slewk Posted July 20, 2019 Posted July 20, 2019 Hey guys I know one doesn't do a lot of back pedalling but i want to sort this out for 2 reasons: 1.) Every time i clean my bike, i back pedal the cranks to clean the cassette / chain ring etc, and not only does the chain drop but the drive train seizes and pulls the derrailer up and the chain just slackens out / sticks. 2.) Sometimes on the trail when i just need to align my crank before dropping in, even a half back rotation causes the same issue. I have to pick up the rear wheel and pedal forward to get the chain free moving again. Issue happens mostly on the biggest cog, which isn't worn or anything. For information sake bike is a 2019 Evil Offering, with a 1x12 Sram NX Eagle drive train I did have a crash when i first got the bike that hit the derailler, so it has a new hanger on for a while now. I can imagine it's chain-line related, but short of adjusting b tension and cable adjustments, I'm not to sure how to solve this. Chain isn't worn either, but maybe a new one will help? Chain length feels right. I guess i could try another derailler but i want to see what are my options first The bike shifts fine 80% of the time in normal riding, i just think 1x12 eagle can be a bit finicky Any suggestions will be greatly appreciated! L
Schnavel Posted July 20, 2019 Posted July 20, 2019 You mentioned you crashed and hit your derailleur, did you replace / realign the hanger? Eagle is especially sensitive to slight misalignements, so I would venture a guess that your hanger is bent, without looking at the bike.
David Marshall Posted July 20, 2019 Posted July 20, 2019 As Schnavel said the Eagle has its moments. Even a new hanger may need alignment and the Sram B screw adjustment is tricky. You need the plastic tool and remember to have the rider on the bike when adjusting. Could also be a problem with the freehub.
thebob Posted July 20, 2019 Posted July 20, 2019 I had the same issue on my GX Eagle. I got the bike on a stand and found that the chain was coming off at only one spot on the cassette. This was because one of the teeth on the cassette was slightly bent and was thus pushing the chain down to the next sprocket. Realigned it with a pair of pliers and all good. As the other posters have indicated, b-screw adjustment is critical. Make sure you have the bike at sag point when doing this.
Lance Stephenson Posted July 20, 2019 Posted July 20, 2019 Hey guys I know one doesn't do a lot of back pedalling but i want to sort this out for 2 reasons: 1.) Every time i clean my bike, i back pedal the cranks to clean the cassette / chain ring etc, and not only does the chain drop but the drive train seizes and pulls the derrailer up and the chain just slackens out / sticks. 2.) Sometimes on the trail when i just need to align my crank before dropping in, even a half back rotation causes the same issue. I have to pick up the rear wheel and pedal forward to get the chain free moving again. Issue happens mostly on the biggest cog, which isn't worn or anything. For information sake bike is a 2019 Evil Offering, with a 1x12 Sram NX Eagle drive train I did have a crash when i first got the bike that hit the derailler, so it has a new hanger on for a while now. I can imagine it's chain-line related, but short of adjusting b tension and cable adjustments, I'm not to sure how to solve this. Chain isn't worn either, but maybe a new one will help? Chain length feels right. I guess i could try another derailler but i want to see what are my options first The bike shifts fine 80% of the time in normal riding, i just think 1x12 eagle can be a bit finicky Any suggestions will be greatly appreciated! LFirstly, 1 x Sram systems tend to hop, skip and have a fluff when back pedaling in extreme gears (the 50T or 10T) because of the chain line, if you put the chain in the middle of the cassette is it doing the same thing?
slewk Posted July 20, 2019 Author Posted July 20, 2019 Thanks for the response guys! @Schnavel correct i did replace the hanger but not the derailler @David I have the official Eagle B tension tool and have it set correctly @the bob i checked the cassette for wear but not for bent teeth, will have a look. I didn't set B tension with Sag, Im guessing i would need someone to sit on the bike for this or vice versa? @DJR how could I fix a sticking freehub? Dissemble and re-grease the pawls? Would that cause the chain so skip or do you think it's 2 problems coinciding? @Lance the 1x11 GX on my previous bike never gave me a single problem, but i can imagine the 1x12 giving more issues. I really dont think that knock on the derailler helped it either. Back pedalling on the middle gears is much more smooth, but still catches on about 5 or 6 rotations
Rich990 Posted July 20, 2019 Posted July 20, 2019 What freehub is it? My freehub died in a way that the ratchets don't disengage and it causes chainsuck and pulls the chain off the chain ring, pulls the derailleur forward, all your symptoms. Would be a good place to start looking. Does it freewheel fine when your rolling along at speed? Does it cause issues if you back pedal at speed?
DieselnDust Posted July 20, 2019 Posted July 20, 2019 If its catching in the middle sprockets then your derailleur is not properly aligned with the sprockets above the guide pulley.
thebob Posted July 20, 2019 Posted July 20, 2019 @the bob i checked the cassette for wear but not for bent teeth, will have a look. I didn't set B tension with Sag, Im guessing i would need someone to sit on the bike for this or vice versa?I managed this by letting air out of the shock and using a tie down to hold the bike at the sag point. I then set the b tension with the tool
slewk Posted July 21, 2019 Author Posted July 21, 2019 So it seems that my problem kinda came to a solution all on its own... At the start of stage 5 at todays Hoogekraal enduro, the chain sucked off and ripped the derailleur jockey wheel clean off haha. What a **** show, but at least now i am forced to get a different one that hopefully works Im thinking the Sunrace 12 spd derailleur as it's compatible with my shifter and cassette. https://www.evobikes.co.za/components/rear-derailleurs/sunrace-rear-derailleur-mx60-10-11-12spd.html What do you guys think?
V18 Posted July 21, 2019 Posted July 21, 2019 Sounds like trashbikitis. Jokes. I would seriously consider going back levelspied. Most of your tjommie are on some variations of shimano derailleur with sunrace casette.
V18 Posted July 21, 2019 Posted July 21, 2019 Also. Freehub must checked. If it fails to disengage this will explain everything.
Yo-Yo Posted July 21, 2019 Posted July 21, 2019 So it seems that my problem kinda came to a solution all on its own... At the start of stage 5 at todays Hoogekraal enduro, the chain sucked off and ripped the derailleur jockey wheel clean off haha. What a **** show, but at least now i am forced to get a different one that hopefully works Im thinking the Sunrace 12 spd derailleur as it's compatible with my shifter and cassette. https://www.evobikes.co.za/components/rear-derailleurs/sunrace-rear-derailleur-mx60-10-11-12spd.html What do you guys think?It’s buggered. Insurance claim and new bike is the only way forward.
BaGearA Posted July 21, 2019 Posted July 21, 2019 It’s buggered. Insurance claim and new bike is the only way forward.+1
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