What did you do to your EBike this week?

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,668
5,227
Coquitlam, BC
The chain began skipping when putting pressure on the cranks but only in the smallest rear cog.
It even did it when on the workstand and I pedalled by hand. What could it be?
  • I gave the bike a good clean and removed bits of grass from the cassette and the jockey wheels.
  • The 12-speed cassette is quite new, has some signs of wear but none at all on the cog in question.
  • The chain is also relatively new and is at 0.13% extension (measured over 100 links).
  • The mech hanger alignment is perfect; at less than 1mm all over the rim vs the target less than 4mm.
  • The shifting remains silky smooth up and down the cassette.
Anyway, once I'd put the bike back together again, the problem had gone! :):unsure:

I can't be that lucky, surely. Unless it was the grass? :unsure:
What else could it have been?
The perfect sized twig, grass, trail debris …things we don’t see or think of in our transmission’s. Even wear and tear can be overlooked and eventually starts affecting other components.

I recently started researching ultrasonic cleaning for our greasy, dirty, icky bike parts. A small tub that will hold a 12 speed cassette, chain, jockey wheels …even a bag of gold earrings 😉.

I just need to justify the price, the size and the amount of times I might use this.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
9,095
9,577
Lincolnshire, UK
Its probably worn, even if does not appear to be, luckly they are sold in separate so you can buy only that sprocket and keep the cassete.
That was exactly my first thought; that either the chain or more likely the cassette was worn.

I removed the chain and stretched it out and measured it over 100 links (50 inches). It measured 50-1/16" or 50.0625, equivalent to 0.125%. Just nicely bedded in! :)

The cassette has only done 791 miles compared to the previous XT cassette on the same bike that had done 2273 miles, ie just over a third as much, so it should be fine. I removed the wheel and got up close to the cassette with a magnifying glass. There was some slight burring on the middle gears, none on the big gears and no sign of any wear at all on the smallest gear (the one giving me a problem). I don't use the smallest gear much, so I was not surprised to see no wear on it. There was no shark finning anywhere on the cassette and no root elongation either. The cassette looked absolutely fine.

In the absence of anything conclusive that can be seen or measured, I'm going to put it down to a build-up of sundry vegetation in the mech. I had been riding in overgrown trails and had picked up a lot of grass, nettles and bracken in the pedals, cassette, mech, and that L-shaped key that sticks out of the rear axle. I removed the most obvious stuff at intervals whilst I was riding along, but I know from experience that crushed vegetation mixed with oil will compact into a black shiny layer that alters the way the mech operates. I say "I know", but I had forgotten, only to be reminded during this event. :oops:
 

B1rdie

E*POWAH Elite World Champion
Feb 14, 2019
899
1,101
Brazil
That was exactly my first thought; that either the chain or more likely the cassette was worn.

I removed the chain and stretched it out and measured it over 100 links (50 inches). It measured 50-1/16" or 50.0625, equivalent to 0.125%. Just nicely bedded in! :)

The cassette has only done 791 miles compared to the previous XT cassette on the same bike that had done 2273 miles, ie just over a third as much, so it should be fine. I removed the wheel and got up close to the cassette with a magnifying glass. There was some slight burring on the middle gears, none on the big gears and no sign of any wear at all on the smallest gear (the one giving me a problem). I don't use the smallest gear much, so I was not surprised to see no wear on it. There was no shark finning anywhere on the cassette and no root elongation either. The cassette looked absolutely fine.

In the absence of anything conclusive that can be seen or measured, I'm going to put it down to a build-up of sundry vegetation in the mech. I had been riding in overgrown trails and had picked up a lot of grass, nettles and bracken in the pedals, cassette, mech, and that L-shaped key that sticks out of the rear axle. I removed the most obvious stuff at intervals whilst I was riding along, but I know from experience that crushed vegetation mixed with oil will compact into a black shiny layer that alters the way the mech operates. I say "I know", but I had forgotten, only to be reminded during this event. :oops:
Check if its skipping to the upper (next) cog or stays on the smallest one. If its jumping to the upper cog, it may be the limit screw needs adjustment, but if it skips while staying on the smallest its because its worn for sure.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
9,095
9,577
Lincolnshire, UK
Check if its skipping to the upper (next) cog or stays on the smallest one. If its jumping to the upper cog, it may be the limit screw needs adjustment, but if it skips while staying on the smallest its because its worn for sure.
Thanks for your continued interest. It is definitely skipping in place, which is why a worn "something" was my first thought. I just can't see anything! I used to work for a company that made chains and chainwheels, all the way from 1/4" pitch right up to 7" pitch triplex chain. So, I should know what to look for, I'm just not seeing it. If the problem returns on my next ride, I will have no option but to start replacing stuff. I already have a new chain so that will be an easy thing to do. I can always take it off again if the problem stays. The next thing will be to see if I can get a replacement cog. I seem to remember that they sell the two smallest ones as a set. If that doesn't fix it, it's a strip down of the mech!

By the way, is it the same sprocket for XTR, XT and SLX. I don't care what it's made from as long as it fits!
M9000, M9100, M8000, M8100, M7000, M7100. Will they all fit?

Later Edit: Yes, they will! M6100/M7100/M8100/M9100
And from Aliexpress you get a 10t and a 12t for £20.37 + postage (dunno how much that will be)/.

 
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steve_sordy

Wedding Crasher
Nov 5, 2018
9,095
9,577
Lincolnshire, UK
Bugger! I have just tried to order from AliExpress and in tiny print it said "this product cannot be shipped to the UK".
Well at least they told me before they took my money, but not until after I'd registered with them.

Edit: And my bike shop said they can't get anything until the middle of August. He said why not buy a cheap Deore cassette and use the bits off that! Not that desperate yet. I still need to test the cassette under a proper load.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
9,095
9,577
Lincolnshire, UK
Ref posts #150-155
I was out today and despite using Boost and powering up a hill, the chain never skipped once on the smallest gear. So it looks like it was just muck in the mech. I'm glad I was right about the wear on the cassette.
 

Mrj35

Member
Sep 29, 2023
194
124
canada
Going to fix my shifter and change out the rear tire, 3rd rear tire this year lol. Will probably do a brake bleed and change the rear pads next week. Then chainring,chain,cassette next month.

Decided i'll use my old rear tires for granite slab riding in the fall. Right now I like the rear tire to be in pretty decent condition for dh riding (siping still exists and knobs not torn up.)
 

Tyjay

Active member
Apr 27, 2020
229
383
Bedlington
Bugger! I have just tried to order from AliExpress and in tiny print it said "this product cannot be shipped to the UK".
Well at least they told me before they took my money, but not until after I'd registered with them.

Edit: And my bike shop said they can't get anything until the middle of August. He said why not buy a cheap Deore cassette and use the bits off that! Not that desperate yet. I still need to test the cassette under a proper load.
Make sure you log into aliexpress then they will ship it
just clicked on the link and it ships to me Northumberland

everytime I looked at anything on there it didn’t ship to uk untill I signed in
 

kefconstruction

Active member
Apr 21, 2023
157
140
Hull
New pedals similar blue but not exact, first ride out tonight and very impressed

PXL_20240716_123931551.jpg
 

Tubby G

❤️‍🔥 Hot Stuff ❤️‍🔥
Dec 15, 2020
2,696
5,421
North Yorkshire
Nice mate, I loved my mt5's on the beast. Not convinced with the code RSC on the crafty yet ?

Yeah I’ve had various including RSC’s and XT’s but the Maguras just suit me perfectly. Trying the HC3 levers which are fully adjustable one finger short stubby so looking forward to them. Got a great deal from Total Bleed Solutions too who are fitting everything 👍🏽
 


Tubby G

❤️‍🔥 Hot Stuff ❤️‍🔥
Dec 15, 2020
2,696
5,421
North Yorkshire
In the quoted " still doesn't work" post you made it shows as a link.
I've experienced what you're saying a few times but that usually happens when I've edited or swapped images I'm adding etc

So my original post today, number #165, does that show the photos or links to the photos ? I can only see links 🤷🏽‍♂️
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,873
6,967
UK
Tried the Marshy gravity bleed method because I've lost my syringe. Worked really well.

Conclusion: World cup mechanics know what they're on about.
 

Cobee

Member
Apr 30, 2023
35
55
Poland
That's a sweet job buddy! 👍
How does it ride?
How long did the adaptors take you to make?
Using the same loom?
Thanks. I love my mod.
I using this over 1000km and I not plan back to original gen2. Design adapters takes me a lot of work, many mesauring and are still improving ;).
If somebody need full set to convert Trek Powerfly 9.7 or 9.9 I can organize full set - adaptors , bolts, covers.
Next is Powerfly 4 gen2. (Blue bike)
I produced 10 brand new sets - people want it. 🤘
1722149388398.jpeg
IMG_7601.jpeg IMG_6455.jpeg IMG_6457.jpeg
 
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