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Issue while changing to small blade at high cadence


Jbr
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Hey guys. I have been riding Q-rings since I got my road bike and I recently changed from an FSA crankset to a Rotor one, but with the same Q-rings, and it seems that since then, if I drop to the small blade while at medium to high cadence (say 90rpm) the chain seems too follow the blade back up on the bottom side and it gets stuck between the blade and the frame... Almost like if the derailer wasn't keeping the chain tight enough to counter that... 

 

Should I maybe remove a link to make the whole thing tighter ? Or just change blades at lower cadence ? Any other suggestions ? My frame now has scratches around the BB and it breaks my heart  :(  :(  

Edited by Jbr
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Hey guys. I have been riding Q-rings since I got my road bike and I recently changed from an FSA crankset to a Rotor one, but with the same Q-rings, and it seems that since then, if I drop to the small blade while at medium to high cadence (say 90rpm) the chain seems too follow the blade back up on the bottom side and it gets stuck between the blade and the frame... Almost like if the derailer wasn't keeping the chain tight enough to counter that... 

 

Should I maybe remove a link to make the whole thing tighter ? Or just change blades at lower cadence ? Any other suggestions ? My frame now has scratches around the BB and it brakes my heart  :(  :(  

 

a few thoughts

1. worn chain or rings? (is this a new chain on old rings for example, which is the textbook example)

2. dirty chain - i used to get this on my mtb when the chain got muddy and poorly lubed

3. this is only a problem in May :)

 

https://www.sheldonbrown.com/gloss_ch.html#chainsuck

http://fagan.co.za/Bikes/Csuck/

Edited by 100Tours
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The chain AND the rings never changed, I only changed the crankset on which the rings are attached, and the guy who did it said he made sure the oval rings were in the same position. 

 

You guys think a new chain would fix it or I must change chain + rings ? I'm going to try and clean both thoroughly even if my chain is rather clean already

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Check chain wear before doing anything else. You may also find that there's been a slight change in chainline that's causing this - try downshifting with the chain at the top and then the bottom end of the cassette and see if there's any difference between the two.

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Did you adjust your front derailleur limits when you changed the crankset? It might be that the position of the blades is not exactly the same as before.

yes, but on the top side of the blade all goes well, the issue is at the bottom side, where the chain follows the blade back up instead of going backwards towards the rear derailer, that's why I was asking about maybe removing links to ad some tension...

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yes, but on the top side of the blade all goes well, the issue is at the bottom side, where the chain follows the blade back up instead of going backwards towards the rear derailer, that's why I was asking about maybe removing links to ad some tension...

What you described is chain suck. Caused by one of the following: 1 Most common is a worn drive-train. Most of the time chainrings and chain needs replacing. New chain on worn chainring will only make matters worse. 2 Dry chain can cause chain suck. 3 Dirty drivetrain. 4 Damaged tooth or teeth on chainring. Even if its not worn, a bent tooth or a tooth wit a burr can cause chain suck. 5. Riding style; if you like cranking big gears and delay shifting to a smaller chainring to the last moment while still applying maximum torque you are likely to run into chain suck problems. Hope this helps.

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oh dear :'(

 

Thanks for all the information.... Until I got the rotor powermeter I used to spin at low RPM/hard gear and then realised my output was way higher on a easier gear/higher RPM so just changed my riding style recently... I'll check all the rest, thanks !

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