Chain Slipping On Smallest Gears!

[Dinnerfork]

I bought a BH atom lynx 6 27.5 pro and for some reason the chain will slip on the smallest gears on the rear. I backed out the B screw on the derailer and it has reduced the occurrence but because its been backed out when I shift into the largest gears the derailer wheel touches the gear. Anyone know whats going on? Maybe something is loose?

 

[steve mercier]

I bought a BH atom lynx 6 27.5 pro and for some reason the chain will slip on the smallest gears on the rear. I backed out the B screw on the derailer and it has reduced the occurrence but because its been backed out when I shift into the largest gears the derailer wheel touches the gear. Anyone know whats going on? Maybe something is loose?

How many miles on that chain?

 

[Sierratim]

I bought a BH atom lynx 6 27.5 pro and for some reason the chain will slip on the smallest gears on the rear. I backed out the B screw on the derailer and it has reduced the occurrence but because its been backed out when I shift into the largest gears the derailer wheel touches the gear. Anyone know whats going on? Maybe something is loose?

Derailleur adjustment is a bit of an art. The Park Tool videos that @Timpo linked to are great. Give them a try.

 

[JRA]

The b tension screw would have little to do with your problem, it’s more important it‘djusted so it clears the largest cog.

If the bikes got a lot of miles its probably the chain and smaller cogs are worn.

If it doesn’t your chain is too long. Derailleur should be biased towards the front sprocket when in your lowest gear. With a chain tool removing links is easy. Plenty of how toos online.

 

[TNEP]

I have the same Bike . I have about 1500 miles on it /9months old. Had the exact same issue from the 1st mile to the 1500th. Had it back to my bike shop/ dealer in Mpls maybe 5 times , he couldn't fix it. I took it to a shop in Tucson over the winter and he changed out my front and rear sprockets and chain. He put on a little bigger sprocket in front ( cant remember what size ) that had 2 more teeth than the original. Works perfect. He said all the gear teeth were worn, although I couldn't tell that by looking at them, and the chain was stretched. I am really enjoying the bike now. I don't ride off trail much at all and I get a little more speed with the new front sprocket size.
The mystery is why a brand new bike would have that trouble there must have been something out of adjustment to cause the slippage and wear. Tucson guy said that Brose motor has a lot of Torque and I will probably have faster wear . We'll see, since I'm in alignment and not getting slippage anymore it should be fine. Dinnerfork you may PM me if you want.

 

[Dinnerfork]

Took it to a shop yesterday they tuned the bike and put a new chain on it. The slipping is even worse. They are trying to get new a new rear cassettes but are on back order. Sorry to resurrect an old tread!

 

[bob armani]

Took it to a shop yesterday they tuned the bike and put a new chain on it. The slipping is even worse. They are trying to get new a new rear cassettes but are on back order. Sorry to resurrect an old tread!

This will happen. I just had the same issue with the 2 smallest cogs (11t-13t) wearing 1st causing more chain slippage after a new chain was installed. Those cogs probably have to be changed. In my case, I could not find replacement cogs for the SunRace cassette, so I just purchased a new cassette. No biggie.

 

[bob armani]

Is your smaller cog worn out?

I do have replaced the smallest cog a few times because they tend to wear out quicker.

1.67US $ 32% OFF|ZTTO Freewheel Flywheel Pinion for Bicycle Bike MTB Cassette Cog in Mountainous Region and Highway 8/9/10/11 Speed 11T/12T/13T|Bicycle Freewheel| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

4.17US $ |ZTTO bicycle cassette gear 8 9 10 11 speed 11T 12T 13T flywheel parts for MTB road bike ZTTO K7 cassette with 1 bicycle part|Bicycle Freewheel| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

1.53US $ 13% OFF|Bike Freewheel Cog 8 9 10 11 Speed 11T 12T 13T Mountain Bicycle Cassette Sprockets Repair Accessories For Shimano|Bicycle Chain| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Some of the smaller cogs from Ali Express in your link are aluminum. I thought it was better to use the ones made of tensile steel which could handle E-bike motor tension much better. In addition, I am not seeing a compatibility chart. JMHO!

 

[bob armani]

Aren't they interchangeable?

I've been using ZTTO 11t cog for Shimano 9 speed, no problem whatsoever.

Great, that's interesting. I think I'll try that next time around and see if these replacements work for my SunRace.

 

[steve mercier]

Took it to a shop yesterday they tuned the bike and put a new chain on it. The slipping is even worse. They are trying to get new a new rear cassettes but are on back order. Sorry to resurrect an old tread!

That is why I have a drawer of spare chains ,cassettes and front rings. I am hoarding it like toilet paper.

 

[bob armani]

Aren't they interchangeable?

I've been using ZTTO 11t cog for Shimano 9 speed, no problem whatsoever.

Is that on a mid-drive or a rear hub drive E-bike?

 

[bob armani]

That is why I have a drawer of spare chains ,cassettes and front rings. I am hoarding it like toilet paper.

Good call. I am beginning to think I may do the same thing with small cogs from Ali Express.

 

[bob armani]

Both actually, I've tried on hub drive and mid drive (TSDZ2).
The wear of ZTTO cogs don't seem to be any worse than Shimano.

Thanks for the heads up. Do you install them yourself, and if so, is it a pretty straight forward swap?

 

[Alaskan]

I use two 4x4 blocks about 12" long and lay the wheel on them, on a work table with the cassette on the up side. It is tall enough to protect the brake rotor while I am working on it. These two tools from Bike Hand make it easy.

BIKEHAND Bike Shimano Freewheel Cassette Install Removal Tool with Chain Whip

BIKE HAND YC748 Mountain Bike Bicycle Repair Kit - 37 Piece for sale online | eBay

Find many great new & used options and get the best deals for BIKE HAND YC748 Mountain Bike Bicycle Repair Kit - 37 Piece at the best online prices at eBay! Free shipping for many products!

ebay.us

 

[bob armani]

Both actually, I've tried on hub drive and mid drive (TSDZ2).
The wear of ZTTO cogs don't seem to be any worse than Shimano.

FYI- Found the steel versions on Aliexpress if you are interested.
Shimano Steel cogs

 

[bob armani]

Just picked up my Ebike after a full swap out of chain and cassette. The LBS mechanic indicated he was fine with leaving the original wax coating on the new chain. Took my 1st ride and I have to say the entire drivetrain is incredibly smooth with no more slipping in the last 2 small cogs. I am now reaching out to the cassette mfg (SunRace) to see if they have small cog replacements. I will also be ordering the steel ones from Aliexpress for comparison. Happy camper!

 

[steve mercier]

Bob if you find as I did the Sunrace cassette wears too quickly perhaps try a Shimano XT or Sram PG ( a bit cheaper) next time.

 

[Alaskan]

Bob if you find as I did the Sunrace cassette wears too quickly to try a Shimano XT or Sram PG ( a bit cheaper) next time

Funny, on my 2018 Delite Mountain, I find the Sunrace 11-46 cassette shifts better and smoother, has better gradation/progression of gears and lasts at least as long, if not longer than the Shimano XT. Different strokes, I guess. As to replacements for the 11 &13 tooth cogs, I buy the Shimano cogs on ebay which although not painted black work just fine.

Shimano XT CSM8000 11Speed 13t Cog https://ebay.us/FcoyJQ

 

[steve mercier]

Funny, on my 2018 Delite Mountain, I find the Sunrace 11-46 cassette shifts better and smoother, has better gradation/progression of gears and lasts at least as long, if not longer than the Shimano XT. Different strokes, I guess. As to replacements for the 11 &13 tooth cogs, I buy the Shimano cogs on ebay which although not painted black work just fine.

Shimano XT CSM8000 11Speed 13t Cog https://ebay.us/FcoyJQ
View attachment 83805

Yes perhaps different cadences for different carcassses (-: I use an 11-42 which may account for the diff in shifting. I have an 11-46 in the drawer but only as a backup as I could not find another 11-42. I have read that the 11-46 does not shift as smoothly as the 11-42 ,in particular from the 37t ring to the 46t. But as far as longevity goes I have only had the single experience with the Sunrace which was underwhelming and I am not giving them another chance. I have 2 Sram PG 1130s and another Deore XT 8000 in the drawer but when they wear out I am going to bite the bullet and switch the whole system to the Sram Eagle XX1

. https://bicicletta.cc/products/sram-xg-1299-xx1-eagle-cassette-12sp?variant=32827049934911

 

[ruffruff]

I had a BH Lynx that did this exact same thing.
I switched out the cassette to a Sunrace and for some reason it performed better in the smaller cogs.