Chainring slotted female nuts ?

[deliquium]

Why are they designed thus?

Has anyone tried to use the

https://www.parktool.com/product/chainr ... %20Bracket

spanner?

Is it the worst ever hand tool?

[Mick F]

Often wondered WHY?

On my Moulton TSR90, the Stronglight Triple has Allen fittings inside and out. One bigger than the other. Big size inside.
I wonder if they can be bought as items and used for other chainsets instead of the slot-drive?

[Brucey]

if the threads are clean and well greased, there is absolutely no need for any such tool; the sleeve will stay put as you tighten the inner part of the bolt with an allen key.

To check that the bolts are clean enough, just run the inner in and out of the outer before you install the bolts.

If the bolts are not clean and well greased, they will be difficult to tighten (regardless of tools used), will be prone to seizure, and may allow all kinds of horrible creaks to develop.

If you insist on not greasing your bolts correctly you will need a tool of some kind. You could buy this VAR one



I dunno if it is any good; I do know that is costs more than three quid though.....

cheers

[robgul]

Agreed that the flat spanner thing is useless - I have a sort of screwdriver like this
bought from Wiggle IIRC - if you clamp the Allen key in a vice pointing upwards and then put the chainwheel side bolt on it you can then (usually) use the screwdriver to turn the "nut" part.

Rob

[Samuel D]

I think the flimsy, unergonomic design of the cheap chainring nut spanner betrays the fact that these nuts (or sleeves) need practically or literally no torque to be held in place. I have such a spanner, because adding it to an online order got me free shipping and reduced my total cost, but I’ve never needed it. As Brucey describes, the nut stays put while you turn the bolt from the other side. If it doesn’t immediately do so, turn the bolt a bit until the vagaries of stiction take care of the problem. In cases where the sleeve continues to spin, mere finger pressure is often sufficient to stop it.

I’m also curious about the history of this chainring bolt design.

[Fraz101]

I have a creak at the BB only when pedalling hard. Wanted to check my chain ring bolts for tightness but they look like this?
Are these rivets?



I'm a trendy consumer. Just look at my wobbly bog brush using hovercraft full of eels

[foxyrider]

Are these rivets?

OMG there's still some of those in use? Thought they'd all died and gone to the big scrap yard in the sky (well the local tip anyhow!)

[foxyrider]

I do have one of these 'spanners' and I do find it useful when the bolts are a bit stubborn - I don't have steel finger tips and I prefer to keep the flesh intact!

[Fraz101]

I'm guessing they are rivets?

[Tigerbiten]

Another vote for an allen key in a vice and the slotted screwdriver from above trick to tighten the chainring bolts .....

[foxyrider]

Not just rivetted but the crank and spider are swaged together too.

Not a great recipe for longevity and no chance of maintaining if anything gets loose

[Fraz101]

It's more a click click twice per revolution,anything other than an extremely light pedalling will cause it to click.

No play or roughness in bb bearing or pedals.

It's definitely coming from chainring/Bb area

[dragonrider]

Brucey refers to tightening these nuts/bolts and suggests if things are cleaned and greased there is unlikely to be problem, but my problem has always arisen when trying to undo them and that is when the confounded slotted nut rotates.

My solution is quick and easy. Snap off the end of a used hacksaw blade and fix it in a mole wrench. As I always keep a used hacksaw blade and I have two ancient and inherited mole wrenches I am never without the requisite tool.

Despite overcoming the problem I think it is a rubbish piece of engineering design in the first place.

[Mick F]

Despite overcoming the problem I think it is a rubbish piece of engineering design in the first place.

Agree.

[Brucey]

Despite overcoming the problem I think it is a rubbish piece of engineering design in the first place.

Agree.

I think it is a very clever piece of design, and it is all based around the fact (a fact that is no longer taught to engineering students BTW; they are told it doesn't make any difference.... ) that a fine pitch thread needs less torque for a given amount of fastener tension; in most cases (assuming you do use grease like you are meant to) you only need one tool to tighten or loosen the chainring bolts, yet there is no need for a special feature to render the sleeves captive.

The first thing you should do with a new chainset is to remove the bolts, test that they run in and out of one another properly as previously described, grease them (threads only) with something decent (like finish line Teflon grease) and put them back together. If you do this you can retighten them in a few seconds whenever you like, you won't have any problems taking them out again even after several years, and you won't be turning the air blue around you, trying to use crappy tools or making spurious claims about whether the design is at fault or not.

BTW if you use an allen key in a bench vice, and a tool in the sleeve as described by robgul (BTW I usually grind one up to suit, using old cutsaw blades which are thicker than hacksaw blades) then it is essential that you turn the crank and the tool together if the bolt is still clamping the assembly together. Otherwise you will be using effort to turn the sleeve within the assembly, which is a complete waste of effort and may overload the tool.

[edit; apologies if this is obvious but if you want to grease the threads of a nut and bolt properly, you need to coat both parts in grease before you assemble them. If you need this to be proven to you, coat the male part only and run it through (a shorter) female part so that the male part protrudes. Usually there is precious little grease evident on the protruding part of the male bolt; most of it will have been wiped off en route.]

cheers