Road Cycling - He says 50/34 better range than 54/39 ?

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vrkelley
05-31-04, 11:24 AM
I'm looking for a triple but it the gearing is more flexible on the double and price is right, might settle for the double. Still walking thru the maze of bikes for sale. One bike seems geared for racing yet has street stuff like blinkies and seat bag.
The guy has a FSA Carbon Pro Elite Compact 50/34 (double front chain ring). He says it gives a better range of gearing than say a 54/39...how is that mechanically possible?
jim-bob
05-31-04, 11:41 AM
I think he probably means that while it gives the same 16-tooth range, more of it is usable by real humans. A 54/11 combination, for instance, gets used fairly rarely, while a 50/11 is a lot more useful. You also get lower gearing on the low end, which gives you something akin to a granny gear without the shame that some people feel at having a triple crank.
jfmckenna
05-31-04, 01:06 PM
The fsa compact is a great set up for in the mountains.
DieselDan
05-31-04, 05:00 PM
Try a 26/36/46 triple.
velocipedio
05-31-04, 07:26 PM
ignore diesel dan. don't get a triple. if you need a low gear, get a 12-27 cassette. if you need a loerw gear than that, go for the compact crankset. if you can't get up a hill with a 34/27, then you are either cycling in the himalayas or dead.
The Terminator
05-31-04, 08:45 PM
Frequently I cycle in the Himalayas. er, at least I feel that way. :) I ride a place that is known by all to be uphill both ways, and just when I think that I am getting the hang of it, it starts to rain.
demoncyclist
05-31-04, 09:03 PM
Better is a very subjective thing. With the 50-34 you will have more choices in the low end and middle range, but you may run out of gears at the top- fast flats may be an issue. The 54-39 is a litle too much for mere mortals, and the standard for a road double is usually 52-39.
shokhead
05-31-04, 09:19 PM
53/39 but whats one more or less tooth. 53/39 and a 12-23 and i've had no problems with hills or speed but i dont do either much. Man, i dont glide along at 25mph.
vrkelley
05-31-04, 09:32 PM
Frequently I cycle in the Himalayas. er, at least I feel that way. :) I ride a place that is known by all to be uphill both ways, and just when I think that I am getting the hang of it, it starts to rain.
Well the Cascades are not the Himalayas (yet). But we get some pretty long acents at 8-15% grades. It's nice to have the bike gearing help with the work.
vrkelley
05-31-04, 09:34 PM
I think he probably means that while it gives the same 16-tooth range, more of it is usable by real humans. A 54/11 combination, for instance, gets used fairly rarely, while a 50/11 is a lot more useful. You also get lower gearing on the low end, which gives you something akin to a granny gear without the shame that some people feel at having a triple crank.
No shame here! I care about arriving and if that means a mixture of Mt bike stuff and racing stuff (and it looks weird) so be it! :D
About that 16tooth range? What's that about?
a 50x34 combined with a 11-23t gives you a wider gearing range than a 53x39 with a 12-23.
the top-end is still there, as a 50x11 is very close to a 53x12, but you get a much easier gear for when the road turns up in the 34x23
capsicum
05-31-04, 11:25 PM
54-39=15 teeth 50-34=16 teeth.
But 39/54 gives a 38.5% change if upshifting [27.8% if downshifting] while 34/50 gives a 47% upshift [32% downshift].
The rear derailer's slack adjustor has to take up the tooth change but your feet feel the percentage change AKA 'ratio of the small ring to the big ring and the ring to the sprocket'.
The 26/36/46 triple: 26-46 is 76.9%, 26-36 is a 38.5%, jump and 36-46 is a 27.8% jump. The 46 top gear will be slower or require a higher cadence than a 50 or 54 on a downhill or flat. If your small cog is a 12t and your pedaling 120 rpm with 700x28 tires, your speed is 36.5mph[46t] 39.8[50t] 43mph[54t].
This is the greatest bike gearing calculator ever, if you don't close the answer window it will just add the new answers to it so you can reveiw/compair them all even if you close the main calculator and comeback later (if you left the answer sheet open).
http://www.sheldonbrown.com/gears/
velocipedio
06-01-04, 05:33 AM
Well the Cascades are not the Himalayas (yet). But we get some pretty long acents at 8-15% grades. It's nice to have the bike gearing help with the work.
i'm not quite sure what advantage you gain from a 30t inner chainring [standard on a triple] and a 25t big cog [standard on a triple] over a 34t inner chainring [standard on a compact] and a 27t big cog. you're pushing 31.5 gear inches, and on the latter it's [wait for it] 33.1. even with a 39t chainring and a 27t cog, your're still looking at 38 inches.
with a triple, you have to accept poor derailleur tuning, long front shifts and more inaccessible gears for a miniscule improvement.
Phatman
06-01-04, 06:53 AM
I would like a 50/34 compact...I'm almost NEVER in my big ring unless I'm going above 25 mph...I like to spin fast when I'm riding, above 100 rpms.
I was actually thinking it might be cool to have just a 42T chainring up front and an 11-32 cassette in the back. I really hate shifting the front chainrings.
shokhead
06-01-04, 07:48 AM
I never do shift the chainrings. With 2800 miles on my bike,i've been in the 53,maybe 5 miles worth.
with a triple, you have to accept poor derailleur tuning, long front shifts and more inaccessible gears for a miniscule improvement.Not true, IMHO. I don't see much of a difference in shifting between my triple and pretty much everyone else with their double on my group rides. Or maybe I'm just not sensitive to it. My front shifts don't appear to take any longer. While I may have more unusable gears, I figure I still get about 3 more lower gears, and smaller jumps between the gears. To my mind, the benefit of a triple is not lower gears but having low gears while keeping narrow gear spacing .
Is there a difference between Shimano and Campy triples? I've got Campy Record brifters, 30-42-52 chainrings, 13-26 9-speed cassette (but thinking about 11-23), Racing-T rear der., and an old Dura-Ace fr. der. designed for a double but that works very well in this set-up.
Laggard
06-01-04, 09:07 AM
With all the talk of triples, you'd think everyone was climbing the alps everyday.
For those who say they rarely use their 53, I'm wondering how often you're cross-chaining. I can't imagine that you rarely use your 12-14 in the back. I mean, you have to go downhill sometime, right?
jfmckenna
06-01-04, 09:54 AM
I notice consistantly on group/club rides where people use triples that when a hill approaches and you are in a pace line the line falls apart b/c the people with the triples are fussing with there gears and those with the doubles are cresting the top of the rollers. Look at a gear chart and you will see that with the compact crank and an 11-27 or some such cassette (with an 11) that you can get almost all the ratios that a triple can offer without the fuss. Just my 2cents...
capsicum
06-01-04, 10:08 AM
My bad I posted some MPH data at a cadence of 100 in my last post that was actually calculated at 120. I've edited it already.
I too live in the cascades and have used the 26 chainring with my biggest [30t]cog many a time. I go for a good 10 hours at a wack sometimes and my legs like to take it easy near the end. I like the low gearing you can get with mtb components(26/36/46 11-30 8sp) and the xt rear lx front derailures with xt shifters are snappy smooth. (my old road bike has a tenspeed set up with friction sucide shifters, remember when you had to tune every shift and even then it would try to spin and grind if any load was applied during the shift)
el Inglés
06-01-04, 10:15 AM
A few years ago Miguel Indurain changed to a 50/40/32 with an 11-23 for his fun riding : does he know something we don´t ?
neilthemeal
06-01-04, 10:29 AM
This is a very interesting thread, I have a question about compacts though. I know with two standard cranks with 53/39, if one is a 172.5 and one is a 170, it will be easier to spin the 170 at a higher cadence.
So my question is if you have 2, 172.5 cranks. One being a compact, say 50/34, and one being a standard 53/39, will the compact have the same effect on a persons cadence without switching crank length?
roadfix
06-01-04, 10:49 AM
A few years ago Miguel Indurain changed to a 50/40/32 with an 11-23 for his fun riding : does he know something we don´t ?
Getting old....
Avalanche325
06-01-04, 11:28 AM
One thing that always comes up is the wider range cogs with a double. Yes, you can have the same top and bottom gears as with a triple. What you are losing though, is the tighter gear ratios. I am sure everyone (The Fixer excluded) has experienced a point where one gear is a little too high and the next is a little too low. The wider ratio cogs are bad for this. A triple allows you to have high gears and low gears AND a tight ratio.
I notice consistantly on group/club rides where people use triples that when a hill approaches and you are in a pace line the line falls apart b/c the people with the triples are fussing with there gears and those with the doubles are cresting the top of the rollers.
What are these guys using, a stick shift? The last time I checked, the shifters on a double and a triple worked pretty much the same. As a matter of fact, they ARE the same. So how are these guys fumbling for gears? They just give it a click like everybody else.
jfmckenna
06-01-04, 12:06 PM
I don't know but it sounds aweful! It's like they can't find the right gear or something mabey there is too many to choose from? I guess since I race I am biased to the double b/c the faster you get to the correct gear the better. Hey btw I think that you should get what ever you want I'm just offering an opinion. I rode a triple for years and whent to a double and absolutly love it. My triple is still there cause it is on my touring bike (thats the only bike I had for years) A loaded bike absolutly definatly needs a triple. Mine is an old friction Suntour and it does indeed work very very well, better than sti from what I have seen on rides. I've never done randaneur or brevets again perhaps a triple is necessary in fact I think most of those guys use them. But since I can really only speek for my self and the original poster can take this with a grain of salt, I like the doubles and feel as though they offer close enough to the same ratios for less trouble.
brent_dube
06-01-04, 12:18 PM
Getting old....
Cipollini is only a few years younger...
I hardly ever use my 52.
a 50/34 is going to have a wider gear selection.
What are these guys using, a stick shift? The last time I checked, the shifters on a double and a triple worked pretty much the same. As a matter of fact, they ARE the same. So how are these guys fumbling for gears? They just give it a click like everybody else.
It seems Shimano hasn't yet figured out how to make indexed front shifting for a triple work on a roadbike. I ride with someone who has a triple. She can drop down from the big ring to the middle without too much fuss but going up from the inner ring always causes her to either overshift or grind in between. Short chainstays on roadbikes makes it difficult to set up and keep a triple working smoothly. I have yet to ride a triple on a roadbike that shifts as nicely and reliably as a double. For MTBs this isn't a problem as chainstays are generally longer and the derailleurs are typically more advanced to handle triples. I would have to say that the XTR front derailleur on my MTB is by far the best shifting front derailleur of any bike I've ridden. Shimano managed to work out indexed front shifting for triples on MTBs just fine... but not on roadbikes. And for all you Campy riders out there with triples... you have another thing to gloat about. :)
shokhead
06-01-04, 12:48 PM
With all the talk of triples, you'd think everyone was climbing the alps everyday.
For those who say they rarely use their 53, I'm wondering how often you're cross-chaining. I can't imagine that you rarely use your 12-14 in the back. I mean, you have to go downhill sometime, right?
Most my rides are 39 and 13,14,15 going into the wind.
vrkelley
06-01-04, 02:34 PM
the derailleurs are typically more advanced to handle triples
Got my interest...So Which mountain bike derailleurs are these?
jfmckenna
06-01-04, 02:47 PM
It seems Shimano hasn't yet figured out how to make indexed front shifting for a triple work on a roadbike. I ride with someone who has a triple. She can drop down from the big ring to the middle without too much fuss but going up from the inner ring always causes her to either overshift or grind in between. Short chainstays on roadbikes makes it difficult to set up and keep a triple working smoothly. I have yet to ride a triple on a roadbike that shifts as nicely and reliably as a double. For MTBs this isn't a problem as chainstays are generally longer and the derailleurs are typically more advanced to handle triples. I would have to say that the XTR front derailleur on my MTB is by far the best shifting front derailleur of any bike I've ridden. Shimano managed to work out indexed front shifting for triples on MTBs just fine... but not on roadbikes. And for all you Campy riders out there with triples... you have another thing to gloat about. :)
The chainstay lenth theory may explain why on my touring bike w/ long chainstays the Suntour friction shifter worked flawlessly???
Got my interest...So Which mountain bike derailleurs are these?
Shimano XTR FD-M952 with the differential plates. I posted something on it a while back in another thread (http://www.bikeforums.net/showpost.php?p=293144&postcount=16).
The chainstay lenth theory may explain why on my touring bike w/ long chainstays the Suntour friction shifter worked flawlessly???
Absolutely. Although it requires extra skill (not much really), friction (or at least non-indexed) shifting a front triple (especially on roadbikes) usually works out to more reliable shifting. If I ever got to a triple crank on my roadie, I'm going to do it with Campy.
ClevelandGuy
06-01-04, 03:04 PM
ignore diesel dan. don't get a triple. if you need a low gear, get a 12-27 cassette. if you need a loerw gear than that, go for the compact crankset. if you can't get up a hill with a 34/27, then you are either cycling in the himalayas or dead.
velocipedio has it right, he has my vote on this one. Hey just ride more and ride hard and ride right through the burn and just keep crankin like you dont care about the pain, and you wouldn't need a triple.
vrkelley
06-01-04, 05:01 PM
I never do shift the chainrings. With 2800 miles on my bike,i've been in the 53,maybe 5 miles worth.
I"m constantly shifting but only use the smallest of the triple on those 8-15% grades (about 1/5 of my total commute). Also the 53 (on the decents) and flats about 1/2 the time. Then the middle chain ring the rest.
When the "new" 5200 comes with just the double...I'm really not sure how it's going to work out on those ascents. Being a lighter weight woman, I don't have the luxury of massive quads like some people in this forum!
When the "new" 5200 comes with just the double...I'm really not sure how it's going to work out on those ascents. Being a lighter weight woman, I don't have the luxury of massive quads like some people in this forum!
What cassette did you pick for the rear? I run a 39/53 double along with a 12-27 9sp cassette in the rear. A 39x27 gets me up even the steepest of hills around here. I'm not setting speed records mind you but I can tackle many of the 1-1/2 mile long 12% climbs that ring the Sammamish Plateau without killing myself.
ParamountScapin
06-01-04, 07:05 PM
I've been using the FSA Compact Pro 50/34 with my Record 10-speed group for about a month now. I find that with a 12/23 cassette I am at the bottom of the cassette with 34 chainring or top of the cassette with the 50 chainring if I am riding at 18-22 mph. For flatland riding I prefer the standard 53/39 chainrings. For climbing I find the 50/34 works well with my bigger cassettes (13/25 & 13/29) and still leaves me plenty of top speed (40+) on the downhill side. Oh, well. Life is full of compromises and I find the 50/34 to be a reasonable one. Especially in the hills.
jfmckenna
06-02-04, 08:01 AM
I've been using the FSA Compact Pro 50/34 with my Record 10-speed group for about a month now. I find that with a 12/23 cassette I am at the bottom of the cassette with 34 chainring or top of the cassette with the 50 chainring if I am riding at 18-22 mph. For flatland riding I prefer the standard 53/39 chainrings. For climbing I find the 50/34 works well with my bigger cassettes (13/25 & 13/29) and still leaves me plenty of top speed (40+) on the downhill side. Oh, well. Life is full of compromises and I find the 50/34 to be a reasonable one. Especially in the hills.
Do you switch cranks out depending on the ride? I've thought about doing that but dont know how good an idea that would be concerning tourquing the bb/crankset on and off ect... I'm sure I would keep the 53/39 for the most part but there are some big mountain century rides around here that concievably could use a compact set up.
Laggard
06-02-04, 08:21 AM
velocipedio has it right, he has my vote on this one. Hey just ride more and ride hard and ride right through the burn and just keep crankin like you dont care about the pain, and you wouldn't need a triple.
Amen! Amazingly there are people who feel they need an even lower gear at the first sign of burning legs and lungs. Just dig deep and ride it out.
ParamountScapin
06-02-04, 10:55 AM
Do you switch cranks out depending on the ride? I've thought about doing that but dont know how good an idea that would be concerning tourquing the bb/crankset on and off ect... I'm sure I would keep the 53/39 for the most part but there are some big mountain century rides around here that concievably could use a compact set up.
No, I don't. I switch bicycles. But I am about to stop doing that, as well, I think. I'll just spin a bit faster or slower on the flats to keep from cross-chaining the drive-train. I have also found that the spacing between the chainrings make the FD adjustment very critical on the compact crank to not have any rubbing and also to not drop the chain off the inside when shifting from the big ring to the small. Takes a bit of playing around with to get set just right. I'll probably switch to a Campy when their compact crank/FD set becomes available in the fall. Then you can buy my FSA compact and ShimaNo DA BB for about half-price.
Do you switch cranks out depending on the ride? I've thought about doing that but dont know how good an idea that would be concerning tourquing the bb/crankset on and off ect... I'm sure I would keep the 53/39 for the most part but there are some big mountain century rides around here that concievably could use a compact set up.
Hmmmm... I just had an interesting thought. Has anyone considered or actually installed two right side crank arms on both sides for really long tours? Put compact rings on one side and a traditional road setup on the other. It'd be kinda like a flip-flop hub. I'm trying to think of the technical problems other than the fact that the pedal threads would be tapped for the wrong direction and you'd need to properly size the spindle and chainline (adjustable BB might solve that problem). I guess you would also have to readjust the front derailleur height too when you flipped it. Anything else? Would the Q-factour be too great?
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