Wits end removing the last screw on chainring
 

Hello,

I have 5 year old bike that I'm learning to service, I'm removing the chainring and have removed the 4/5 hex keys with the chainring wrench but the last nut simply won't unscrew however tight I hold the wrench it simply rotates over it :(

Any idea how else I can remove it? Any help is appreciated
https://cimg0.ibsrv.net/gimg/bikefor...6aacecbd59.jpg

I would lay it flat drive side down, add penetrating oil, and let it soak a day or two. If the chain has that much rust then the chain ring bolt might have rust too.

Thanks for the reply. The nut is actually really loose, sprayed it with wd-40 but the wrench doesn't seem to stay in the groove while I turn it - I'm holding it down with all my might

Here is a gif https://gifyu.com/image/u1VY

Clamp the wrench down to the chainring with vice grips and loosen with allen keys.

Try the above. Also, I have had good luck with an electric impact wrench. My last stuck chainring bolt I had to drill out. Not too bad of a job. Replacements are not too expensive.

However you get them out, I’d advise replacing them with truvativ chainring bolts, which use hex holes on both sides.

The VAR-35200 is designed for this type of chore. Unfortunately, it's not cheap, but perhaps a local bike shop has one and can remove the bolt for you? Make sure the bolt threads are lubricated to reduce the chances of this happening again.

It looks like that tool is designed primarily for tightening chainring bolts, not loosening them. As soon as you begin to loosen the bolt, it will lose its grip on the nut, and allow it to spin in the chainring it the bolt is seized up inside the nut.

That appears to be a spring on the device, not a thread. So as you turn to extract the bolt, it wont back off.
Not the best picture if you're trying to sell em!

Barry

Hard to tell from the picture, but I can see your point and how it would work. Still, I doubt that the spring would provide sufficient clamping force on the nut to keep it from spinning if it was seized on the bolt.

It both loosens and tightens. I have one of the newer versions and use it all the time at the shop. I don't think it would do much on a bolt that's really stuck though.

https://www.vartools.com/en/combined...s-var-p828.php

Yeah, I realize that now that I saw that it was spring loaded, rather than threaded like a chain breaker tool. But, like you said, the spring force would probably not prevent the chainring nut from spinning if it was seized on the bolt. Curious, how do you deal with stuck chainring bolts ?

A drill, bolt extractor tool and hammer.

I have a Craftsman set, not expensive; instructions on the tool sleeve. Drill, hammer in the tap and unscrew with box wrench around the tap.

That won’t work in this case. The problem is not that the bolt socket is stripped, but rather that the nut is spinning in the chainring as the bolt is turned. What is needed is something to keep the nut from moving as the bolt is turned.

This usually does the trick:

https://www.vartools.com/en/chainrin...r-var-p409.php

Have you ever seen a chainring bolt?

Cool ! :thumb:

Unless you have a means to secure the slotted nut to prevent it from spinning (precisely the OP's problem), there's no way to drill it out; the whole assembly will just spin.

Good to know VAR is still around and making tools as well as doing a few other useful things in the industry. Not as nice as the old stuff but modernized can be good as well.

If you hold the outside with an allen wrench, you can drill the inside. Big enough bit to do the job but not touch the crank spider or chain rings. If you're good with a vise grip you may want to give that a try first.

When I drilled mine out 2 weeks ago I used the little wrench tool on the back and drilled out the hex side. The worn nubs still had enough grip to let me drill the bolt out. Not too bad a job. The bolt poped out with no damage to the crank arm.

Ride Safe,

Joe

Try heating with a torch. Otherwise just drill it out.

Thanks for the suggestion, I even went to my local bike ship and they said he couldn't remove it either. Either way I'm looking to upgrade from the stock chainring so I suppose it's the time now :)

Thanks everyone for the reply, I will try drilling it out or perhaps replace the 5 year old stock chainring