Worn bike drive train

 I've seen a few posts on Facebook which ask, "is my chainring worn out", "should I replace my chainring."

I have just replaced a crankset, probably beyond its expected lifespan, which shows clearly what a worn out chainring looks like.

Side by side, the new and the old. Surprisingly, that chainring was not skipping. I only looked at it because the whole drive train sounded clunky!

I am pretty sure this got to that stage quickly because the chain was worn out. I checked the chain a month or so ago but in that time, it has gone from acceptable to thoroughly useless. I blame the wet mud at this time of year.

A chain guide is the best way to check a chain and easy to use.

I was interested in looking at how a chain wears. I have heard people refer to chains as stretching. This is misleading because the components of the chain do not stretch but the pivots wear smaller allowing play. If you push and pull two links you can see and feel the movement of the links. A new chain has virtually no movement along the length of the chain.

In the case of a severely worn chain, if you pull it taught and offer it up against a new chain, you can see how much play there is.

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Bike maintenance experience

You can watch all the YouTube videos and follow all the instructions to the letter but sometimes you only get it right with experience.

My bike has been rattling for a week or so and finally I found the issue.

The cassette was loose.

When I changed the rear wheel, I had set it up exactly as per the original. What I now know is that there are sufficient differences between freehub drivers that some of them need spacers.

I've stripped it down, cleaned it up and fitted a 1mm spacer.

That's enough to allow the lock ring to clamp down on the cassette rather than on to the end of the freehub driver!

That's done the trick and the cassette is secure. I've adjusted up the gear change and taken it for a short test ride.

I also had a creaky bottom bracket (BB). Apparently this is not uncommon and not always easy to fix.

My attempt, at a fix, is to take the cranks off, put the BB press back on and clamp it tighter. I then re-assemble it.

The short test ride tonight is not sufficient to know if the creak is still there or not.

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Update:
I've been for several rides. The creak was gone initially but returned on the third ride as noisy as ever.

"I wonder if anyone will ever do do a SRAM dub compatible press fit bottom bracket with a threaded inner sleeve to lock it in place?"
Perhaps I need to work on that design.

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Derailleur front mount cover

On bikes that ship without the front derailleur but with the welded on mount, they usually have a blanking cover on the bracket.

Typically a plastic tile or even an aluminium shaped billet. Easy enough to buy but also very easy to model and 3D print.

I've created some custom ones.

3D printed.

I filled the letters with Milliput and sprayed with clear lacquer.


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25.4mm wide, 26.5mm tall, 4.6mm thick, 2mm radius corners. 5mm wide x 2.2mm deep keyway on the back. Fit using an M6x10mm or M6x12mm countersunk screw.

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