Drive train sounding gritty/rough

Duelsy

Member
Oct 22, 2019
36
30
England
Loving my Decoy so far, put it through a few seriously testing rides. I've only had it for a couple of weeks but have done a lot of riding in that time, all in pretty poor conditions as I live in England. :cool:

This weekend was particularly wet, huge puddles and deep mud. Bike handled it all pretty much flawlessly. Got home and cleaned the bike down and noticed the chain had a very gritty noise to it and the changes don't feel totally smooth. I've given the chain a good clean using the tool from PT and I've lubed it up but still not sure if it sounds perfect. Was a pretty aggressive ride at the weekend with plenty of slipping and sliding, so I'm wondering if the derailleur/hanger might have been bent slightly. The adjustment in the settings is currently at +4, which allows me to change into all gears, anything less and I can't get onto the smallest cog. All limit screws seem to still be set correctly, no chain jumping off etc.

I may well just be being overly cautious, as it's my first EMTB and it's brand new. However thought it wouldn't hurt to post and get some opinions, any help/comments is appreciated. (y)

Will attach some photos and a couple of videos from my phone after posting the thread. If people want different views or different gears selected etc then let me know and I can upload some more tomorrow. :)

61E408CD-F464-4D87-B279-45E3749D7EF8.jpeg
61E408CD-F464-4D87-B279-45E3749D7EF8.jpeg
F504FFF9-C636-4B70-BE57-4517B3C3EF4A.jpeg
BB5A9566-63F4-4B05-9A9F-55F61D472247.jpeg



Video before cleaning tonight:



Video after cleaning/oiling chain etc:

 
Last edited:

Gary

Old Tartan Bollocks
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Gear set-up is no different on an Emtb to a regular mtb. No amount of odd angled photos or phone video shared online is going to allow any of us to judge the alignment of your rear mech or hanger. Nevermind your limits, B-tension, indexing or cables
you don't sound at all experienced with gears so just take it to your local bike shop.
a gear tune. (checking alignment, condition of chain/cassette/chainring, cables and indexing your cables - replacing if required) won't cost you much.
 

Gary

Old Tartan Bollocks
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Ps. Can't see what mech you have (so I could be wrong here) but by the look of it it's a shimano and your clutch looks to be switched OFF.
Never ride an Emtb with the clutch off. it not only helps retain the chain but also stops the front chainring from causing chainsuck. which with a motor (not stopping imediately when you realise and stop pedalling) can cause far worse damage.
 

outerlimits

E*POWAH BOSS
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Feb 3, 2018
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I’d take the chain off and clean it in petrol 3 times using clean petrol and container each time. Adjust the upper and lower limits before fitting the chain. Fit and lube the chain, and set the b tension. Then index it with cable tension adjustment.
If you can’t index it properly then it’s likely the alignment is out or your cable gummed up. Straighten hanger or replace cable if needed.
 

TransAmMan

Active member
Sep 18, 2019
154
142
Canada
Agree with the poster above .. it "looks" like the clutch lever is OFF. Flip the grey plastic lever UP and see if it improves
 

Duelsy

Member
Oct 22, 2019
36
30
England
Thanks for the replies guys. I moved that during cleaning, the clutch was 100% on during use (y). I knew I should have redone the photos/videos when I saw that too :ROFLMAO:. Noise is still there with the clutch engaged.

@Gary I'm definitely not as aufait with gearing as other MTB'ers. I've ridden BMX my whole live and have only recently started MTB'ing in earnest. Have ridden them plenty before but usually rentals etc. I have no objection to taking it to a LBS but really like getting hands on with mechanical stuff, so would like to learn about it.

Will take the chain off tonight and give it a thorough clean as suggested and report bike.

Worth mentioning that the bike comes with electronic shifting (Shimano SWE7000R), Shimano XT Di2 rear derailleur and e-thirteen TRS Plus cassette.
 

outerlimits

E*POWAH BOSS
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Feb 3, 2018
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Thanks for the replies guys. I moved that during cleaning, the clutch was 100% on during use (y). I knew I should have redone the photos/videos when I saw that too :ROFLMAO:. Noise is still there with the clutch engaged.

@Gary I'm definitely not as aufait with gearing as other MTB'ers. I've ridden BMX my whole live and have only recently started MTB'ing in earnest. Have ridden them plenty before but usually rentals etc. I have no objection to taking it to a LBS but really like getting hands on with mechanical stuff, so would like to learn about it.

Will take the chain off tonight and give it a thorough clean as suggested and report bike.

Worth mentioning that the bike comes with electronic shifting (Shimano SWE7000R), Shimano XT Di2 rear derailleur and e-thirteen TRS Plus cassette.
Also if you have an alloy chainring it will wear quickly in gritty conditions. It will make noise under load with a new chain.
 

Gary

Old Tartan Bollocks
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Thanks for the replies guys. I moved that during cleaning, the clutch was 100% on during use (y). I knew I should have redone the photos/videos when I saw that too :ROFLMAO:. Noise is still there with the clutch engaged.

@Gary I'm definitely not as aufait with gearing as other MTB'ers. I've ridden BMX my whole live and have only recently started MTB'ing in earnest. Have ridden them plenty before but usually rentals etc. I have no objection to taking it to a LBS but really like getting hands on with mechanical stuff, so would like to learn about it.

Will take the chain off tonight and give it a thorough clean as suggested and report bike.

Worth mentioning that the bike comes with electronic shifting (Shimano SWE7000R), Shimano XT Di2 rear derailleur and e-thirteen TRS Plus cassette.

Fair enough mate. It\s definitely something you should learn.
If you can be bothered trawling through youtube you'll find tutorials on setting up gears, limit screws. b tension and indexing. No doubt there'll be a few on Di2.
The one thing your LBS is sure to have and you probably won't tho is a mech hanger alignment tool. it's possible to check it without one. (using a steel rule or meter stick placed against the flat of the hanger with the mech removed) but not quite so accurate,
When you check your chain check every link is straight and every pin tight.
also. Ignore the advice from outerlimits to set limit screws with no chain. you need the chain on to set limits and B tension. (whether electronic or mechainical).
 

outerlimits

E*POWAH BOSS
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Yeah ignore me, I stuffed that up
You can set your upper and lower limits without the cable connected,
Not without the chain connected, like I said ?‍♂️
Thanks Gary
 

Gary

Old Tartan Bollocks
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Yeah ignore me, I stuffed that up
You can set your upper and lower limits without the cable connected,
Not without the chain connected, like I said ?‍♂️
Thanks Gary
when setting limits with Di2 you want the mech wired up (and do it by eye looking at the actual screws and stops)
with mechanical you can set limits with or without the cable. but if you do it without, make sure to only *pinch* the arm at the cable pinch bolt and the cable outer entry arms together rather than pushing on the knuckle or mech body to set your low limit as they flex if you do it that way.
 

Duelsy

Member
Oct 22, 2019
36
30
England
Morning all, thought I'd give an update. As before please note I have Di2 electronic shifting with an XT derailleur, so no cable adjustment.

Decided to strip everything and start from scratch:
  1. Removed chain and deep cleaned it.
  2. Deep cleaned the cassette and front sprocket. Noticed a few teeth on the largest cog of the rear cassette that looked slightly chipped. Brand new so not great.
  3. Removed derailleur and cleaned it. I noticed the cage looked damaged, see image. This is pretty flimsy, which I imagine is how it's designed. Gently bent this straight.
  4. Checked hanger with alignment tool, was very slightly out. Fixed this and now sitting perfectly true when checked in all positions.
  5. Once everything was clean I reassembled everything and lubed the chain.
  6. The majority of the gritty noise is now gone, so moved onto alignment.
  7. B limit screw set as per manual to correct gap.
  8. H/L limit screw backed all the way off.
  9. I then followed the Di2 manual and moved the bike into 5th gear.
  10. I then used the electronic shift adjustment to move the derailleur inwards towards the cassette until I heard the chain just rubbing the next biggest cog.
  11. I then moved adjusted the derailleur 5 clicks outwards, as per manual. The shift adjustment reading sits at -1 in this position.
  12. Bike can freely shift all the way up to 1st gear. Set this limit screw.
  13. I then tried to move all the way through to 11th but could only get to 10th, when it tries to drop into the highest gear it just sits there "clicking" until you switch back to the previous one.
  14. If I go back into shift adjustment and move it to +2 (so 3 click change) then the bike can successfully move into 11th gear. Set this limit screw.
  15. I then shift back to 2nd which all feels okay, chain has clearance from the biggest cog and isn't rubbing on it at all.
  16. However when I go to change into 1st the change feels quite rough, almost as if the chain is pressing into the cog and "dragging" up the side of it before it gets to the teeth, feels quite stiff on the cranks (when turning by the hand with the bike in the stand).
So I've improved it but still got issues unfortunately, with it being a new bike I'd prefer it to be perfect though. Have ridden the bike aggressively and had a couple of offs but the derailleur has never gone into its emergency protection mode etc.

For now I've adjusted it so that I can easily get into 1st and will just not use 11th.

Picture of derailleur cage before being removed from bike:

EF21DE7A-70FD-45DA-8D06-31284556E7B2.jpeg
 
Last edited:

Hol47

Member
Sep 28, 2019
83
23
Uk
Sounds like you might have a faulty cassette. Mine came with the same. Check the serial number on the back. If it starts with a number 26 or lower you can call E Thirteen and they send you a new lower cassette which should allow you to shift through all the gears. There's a thread on here about it.
 

Gary

Old Tartan Bollocks
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The largest sprocket on a Shimano cassette has teeth that are intentionally shorter (to aid shifting)

Your mech is bent. It needs replacing if perfect shifting is to be attained.
My guess is that if you were to rotate the cage 180deg it no longer follows a parallel plane to the Hanger. But the parallelogram may also no longer be parallel.
It's just what happens with a knock. Expensive to remedy unfortunately. just one of the reasons I'd never have DI2 on an mtb of my own . (I love it on roadbikes tho)
 

Duelsy

Member
Oct 22, 2019
36
30
England
Sounds like you might have a faulty cassette. Mine came with the same. Check the serial number on the back. If it starts with a number 26 or lower you can call E Thirteen and they send you a new lower cassette which should allow you to shift through all the gears. There's a thread on here about it.

Will check the serial number and drop them an email if I need to, thanks for the info mate. (y)


The largest sprocket on a Shimano cassette has teeth that are intentionally shorter (to aid shifting)

Your mech is bent. It needs replacing if perfect shifting is to be attained.
My guess is that if you were to rotate the cage 180deg it no longer follows a parallel plane to the Hanger. But the parallelogram may also no longer be parallel.
It's just what happens with a knock. Expensive to remedy unfortunately. just one of the reasons I'd never have DI2 on an mtb of my own . (I love it on roadbikes tho)

Yeah think you're probably right, does look a bit of a mess. Such a shame as everything else on the bike is perfect! Just one of those things I guess, unlucky that the hanger hasn't gone instead. Will look at getting a replacement ordered up, in the mean time I'll just make do with no 11th gear.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,947
9,298
Lincolnshire, UK

If I was Richard Cunningham, the owner of the bike in the pics, I would be ashamed at the amount of rust on the chain. The whole set up looks as though it hasn't seen any lube for months. No wonder it was creaking!

I was really surprised, because Richard Cunningham is one of the gurus of Pink Bike. It was him that got me onto lower tyre pressures.
 

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