Chain slipping only in big Blade & Smallest Cog?

[Skylark]

Have this weird thing happening, the chain is slipping only when in small front Blade & Smallest Cog and putting the max power on the cranks. Don't often run that combo but from time to time without thinking I do, had a few sketchy experiences trying to get out of trouble in the small blade and I gear done into the smallest 11t cog to speed up and then just at the worst moment the chain slips.

 

Running X9 cranks 39/26t & 11-36 cassette, 10-speed

Only slips when in the 26t blade to 11t cog - using long cage XT Plus RD with clutch.

Edited July 24, 2013 by Skylark

[Johan Bornman]

Your 11 sprocket is worn out. You push big gears and use that sprocket a lot. An easy cure is to find an 11 from some other discarded cassette. Most people don't ever wear those.

[Skylark]

Your 11 sprocket is worn out. You push big gears and use that sprocket a lot. An easy cure is to find an 11 from some other discarded cassette. Most people don't ever wear those.

 

But the 11 doesn't slip with the big blade and I rarely ride in the 11 cog.

That's what is baffling!

 

I looked at it and it appears relatively unworn, it only slips with the small blade when I stand on the cranks and go full power otherwise its fine.

 

But good call on the swapping an 11 from some other discarded cassette, I have one from my old cassette - that's sometimes why you hang on to old junk!!

[TiBones]

[Sanderis]

You can check your chain for wear as well .

[Thor Buttox]

I yield to those with more knowledge, but I had the exact same problem and it turned out to be the limit screws on the rear derailleur

[ChunkyMonkey]

Your 11 sprocket is worn out. You push big gears and use that sprocket a lot. An easy cure is to find an 11 from some other discarded cassette. Most people don't ever wear those.

You did not wear out the 11t, no one ever does....

You did however cross your chain, if the chain is warn(it sounds like it?) and you cross it (smallest ring to smallest cog) you dont have enough chain contact, and virtually no tension on the chain... Slip!!

My suggestion, ...think before you shift, and use your gears more wisely, don't cross the chain, that wears out the link plates...

Edited July 24, 2013 by ChunkyMonkey

[ChunkyMonkey]

Read this article from MTB Guru... Useful stuff:

 

Momentum is your friend

 

Pedaling is hard work so you want to do as little as you can get away with. Look at that a little differently; if you want to get as much speed as possible from your efforts in the engine room, momentum is your friend. Once your bike is rolling you want to do all you can to maintain that speed and that means using your momentum.

http://gallery.mailchimp.com/88ca9c3dbbe35ff6efc5284eb/images/momentum_friend.gif

Confused?... It’s all about planning ahead. For example, there is a steep rise on the trail a few meters ahead (Point C), and it’s too steep and too long to simply freewheel over. Most riders will freewheel till they start running out of momentum (Point B) and then scratch around in their gearbox to find the correct gear [you can hear this in most races when riders are caught out; crunch crunch as they powershift and tiny little pieces of their drive train brake off and lighten their bikes ;-)] and then start pedaling from the bottom, crunching down through the gears plodding and grinding to the top in a low gear.

Or

You could boost your speed (Point A) before you hit the rise then stay in the higher gear speed up (Point B) and pedal out of the saddle maintaining your speed over the top (Point C). There are no prizes for guessing which is the faster way up and over, BUT the most surprising part is that the faster out the saddle effort is far more energy efficient than the low slow approach. By maintaining your speed you will hit the next section of the tail faster, giving you more forward momentum to attack whatever’s coming up next, this enables you to carry your speed on and on……..

 

Getting this approach right takes concentration and practice, but when you clear a fast section of single-track this way you will be able to feel the “flow”.

There are two keys to using momentum effectively:

1.) Looking well ahead

2.)Pre-selecting the right gear. Finding yourself in the wrong gear wastes time, energy and forward momentum as you struggle to find the right gear – and crunching gearshifts aren’t great for your drive trains health either. Shift lightly when you’re not putting the power down and shift early by choosing your line and making decisions before the trail changes again.

(Click here to read how to shift correctly)

 

Next time we will chat about fork set-up

 

"The best mountain biker out there is the one having the most fun"

~MTB Guru~

Edited July 24, 2013 by ChunkyMonkey

[Skylark]

You did not wear out the 11t, no one ever does....

You did however cross your chain, if the chain is warn(it sounds like it?) and you cross it (smallest ring to smallest cog) you dont have enough chain contact, and virtually no tension on the chain... Slip!!

My suggestion, ...think before you shift, and use your gears more wisely, don't cross the chain, that wears out the link plates...

 

That's what I think is happening.

This problem only cropped up after I replaced the chain with a brand new one.

And changed from XTR Med cage RD to XT long cage with clutch

[braailegend]

No he he didn't cross, He's having problems on big front, small back... Which is your heaviest gear and chain is straight.

only piece I can add...Chainguide.

 

But im no expert in gears

 

- " the chain is slipping only when in big front Blade & Smallest Cog"

- "Only slips when in the 26t blade to 11t cog"

 

 

For the bottom case it crosses, but initial statement, was what confused most.

Edited July 24, 2013 by braailegend

[Skylark]

I yield to those with more knowledge, but I had the exact same problem and it turned out to be the limit screws on the rear derailleur

 

Did you resolve it by correcting the lower limit - ie allowing the rd to go lower?

I will need to check this out!

[Skylark]

No he he didn't cross, He's having problems on big front, small back... Which is your heaviest gear and chain is straight.

only piece I can add...Chainguide.

 

But im no expert in gears

 

- " the chain is slipping only when in big front Blade & Smallest Cog"

- "Only slips when in the 26t blade to 11t cog"

 

 

For the bottom case it crosses, but initial statement, was what confused most.

 

Oops!!!!!

You read correctly in the one instance but I wrote it wrong!

It is supposed to read "small front blade & smallest cog"

Have corrected my first post.

 

Going to try the limit screw fix now.. will report back

[Johan Bornman]

But the 11 doesn't slip with the big blade and I rarely ride in the 11 cog.

That's what is baffling!

 

I looked at it and it appears relatively unworn, it only slips with the small blade when I stand on the cranks and go full power otherwise its fine.

 

But good call on the swapping an 11 from some other discarded cassette, I have one from my old cassette - that's sometimes why you hang on to old junk!!

 

Without the bike in front of me it is just a guess, of course. But the reason I suspect a worn sprocket is because it happens with high torque - you alluded to high torque when you said only small chainring. Often the big doesn't produce enough.

[Thor Buttox]

Oops!!!!!

You read correctly in the one instance but I wrote it wrong!

It is supposed to read "small front blade & smallest cog"

Have corrected my first post.

 

Going to try the limit screw fix now.. will report back

Good luck... the only other similar thing that has worked was a few turns on the gear cable tensioner on the rear derailleur. My problem was that it kept trying to settle on the second smallest cog, so it sounds similar. (I'm speaking under correction cos I always get this confused but I think I had to tighten my cable so that it "held" the derailleur out towards the small cog.) If that doesn't solve it, it's probably wear and tear cos I once had one of the middle cogs that slipped and it was uneven wear.

[Flowta]

Did you resolve it by correcting the lower limit - ie allowing the rd to go lower?

I will need to check this out!

 

Also check how much slack you have in the chain.

 

If in small and small, it might be too long for the derailleur to take up the slack.

[Skylark]

Good luck... the only other similar thing that has worked was a few turns on the gear cable tensioner on the rear derailleur. My problem was that it kept trying to settle on the second smallest cog, so it sounds similar. (I'm speaking under correction cos I always get this confused but I think I had to tighten my cable so that it "held" the derailleur out towards the small cog.) If that doesn't solve it, it's probably wear and tear cos I once had one of the middle cogs that slipped and it was uneven wear.

 

That's not the limit screw settings bru!

You talking about indexing.

Anyway I tried the limit screw and it didn't help