Shimano Parts advice

For discussions about bikes and equipment.
Post Reply
chrisclaydon48
Posts: 14
Joined: 27 Oct 2021, 4:50pm

Shimano Parts advice

Post by chrisclaydon48 »

Hello
I have an old Trek Xcaliber and around 18 months ago I fitted a Bafang mid drive motor that works well.
There is just one problem with this bike and that is the rear derailleur requires constant adjustment, I can get it set up on the stand with no skipping and good changes both up and down, go out for a ride with no issues but after a few days the chain seems to slip occasionally so I set it up again. Someone has suggested that I change the derailleur to a better one with a clutch and this will solve the issues.
I am not sure of what parts I should buy I already have a new Shimano Deore RD-M5120-SGS derailleur but obviously that is will not work with my existing equipment.
The current set up is a Shimano Acera M3000 shifter
Shimano Acera M3000, Shadow derailleur
Shimano HG20, 11-34, 9 speed cassette
So if someone could please advise on the parts required I am quite prepared to replace all these parts and the chain if necessary.

Thanks for reading this
Chris
rjb
Posts: 7200
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Shimano Parts advice

Post by rjb »

The majority of gear slipping and poor changing due to frequent attention to adjustment are due to stiction problems in the cables. Make sure the cable runs are smooth without kinks. Lub the cable inners. The chain slipping may be due to wear. Check the chain using a steel rule over 12". A reading of 1/16" over 12" is ok but anymore indicates a new chain may be needed. If it's 1/8" over you will also need a new cassette.
Check your rear mech hanger is inline, letting your bike fall over is a frequent cause of a bent hanger which will also give you poor shifting.
So for starters,
1, check your cables
2, check chain wear
3, check your derailleur hanger.
Let us know what you find or if you need more advice.
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
Eyebrox
Posts: 581
Joined: 5 Aug 2015, 8:56pm
Location: Ayrshire

Re: Shimano Parts advice

Post by Eyebrox »

When you say the chain slips, is it moving sideways to other cogs? Or is it slipping on the same cog as you put some effort into pedalling? If it is the latter the problem is likely to be a worn cassette. The chain and cassette will mesh perfectly on a workstand because the drivetrain is under no pressure and there's no weight perched above the back wheel. Out on the road when some serious pedalling is being done, the chain can slip off the worn teeth of a cassette. It will happen most often in well-used parts of the cassette where the cogs are constantly engaged. Try another cassette. Could borrow one or buy one - it will come in handy whether the problem is correctly diagnosed or not. The chain may also have "stretched". A chain checker tool will confirm if this is the case.
wirral_cyclist
Posts: 1024
Joined: 17 May 2010, 9:25pm
Location: Wirral Merseyside

Re: Shimano Parts advice

Post by wirral_cyclist »

Photos will help, so one of cassette in smallest cog so all other teeth are visible (focus on the slipping cog if you know which), photo of derailleur in middlish gear from directly behind too.
chrisclaydon48
Posts: 14
Joined: 27 Oct 2021, 4:50pm

Re: Shimano Parts advice

Post by chrisclaydon48 »

Hello
Firstly thanks for your answers.
I do not pull away in the highest gear.
The cable inner and outer were replaced in January 2022
The chain was replaced in June 2022 (KMC X900
The rear cassette was replaced in August 2022
The only parts I have not replaced are the shifter and the derailer
I have ridden around 1000 miles in the last year so these parts should be good.
The hanger looks good and after adjustment it is fine for several miles before any issues occur.

Regards Chris
Eyebrox
Posts: 581
Joined: 5 Aug 2015, 8:56pm
Location: Ayrshire

Re: Shimano Parts advice

Post by Eyebrox »

Hi Chris. These parts are all relatively new. Everything appears to be in order. I suggest you ask a bike shop to have a look. They will check it and bill you for this or check it and do the repair and bill you for the completed job which will come with a guarantee. If you take the first option ask for a breakdown of what's wrong and which parts if any are needed. This will give you an insight into working with bicycle gearing. Then perhaps you can return to the forum and let us know the diagnosis. Best of luck.
Carlton green
Posts: 3645
Joined: 22 Jun 2019, 12:27pm

Re: Shimano Parts advice

Post by Carlton green »

When you say the chain slips, is it moving sideways to other cogs? Or is it slipping on the same cog as you put some effort into pedalling?
An answer to the above might help better brains than mine point the OP towards some improvement.
I suggest you ask a bike shop to have a look.
Caveat Emptor, etc. Like other places bike shops, of course, vary somewhat in qualities …

I’m not sure that the thread tittle is that helpful to the OP. To me his issues don’t seen to be particularly Shimano specific and do seem to be primarily about an electric bike conversion, or rather the results of an electric assist conversion.

I don’t much like index shifting on derailleur systems, amongst too many other things you’re dependent on the shifter remaining fault free, sometimes they’re not quite so. Of course when it all works as intended it’s wonderful, etc., but …

I’m a bit old school; nine speeds seems like thin sprockets, thin chain and tight tolerances to me - pushing the envelope can result in problems.

Is the readjustment always in the same direction? Are the cable housing ends clean and well seated? Is the cable slipping?

Is there play or unintended movement at the rear hub?
Don’t fret, it’s OK to: ride a simple old bike; ride slowly, walk, rest and admire the view; ride off-road; ride in your raincoat; ride by yourself; ride in the dark; and ride one hundred yards or one hundred miles. Your bike and your choices to suit you.
chrisclaydon48
Posts: 14
Joined: 27 Oct 2021, 4:50pm

Re: Shimano Parts advice

Post by chrisclaydon48 »

Recently it has been the B screw that requires adjustment.
As the slipping only occurs in the highest gears, perhaps the chain is to long.
It is a standard 9 speed chain and my sprocket is 42 teeth.
Post Reply