....about ready to assemble a new bike. ...campy components if that matters. 11-21 rear cogs with a short cage rear derailleur.
I've seen different advice about the best chain length on the web. As near as I can tell, I want to size when in the small-small combination and make sure that the chain is short enough so that the bottom pulley does not contact any other portion of the derailleur. I also want to make sure that I can change to the large-large combination (even though that shouldn't be used in practice). ...but I also want to adjust the derailleur's tension screw so that top pulley comes close but does not touch the largest or smallest cog. ...but what if the above can be accomplished with a few links either in or out of the chain? Some say that when sizing a shimano system, the length is correct when the rear derailler is near verticle when in the small-large combination (but I'll have campy).
So what should I know here in terms of chain length and tension adjustment?
"Jeff" <[email hidden]> wrote in message news:[email hidden]...
Okay, in checking the web further, I've found a post on this list by Jobst Bryant that recommends placing the chain in the second to smallest cog and the smallest ring (the smallest sizes that should be used) and then allowing the chain to remain the longest length possible that will prevent any slack.
....but why not do this on the small/small combination? I realize that one should not use this combination, but one could go there accidentially, and if so I would assume that you would then want to prevent chain slack and keep the top pulley off of the small cog.
...about ready to assemble a new bike. ...campy components if that matters. 11-21 rear cogs with a short cage rear derailleur.
I've seen different advice about the best chain length on the web. As near as I can tell, I want to size when in the small-small combination and make sure that the chain is short enough so that the bottom pulley does not contact any other portion of the derailleur. I also want to make sure that I can change to the large-large combination (even though that shouldn't be used in practice). ...but I also want to adjust the derailleur's tension screw so that top pulley comes close but does not touch the largest or smallest cog. ...but what if the above can be accomplished with a few links either in or out of the chain? Some say that when sizing a shimano system, the length is correct when the rear derailler is near verticle when in the small-large combination (but I'll have campy).
So what should I know here in terms of chain length and tension adjustment?
Jeff
Proper chain length is when the chain is long enough to allow the large/large combo without anything getting damaged, and no longer. A good generic way of figuring it is the "Largest Cog and Largest Chainring Method" here: http://parktool.com/repair/readhowto.asp?id=26 .. It doesn't make sense under any circumstances to size the chain the small/small combo. If there's any kind of rub or excessive slack in the small/small combo, it's because the chain is either too long and/ or the capacity of the RD is being exceeded. There's no difference in determining chain length between different component groups/mfgs.
"Jeff" <[email hidden]> wrote in message news:[email hidden]...
Okay, in checking the web further, I've found a post on this list by Jobst Bryant . . .
[snip]
Dear Jeff,
Good ol' Jobst Bryant!
Mr. Bryant, he runs cattle out near Amarillo and drives prit-near the biggest black pick-'em-up truck in those parts, but he purely loves to talk bi-sickles with his cousin, Jobst Brandt, whut lives out Stanford-way and likes yaller more'n black.
...about ready to assemble a new bike. ...campy components if that matters. 11-21 rear cogs with a short cage rear derailleur.
I've seen different advice about the best chain length on the web. As near as I can tell, I want to size when in the small-small combination and make sure that the chain is short enough so that the bottom pulley does not contact any other portion of the derailleur. I also want to make sure that I can change to the large-large combination (even though that shouldn't be used in practice). ...but I also want to adjust the derailleur's tension screw so that top pulley comes close but does not touch the largest or smallest cog. ...but what if the above can be accomplished with a few links either in or out of the chain? Some say that when sizing a shimano system, the length is correct when the rear derailler is near verticle when in the small-large combination (but I'll have campy).
So what should I know here in terms of chain length and tension adjustment?
I use Sheldon Brown's method, which is to run the chain around the large chain ring/ largest cog without going through the derailleur, then pulling the ends together and allowing one extra full link (an inner and an outer) to hang down, then cut the rest of off. I've used this on both my road and mountain bike with good results every time. It will still allow use of the large chain ring/ large cog (I know, shouldn't do that, but once in a while I'm almost to the top of a hill and don't want to shift the chain ring). I never use the small/small connection, but it will work if you do it this way.
...about ready to assemble a new bike. ...campy components if that matters. 11-21 rear cogs with a short cage rear derailleur.
I've seen different advice about the best chain length on the web. As near as I can tell, I want to size when in the small-small combination and make sure that the chain is short enough so that the bottom pulley does not contact any other portion of the derailleur.
5-15mm clearance between the chain and the derailleur body and you are done. That will give youi enough for big-big combos and allow the top pulley to be close to the cogs w/o hitting them.
I also want to make sure that I
Quoted message said:
can change to the large-large combination (even though that shouldn't be used in practice). ...but I also want to adjust the derailleur's tension screw so that top pulley comes close but does not touch the largest or smallest cog. ...but what if the above can be accomplished with a few links either in or out of the chain? Some say that when sizing a shimano system, the length is correct when the rear derailler is near verticle when in the small-large combination (but I'll have campy).
So what should I know here in terms of chain length and tension adjustment?
...about ready to assemble a new bike. ...campy components if that matters. 11-21 rear cogs with a short cage rear derailleur. I've seen different advice about the best chain length on the web. As near as I can tell, I want to size when in the small-small combination and make sure that the chain is short enough so that the bottom pulley does not contact any other portion of the derailleur. I also want to make sure that I can change to the large-large combination (even though that shouldn't be used in practice). ...but I also want to adjust the derailleur's tension screw so that top pulley comes close but does not touch the largest or smallest cog. ...but what if the above can be accomplished with a few links either in or out of the chain? Some say that when sizing a shimano system, the length is correct when the rear derailler is near verticle when in the small-large combination (but I'll have campy). So what should I know here in terms of chain length and tension adjustment?
Quoted message said:
I use Sheldon Brown's method, which is to run the chain around the large chain ring/ largest cog without going through the derailleur, then pulling the ends together and allowing one extra full link (an inner and an outer) to hang down, then cut the rest of off. I've used this on both my road and mountain bike with good results every time. It will still allow use of the large chain ring/ large cog (I know, shouldn't do that, but once in a while I'm almost to the top of a hill and don't want to shift the chain ring). I never use the small/small connection, but it will work if you do it this way.
That is excellent advice.
On older single pivot spring derailleurs such as Campagnolo's models 1960 to 1985, with their early crude cage designs, and a close ratio (freewheel low gear at 21 or 23 for example) you'll get better shift response by running as much chain as possible. I set those up in the small front/ smallest rear with ample chain while avoiding sag.
For OP's modern equipment, Smoky wrote it well: "big-big plus 2 rivets". -- Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971
...about ready to assemble a new bike. ...campy components if that matters. 11-21 rear cogs with a short cage rear derailleur. I've seen different advice about the best chain length on the web. As near as I can tell, I want to size when in the small-small combination and make sure that the chain is short enough so that the bottom pulley does not contact any other portion of the derailleur. I also want to make sure that I can change to the large-large combination (even though that shouldn't be used in practice). ...but I also want to adjust the derailleur's tension screw so that top pulley comes close but does not touch the largest or smallest cog. ...but what if the above can be accomplished with a few links either in or out of the chain? Some say that when sizing a shimano system, the length is correct when the rear derailler is near verticle when in the small-large combination (but I'll have campy). So what should I know here in terms of chain length and tension adjustment?
Quoted message said:
I use Sheldon Brown's method, which is to run the chain around the large chain ring/ largest cog without going through the derailleur, then pulling the ends together and allowing one extra full link (an inner and an outer) to hang down, then cut the rest of off. I've used this on both my road and mountain bike with good results every time. It will still allow use of the large chain ring/ large cog (I know, shouldn't do that, but once in a while I'm almost to the top of a hill and don't want to shift the chain ring). I never use the small/small connection, but it will work if you do it this way.
That is excellent advice.
On older single pivot spring derailleurs such as Campagnolo's models 1960 to 1985, with their early crude cage designs, and a close ratio (freewheel low gear at 21 or 23 for example) you'll get better shift response by running as much chain as possible. I set those up in the small front/ smallest rear with ample chain while avoiding sag.
That's what I did when I swapped out the Altus on my new city scoot for a Deore mech, as I'd already threaded everything through and buttoned it up. I could probably remove three or four links--but there's no sag with small small and it shifts great, so why bother? Seems modern drivetrains aren't terribly fussy, at least long cage systems, a couple links too long, and it's no bother. I took my first longer twenty mile tootle in street clothes on this guy this evening and was amused at how crisply the $45 combo of shifters and rear mech worked. Low end Shimano is a wonder, if inelegant.
However, would optimizing the chain length by those four links or so give me even more crispy shifting action? FWIW, the B-screw is set with beer guided precision!
<[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Jeff said:
Dear Jeff,
Good ol' Jobst Bryant!
Mr. Bryant, he runs cattle out near Amarillo and drives prit-near the biggest black pick-'em-up truck in those parts, but he purely loves to talk bi-sickles with his cousin, Jobst Brandt, whut lives out Stanford-way and likes yaller more'n black.
Quoted message said:
Carl Fogel
I guess us folks out in Texas don't spell all that right good, especially when it comes to last names.
"Qui si parla Campagnolo-www.vecchios.com" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
On Sep 23, 2:24 pm, "Jeff" <[email hidden]> wrote:
Quoted message said:
Quoted message said:
I've seen different advice about the best chain length on the web. As near as I can tell, I want to size when in the small-small combination and make sure that the chain is short enough so that the bottom pulley does not contact any other portion of the derailleur.
5-15mm clearance between the chain and the derailleur body and you are done. That will give youi enough for big-big combos and allow the top pulley to be close to the cogs w/o hitting them.
So I see that there is a definite consensus about chain length. ...kind of like on seat heights. ...was riding tonight and someone told me that it looked like my seat was about 1/2 inch too high. ...last week someone else convinced me that it was 1/2" too low so I raised it by that. ...can remember a similar story in a book I read somewhere. ...pro cyclist told someone that their seat should be higher, so the rider stopped, fiddled with the thing but didn't really change anything, got back on and the same pro proclaimed that it now looked perfect.
....anyway, the chain length based upon the small/small with the details you've mentioned above seem to make the most sense to me. ...will give that a try and see how it compares to the other methods in terms of resulting suggested length.
<[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Jeff said:
Dear Jeff,
Good ol' Jobst Bryant!
Mr. Bryant, he runs cattle out near Amarillo and drives prit-near the biggest black pick-'em-up truck in those parts, but he purely loves to talk bi-sickles with his cousin, Jobst Brandt, whut lives out Stanford-way and likes yaller more'n black.
Quoted message said:
Carl Fogel
I guess us folks out in Texas don't spell all that right good, especially when it comes to last names.
J
Dear Jeff,
'Taint just Texas!
Them folks out in Deptford cain't spell last names none too good, neither.
I was in a sweat to find out all about that Chris Marlowe fellow, but by and by they let it out that he'd been dead a considerable long time; so then I didn't care no more about him, because I don't take no stock in dead people, 'specially if they got fourteen ways to spell their own name:
<[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Jeff said:
<[email hidden]> wrote in message news:[email hidden]...
Dear Jeff,
'Taint just Texas!
Them folks out in Deptford cain't spell last names none too good, neither.
I once had a very new and young psychology professor in graduate school who corrected me when I wrote, "the effect of x on y was small." She insisted that it should be "affect" - all good psychologists, of course, are particularly interested in affect. I suggested, of course, that my original spelling was correct. She checked further and wrote back, "your right." ....true story. ...but she was from California, not Texas.
...about ready to assemble a new bike. ...campy components if that matters. 11-21 rear cogs with a short cage rear derailleur.
I've seen different advice about the best chain length on the web. As near as I can tell, I want to size when in the small-small combination and make sure that the chain is short enough so that the bottom pulley does not contact any other portion of the derailleur. I also want to make sure that I can change to the large-large combination (even though that shouldn't be used in practice). ...but I also want to adjust the derailleur's tension screw so that top pulley comes close but does not touch the largest or smallest cog. ...but what if the above can be accomplished with a few links either in or out of the chain? Some say that when sizing a shimano system, the length is correct when the rear derailler is near verticle when in the small-large combination (but I'll have campy).
So what should I know here in terms of chain length and tension adjustment?
Jeff
Shimano says one inch longer than tight over large/large combination.(well, they say 2 links, but 1/2" pitch, that's 1 inch) Works for me. A bit sloppy amall/small with a 72 inch chain.
Mr. Bryant, he runs cattle out near Amarillo and drives prit-near the biggest black pick-'em-up truck in those parts, but he purely loves to talk bi-sickles with his cousin, Jobst Brandt, whut lives out Stanford-way and likes yaller more'n black. Carl Fogel
I guess us folks out in Texas don't spell all that right good, especially when it comes to last names.
"Qui si parla Campagnolo-www.vecchios.com" <[email hidden]> wrote in messagenews:[email hidden]...
Quoted message said:
Jeff said:
I've seen different advice about the best chain length on the web. As near as I can tell, I want to size when in the small-small combination and make sure that the chain is short enough so that the bottom pulley does not contact any other portion of the derailleur.
Quoted message said:
5-15mm clearance between the chain and the derailleur body and you are done. That will give youi enough for big-big combos and allow the top pulley to be close to the cogs w/o hitting them.
So I see that there is a definite consensus about chain length. ...kind of like on seat heights. ...was riding tonight and someone told me that it looked like my seat was about 1/2 inch too high. ...last week someone else convinced me that it was 1/2" too low so I raised it by that. ...can remember a similar story in a book I read somewhere. ...pro cyclist told someone that their seat should be higher, so the rider stopped, fiddled with the thing but didn't really change anything, got back on and the same pro proclaimed that it now looked perfect.
...anyway, the chain length based upon the small/small with the details you've mentioned above seem to make the most sense to me. ...will give that a try and see how it compares to the other methods in terms of resulting suggested length.
Jeff
The problem with the method involving checking for clearance in the small/small combo is that the chain will be longer than it needs to be if you're using much less than the maximum capacity of the rear derailer, and shorter than it needs to be if you're exceeding it.
"Jeff" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Okay, in checking the web further, I've found a post on this list by Jobst Bryant . . .
[snip]
Dear Jeff,
Good ol' Jobst Bryant!
Mr. Bryant, he runs cattle out near Amarillo and drives prit-near the biggest black pick-'em-up truck in those parts, but he purely loves to talk bi-sickles with his cousin, Jobst Brandt, whut lives out Stanford-way and likes yaller more'n black.
Cheers,
Carl Fogel
Are you guys native speakers, or are you using one of these invaluable services:
"Nate Knutson" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
On Sep 23, 7:07 pm, "Jeff" <[email hidden]> wrote:
Quoted message said:
The problem with the method involving checking for clearance in the small/small combo is that the chain will be longer than it needs to be if you're using much less than the maximum capacity of the rear derailer, and shorter than it needs to be if you're exceeding it.
Okay - I won't be exceeding the capacity of the rear derailleur so put that one aside.
....and the article I mentioned claimed that shifting worked best when the chain was as long as possible when all else (i.e., clearances) were proper.
Are you speaking about the weight of a few links here when you mention, "longer than it needs to be" - in other words, what are you arguing are the downsides to a chain that is "longer than it needs to be?"
Okay - I won't be exceeding the capacity of the rear derailleur so put that one aside.
...and the article I mentioned claimed that shifting worked best when the chain was as long as possible when all else (i.e., clearances) were proper.
Are you speaking about the weight of a few links here when you mention, "longer than it needs to be" - in other words, what are you arguing are the downsides to a chain that is "longer than it needs to be?"
Go back to Andrew's post, he said it well - at least on vintage bikes, which is all I claim expertise in. I always maximize length on the small, small as far as I can without sag or derailleur pulley problems. Large - large cog shifts always seem to be smoother with a little more chain - and sometimes downright slow when the chain is on the tight side.
On Sep 23, 7:07 pm, "Jeff" <[email hidden]> wrote: The problem with the method involving checking for clearance in the small/small combo is that the chain will be longer than it needs to be if you're using much less than the maximum capacity of the rear derailer, and shorter than it needs to be if you're exceeding it.
Okay - I won't be exceeding the capacity of the rear derailleur so put that one aside.
...and the article I mentioned claimed that shifting worked best when the chain was as long as possible when all else (i.e., clearances) were proper.
Are you speaking about the weight of a few links here when you mention, "longer than it needs to be" - in other words, what are you arguing are the downsides to a chain that is "longer than it needs to be?"
J
Well, to be honest the "better shifting" argument isn't something I've heard or thought about. I suppose the idea is that if you do it that way, the guide pulley will be as close to the cogs as possible more often? That may make some sense. Longer than necessary will also result in increased chain slap and, on bikes where it's relevant, slightly increased risk of derailment.
It may be worth noting that it's not uncommon for an RD's capacity to be slightly past capacity without anyone noticing. For example, a shortcage rd with 27t capacity, used with an 11-28 and a 39/53. Use the small/small method on that, and big problems *could* result.
"Jeff" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
Okay, in checking the web further, I've found a post on this list by Jobst Bryant . . .
[snip]
Dear Jeff,
Good ol' Jobst Bryant!
Mr. Bryant, he runs cattle out near Amarillo and drives prit-near the biggest black pick-'em-up truck in those parts, but he purely loves to talk bi-sickles with his cousin, Jobst Brandt, whut lives out Stanford-way and likes yaller more'n black.
Cheers,
Carl Fogel
Are you guys native speakers, or are you using one of these invaluable services:
As one of my Colorado professors remarked, "Where I come from, we 'warsh' in the well of English undefiled."
After the students stopped snickering at his horrifying mid-West colonial mis-pronunciation of "wash", he would point out that Chaucer's spelling leaves no doubt that he pronounced "ass" as "[censored]" or "erse", using the same r-flavored schwa that looks and sounds so silly when we colonials contemplate the mother country's peculiar inability to speak even vulgar English correctly.
