Chain drop issue

Back by popular demand, the general all-things Road forum!

Moderator: robbosmans

JBeauBikes2
Posts: 37
Joined: Wed Jun 28, 2017 5:00 am

by JBeauBikes2

Lately I've been dropping my chain on every single ride. I've had it in the LBS 5 different times to fix the issue but they can't seem to figure it out.

In February I switched from my ultegra crankset to a rotor 3D with praxis works rings for my P2M and the switch was fine, shifting was actually a little more crisp when I made the change. About 6 weeks ago they put a new chain on and changed FD shift cable and that's when it all started. It drops 7/10 times going from the small to big ring at high and low cadences.

The bike is a Felt AR3, in case the FD mount position on the bike has anything to do with it.

Any ideas?

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



jobvisser
Posts: 120
Joined: Sun Aug 14, 2016 10:24 am

by jobvisser

JBeauBikes2 wrote:Lately I've been dropping my chain on every single ride. I've had it in the LBS 5 different times to fix the issue but they can't seem to figure it out.

In February I switched from my ultegra crankset to a rotor 3D with praxis works rings for my P2M and the switch was fine, shifting was actually a little more crisp when I made the change. About 6 weeks ago they put a new chain on and changed FD shift cable and that's when it all started. It drops 7/10 times going from the small to big ring at high and low cadences.

The bike is a Felt AR3, in case the FD mount position on the bike has anything to do with it.

Any ideas?

probably the front derailleur that just too far out
---> :oops: Send me a pm to order world's lightest low carbon fiber dust covers! (1g) :oops: <---

nemeseri
Posts: 794
Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

Where does the chain end up? Over the bigger ring or between the rings?
Based on the information you gave, I believe it's just a simple outer limit screw adjustment, but it would be shocking if that's something your LBS didn't try already. Other things to check: chain direction (in the case of asymmetric chains).

Is it an ultegra FD btw?

Oh and you can simply try to set up your front shifting based on the shimano manual. It's not rocket science and it's hard to make things worse at this point.

JBeauBikes2
Posts: 37
Joined: Wed Jun 28, 2017 5:00 am

by JBeauBikes2

nemeseri wrote:Where does the chain end up? Over the bigger ring or between the rings?
Based on the information you gave, I believe it's just a simple outer limit screw adjustment, but it would be shocking if that's something your LBS didn't try already. Other things to check: chain direction (in the case of asymmetric chains).

Is it an ultegra FD btw?

Oh and you can simply try to set up your front shifting based on the shimano manual. It's not rocket science and it's hard to make things worse at this point.


The chain always ends up between the bottom bracket and the inner ring, and yeah it is an Ultegra FD. The chain is also Ultegra. I'm going to play with it a little and see if I can't get it functioning right, I'll check the outer limit screw too.

Zakalwe
Posts: 786
Joined: Sun Jun 17, 2012 3:15 pm

by Zakalwe

It's dropping off the inside of the small ring when you change up to the big ring? That shouldn't even be possible as long as the cable is pulling the derailer outwards properly. Is the cable routed through the BB guide properly? Is the cable end seated in the shifter properly? Is the cable housing snug against the shifter and cut square, not moving back and forth under the bar tape? Did any washers etc fall out of the shifter when renewing the cable?

kode54
Posts: 3748
Joined: Tue May 23, 2006 9:39 pm

by kode54

HG-901 chain is one direction. maybe they put it on the wrong side?
- Factor Ostro VAM Disc
- Factor LS Disc
- Specialized Aethos Disc
- Sturdy Ti Allroad Disc
- Guru Praemio R Disc

JBeauBikes2
Posts: 37
Joined: Wed Jun 28, 2017 5:00 am

by JBeauBikes2

Zakalwe wrote:It's dropping off the inside of the small ring when you change up to the big ring? That shouldn't even be possible as long as the cable is pulling the derailer outwards properly. Is the cable routed through the BB guide properly? Is the cable end seated in the shifter properly? Is the cable housing snug against the shifter and cut square, not moving back and forth under the bar tape? Did any washers etc fall out of the shifter when renewing the cable?


The chain makes it to the large cog and deflects to the inside between the small ring and BB. The cable is definitely pulling the derailleur outside. Nothing is off with the cable housing. I trust the shop that did the housing, I bought the chain from a different shop and they installed it as well. I can see if any washers are missing the next time I take it to the shop and see if that's causing issues.

JBeauBikes2
Posts: 37
Joined: Wed Jun 28, 2017 5:00 am

by JBeauBikes2

kode54 wrote:HG-901 chain is one direction. maybe they put it on the wrong side?


The chain on there is the shimano HG-701, the chain markings are facing outward so that seems to check out!

Part of me feels like it could just be chain tension? If the chain had too much tension, would shifting while pedaling cause the chain to deflect back towards the BB if it had too much tension to make it completely over to the big ring?

rpowell
Posts: 59
Joined: Tue Sep 10, 2013 12:47 am

by rpowell

ive had a bent chainring tooth that caused similar problems. spin the cranks without the chain on and you can see quickly if they are aligned.

jobvisser
Posts: 120
Joined: Sun Aug 14, 2016 10:24 am

by jobvisser

have you gone back to your lbs ? they made this problem for you so they might aswell fix it for free
---> :oops: Send me a pm to order world's lightest low carbon fiber dust covers! (1g) :oops: <---

JBeauBikes2
Posts: 37
Joined: Wed Jun 28, 2017 5:00 am

by JBeauBikes2

jobvisser wrote:have you gone back to your lbs ? they made this problem for you so they might aswell fix it for free



I've had it in the shop 5 times so far including this morning. They said it was all good, I took it for a spin and dropped my chain the first time I shifted from little to big.

It was worse a few weeks ago, not sure how but the chain dropped from the big ring as I was coming out of a corner in a Crit. It's at least not doing that now, but I'm going to take it back in tomorrow to see if they can get this dialed in.

I'm going to play around with the limit screws, maybe the FD can't move out far enough? I'm sure the shop would have caught that as it seems obvious if the chain is dropping inbetween the BB and small ring. The front cable looks fine, it's stiff but it's a fairly new cable. It's just illogical to drop the chain on the inside when the FD is position for the outer ring

User avatar
Hellgate
Posts: 189
Joined: Mon Mar 27, 2017 8:49 pm

by Hellgate

Have you looked at Shimanos technical manuals and compared the specs to your set up?

I'm a life long Campy guy, but they are all pretty much the same.

Make sure the outer plate of the FD is parallel to the chain ring. Adjust the outer limit screw in the small COG. Then adjust in the small chainring, the inner limit screw with the chain on the large cog.

Also check that the rear triangle is parallel and not out of alignment.

Sent from my SAMSUNG-SM-G900A using Tapatalk

User avatar
wheelsONfire
Posts: 6283
Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

Have had same issue. Using Both UL chain and the new HG 901 (in correct direction)
I ran 44/33, swapped to 46/34 which solves the problem.
I also adjusted the FD and the RD, did not change a thing, quite possibly the one thing that happened, was that it started to threw off the chain at the big chainring to.
Really weird and it damages paint and in due time, it will chew carbon.
I don't know to date, what caused this, only idea i had was to use a chain suck device but could not find one fitting my bike.
However, you could check if you can shorten your chain. Run big ring at the cassette and big ring at your crankset.
Then you can pull the rear RD and see if there is more slack/ give and if the RD can stretch further.
Then you possibly can cut chain some more.
Bikes:

Ax Lightness Vial EVO Race (2019.01.03)
Open *UP* (2016.04.14)
Paduano Racing Fidia (kind of shelved)


Ex bike; Vial EVO D, Vial EVO Ultra, Scott Foil, Paduano ti bike.

fogman
Posts: 1067
Joined: Fri Oct 30, 2009 10:36 pm

by fogman

I am having this same issue with my 2016 Campagnolo Super Record front derailleur. And my K-Edge chain catcher is not doing its job. The chain somehow is finding its way between the chain catcher and the BB.


Sent from my iPhone using Tapatalk
It's all downhill from here, except for the uphills.

2lo8
Posts: 551
Joined: Thu Mar 31, 2016 10:32 am

by 2lo8

I'm guessing what happens is the chain tries to climb up the big ring, but will not settle on the teeth for whatever reason, issue with chainrings, incomplete shift, poor setup. This is fairly common when using mismatched or mistimed or severely worn chewed up chainrings where the chain will be picked up by the ramps, but the rollers are not in the right place to settle on the teeth. The chain then falls off the big ring and does not land on the small ring. The reason it fails so catastrophically and chain catchers do little to prevent it is because this happens in front of the chain catcher and derailer, so there's nothing to guide the chain to settle on the small ring, it just falls off the big ring, there's no links secure on the big ring, it then jumps over or bounces over the small ring then onto the bottom bracket shell. Once there if the chainrings catch on the chain, they can force the chain past the catcher. Catchers aren't strong enough to resist the chain being wedged between them, they just help guide the chain when it falls off the big ring. With a normal shift, the chain is destabilized at the derailer, and teeth are still engaged with the chain from before the shift, so the front chainring is pulling, tensioning and stabilizing the chain and it is pulled through the front derailer and laid down onto the small ring.

I'd still change LBS. 5 times is a waste of time.
[14lb(6.35kg) of no carbon fiber]
[2lo8.wordpress.com]
Your one-stop source for information and reviews on cheap eBay bike junk.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



Post Reply