Replace chain ring and look at bottom bracket

bikegangster

Hello. The teeth on the 34t chainring is worn and obviously needs to be replaced. The 50 teeth ring is a little worn but nowhere near as bad as the 34 ring.

Shall I replace the rings or the whole crankset? I don't think there's anything wrong with the crank. I can still pedal.

As for the bottom bracket, it may be worth inspecting too. Especially it was not once serviced after I bought the bike in 2016! At least there's no friction/resistance as I spin the crank after all those years of heavy use.

And I don't know if I require the bottom bracket cleaned out and re-greased or get it replaced with a new one. Problem is my current bottom bracket is press-fit and apparently they're a pain in the arse to work with than a non-press fit. I may have to take the bike to a bike mechanic as I don't know how to service a bottom bracket myself. Shall I ask the mechanic to clean and re-grease the current bracket or I buy a new one and ask him to install it?

The crank is a Shimano RS500, from the 105 groupset range. I'm not sure about the bottom bracket but its all I know its Shimano made. Thank you.

slowmart

It depends on your outlook, is there play in the bottom bracket? See if you can move the cracks from side to side to see if there’s any play.

Whilst it may be the original bottom bracket from 2016 you haven’t mentioned actual mileage, heavy use is subjective where miles provides a better insight.

You’ll need a press to remove and fit a new bottom bracket, you can pick up one fairly cheaply from eBay and there are plenty of tutorials on YouTube on how to do this. Hambini is a great source for a successful outcome.

Just change the rings unless you want to change your crank arm length.

If you’ve no appetite for doing the work yourself take it to a decent mechanic and let them determine the best way forward.

Mad_Malx

My lbs extracted a fitted the bb I supplied for £20.

As above, BB life dependent on miles done as well as conditions ridden in. I did my first change after 10 years and 10,000 miles of mostly dry riding, although it had been clicking for a while. It’s very unlikely it would go from smooth to unusable in the course of a ride, so I would wait until it’s clicking or creaking.

Mad_Malx

Might be worth comparing the cost of two new rings with the cost of a new chainset if you were thinking of replacing both.

bikegangster

Thank you gentlemen. I just changed the chainring. Wasn't as hard as I thought. The only annoyance is I bought a chainring bolt tool and I think it was the least useful tool in my whole repair work. I just put in an allen key in the bolt and turn. the bolt tool was almost not needed. The friction will hold the bolt so I can unscrew it. I almost damaged the bolt by twisting the bolt tool in one direction and an allen key in the opposite. I was expecting the bolt to spin like a ball bearing if I stick in my allen key without a bolt tool and try to remove it.

The chainring I bought is a 36 teeth in black. I cannot have silver as it will ruin the look of my bike. I want a 34 teeth but I can't find it as my RS500 is too old, so its becoming more rare and harder to find replacement parts. An eBay seller has a 34 teeth ring available but he's based in Taiwan and I have to wait like 3 to 4 weeks so I look for another eBay seller or another website thats UK based so I get the fastest delivery times.

The crank and bottom bracket is fine. No play, no creaks, no wiggles.

Hills are slightly harder to climb due to 36 teeth. I miss my 34 teeth.

Ben6899

I almost guarantee those chainring bolts are not tight enough, if you didn't use the chainring bolt tool.

bikegangster

oxoman said:

What about fitting a compatible ring of the correct BCD etc that you require. Spa cycles springs to mind.
https://www.spacycles.co.uk/

PCD is 110mm. Not all chainrings on the website say it can support Shimano 105 and 11 speed.

Oh wait, I just found one. https://www.spacycles.co.uk/m8b0s149p3567/STRONGLIGHT-110-BCD-Zicral-Inner-11-speed-4-arm

I hope it will be fine installing a third party component. Its too late as I already got a new chainring but I might buy another just for fun.

EDIT: As it goes, forget that. I realised thats a four-arm. I need a five-arm!