Avalanche325

Well, Shimano designed it. And Shimano says that it is designed for everything except big-big, little-little. Ahhh, what do THEY know about bicycle drive trains anyway**********

The car was NOT designed for that. And the owners manual tells you NOT to do it. So, this would be the same as big-big, and little-little. Not designed for it - not reccomended - can be done.

It is fine if you want to be more restrictive than the manufacturers reccomendation. But, your chain and cogs are not going to burn up by staying within Shimano's reccomendations.

Brett 12

If definitley couldn't hurt to use one. Regular front derailleur works fine though.

gabiker

I haven't been riding it long. I came from a 53/39 and 12/27 which was nice and I did OK with it, but I have wanted something for long climbs for awhile, however I never wanted a triple. I am making climbs now that I used to get out of the saddle on part of them just to get up, but I am staying in the saddle the whole climb without mashing near as hard. The FSA carbon crank seems stiffer and is about 127 grams lighter. An added benefit is it dampens some of the road vibration as well so I am very happy with it so far. I should have the 11/28 on it next week so I will let you know.

Galico

I finialized the order today, went with the Ultegra Triple 10-and the 12/25 Dura Ace Cassette. The savings make buying the Easton Ascent II wheels a no brainer (I was going to use my Joe Young Custom Wheels off my current bike see https://www.youngwheels.com/) and I am going to use Dura Ace Breaks. It will be under 17 lbs. This thread has been a good one for me and I think others who got involved. Just one note of interest. I support my bike shop and because I have been a good patron I get good deals. This whole project from my bike shop is comming in at 20% less than any online selllers price. it will be assembled by a master wrench. I'll post a Pic. and you have all contributed. Thanks

velocipedio

i'll say this once:

modern road bikes with short chainstays are not suited to triples.

there.

the sort chain length means that the chainline has to traverse too wide an angle to get crisp shifting on a triple. this is not the case with mtbs and touring bikes with longer stays. moreover, mtb chainrings are smaller than road chainrings, so the rear derailleur has to throw less chain.

use a triple if you like, but you will never shift as crisply as with a double. a compact crankset gives you moust of the low gears you'll need to climb everything but walls, with a better chainline and less chain than a triple. if you need something lower than 34x25 or 34x27, then you're moving at about 10 km/h and every kid on a trike will be passing you.

if you need a triple, go for it. live with the sloppy shifting and don't complain when your lbs wrench can't make it better.

Brett 12

This is the kind of nonsense that makes people buy what is wrong for them.

I'm a double guy (I've owned both a 53/39 and compact).

I just test rode a triple recently......after doing so I realize most of you are full of s****. The damn thing shifts fine.

Mechanical glitches? Sure, Maybe if you are doing the adjusting yourself and you don't know what the hell you are doing.

Sydney was right all along. If you can't make a triple work.......maybe you need to take it to a real mechanic.

Rowan

Wow! Revelation! Does that mean us older riders can come out of the triple closet?

Whatever your past, Brett 12, under whatever guise, this post does more to preserve knees and cycling enthusiasm than any other on this list -- especially among 25+ riders.

And it even validates sydney!

Lectron

Thank god you want repeat that.

Talking about insulting your own intelligence. You really shouldn’t do that.
Now if you read this, enlighten us. How many mm more did the chainstays use to be ?

JoeOxfordCT

I think people should just ride what they are comfortable with. I too mulled the triple vs. double/compact thing too. I ended up going compact but that doesn't mean that I wouldn't do triple at some point in the future or that I couldn't have done it now and been happy. Let's remember that for those of us who aren't racing, the main thing is to be out cycling, and cycling comfortably. I want to be as fast as possible while still being confident that I have enough gearing to conquer any climb I may happen upon. If there were no such thing as a compact I would have gone triple, if there were no such thing as a 39-27 combo I would have definitely gone triple. If at some point in the future I need/want more gears than I can get with 50-34 with a 10sp 11-28, I'll go for a triple.

I'll go for the quad when they make it if that's all I can ride rather than not ride at all

GA Biker - I'll definitely be interested to hear your feedback on the 11-28 when you get & ride it !

Rowan

Yes. You are right.

It's those who diss triples as being a non-option that cause the problem. Usually they are young bucks for whom knee problems are not a problem... until they get old.

To declare my interest, I tour. I have heard of so many people being discouraged from using triples or 22-32-44 combinations by bike shop staff whose only interest is in flat-land racer activity. Even on forums discussing frame design and wheel designs, big gears seem to be an issue, rather than ensuring everyone is comfortable with lower gearing.

oldspark

This may be a simple observation but my mb (it's a triple- duh) shifts fine, my road bike is a double so I know what a double shifts like. Now someone can tell me what I don't know about this subject. FCOFL

Galico

[QUOTE=velocipedio[you need a triple, go for it. live with the sloppy shifting and don't complain when your lbs wrench can't make it better.[/QUOTE]

I have over 11.000 miles on my triple in two years. At first I had shifting problems due to a defectinve FD, but my wrench has been able to keep this old 105/ultega smooth. We have climbs here in our big mountains (Utah) where my granny gears got me to the top. I can mash larger gears now that I have the hours in my legs but when I began I got up those hills, Old women with walkers heading to bingo passed me, but I made it and accomplished my goals. It suits me-it works for me and I may put a compact on my currant bike that is facing a semi retiremet just for variety. YOu know Variety is the spice of life-my wife says only in bikes

miamijim

Not that it realy matters but a 53/12 is more efficient even if its the same gear inches as a 50/11.

"In a derailleur transmission there is often a difference of 1 to 3% in effieciency between adjacent gears. A 1% improvement in efficiency will mean 12 seconds or more in a 25-mile TT.....A 52/15 gear combination will have a higher effieciency than a 42/12...For high effieciency the trick seems to be avoid combinations using sprockets smaller than 14t."

HIGH-TECH Cycling, Second Edition, P.37 Edmund R. Burke, Phd, editor

JoeOxfordCT

Interesting point. Can you please explain exactly what you mean by increased efficiency ?

Avalanche325

Bo-oh-oh-oh-oh-ohgus!!!!!!!!!!!!!

The cogs on a double and triple are exactly the same. The SHIFTING mechinisim on a double and triple are EXACTLY the same. The only thing different is the chain tensioner (cage), which has NO effect on the shifting. A double and a triple rear der shift the same.

The chainline thing - nice try. Still Bo-oh-oh-oh-ohgus!!!!!!!!!!!!!!!

Brett 12

Wow!

I'm blow away by this too. It just doesn't seem logical. gear inches are gear inches. As long as the chainline is the same there shouldn't be any difference in efficiency.

I think miami jim is misinturpreting the book though......the author is trying to make a point about chainlines. he mentions 14T becasue normally that is the 3rd cog from the outside in a cassette and those cogs tend to have straighter chainlines than the smallest cogs (big chainring is more towards center of cassette than the very outside)

miamijim

Brett, I'm not mis-interpreting the book. I think it has to do with the smaller diameter of the cog. A smaller diameter has a smaller radius therefore torque multiplication may be different. Chainline, as mentioned in the book is a different topic.

This same principle happens to cars on a dyno. If a car is putting down 300 rear wheel HP and you change the gearing or diameter of the rear wheel HP numbers change. If doesnt make sense but it happens.

miamijim

The book tested the alignment theory:

"If the derailleur chain is in misalignment, crossing from the outer chain ring to the inner sprocket or from the inner chain ring to the outer sprocket doesn't seem to greatly effect efficiency. Modern chains bend so freely that with indexed shifting, which assures proper derailleur alignment, cross chains dont seem to cause appreciable added friction."

Same book, same page.

SDS

I had read previously that larger chainrings and cogs are slightly more efficient. It has to do with the chain changing direction, and the greater bending of the links around the smaller radiuses of the smaller cogs and chainrings. Those of you who have been doing this for a while will have noted that derailleur jockey pulleys keep getting bigger and bigger......

Brett 12 and I have previously discussed the cogging effect of 11T rear cogs, v. larger ones. Apparently as the chain leaves the top of the cog to return to the chainring, there is variation in ratio (?) as the chain bears on different parts of the tooth, which reduces efficiency, this effect occurring only on cogs of 11T or less with 1/2" pitch chain. I knew enough to mention it and name it properly ("cogging effect"), and note that you can feel some vibration in the drivetrain in the 11T that is not present in the 12T, but I still haven't read up on it, because that exceeds my need for knowledge on the subject. If true, it certainly marks a point at which there is a stepwise reduction in efficiency of smaller cogs.

Brett 12

I see your point now. That is interesting. This kind of reminds me of the crank length arguments I read (though I don't think they are analogous).

Short cranks make more power than long cranks if the gearing used for the test is very low.






The more I think about that cogging effect the more it makes sense. I'm guessing the ratio slightly changes becasue the chain isn't able to completely conform to the size of the small cog.

terrymorse 

The greater losses on a small cog are caused by the chain links having to bend at a larger angle to wrap around the cog.

Brett 12

That's what I figured. Just wonder what the % loss or change in efficiency is compared to 12T?

Dchiefransom

I'm still wiping the drool off my keyboard over his mentioning the triple crank with 28/39/52(3) tooth count. Since all the front derailleurs list a capacity of 15 teeth, is it just the big jump from 28 to 42 that makes swapping the 30 on a triple to a 28 not desirable?

Brett 12

That is for double front derailleur. We are talking about triples.

Besides that 15 tooth limit on double front derailleurs gets broken all the time whenever a compact crank is installed...no problems either.

terrymorse 

Data on the subject is pretty hard to find, but here's a chart I pulled from a Human Power journal:



Spicer et al, On the efficiency of bicycle chain drives;
Human Power, the Journal of the IHPVA; Number 50, Spring 2000

Here's a link to the PDF containing the chart.