[RBW] Re: Front Derailleur Fails
On Saturday, August 16, 2014 5:39:55 PM UTC+2, Bill Lindsay wrote: Honestly, I'd just chalk it up to bad luck and not sweat it. +1 -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
[RBW] Re: Front Derailleur Fails
Close shouldn't be a problem, because it minimizes torsion on the cage. I take the clear a penny approach when adjusting height of my FD - a penny resting against the large ring should clear the cage all the way around. From this photo, https://www.flickr.com/photos/stonehog/14746522120/in/set-72157646102516140/ it looks like the cracks had been growing for a long time. Did you move it from another bike? If you don't need a triple. the smaller opening of a road double is going to make for a stronger cage. On Saturday, August 16, 2014 3:10:19 AM UTC-5, stonehog wrote: In 30+ years of riding, I've never had problems with front derailleurs. Now in the last year, I've had 2 break on me during normal riding. The first was a Shimano CX70 on a brevet last summer. I had some problems with the cage bending out due to chainsuck on that guy, so I wasn't too surprised. The other day on my commute home, I popped the cage on a Campy Centaur triple. It was a similar break at the top of the cage with a clean edge break. It doesn't feel like I'm hard on the shifting, but something must be up. Both breaks have been on my AHH with a Rene Herse 44x28 crankset. I adjust the derailleurs to be close to the top of the big ring with 1-2mm spacing as spec'd. No problem with another CX70 on my Hunqapillar and XD600 48x34 double. Similar mileage, and if anything, more abuse. Here are some pics: https://www.flickr.com/photos/stonehog/sets/72157646102516140/ Any suggestions? Do they just not make 'em like they used to? Brian Hanson Seattle, WA On Saturday, August 16, 2014 3:10:19 AM UTC-5, stonehog wrote: In 30+ years of riding, I've never had problems with front derailleurs. Now in the last year, I've had 2 break on me during normal riding. The first was a Shimano CX70 on a brevet last summer. I had some problems with the cage bending out due to chainsuck on that guy, so I wasn't too surprised. The other day on my commute home, I popped the cage on a Campy Centaur triple. It was a similar break at the top of the cage with a clean edge break. It doesn't feel like I'm hard on the shifting, but something must be up. Both breaks have been on my AHH with a Rene Herse 44x28 crankset. I adjust the derailleurs to be close to the top of the big ring with 1-2mm spacing as spec'd. No problem with another CX70 on my Hunqapillar and XD600 48x34 double. Similar mileage, and if anything, more abuse. Here are some pics: https://www.flickr.com/photos/stonehog/sets/72157646102516140/ Any suggestions? Do they just not make 'em like they used to? Brian Hanson Seattle, WA -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
[RBW] Re: Front Derailleur Fails
That's bizarre. You would think a derailer wouldn't break like that at that place because any pressure/ movement would make the derailer move, not resist and break. Does the chain sometimes jam between the big ring and the derailer when shifting into the large ring? That's the only thing I can think of that would stress the cage to make it break like that. But I am no expert. Chain suck maybe? Old age? Mine jams sometimes. Operator error I think. Shifting too far too fast. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
[RBW] Re: Front Derailleur Fails
a derailleur cage is a C-shaped channel. Pulling the chain in either direction puts opening loads on the sides and especially inside corners of the channel. You would hope it's not going to fatigue, but that's the failure mode, slow crack growth. On Monday, August 18, 2014 9:58:11 AM UTC-5, lungimsam wrote: That's bizarre. You would think a derailer wouldn't break like that at that place because any pressure/ movement would make the derailer move, not resist and break. Does the chain sometimes jam between the big ring and the derailer when shifting into the large ring? That's the only thing I can think of that would stress the cage to make it break like that. But I am no expert. Chain suck maybe? Old age? Mine jams sometimes. Operator error I think. Shifting too far too fast. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
[RBW] Re: Front Derailleur Fails
The only FD I have broken in 35 years was the clamp on a pretty Chorus. 16 is a big lift and does stress the derailler, getting the chain stuck between the derailler and ring could weaken the joint. The bottom of the derailler has more flex while the top is secured, so maybe that contributed to weakening over time. How are the rings? Ramped? New or worn? Just as an aside, don't you find that 16 tooth difference creates an awkward shifting patter? It always seems to me that you are making many shifts harder in order to get half a gear lower at the bottom. Michael On Monday, August 18, 2014 10:58:11 AM UTC-4, lungimsam wrote: That's bizarre. You would think a derailer wouldn't break like that at that place because any pressure/ movement would make the derailer move, not resist and break. Does the chain sometimes jam between the big ring and the derailer when shifting into the large ring? That's the only thing I can think of that would stress the cage to make it break like that. But I am no expert. Chain suck maybe? Old age? Mine jams sometimes. Operator error I think. Shifting too far too fast. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
[RBW] Re: Front Derailleur Fails
alignment could be a factor here, too. If the cage is grabbing the chain way far back on the cage, that puts a very big moment at the cracked corners. This load would be minimized by having the derailleur aligned to contact the chain as far forward on the cage as possible. On Monday, August 18, 2014 10:41:10 AM UTC-5, Ron Mc wrote: a derailleur cage is a C-shaped channel. Pulling the chain in either direction puts opening loads on the sides and especially inside corners of the channel. You would hope it's not going to fatigue, but that's the failure mode, slow crack growth. On Monday, August 18, 2014 9:58:11 AM UTC-5, lungimsam wrote: That's bizarre. You would think a derailer wouldn't break like that at that place because any pressure/ movement would make the derailer move, not resist and break. Does the chain sometimes jam between the big ring and the derailer when shifting into the large ring? That's the only thing I can think of that would stress the cage to make it break like that. But I am no expert. Chain suck maybe? Old age? Mine jams sometimes. Operator error I think. Shifting too far too fast. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
[RBW] Re: Front Derailleur Fails
Michael, 26T to 42T step on my Cyclotouriste with a venerable Shimano 600EX FD is a simple click and noiseless transition - chain suck is impossible on this setup. On Monday, August 18, 2014 10:41:55 AM UTC-5, Michael Hechmer wrote: The only FD I have broken in 35 years was the clamp on a pretty Chorus. 16 is a big lift and does stress the derailler, getting the chain stuck between the derailler and ring could weaken the joint. The bottom of the derailler has more flex while the top is secured, so maybe that contributed to weakening over time. How are the rings? Ramped? New or worn? Just as an aside, don't you find that 16 tooth difference creates an awkward shifting patter? It always seems to me that you are making many shifts harder in order to get half a gear lower at the bottom. Michael On Monday, August 18, 2014 10:58:11 AM UTC-4, lungimsam wrote: That's bizarre. You would think a derailer wouldn't break like that at that place because any pressure/ movement would make the derailer move, not resist and break. Does the chain sometimes jam between the big ring and the derailer when shifting into the large ring? That's the only thing I can think of that would stress the cage to make it break like that. But I am no expert. Chain suck maybe? Old age? Mine jams sometimes. Operator error I think. Shifting too far too fast. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
[RBW] Re: Front Derailleur Fails
I wouldn't be surprised if it is the ring spread. I may go with a 42 or even 40 - don't need much on the top end these days - I like to coast down hills, and the 11t in back is a big gear. Derailleur was new, not moved, and the rings are new, unramped. I had a fair amount of small ring to big ring chain suck originally with 9-speed chains, so the CX70 got some wear from that early on until I moved to 7 and then 8 speed setups. Never had this issue with the Campy - it just popped out one day. The big jump theory holds weight. Brian On Monday, August 18, 2014 8:41:55 AM UTC-7, Michael Hechmer wrote: The only FD I have broken in 35 years was the clamp on a pretty Chorus. 16 is a big lift and does stress the derailler, getting the chain stuck between the derailler and ring could weaken the joint. The bottom of the derailler has more flex while the top is secured, so maybe that contributed to weakening over time. How are the rings? Ramped? New or worn? Just as an aside, don't you find that 16 tooth difference creates an awkward shifting patter? It always seems to me that you are making many shifts harder in order to get half a gear lower at the bottom. Michael On Monday, August 18, 2014 10:58:11 AM UTC-4, lungimsam wrote: That's bizarre. You would think a derailer wouldn't break like that at that place because any pressure/ movement would make the derailer move, not resist and break. Does the chain sometimes jam between the big ring and the derailer when shifting into the large ring? That's the only thing I can think of that would stress the cage to make it break like that. But I am no expert. Chain suck maybe? Old age? Mine jams sometimes. Operator error I think. Shifting too far too fast. -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
[RBW] Re: Front Derailleur Fails
Honestly, I'd just chalk it up to bad luck and not sweat it. On Saturday, August 16, 2014 1:10:19 AM UTC-7, stonehog wrote: In 30+ years of riding, I've never had problems with front derailleurs. Now in the last year, I've had 2 break on me during normal riding. The first was a Shimano CX70 on a brevet last summer. I had some problems with the cage bending out due to chainsuck on that guy, so I wasn't too surprised. The other day on my commute home, I popped the cage on a Campy Centaur triple. It was a similar break at the top of the cage with a clean edge break. It doesn't feel like I'm hard on the shifting, but something must be up. Both breaks have been on my AHH with a Rene Herse 44x28 crankset. I adjust the derailleurs to be close to the top of the big ring with 1-2mm spacing as spec'd. No problem with another CX70 on my Hunqapillar and XD600 48x34 double. Similar mileage, and if anything, more abuse. Here are some pics: https://www.flickr.com/photos/stonehog/sets/72157646102516140/ Any suggestions? Do they just not make 'em like they used to? Brian Hanson Seattle, WA -- You received this message because you are subscribed to the Google Groups RBW Owners Bunch group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
