Chain Ring Issue - Query

ROK ON

I think that my front chainring is slightly dented.

Several times yesterday on a cycle the chain would not stay on the FRONT ring when in a fast gear at 11 thru 14 sprocket on the REAR.

Optically, it does seem as if the ring is dented as when I look at a revolution, there is a point where it moves inwards then outwards.

I am going to buy a new chainring - question. Other than an Allen Key, do I need any special tools to change a front chain ring.

FWIW - it is an Shimano Ultegra SL 50 tooth ring that I would be changing (110bcd).

RobFowl

No, Allen key only
Have you tried a hammer first

Raam

You might need something to stop the bolt housing turning behind the ring. There is a special tool, but a large flat head screwdriver will do the same job. Shimano I assume? Mostly it's not needed though.

Keep_Her_Lit

An allen key on its own will sometimes suffice. If you're lucky, the chainring nut will grip the back of the chainring with enough friction to stop it from turning while the bolt is being tightened.

But often the nut and bolt will begin turning together before they are fully tightened. In that case, you may or may not be able to stop the nut from turning with a flat bladed screwdriver; it depends on whether the chainring bolt protrudes into the slot as it is being tightened.

A chainring peg spanner will do the trick regardless and is a cheap and cheerful little tool. This seems like the perfect excuse to expand your collection ...




http://www.chainreactioncycles.com/Models.aspx?ModelID=10182

padjo5

Had the same problem, after derailling a chain. Tried the hammer approach, to no avail! Very simple procedure to replace it, with 2 Allen keys.

Lumen

Pliers work better than a hammer.

C3PO

Lumen wrote: »

Pliers work better than a hammer.

.... and an adjustable spanner better again!

Raymzor

Why not remove the chain outer chainring, lay it on a flat surface, and this will indicate if it is bent-this will help you find where in the chainring the distortion is. is there any movement on your bottom bracket?

doozerie

Lumen wrote:

Pliers work better than a hammer.

True, but using a hammer is ultimately more satisfying. This philosophy applies to any aspect of bike maintenance, in fact - removing wheels, saddles, brakes pads, etc., can all be done better with appropriate tools, but none of those tools yield the endorphin rush that you get from having "bate the bastards off" with a trusty hammer. It's a man thing.

...the tears that follow when you realise you've destroyed various parts of your bike, that's not so manly so we don't talk about that.

Lumen

doozerie wrote: »

True, but using a hammer is ultimately more satisfying

You don't need to convince me of this. I melted part of my powermeter crankset with a blowtorch.

doozerie wrote: »

...the tears that follow when you realise you've destroyed various parts of your bike

I don't cry. I just sit amongst the carnage, staring into space, transfixed by my own idiocy.

doozerie

Lumen wrote:

You don't need to convince me of this. I melted part of my powermeter crankset with a blowtorch.

I am in (manly) awe. You are an inspiration. My collection of hammers suddenly seems inadequate.

Lumen wrote:

I don't cry. I just sit amongst the carnage, staring into space, transfixed by my own idiocy.

On the plus side, you can use your blowtorch to burn the sh1t out of that space you are staring into, which is almost as good as hitting expensive things with a hammer. The glass is half full, what's more, it's half full of petrol!

jimm

ROK ON wrote: »

I am going to buy a new chainring - question. Other than an Allen Key, do I need any special tools to change a front chain ring.

FWIW - it is an Shimano Ultegra SL 50 tooth ring that I would be changing (110bcd).

Some of the Ultegra chainrings have bolts with Torx heads and an Allen Key won’t fit them. I discovered this when I had to change the 34 ring on a compact chainset. In my case it was the Ultegra Ice Grey version. Best to check what chainring bolts are on yours before starting. I also used the tool that Keep_Her_Lit suggested and had no problems.