Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Broken 105 Di2 Rear Derailleur

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Broken 105 Di2 Rear Derailleur

Old 02-20-24, 09:17 AM
  #26  
Senior Member
 
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,731

Bikes: 1989 Cinelli Supercorsa

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3478 Post(s)
Liked 2,897 Times in 1,760 Posts
Originally Posted by Koyote
Do you know what "JRA" stands for?
Juvenile Rheumatoid Arthritis?
smd4 is online now  
Old 02-20-24, 09:32 AM
  #27  
SE Wis
 
dedhed's Avatar
 
Join Date: Apr 2005
Location: Milwaukee, WI
Posts: 10,486

Bikes: '68 Raleigh Sprite, '02 Raleigh C500, '84 Raleigh Gran Prix, '91 Trek 400, 2013 Novara Randonee, 1990 Trek 970

Mentioned: 40 Post(s)
Tagged: 0 Thread(s)
Quoted: 2737 Post(s)
Liked 3,378 Times in 2,043 Posts
Originally Posted by smd4
Juvenile Rheumatoid Arthritis?
just riding along
dedhed is offline  
Old 02-20-24, 09:33 AM
  #28  
Senior Member
 
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,731

Bikes: 1989 Cinelli Supercorsa

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3478 Post(s)
Liked 2,897 Times in 1,760 Posts
Originally Posted by dedhed
just riding along
I know. Also known as a "dick move."
smd4 is online now  
Old 02-20-24, 09:52 AM
  #29  
Senior Member
 
Join Date: Apr 2019
Location: UK
Posts: 1,404
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 682 Post(s)
Liked 453 Times in 338 Posts
Originally Posted by howaboutme
I think what happened is that I tend to let my drive foot (left in this case) get started, which then has my right crank at Noon. I start the clip in process at Noon and if I don't pay attention and can't get the clip in process right, my foot slips backwards. So it's not because I clip at the 9 o clock position. It's slipping from the Noon ish position backwards. Again, super unlucky this one time and hopefully a fluke. I will be super careful next time and will likely not worry about trying to clip on on the first attempt and just soft pedal w/ right shoe sitting on the pedal and then when I'm out of the intersection and feel less stress, then clip in.
Yeah, that’s a good idea but take care, slipping off can cause some nice shin scrapes if you suddenly discover you need to hurry up. You’ve made me think about how I clip in now and I think I gently toe the pedal, at noon, forward to get it horizontal and then slide the shoe along it to find the socket and then gently push once I’m sure it’s in the right place so I’m putting some power to the chain as it snaps in. Never had the shoe slip backwards doing that although I have, as above, had it go off the side if careless or even misalign and get my shoe up against the crank and had to start again a few strokes later. Usually this is all by feel although I might glance to check the pedal is “spring downward” when I start.

and I do all of this in a big gear because it buys me more time to clip in.

What sort of pedals are you using?
choddo is offline  
Old 02-20-24, 09:54 AM
  #30  
ignominious poltroon
 
Polaris OBark's Avatar
 
Join Date: Jan 2022
Posts: 3,988
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 2216 Post(s)
Liked 3,397 Times in 1,773 Posts
Originally Posted by smd4
Of course I know. Warranties--Shimano's included--usually only cover defects in materials or workmanship. This damager is neither.
Looks like the material snapped.

If caused by an accident (crash), I agree.

If JRA, as I specified, then it is worth a try.

Shimano has warrantied stuff for me under less compelling conditions (which I informed them of).
Polaris OBark is offline  
Old 02-20-24, 09:57 AM
  #31  
ignominious poltroon
 
Polaris OBark's Avatar
 
Join Date: Jan 2022
Posts: 3,988
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 2216 Post(s)
Liked 3,397 Times in 1,773 Posts
Originally Posted by howaboutme
I don't. What does it mean?
"Just Riding Along", meaning you didn't do anything out of the ordinary.

I still think it is worth a try. The worst they can say is no. If it works out well, you have a new back-up/replacement.
Polaris OBark is offline  
Old 02-20-24, 10:09 AM
  #32  
Senior Member
 
Join Date: Sep 2017
Posts: 7,815
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 6919 Post(s)
Liked 10,909 Times in 4,659 Posts
Originally Posted by Koyote
Do you know what "JRA" stands for?
Originally Posted by smd4
Juvenile Rheumatoid Arthritis?
Your confusion now makes sense.
Koyote is offline  
Old 02-20-24, 10:13 AM
  #33  
Senior Member
 
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,731

Bikes: 1989 Cinelli Supercorsa

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3478 Post(s)
Liked 2,897 Times in 1,760 Posts
Originally Posted by Koyote
Your confusion now makes sense.
You'd probably pull a JRA.
smd4 is online now  
Old 02-20-24, 12:43 PM
  #34  
Junior Member
Thread Starter
 
howaboutme's Avatar
 
Join Date: Jan 2024
Location: Northern VA
Posts: 83

Bikes: 2023 Giant Defy Advanced 1

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 40 Post(s)
Liked 29 Times in 15 Posts
Originally Posted by choddo
Yeah, that’s a good idea but take care, slipping off can cause some nice shin scrapes if you suddenly discover you need to hurry up. You’ve made me think about how I clip in now and I think I gently toe the pedal, at noon, forward to get it horizontal and then slide the shoe along it to find the socket and then gently push once I’m sure it’s in the right place so I’m putting some power to the chain as it snaps in. Never had the shoe slip backwards doing that although I have, as above, had it go off the side if careless or even misalign and get my shoe up against the crank and had to start again a few strokes later. Usually this is all by feel although I might glance to check the pedal is “spring downward” when I start.

and I do all of this in a big gear because it buys me more time to clip in.

What sort of pedals are you using?
I'm using Look. I'm just getting back into cycling after a few decades off so I'm not nearly as competent as I should be.
howaboutme is offline  
Old 02-20-24, 12:43 PM
  #35  
Junior Member
Thread Starter
 
howaboutme's Avatar
 
Join Date: Jan 2024
Location: Northern VA
Posts: 83

Bikes: 2023 Giant Defy Advanced 1

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 40 Post(s)
Liked 29 Times in 15 Posts
Originally Posted by Polaris OBark
"Just Riding Along", meaning you didn't do anything out of the ordinary.

I still think it is worth a try. The worst they can say is no. If it works out well, you have a new back-up/replacement.
Too late. I've already bought and replaced it.
howaboutme is offline  
Old 02-20-24, 12:51 PM
  #36  
Senior Member
 
Join Date: Apr 2019
Location: UK
Posts: 1,404
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 682 Post(s)
Liked 453 Times in 338 Posts
Originally Posted by howaboutme
Too late. I've already bought and replaced it.
Worth a try if you still have the broken one. i’ve still got a spare Ultegra shifter from years ago because I did exactly that.

I use Look as well. They do tend to behave themselves as long as you don’t shoot off too fast and spin the pedal. The thing I didn’t say was I do all of that out of the saddle. Maybe everyone does but thought it worth mentioning explicitly.
choddo is offline  
Old 02-20-24, 12:54 PM
  #37  
ignominious poltroon
 
Polaris OBark's Avatar
 
Join Date: Jan 2022
Posts: 3,988
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 2216 Post(s)
Liked 3,397 Times in 1,773 Posts
Originally Posted by howaboutme
Too late. I've already bought and replaced it.
Unless you tossed the old one into the trash, it isn't too late. Send it to Shimano. They will inspect it and replace it if they decide it is a warranty issue (I have no idea, but I have big feet, am right-footed, and have had Di2 for almost 10 years without issue, so there might be a new design flaw in the 12-speed 105.)

At the very least, keep the old one for spare parts. Your bike shop should have pursued the warranty for you.
Polaris OBark is offline  
Likes For Polaris OBark:
Old 02-20-24, 12:56 PM
  #38  
ignominious poltroon
 
Polaris OBark's Avatar
 
Join Date: Jan 2022
Posts: 3,988
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 2216 Post(s)
Liked 3,397 Times in 1,773 Posts
Originally Posted by smd4
Juvenile Rheumatoid Arthritis?
I had someone in my research group who suffered from this. I wouldn't wish it on anyone.
Polaris OBark is offline  
Old 02-20-24, 01:28 PM
  #39  
Junior Member
Thread Starter
 
howaboutme's Avatar
 
Join Date: Jan 2024
Location: Northern VA
Posts: 83

Bikes: 2023 Giant Defy Advanced 1

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 40 Post(s)
Liked 29 Times in 15 Posts
I still have it so....

Incidentally, I am at the office today and my colleague brought his bike in w/ the older 105 rear derailleur and it's all metal!!! The part that broke, which on mine is plastic, was all metal before.
howaboutme is offline  
Old 02-20-24, 01:57 PM
  #40  
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,631

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5749 Post(s)
Liked 2,506 Times in 1,383 Posts
Originally Posted by howaboutme
I don't. What does it mean?
Anyone who's worked in a bike shop has heard it countless times.

It's the opening phrase of a warranty request.

I was just riding along........

.
FBinNY is offline  
Likes For FBinNY:
Old 02-20-24, 02:12 PM
  #41  
ignominious poltroon
 
Polaris OBark's Avatar
 
Join Date: Jan 2022
Posts: 3,988
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 2216 Post(s)
Liked 3,397 Times in 1,773 Posts
Originally Posted by howaboutme
I still have it so.....
Send it to their office in Irvine. Be prepared to wait a month while hearing nothing. If it is approved, a new one will arrive unannounced at your door-step.
Polaris OBark is offline  
Likes For Polaris OBark:
Old 02-21-24, 02:49 AM
  #42  
Senior Member
 
jgwilliams's Avatar
 
Join Date: Aug 2004
Location: Surrey, UK
Posts: 870

Bikes: Dolan Tuono 105 Di2, custom built 653 and 531 bikes with frames by Barry Witcomb, Sonder Dial XT mountain bike and a Brompton folding bike.

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 298 Post(s)
Liked 141 Times in 100 Posts
That was unfortunate. I've had an opposite issue where my foot slipped forward when I was trying to clip, hit the QR lever and undid it. Fortunately, I noticed immediately. Yet another plus for thru axles, I guess.
jgwilliams is offline  
Likes For jgwilliams:
Old 02-21-24, 03:20 AM
  #43  
Method to My Madness
 
Join Date: Nov 2020
Location: Orange County, California
Posts: 3,635

Bikes: Trek FX 2, Cannondale Synapse, Cannondale CAAD4, Santa Cruz Stigmata GRX

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 1937 Post(s)
Liked 1,458 Times in 1,010 Posts
Originally Posted by t2p
are you right leg dominant ? do you kick a ball with right leg / foot ?
This series of questions is kind of off-topic but very interesting. Yes, to both questions. I am also right-handed in everything except hockey, which I play with a left-handed stick.

Originally Posted by t2p
is your right leg stronger ?
Not sure, because I do not have any power meter. My left leg may be marginally stronger, but maybe because I always launch my bike with a left leg stroke. I often put more weight on my left foot when I am standing still for a while. But if I was doing a long jump with a running start, I would jump off my right foot and land on my left foot.

Originally Posted by t2p
when you mount the bike do you plant left leg / foot on the ground and swing right leg up and over the bike (top tube) ?
Yes. I have never tried the opposite direction; I may not be even able to do so.

Originally Posted by t2p
do you ride a motorcycle ?
No, but why would riding a motorcycle matter?

Originally Posted by t2p
if answer to above is ‘yes’ - typically you would clip in with right shoe first
This is the weird and interesting part: I always clip in my left foot first, launch my bike with a left pedal stroke, lower my bum onto the saddle, and then clip in my right foot, usually when the pedal is at or just past top dead center.

When coming to a stop I feel more comfortable unclipping my right foot when the pedal is at or just past bottom dead center and putting my right foot on the ground, because I feel more balanced at slow freewheeling speed when my left foot is clipped in and the left pedal is at bottom dead center, which matches my standing posture.
SoSmellyAir is offline  
Old 02-21-24, 08:00 AM
  #44  
Senior Member
 
Kontact's Avatar
 
Join Date: Apr 2011
Posts: 6,913
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 4319 Post(s)
Liked 1,506 Times in 980 Posts
Originally Posted by howaboutme
I still have it so....

Incidentally, I am at the office today and my colleague brought his bike in w/ the older 105 rear derailleur and it's all metal!!! The part that broke, which on mine is plastic, was all metal before.
Exactly my point.
Kontact is offline  
Old 02-21-24, 08:02 AM
  #45  
Senior Member
 
Kontact's Avatar
 
Join Date: Apr 2011
Posts: 6,913
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 4319 Post(s)
Liked 1,506 Times in 980 Posts
Originally Posted by jgwilliams
That was unfortunate. I've had an opposite issue where my foot slipped forward when I was trying to clip, hit the QR lever and undid it. Fortunately, I noticed immediately. Yet another plus for thru axles, I guess.
Your QR lever wasn't nearly tight enough or at a proper angle if this happened.
Kontact is offline  
Likes For Kontact:
Old 02-21-24, 08:02 AM
  #46  
Senior Member
 
Join Date: Oct 2008
Location: Right where I'm supposed to be
Posts: 1,630

Bikes: Franklin Frames Custom, Rivendell Bombadil

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 115 Post(s)
Liked 208 Times in 126 Posts
I think derailleur ought to be able to endure a foot flying off the pedal. Plastic has no business being used where it is in that derailleur. I'd still send it for warranty. If denied, so what. If they send you a new one, sell it or donate it, but myself I'd never trust such a design. Shimano's turned "soft" .... ahahahaha... literally.
Garthr is offline  
Likes For Garthr:
Old 02-21-24, 08:21 AM
  #47  
Senior Member
 
jgwilliams's Avatar
 
Join Date: Aug 2004
Location: Surrey, UK
Posts: 870

Bikes: Dolan Tuono 105 Di2, custom built 653 and 531 bikes with frames by Barry Witcomb, Sonder Dial XT mountain bike and a Brompton folding bike.

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 298 Post(s)
Liked 141 Times in 100 Posts
Originally Posted by Kontact
Your QR lever wasn't nearly tight enough or at a proper angle if this happened.
Frankly, that's tosh. There's no point having QR if it's so tight it can't be undone by hand, and the angle was pretty much dictated by the design of the fork.
jgwilliams is offline  
Old 02-21-24, 08:23 AM
  #48  
Senior Member
 
Join Date: Sep 2017
Posts: 7,815
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 6919 Post(s)
Liked 10,909 Times in 4,659 Posts
Originally Posted by Polaris OBark
Unless you tossed the old one into the trash, it isn't too late. Send it to Shimano. They will inspect it and replace it if they decide it is a warranty issue (I have no idea, but I have big feet, am right-footed, and have had Di2 for almost 10 years without issue, so there might be a new design flaw in the 12-speed 105.)

At the very least, keep the old one for spare parts. Your bike shop should have pursued the warranty for you.
If the RD broke and the derailleur hanger is intact, then it is a faulty design, IMO.
Koyote is offline  
Likes For Koyote:
Old 02-21-24, 08:27 AM
  #49  
Junior Member
Thread Starter
 
howaboutme's Avatar
 
Join Date: Jan 2024
Location: Northern VA
Posts: 83

Bikes: 2023 Giant Defy Advanced 1

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 40 Post(s)
Liked 29 Times in 15 Posts
I submitted a ticket or whatever it's called last night. There's no room for pictures, just description so we'll see. the RD was on a new bike so that's a bit more complicated. We'll see.
howaboutme is offline  
Likes For howaboutme:
Old 02-21-24, 08:55 AM
  #50  
Senior Member
 
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,731

Bikes: 1989 Cinelli Supercorsa

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3478 Post(s)
Liked 2,897 Times in 1,760 Posts
Originally Posted by jgwilliams
Frankly, that's tosh. There's no point having QR if it's so tight it can't be undone by hand, and the angle was pretty much dictated by the design of the fork.
Not really. The QR doesn't have to be so tight that you can't open it by hand, and you can position the lever in unlimited angles--even straight down if that's what floats your boat.
smd4 is online now  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.