RH Clark

Do any of you know which is the widest cage Shimano front derailleur for a 3 ring chainring? I am using a Sora on my Surly LHT. I only shift using friction. I have a 10 speed rear cassette and would like to minimize having to constantly trim the front derailleur with less than perfect chain line. I do realize that cross chaining should be minimized as well. I would just like a little more room without so much fiddling for perfect placement. I do not want to change to a 1X11 or such. Thanks.

cyccommute 

You probably have it. It’s been a long time since I measured the width of the inner plates but Tiagra and Sora were much wider than 105 and Ultegra.

That said, it shouldn’t make any difference. 10 speed cassettes aren’t wider than 9 speed.

70sSanO

I don’t know what “less than perfect” means.

How many cogs do you get?

Are you getting 9 out of 10 without trimming when in middle ring?

8 out of 10 on inner ring?

Also, I would guess a mtb FD might be wider.

John

cyccommute 

Particularly a Sram one. Shimano isn’t particularly good at front derailers, either road or mountain. The cheaper Shimano of either road or mountain are more forgiving. Sram doesn’t have that problem.

hokiefyd 

I was going to suggest a low-end front derailleur designed for 3x6 or 3x7 drivetrains (such as a Tourney or similar). I think the cages get slightly narrower as the intended chains got narrower (9, 10, 11, etc.).

RH Clark

I don't know for sure how many in the middle ring as I stay mostly in the outer unless loaded down, which comprises about 90% of my ride time . It's more like the middle 4-5 rear cogs without trimming when in the front middle ring than 8 though.

Iride01 

I assume it's the rubbing of the chain making noise when in or near the big big or small small that is causing you to trim. Which begs the question... Why are you in those gears so often for you to have to constantly be trimming for it to annoy you?

If widening the cage was a solution for the issue of not having to trim, then wouldn't you think the manufacturers would have done that simple thing and not added the complication and cost to the manufacture of FDR's and shifters?

If you are often or constantly in the range of gears that require trimming then you need to change up your gear ratios. If it's just that you get annoyed by the scrubbing of the chain on the DR cage, then get a bike with longer chain stays. That will minimize the need for trim.

ClydeClydeson

Trimming the F der is the standard, sorry to tell you. Even the higher level groups have trim clicks built in for when the chain angle changes. THe issue, and I can certainly relate, is that bar end shifters take an extra step of moving your left hand, usually immediately after having replaced your right hand, down to the shifter.

If it's really bugging you, consider getting STI levers ('brifters') whose ergonomic advantage will seriously reduce the effort required for trimming the FD.

RH Clark

Appreciate the input guys. To answer a couple questions.

If widening the cage was a solution for the issue of not having to trim, then wouldn't you think the manufacturers would have done that simple thing and not added the complication and cost to the manufacture of FDR's and shifters?
No, I don't think manufacturers are interested in simplest and least costly solutions, which includes about everything related to friction shifting. I think they are much more interested in designing something cheaper to manufacture which allows greater profit. Why spend a few cents to make a wider FD that only works better for a few who choose friction when they can make ultra expensive wide range cassettes, that need more expensive chains and chain rings?

If it's really bugging you, consider getting STI levers ('brifters') whose ergonomic advantage will seriously reduce the effort required for trimming the FD.
I have no issues moving around on the bars or even using down tube shifters. I wouldn't trade the bullet proof simplicity of friction for a brifter. Trimming isn't an unsurmountable obstacle. A wider cage would just allow less of it.

cyccommute 

The reason for complication is to improve the speed of the shift and to work better with indexing. The added cost is worth the end result or they wouldn’t do it.

Quite trying to find conspiracies where none exist. Manufacturers don’t care on wit for friction shifting of any kind. That ship sailed almost 30 years ago. We are reaching a point where they don’t even care about front derailers. They don’t want to make derailers that might work better with friction because they would sell 10 of them a year and it would take until the sun burns out to recover their investment. I’m not sure that a less complicated front would work better for the front. The ramps and lifts on modern front derailers along with the pins and ramps on the chainwheels do make for much quicker, smoother, and better shifting.

Again, a ship that sailed decades ago. I have 9 speed STI shifters on my road bikes. They are all from 2000 to 2004. One of them has in excess of 25,000 hilly, all weather miles (lots and lots of shifts) on it and it is as bullet proof as any shifter I’ve ever used. Another set has 10,000 touring miles on them in about half of all the US states and have never given me a moment of problems.

If you want simplicity, why not look for older front derailers without all the modern improvements? There are loads of them on Fleabay.

Iride01 

Trim is needed because you have to push the chain up onto or off the front rings to get it to the next. Trim lets you put the cage a tad back from the amount it took to get the chain onto that ring so some or all the rubbing is eliminated.

If you had a wider DR, then you might get poor to no ability to shift. The wider cage will also let the chain fall off the ring at what will probably be inopportune times for you.

No conspiracy. Just design issues.

70sSanO

I’m still running friction on my road bike triple and can get just about as many gears as needed without trim. I’m only running 8 speed, but I get 7 on the large and small rings and all 8, if I hit it just right in the middle; middle ring cage placement is user dependent.

Because it is friction I’m running an early 90’s XTR M900 FD. I think an XT M750 might even be wider; I’m sure the LX and Deore are similar. Keep in mind there is no trim function on mtb trigger shifters.

The one caveat using a mtb FD has to do with chainring size. Mtb FD’s are not happy with larger chainrings than what they were designed to use, so you have to be aware of the tooth capacity, with maybe a little bit of fudge.

I have also been known to “enhance” the cage width of older FD’s by removing the screw, holding the front and back plates together, and placing a washer and then attaching the plates back together. It is minimal at best and really only helps in the small ring.

John

wesmamyke

I seem to remember someone widening the front derailleur by replacing the little spacer at the tail of the cage. The reason was very silly, like running a mountain quad or something. Certainly possible if it's bolted with a spacer, not riveted like they tend to be now.

RH Clark

Wouldn't those issues of moving a chain too far only apply to indexed shifting? With friction, the derailleur shouldn't push a chain too far as long as the high and low stops were set properly. Yes, you would need to trim back after the shift but a wider cage would allow full access to the rear cogs without trimming any more.

I never accused anyone of a conspiracy. I simply stated that there is no money to be made improving friction shifting. The industry is absolutely focused on whatever makes the most money ,as are all industries. That focus is more toward what sells best rather than what works best. It's just the nature of business. All anyone has to do is to look how racing has effected the industry. 99% of riders would be better served by simpler and more durable components rather than lighter and faster, yet everyone wants to buy the stuff the pro's use so they can be just like them, even though they will never ride at the level where those things become an advantage.

cyccommute 

No. Index moves the chain a specific amount which is set by the detents in the shifter. It’s a fairly precise movement although it can be off if the cable isn’t adjusted properly. The width of the derailer is what allows for shifting over the cassette range and some derailers are wider than others. There is usually a trim click on index shifters on the inner or middle chainring which allows for the derailer not being wide enough.

Friction, on the other hand, moves only as much as you move the cable. It’s very easy to over- or undershift. Friction should require almost constant trimming because each shift is just a guess as to where it should be. But you have infinite adjustability.

There was lots of money in improving friction shifting. It was called indexed shifting. Shimano and Sram made bucket loads of money on “improving” friction shifting.

And those advantages have been pushed further and further down the line. Shimano Alivio used to be a poorly made set of components. The line still has warts but their derailers are of about the same quality now as XT was in the mid90s. Their shifters are far better as well. Sora and Tiagra used to be awful as well but now even Claris is some pretty good stuff. All that came from racing and the developments of making higher quality components.

I don’t agree with everything that bicycle manufacturers do…don’t get me started on 29er and 1x and 12 speed no front derailers…but there are things that have done that make our lives easier. I like being able to “click” and the bike shifts without my thinking about it. As I said above, I don’t find the STI to be delicate or futz. I do find them to be much easier to use than friction. As long as you understand how the cable makes the mechanism work, they aren’t that hard to adjust either.

Iride01 

I still don't understand why you think wider FDR cage will be better. You realize that it is the side of the DR cage that has to push the chain onto the next ring don't you? So if the chain is on the biggest or smallest cog on the cassette, then the angle of the chain will rub the DR cage no matter how wide you make it because that side of the cage had to travel that far to let the chain complete the shift.

So when the shift is completed, something will have to move the side plate of the front DR cage slightly away from the chain.

The real solution would be to only use one ring on the front and one cog on the back. However most of us not doing track racing indoors are not going to like that much. An IGH will solve the issue entirely and allow you to have gears. However most of us aren't satisfied with the gearing range of IGH's and their weight and cost is a little more.

Another solution might be to add some length to the chain stays so the chain won't be at so bad an angle to rub the cage. But that will lengthen the wheel base and that has implications for handling some won't desire.

RH Clark

Yes, you are exactly right. The less trimming wouldn't be in not having to move the derailleur when initially changing front rings. The les trimming would be in not having to adjust trim again as the chain travels up or down the rear gear range.
Yes, all those solutions you mentioned are great. I didn't intend to start an argument with anyone. I just knew a slightly wider FD would be a simple and inexpensive solution. You guys have a great day.