it happened again...

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Lots of VAR stuff, some Park Tools and random bits and bobs. Started sorting my tools yesterday and the final purchase showed up today.

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