Who else has issues jumping in/out of gears on their mid drive rear cogs?

[Zambam]

For 500 miles, I had a TSDZ2 in a an old 1987 Raleigh Mtn Tour Seneca with 6 spd freewheel and the rear cogs worked well with no issues. A few weeks ago I moved the mid drive to another old Raleigh (2000 M80 w. very little use- practically new). It has a freehub 8 spd cassette and the bike jumps in and out of gears often. I tried adjusting the rear derailleur and cable tension which didn't help much. Maybe I'm not doing a good job with the adjustment?

I do not use the highest and lowest cogs and have adjusted them out with the hi/lo limit screws. I use mostly cogs 3, 4 and 5, those are the gears that jumps. Say I'm in gear 3 and pedaling, I hear a clunk, feel loss of resistance on the pedal for 1/4 of a revolution when it shifts to the next higher or lower gear.

Very annoying! Any suggestions? Keep adjusting? Get a 6 spd cassette? Get a different derailleur/ shifter?

 

[Diggs]

Get a different derailleur

When was the last time you lubed your derailleur? Sounds like it's sticky and hanging up.

 

[A-DamW]

A few weeks ago I moved the mid drive to another old Raleigh (2000 M80 w. very little use- practically new).

Assuming it shifted well before adding the mid-drive, have you tried:
1. Making sure the derailleur is not bent.
2. B-screw adjustment.

I use this method to straighten the hanger, works a treat!

For the B-screw, in my general observation,
if the upper derailleur jockey wheel is adjusted too far below the cassette
it can slow shifting, and sometimes pulls the chain to the next cog in a way
that causes the chain to ride on top of the teeth for a revolution until it drops into place with a clunk.

Get the bike in a stand, or flip it upside down, so you can observe closely while shifting/adjusting.

 

[neptronix]

..many of these cheaper asian add-on drives create offsets and may also have some internal play in them which could interfere with shifting..

Kind of a PITA, it's why i'm not a fan of them, they don't play well with the bicycle drivetrain or pedaling, often enough.

 

[Guerney]

Very annoying! Any suggestions? Keep adjusting? Get a 6 spd cassette? Get a different derailleur/ shifter?

Try removing a chain link? If no joy, remove another?

 

[Zambam]

When was the last time you lubed your derailleur? Sounds like it's sticky and hanging up.

I've not lubed it. Wouldn't hurt to give it some which I will. Bike was ridden 5 times since new then went in climate controlled storage for 20 years before I bought it. Bike looks new except for dust in nooks and crannies.

 

[Zambam]

..many of these cheaper asian add-on drives create offsets and may also have some internal play in them which could interfere with shifting..

Kind of a PITA, it's why i'm not a fan of them, they don't play well with the bicycle drivetrain or pedaling, often enough.

There is no play that I can feel when wiggling the chain ring on the drive. Also, there was no problems with the other bike it was installed in. Do you still think the problem is due to play in the drive?

 

[Zambam]

Try removing a chain link? If no joy, remove another?

Bike had no issues shifting through all gears (24) before I installed the TSDZ2. What would removing chain links do?

 

[scianiac]

Besides all the standard derailleur checks, screws, tension, hanger alignment what chainring do you have on the TSDZ2, some of them have a lot of offset which makes chainline kinda poor. If you aren't using the smallest cog, which I find I can't use anyway on mine as it slips due to too much power you could move the smallest cog to the inside which will move all the other gears outward improving chainline and depending on what the derailleur looks like move it closer to the gears in the same way the B-tension screw does. It's probably just something with the derailleur setup but after you've checked all of that maybe worth a shot, and if nothing else would improve chainline with no downside since you have locked out the smallest cog anyway. I've only found chain length to be critical if the derailleur has an offset idler which will make the chain length affect how close are far the idiler is from the cassette.

 

[neptronix]

Removing a chain link would be very helpful if your chain is too slack.
A too slack chain could be responsible for some shenanigans.

I also suggest checking the mid drive unit for play.

 

[Zambam]

Besides all the standard derailleur checks, screws, tension, hanger alignment what chainring do you have on the TSDZ2, some of them have a lot of offset which makes chainline kinda poor. If you aren't using the smallest cog, which I find I can't use anyway on mine as it slips due to too much power you could move the smallest cog to the inside which will move all the other gears outward improving chainline and depending on what the derailleur looks like move it closer to the gears in the same way the B-tension screw does. It's probably just something with the derailleur setup but after you've checked all of that maybe worth a shot, and if nothing else would improve chainline with no downside since you have locked out the smallest cog anyway. I've only found chain length to be critical if the derailleur has an offset idler which will make the chain length affect how close are far the idiler is from the cassette.

I have the 42 teeth TSDZ2 chainring. The chain line is definitely not as good (on the largest and smallest sprockets) on this 8 spd freehub cassette as the 6 spd freewheel that the TSDZ2 was previously installed in.

Removing a chain link would be very helpful if your chain is too slack.
A too slack chain could be responsible for some shenanigans.

I also suggest checking the mid drive unit for play.

How do I determine if the chain is too slack or not? The bike shifted fine through all 24 gears with no issues before I installed the TSDZ2.

I did check the mid drive unit for play and there isn't much that I can feel by wiggling the chain ring and axle. This TSDZ2 drive has less than 600 miles on it so relatively new and not worn out, yet.

 

[Zambam]

Assuming it shifted well before adding the mid-drive, have you tried:
1. Making sure the derailleur is not bent.
2. B-screw adjustment.

I use this method to straighten the hanger, works a treat!

For the B-screw, in my general observation,
if the upper derailleur jockey wheel is adjusted too far below the cassette
it can slow shifting, and sometimes pulls the chain to the next cog in a way
that causes the chain to ride on top of the teeth for a revolution until it drops into place with a clunk.

Get the bike in a stand, or flip it upside down, so you can observe closely while shifting/adjusting.

That's a pretty neat trick using a quick release rear wheel as a derailleur hanger adjust gauge/tool. Unfortunately I don't have one. I see how the Park DAG tools work- pretty simple. I think a cheap one from Aliexpress https://www.aliexpress.us/item/3256...U98vFm77&utparam-url=scene:search|query_from: will do the job. I may buy one or go to my LBS to have them check it. More fun to DIY so I think I will just buy one.

 

[Guerney]

Bike had no issues shifting through all gears (24) before I installed the TSDZ2. What would removing chain links do?

Might be worth trying, was on mine - the chainline was ever so slightly off, and additional tension was not possible to apply to the chain any other way, had tried all adjustments. Works wonderfully now. I simply remove two links from any new KMC X8 chain.

 

[Gruesome]

I have the 42 teeth TSDZ2 chainring. The chain line is definitely not as good (on the largest and smallest sprockets) on this 8 spd freehub cassette as the 6 spd freewheel that the TSDZ2 was previously installed in.

Maybe there is a misunderstanding about the term 'chain line'. Scianiac suggests moving the sprockets you actually use further outwards by one sprocket position, under the assumption that your motor moved the front chainring(s) and thus the chain position further out than it was before without the motor. 'Chain line' refers to that lateral position.
You seem to be referring to the maximum chain angles from the front chain ring(s) to the smallest and largest sprocket. Moving the front chain ring outwards should make the angle for the smallest sprocket smaller (better aligned chain), and the angle for the largest sprocket larger (worse).

 

[Zambam]

Maybe there is a misunderstanding about the term 'chain line'. Scianiac suggests moving the sprockets you actually use further outwards by one sprocket position, under the assumption that your motor moved the front chainring(s) and thus the chain position further out than it was before without the motor. 'Chain line' refers to that lateral position.
You seem to be referring to the maximum chain angles from the front chain ring(s) to the smallest and largest sprocket. Moving the front chain ring outwards should make the angle for the smallest sprocket smaller (better aligned chain), and the angle for the largest sprocket larger (worse).

I am not a bicycle person. Only started working on them recently. Maybe I do not fully understand what "chain line" is exactly. In my mind, it's the line the chain makes between the chain ring and the rear sprockets. Chain line cannot be perfectly straight except for maybe one sprocket in the middle of the set. Because of the width of the sprocket set (more sprockets= wider) the largest and smallest sprockets has the worse chain line.

 

[Gruesome]

Me neither. That straight line connecting one chain ring (usually the largest, if I'm not mistaken) and one sprocket is at a certain distance from the mid plane of the bicycle. That distance is often called 'chain line'. Maybe it should be called 'chain line distance from bike midplane', or something like that. You would have to ask a bicycle person.

 

[Hillhater]

Look closely for a stiff chain link or two…not always fixed with chain lube, so be dilligent.
….or just try a different/new chain

 

[docw009]

Bike had no issues shifting through all gears (24) before I installed the TSDZ2. What would removing chain links do?

Whenever I had the chain jumping out of gears on a new mid motor install, the chain was too long. Removing a link or two was the fix. When you break the chain you can also follow the SHeldon Brown to see if it really is too long.

 

[Zambam]

Whenever I had the chain jumping out of gears on a new mid motor install, the chain was too long. Removing a link or two was the fix. When you break the chain you can also follow the SHeldon Brown to see if it really is too long.

Take a look at the position of the lower jockey wheel of these 2 pics, on the smallest and largest sprocket. Do you still think the chain is too long?

 

[neptronix]

Doesn't look too long.

Do you have a bike shop nearby? they could help diagnose this!

 

[Zambam]

Could the chain be too short? With chain on the largest sprocket, shouldn't the jockey wheel/ pivot arm be pointing vertically down to the ground, and not toward the chain ring like in the pic?

 

[neptronix]

Looks roughly correct from here.

I'd recommend getting a bike shop to look at it

 

[biphaeboh]

Could the chain be too short? With chain on the largest sprocket, shouldn't the jockey wheel/ pivot arm be pointing vertically down to the ground, and not toward the chain ring like in the pic?

It looks okay. Its similar to the picture on the park tool website.

Chain Length Sizing

This repair help article will take you step by step through the different methods of sizing a bike chain for your drivetrain.

www.parktool.com

 

[Guerney]

Take a look at the position of the lower jockey wheel of these 2 pics, on the smallest and largest sprocket. Do you still think the chain is too long?


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Man that looks clean! Makes me wonder if the issues you describe are due to a lack of lube - as someone has already mentioned, there could be a stiff link(s). Application of lube would make it more supple. Lube everything. As recommended by @d8veh on the pedelecs.co.uk forum (my regular haunting grounds), I use Hypoid 90. I never normally clean the drivechain on my bike, but applied some to my chain last night because of recent skippiness in middle gears caused by road grime, which led to an unsupple chain which skipped: I wiped the chain with newspaper because it's a compacted slightly rough sheet material with no problematically large loose fibres, then applied Hypoid 90, ran up and down the gears a few times to work it into the chain: No more skipping in middle gears.

 

[Zambam]

My derailleur alignment tool from Aliexpress finally showed up yesterday. I mounted the tool on the hanger and found the hanger was slightly bent at the 6 o'clock position (tool arm was 1" inwards past the rim). I bent it back with the tool and was surprised it didn't take much force. The hanger must be made of very soft steel to protect the derailleur. The jumping in/ out of gear issue is gone and it's shifting much better now.