Cross Chaining Problems with a triple



sergen

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Jul 28, 2003
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I've never used a triple chainring but have now set my mind on a Giant bike with a 53/39/30 and a 10 speed 12/25 at the back.

Having only ever ridden a 52/42 before (impossible for the hilly area where I live!) I was wondering about the issues involved with cross chaining, specifically when using the middle ring of a triple.

Let's say you were going up a hill using your middle ring (39 teeth) and were in your 21 sprocket at the back. Would you still be able to stay in the middle ring and shift down to the 23 and 25 sprockets if the gradient increased, or would the fact that you have a 30 tooth small ring at the front mean that the angle of the chain would be too severe to use the smallest gears whilst on the middle ring?

Obviously on a double chainset you could shift into the 23 and 25 without any worries about the chain angle.

But if you're going up a hill and your bike has a triple, assuming that you are already in 39x21, would it be wiser to shift down to a 30x19 ratio rather than a 39x23?

I guess that there would be similar cross chaining issues at the front using a 39x12 also (not that I could ever see myself using that scenario - I'm just interested to know)?

Many thanks
 

bernmart

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Jun 4, 2005
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The other day I was riding along in what I thought was the 42/27 combo (middle chainring, largest cassette sprocket), and was concerned that the chain sounded noisy. I looked down, and found that I'd accidentally shifted to the 52 chainring, and was thus cross-chaining very severely. Obviously, I shifted back to the 42. Point is that other than the noise everything was OK, though probably chain wear would have been severe had I continued in the 52/27 indefinitely. My experience is that the middle chainring, where I am 90% of the time, can handle the full cassette range, the 52 can handle anything but the two largest sprockets, and the granny chainring any but the two smallest sprockets on the rear. Mind you, I can shift throughout the range, but the rig complains.

I routinely shift to the granny chainring while on the 27, then upshift a gear or two. No problems.
 

shannons dad

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Jul 10, 2005
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I've run triples on two roadies in the past and the only problem I ever noticed was slight rubbing on the front mech cage at either extreme. Easiy fixed by tweaking the adjusters on the cable if it was a long climb. The only rule I had was to stay within the bottom four cogs if on the big ring, or top three cogs if on the small ring.
 

dhk

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Sep 1, 2003
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sergen said:
I've never used a triple chainring but have now set my mind on a Giant bike with a 53/39/30 and a 10 speed 12/25 at the back.

Having only ever ridden a 52/42 before (impossible for the hilly area where I live!) I was wondering about the issues involved with cross chaining, specifically when using the middle ring of a triple.

Let's say you were going up a hill using your middle ring (39 teeth) and were in your 21 sprocket at the back. Would you still be able to stay in the middle ring and shift down to the 23 and 25 sprockets if the gradient increased, or would the fact that you have a 30 tooth small ring at the front mean that the angle of the chain would be too severe to use the smallest gears whilst on the middle ring?

Obviously on a double chainset you could shift into the 23 and 25 without any worries about the chain angle.

But if you're going up a hill and your bike has a triple, assuming that you are already in 39x21, would it be wiser to shift down to a 30x19 ratio rather than a 39x23?

I guess that there would be similar cross chaining issues at the front using a 39x12 also (not that I could ever see myself using that scenario - I'm just interested to know)?

Many thanks
If your FD is correctly adjusted, should be no problem using your middle chainring with your largest cog. The STI trim-click should handle any rub you have on the FD cage. I have a 53/39/30 set up, with a 12-25 9 sp cassette, and the 39/25 works just fine.

On long/steep hills I want (ok, need...) to climb seated below 10 mph, the inner ring is great. I'll usually shift into the little ring at the bottom, maybe from 39/19 to 30/19. The triple is great for seated climbing on long grades as you gain a tight set of four climbing gears (e.g., from 19-25) which are easy to shift during the climb.
 

gclark8

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Apr 13, 2004
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If you have a home trainer, set it up and watch the chainline, I can use 6 of the 9 in the casssette with the 30t, all of the 9 with the 42, 5 of the 9 with the 52.

The trim feature for the middle ring is a real blessing. :cool:
 

boudreaux

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Oct 16, 2003
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gclark8 said:
If you have a home trainer, set it up and watch the chainline, I can use 6 of the 9 in the casssette with the 30t, all of the 9 with the 42, 5 of the 9 with the 52.

The trim feature for the middle ring is a real blessing. :cool:
Ya know, it's like this....With a triple the midle ring in in about the same position as the big ring with a double. Do ya use all nine with the big ring on a double... :rolleyes: ....Think about it a bit folks!!
 

new2bikes

Banned
Feb 6, 2005
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Question regarding the STI trim-click from a fairly new rider: Would someone please explain, in detail, how to maneuver the STI trim-click? I've yet to figure out exactly how to use it. I understand that it's a half-click but am unclear as to whether I should be using the left gear shift or the left brake lever/shift? I can't seem to feel the difference between a half-click and a full shift. Thanks.
 

bernmart

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Jun 4, 2005
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new2bikes said:
Question regarding the STI trim-click from a fairly new rider: Would someone please explain, in detail, how to maneuver the STI trim-click? I've yet to figure out exactly how to use it. I understand that it's a half-click but am unclear as to whether I should be using the left gear shift or the left brake lever/shift? I can't seem to feel the difference between a half-click and a full shift. Thanks.
I'd like to know more about this feature also.
 

shannons dad

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Jul 10, 2005
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To the best of my knowledge, a trim click is only available on 2 speed shifters and they're for use with the smaller chainring on a double chainring bike. Because that ring is often used with the whole of the cassette range, the chain is going from one extreme to another and causes the chain to rub on the front derailleur cage. In it's bottom position the chain can be used on the top half of your cassette, clicking it again moves the derailleur cage up a notch so the chain can be used on the bottom half of your cassette. One more click moves the front derailleur up a full shift to the big ring. If that makes any sense!
 

butchh

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Apr 23, 2005
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A good question. I went through the learning process with my Felt 80 this spring. I went to the Shimano web site and downloaded the information on adjusting the shifters. There in plain english is the answer. If you have a bit of trouble visualizing this, turn your bike over and start going through the gears. When you are in the large gear (on the crank) and the small gear on the rear, shift to the middle gear on the crank. Then begin going to the larger gears on the rear. As you approach the largest gears you begin to notice that the chain is beginning to rub on the front shifter. At this point, attempt a "half shift". The chain guide will move about one sixteenth of an inch and eliminate the interference. It's kind of cool!
 

li rider

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Oct 11, 2004
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I could not find the info you cited on the Shimano web site. Do you half shift to the big gear on the crank or to the small gear on the crank to try to half shift?

butchh said:
A good question. I went through the learning process with my Felt 80 this spring. I went to the Shimano web site and downloaded the information on adjusting the shifters. There in plain english is the answer. If you have a bit of trouble visualizing this, turn your bike over and start going through the gears. When you are in the large gear (on the crank) and the small gear on the rear, shift to the middle gear on the crank. Then begin going to the larger gears on the rear. As you approach the largest gears you begin to notice that the chain is beginning to rub on the front shifter. At this point, attempt a "half shift". The chain guide will move about one sixteenth of an inch and eliminate the interference. It's kind of cool![
 

dhk

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Sep 1, 2003
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I have a DA 9 speed triple, and the trim-click feature works on all three chainrings. To trim the FD in, you just a half-click on the left shift lever. To trim out, you just push the brake lever about half as far as a shift....no click is heard or felt going out.

If the FD is cable tension is adjusted correctly, no trim should be needed unless you're near the extremes of the cassette. If you shift, and hear noise, just look down at the FD cage and see which side is hitting the chain. If it's the outside hitting, push the brake lever to move the cage out; if inside is hitting, half-click the small lever to let it come in.

The difference between a half-click trim in and a full shift to a smaller ring took a couple of weeks (and a couple of surprise downshifts to little ring, complete with thrown chain) to sort out. But now it's just second nature; doesn't require much thought at all.
 

2boysintow

New Member
Aug 22, 2005
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sergen said:
I've never used a triple chainring but have now set my mind on a Giant bike with a 53/39/30 and a 10 speed 12/25 at the back.

Having only ever ridden a 52/42 before (impossible for the hilly area where I live!) I was wondering about the issues involved with cross chaining, specifically when using the middle ring of a triple.

Let's say you were going up a hill using your middle ring (39 teeth) and were in your 21 sprocket at the back. Would you still be able to stay in the middle ring and shift down to the 23 and 25 sprockets if the gradient increased, or would the fact that you have a 30 tooth small ring at the front mean that the angle of the chain would be too severe to use the smallest gears whilst on the middle ring?

Obviously on a double chainset you could shift into the 23 and 25 without any worries about the chain angle.

But if you're going up a hill and your bike has a triple, assuming that you are already in 39x21, would it be wiser to shift down to a 30x19 ratio rather than a 39x23?

I guess that there would be similar cross chaining issues at the front using a 39x12 also (not that I could ever see myself using that scenario - I'm just interested to know)?

Many thanks
Switch to Compact cranks... I'll never do triple again.... But I do have multiple bikes for the flat rides, otherwise I'd run out of gears on some sections with compact set-up.
 

Doctor Morbius

New Member
Mar 15, 2004
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My MTB can handle all 9 gears in back while in the middle sprocket but none of my road bikes can. It could be due to the spacing of the deore front der on the MTB. Maybe it's larger than the 105 front ders on my road bikes. I don't know.

I know I've spent several hours trying to adjust my road bikes to handle all 9 gears in back while in the middle (42t) sprocket of my road bikes but gave up. It wasn't worth the time. Everything works great provided I keep the chainline fairly straight.
 

butchh

New Member
Apr 23, 2005
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li rider said:
I could not find the info you cited on the Shimano web site. Do you half shift to the big gear on the crank or to the small gear on the crank to try to half shift?

butchh said:
A good question. I went through the learning process with my Felt 80 this spring. I went to the Shimano web site and downloaded the information on adjusting the shifters. There in plain english is the answer. If you have a bit of trouble visualizing this, turn your bike over and start going through the gears. When you are in the large gear (on the crank) and the small gear on the rear, shift to the middle gear on the crank. Then begin going to the larger gears on the rear. As you approach the largest gears you begin to notice that the chain is beginning to rub on the front shifter. At this point, attempt a "half shift". The chain guide will move about one sixteenth of an inch and eliminate the interference. It's kind of cool![
I could not find it either. But I did print it. Quote: Note: There are two derailleur positions for the intermediate chainring. When making the cable adjustment, make sure that the deraileur is in the inner side (toward the small chainring) of the two positions. Locate the derailleur to this position by shifting from the largest to the intermediate chainring(recommended) or by shifting from the small to the intermediate chainring, then gently press lever (b) until a small click is felt(to position the derailleur to the inner side of the intermediate chainring). End quote)

Lever b is the small lever for shifting, located behind your brake lever. I hope this helps.
 

li rider

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Oct 11, 2004
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thanks.

i tried it this morning. in the granny ring, it worked fine (which i realize was doing anyway). when i tried it in the middle ring, i always ended up down in the granny ring. i'll keep trying.


butchh said:
I could not find it either. But I did print it. Quote: Note: There are two derailleur positions for the intermediate chainring. When making the cable adjustment, make sure that the deraileur is in the inner side (toward the small chainring) of the two positions. Locate the derailleur to this position by shifting from the largest to the intermediate chainring(recommended) or by shifting from the small to the intermediate chainring, then gently press lever (b) until a small click is felt(to position the derailleur to the inner side of the intermediate chainring). End quote)

Lever b is the small lever for shifting, located behind your brake lever. I hope this helps.
 

butchh

New Member
Apr 23, 2005
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Keep it simple. I have a 2004 Felt 80. It is a Tiagra/105 mix. To get to finding this thing, what I did is set my bike upside down on my radial arm saw bench and shifted into the largest sprocket on the crank (my bike is a triple). Started moving the pedals with my hand and then shifted into the middle sprocket on the crank. I was in the smallest gear on the rear. I then began shifting the rear derailleur one gear at a time toward the largest. As I approached the largest gears the chain began "ticking" the front derailleur. At this point I pushed the front derailleur shifter a small amount (possibly only one-quarter of the normal stroke) as to go to the smallest sprocket on the crank. What happens is that a built in detent exists and the front derailleur moves only a small amount and the chain now does not touch the front derailleur. It is called "trimming".

I hope this helps.