I am intending fitting a 36-42-48 chainring ratio.
At 6 tooth difference, that is less than the normal 10.
Has anyone either experience or knowledge that would anticipate problems? I could, of course, find out by trial and error, but picking other riders' brains is easier, quicker and cheaper.
A possible problem could be clearance between the inner changer plate and the smaller ring.
JohnW
Front Changer
-
TATANAB
Re:Front Changer
On one machine I have 46/40/26 whith which I use a Campag Veloce double changer. It works just fine.
Maybe the combinations we are talking about work for me because I use Campag, and so do not have a truly indexed front changer. Equally, perhaps they will not work with Shimano specifically because the front is truly indexed.
I think too much emphasis is placed on "do I need a triple or double changer", "are the rings the right size", "my changer was designed with a 52 ring, will it work with a 48". These are all questions that appear frequently on various forums. The front changer is a simple and fairly brutal device, especially if you do not used Shimano style indexing you can make it do all sorts of things quite well.
Maybe the combinations we are talking about work for me because I use Campag, and so do not have a truly indexed front changer. Equally, perhaps they will not work with Shimano specifically because the front is truly indexed.
I think too much emphasis is placed on "do I need a triple or double changer", "are the rings the right size", "my changer was designed with a 52 ring, will it work with a 48". These are all questions that appear frequently on various forums. The front changer is a simple and fairly brutal device, especially if you do not used Shimano style indexing you can make it do all sorts of things quite well.
-
TATANAB
Re:Front Changer
Having re-read the bottom line of your question things become clearer and I must modify my original comment.
It looks like you intend to use a modern triple front changer with the very deep and shaped inner plate. In that case you are right that it will probably foul the middle ring when you are trying to use the big ring.
I suppose I get away with it because I am using a double changer so do not have the deep plate.
It looks like you intend to use a modern triple front changer with the very deep and shaped inner plate. In that case you are right that it will probably foul the middle ring when you are trying to use the big ring.
I suppose I get away with it because I am using a double changer so do not have the deep plate.
-
CJ
Re:Front Changer
In the "good old days" before everything became so specialised, we always used to work triples with mechs meant (presumably) for doubles. They worked okay provided that there wasn't more than about 6T difference between outer and middle, which was just fine for splitting a wide-ratio 14-32T, 5-speed freewheel (remember those?) into "half steps". For many years our tandem sported a 52,47,28T chainset, that was worked very nicely thankyou by a Dura-Ace mech of 1978 vintage – long before indexing of any sort.
Those days (and mechs) are gone, but I'm glad to hear that a modern double mech, or at least a Campag Veloce double mech, still has enough throw and capacity to work a 20T "half-step-granny" triple. Looks like just the thing for JohnW. Thanks for that information Tatanab. Any idea if it might handle a few more teeth? How much/many mm space is there under the chain when on little ring and middle sprocket?
Those days (and mechs) are gone, but I'm glad to hear that a modern double mech, or at least a Campag Veloce double mech, still has enough throw and capacity to work a 20T "half-step-granny" triple. Looks like just the thing for JohnW. Thanks for that information Tatanab. Any idea if it might handle a few more teeth? How much/many mm space is there under the chain when on little ring and middle sprocket?
-
TATANAB
Re:Front Changer
The clearance between the bottom of the cage and the chain when on the middle sprocket (20T) is 10mm or more, so it should handle a smaller chainring comfortable. Changing up from the small ring is not exactly elegant, but it works ok.
-
JohnW
Re:Front Changer
Thank you TANTAB and CJ.
The reason why I need something a bit lower than the standard 52-42 is that on knee has begun to make its presence felt and I have been medically advised to walk up steep hills !!!! ( can you imagine that?) or get lower gears. I have tried 52-42-30 and I find that the 30 tooth inner ring gets me up everything whilst sat in the saddle - Fleet Moss, Shaking Moss, Buttertubs, Park Rash etc - all of them with ease. The other chaps in the Halifax section had been telling me to do that for years, and now I find that they were right!).
I am 62, and thinking in terms of my needs for the next ten years, and will convert my touring bike to 43-36-26 over the winter - I have found that I can do without 52 teeth now - and with a Campag Veloce chainset moving from my touring to my "faster" bike, I am limited to a 42 or over middle ring - 36-42-48 will give me consistency at the bottom end with my touring bike, and a ratio that I am used to in the middle, with a higher gear opportunity on the big ring in case I fancy my chances with the wind behind me.
Your replies have heartened me, and by coincidence I propose a Dura-Ace changer of about 1978 vintage for the 48-42-36 chainset!
Thank you again for imparting your knowledge - I will let you know how I go on.
JohnW
The reason why I need something a bit lower than the standard 52-42 is that on knee has begun to make its presence felt and I have been medically advised to walk up steep hills !!!! ( can you imagine that?) or get lower gears. I have tried 52-42-30 and I find that the 30 tooth inner ring gets me up everything whilst sat in the saddle - Fleet Moss, Shaking Moss, Buttertubs, Park Rash etc - all of them with ease. The other chaps in the Halifax section had been telling me to do that for years, and now I find that they were right!).
I am 62, and thinking in terms of my needs for the next ten years, and will convert my touring bike to 43-36-26 over the winter - I have found that I can do without 52 teeth now - and with a Campag Veloce chainset moving from my touring to my "faster" bike, I am limited to a 42 or over middle ring - 36-42-48 will give me consistency at the bottom end with my touring bike, and a ratio that I am used to in the middle, with a higher gear opportunity on the big ring in case I fancy my chances with the wind behind me.
Your replies have heartened me, and by coincidence I propose a Dura-Ace changer of about 1978 vintage for the 48-42-36 chainset!
Thank you again for imparting your knowledge - I will let you know how I go on.
JohnW