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Blathma

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Discussion starter · #1 ·
New krampus... Came with deore sl-m6100 shifter, rd-m6100 derailer and a sunrace csmz800 cogset. 12 speed.

Upshift works fine, single, double and triple shifts. Downshift works mostly...

Down shifting from 12-6 is fine but from 5th thru 3rd it skips..as in nothing happens.. I have to keep clicking until it drops into 2nd, then shift up to get what I want. If I click down and wait... It'll randomly drop into gear or not at all.. but only for those gears.

Statically on the workbench the shifter works perfectly. Is it a load issue? It's it the cogset?

I've also noticed that it prefers that I stop pedaling to down shift, not always but it avoids the abrupt clunk onto the next cog.

Or is this just a cheapy setup and expected?
 
#2 ·
Blathma said:
New krampus... Came with deore sl-m6100 shifter, rd-m6100 derailer and a sunrace csmz800 cogset. 12 speed.

Upshift works fine, single, double and triple shifts. Downshift works mostly...

Down shifting from 12-6 is fine but from 5th thru 3rd it skips..as in nothing happens.. I have to keep clicking until it drops into 2nd, then shift up to get what I want. If I click down and wait... It'll randomly drop into gear or not at all.. but only for those gears.

Statically on the workbench the shifter works perfectly. Is it a load issue? It's it the cogset?

I've also noticed that it prefers that I stop pedaling to down shift, not always but it avoids the abrupt clunk onto the next cog.

Or is this just a cheapy setup and expected?
Click to expand...
so H/L screw's responsible for limit on up and bottom
b-screw - distance from the cogs
cable tension - précisément of shifting
clutch adjustment - chain tension, how easy to shift

despite being budget, it shifts perfectly fine as it is expected, just play with adjustment based of what they are responsible for
 
Discussion starter · #3 ·
I'll take a look at that...
Just very odd that 12 down to 5 is no problem... But 5 down to 3... Nothing... Click... Nothing... Click again.. Nothing.. Have to click again... Then it jumps down to 2nd. Then I can go up to whatever gear.. But again let's say I'm in 4th.. no response on the down shift till it hits 2nd again. Pedal, no pedal.. Doesn't matter. 2nd to 1st requires that I stop pedaling to avoid the sudden slam clunk into 1st.

Similar deal with gears 12-5.. while it shifts down.. It's slamming into gear.. loud clank clunk. Even on downhill runs where loads should be very low.
 
#4 ·
Blathma said:
I'll take a look at that...
Just very odd that 12 down to 5 is no problem... But 5 down to 3... Nothing... Click... Nothing... Click again.. Nothing.. Have to click again... Then it jumps down to 2nd. Then I can go up to whatever gear.. But again let's say I'm in 4th.. no response on the down shift till it hits 2nd again. Pedal, no pedal.. Doesn't matter. 2nd to 1st requires that I stop pedaling to avoid the sudden slam clunk into 1st.

Similar deal with gears 12-5.. while it shifts down.. It's slamming into gear.. loud clank clunk. Even on downhill runs where loads should be very low.
Click to expand...
Shifting down into minimal load shouldn't be terribly loud. I guess it is relative. I had similar issue with cassette tightness. In addition, before any derailleur adjustment, check the hanger.
 
#8 ·
Blathma said:
New krampus... Came with deore sl-m6100 shifter, rd-m6100 derailer and a sunrace csmz800 cogset. 12 speed.

Upshift works fine, single, double and triple shifts. Downshift works mostly...

Down shifting from 12-6 is fine but from 5th thru 3rd it skips..as in nothing happens.. I have to keep clicking until it drops into 2nd, then shift up to get what I want. If I click down and wait... It'll randomly drop into gear or not at all.. but only for those gears.
Click to expand...
I have the same parts installed on my bike.
Deore M6100 with the Sunrace 800 cassette.
And I had the same issues when installing this group, but got a great tip here in the Shimano sub forum.

Check the B-line on the derailleur.
For Sunrace cassettes the biggest 51t cog needs to be between 1,5 to 2 mm below the B-line to make it work properly. Sunrace shift ramps are slower than Shimano, or Sram. That's why.

Also imo Shimano's 12 speed mechs even are more finicky to cable tension than Eagle.
So B-screw and tension needs to be just ride.
My drivetrain has now over 1200 km on the clock and shifts pretty well for such a cheap groupo.
 
Discussion starter · #9 ·
OneTrustMan said:
I have the same parts installed on my bike.
Deore M6100 with the Sunrace 800 cassette.
And I had the same issues when installing this group, but got a great tip here in the Shimano sub forum.

Check the B-line on the derailleur.
For Sunrace cassettes the biggest 51t cog needs to be between 1,5 to 2 mm below the B-line to make it work properly. Sunrace shift ramps are slower than Shimano, or Sram. That's why.

Also imo Shimano's 12 speed mechs even are more finicky to cable tension than Eagle.
So B-screw and tension needs to be just ride.
My drivetrain has now over 1200 km on the clock and shifts pretty well for such a cheap groupo.
Click to expand...
I will check that, thanks.
 
Discussion starter · #10 ·
Here's what I found..
6th to 5th, on down to 1st.. the cogset and chain clearances. The chain sits on the cog and is pinned by the next lower gear in that it can not drop directly into it but has to skip to the next one down. Pics for reference...
I'll check the b-line is it? And see if that helps. But from what I can see this is a chain/cog issue.
Or am I reading this wrong?
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#12 ·
Also check the cage, if they're bent it'll behave similarly.

Got a pic from the back showing the entire assembly?
 
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Discussion starter · #14 ·
So I backed the b screw all the way out, that seems to have resolved the issue. It's not 100% perfect, still a touch slow to shift in those gears but it no longer skips them.
It's it normal for the angle screw to not be engaging at all?
Crazy angle going from 12 to crank past the tire.. too short of a chainstay length I suppose on this frame. 435mm IRC..
 
#15 ·
Blathma said:
So I backed the b screw all the way out, that seems to have resolved the issue. It's not 100% perfect, still a touch slow to shift in those gears but it no longer skips them.
It's it normal for the angle screw to not be engaging at all?
Crazy angle going from 12 to crank past the tire.. too short of a chainstay length I suppose on this frame. 435mm IRC..
Click to expand...
Angle screw? Do you mean the b-screw?
If it is all out it could be that your chain is too short.

A short chainstay will make the angle look worse.
Has your bike a 148mm boost rear dropout?
Maybe check your chainline.
 
Discussion starter · #16 ·
OneTrustMan said:
Angle screw? Do you mean the b-screw?
If it is all out it could be that your chain is too short.

A short chainstay will make the angle look worse.
Has your bike a 148mm boost rear dropout?
Maybe check your chainline.
Click to expand...
Yeah the b screw.
The bike is as delivered from the bike shop. No idea on what the length should be, I assumed it's correct. Bike shop is a major surly dealer, figured they'd have it set correctly.
Granted my old rig was 20 yrs old, and a 3x7 setting it up is similar, just hadn't run into this exact issue before. Cogsets are massive now.

Yeah, 148 boost rear.
 
#18 ·
Blathma said:
The bike is as delivered from the bike shop. No idea on what the length should be, I assumed it's correct. Bike shop is a major surly dealer, figured they'd have it set correctly.
Click to expand...
I wouldn't be so sure.
Shimano has a chain length guideline for full suspension bikes and hardtails.

While their fs guideline is correct, their hardtail guideline is wrong. It makes the chain too short.
At least for Sunrace cassettes were you need less b-screw.

If your b-screw is already all the way out, it simply means you chain is too short.
But a picture in the smallest cog would be helpful to figure it out.
 
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