Question on TT chain rings

Triathlon Forum
1

Sorry if this is a bit off topic, but anyone have any opions or ideas on comparing / contrasting FSA K-Force TT 55T & Shimano Dura Ace Triathlon Chainring 55T?

Is this just a bling issue with FSA having “carbon” added to their ring? At first, I thought the FSA ring would weigh less, but the numbers I’ve found go against this. Only other thing I can think of is a stiffness issue - again, carbon should / might make a difference, but then the question comes up - how much of a difference is it? I had a DA 56 ring a while back and don’t recall it being flexy. Now I’ve got the FSA ring. Yeah, it’s got the bling factor, but big deal…

This all came up on a group ride today and we couldn’t really come up with any definite ideas…any others out there?

thanks,
Chris

2

There will be little measurable difference between rings, either aerodynamically or flexability. I could run a standard Shimano, FSA, TA, or any other ring and not notice any difference. Mind you, if you need a 55 or 56 ring you can put out way more power than me.

Marketing hype, it’s wonderful :~)

The FSA is fairly bling, but I can think of better bling chainrings to get. Try these

3

I hate to say it…I have… :frowning: Got mine for a steal off eBay. Lasted a whopping three rides (one race) before it started to delaminate. Amazingly light. Got no plans to do that again.

Thanks for the info…not what I hoped for, but still good to know. :slight_smile:

-Chris

4

I hate to say it…I have… :frowning: Got mine for a steal off eBay. Lasted a whopping three rides (one race) before it started to delaminate. Amazingly light. Got no plans to do that again.

Thanks for the info…not what I hoped for, but still good to know. :slight_smile:

-Chris

Ah Ha! I think I’ve spotted the problem. :slight_smile:

As to the original issue, I’d be surprised if anyone has a good answer for it.

5

I have the FSA lenticular (all aluminum). 55/42 pair. I’ve been very happy with them. There is some evidence that the solid rings make a marginal, but measurable, aerodynamic difference. A completely aero crankset, like the carbon-wrapped Campy set-up on Floyd’s BMC is obviously the ideal for aerodynamics, but the solid rings (especially with a solid spider) will save some time/power, albeit very minimal. If you need chainrings, though, the FSA ones are about half the price of Shimano, and that’s always a factor…

6

Good point - cost - didn’t think about that. I was just hoping for a technical one and doesn’t look like that’s (really) going to pan out.

But, it’s new, should last some time, etc. I’m happy with it.

Neil, don’t even get me started on eBay…but I wanted to try a carbon ring and now I can say I have. Sort of reminded me of the 70s drilled out gear. :slight_smile:

-Chris

7

Hummm…

56T ring? Can you say “cross chained.”

Hey CB do me a favor. Put your 54T D-ace ring back on. If you can really spin it out in the 11T for the length of ANY TT, come back and I’ll answer your question.

Seriously though, other brands may be more “quan” but, you can’t beat Shimano engineering.

Good luck and fast racing.

8

In my experience the cost delta between FSA and Shimano is accounted for by shift quality, that is, the Shimano rings will offer better shifting up front.

9

Gee, will you answer my questions? I did an entire 50k ttt in the 55x11 this season - does that make me cool?

No offense, but come on - there are plenty of people on here who can -and do - need/use these types of gear ratios to good effect.

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10

Did you get your cadence over 50rpm? How are the old knees holding up?

Sorry Fred, I was having a little fun with my reply. I didn’t mean to offend you or anyone else.

Good luck and fast racing.

11

Cadence is fine, knees are fine. District TT titles are fine, too, thanks.

I’m not even close to being the fastest TT rider on this board, but suffice to say I’m more than fast enough to justify the gear choice, and have the medals to back it up.

It’s easy to forget, but there are some serious cats on this board (note-I’m not one of them,) and it’s probably a good idea to check assumptions like “that’s a ridiculous gear ratio” at the door when you enter.

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12

In my experience the cost delta between FSA and Shimano is accounted for by shift quality, that is, the Shimano rings will offer better shifting up front.

That implies that you ever need to shift out of the big ring!

13

Us high-country folk frequently do.

I can’t tell you the number of 12-27 cassettes I sell to triathletes in these parts. Many would be better off with compact (50-11 being a taller gear than 53-12 by a very slim margin).

I wrote about this in my Inside Triathlon column some months ago.

14

Why not move all the way up to 60x11.

http://candy.bbsnavi.net/trjachc/www.bikeforums.net/archive/index.php/t-100497

15

Cadence is fine, knees are fine. District TT titles are fine, too, thanks.

I’m not even close to being the fastest TT rider on this board, but suffice to say I’m more than fast enough to justify the gear choice, and have the medals to back it up.

It’s easy to forget, but there are some serious cats on this board (note-I’m not one of them,) and it’s probably a good idea to check assumptions like “that’s a ridiculous gear ratio” at the door when you enter.

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Your cadence is in the 80s I assume? that’s still over 50kph for 50km, which is impressive, but if you do 90+, you should have a crack at Boardman’s absolute Hour record, it’s only a couple of revs away.

I’m lucky if I can do 40kph.

16

Fred,

Again, my replies were a bit “tounge in cheek.” Sorry if I offended.

Now, while I do believe that there are a VERY SMALL number of people on this board who can, “use these gear ratios to EFFECT.” Read again, “to effect.”

I also believe that the actual NEED for a 56/55-11 or 12 is highly misunderstood. I really wouldn’t want the average or, even above average triathlete thinking, “Man, old Fred’s pushing a large pizza and he’s fast. I need a pizza for a big ring too.”

Personal experience:

I by no means would be considered a elite TTer. However, I can throw down a 1:01 on a flat 40K course after the swim. Last season I un-intentionally left my COMPACT(50-34) front rings on after a hill climb. I ended up having to race 40K with the compact the next weekend. Time, 1:01 and change. That’s in the FIVE-O!

So, 55-56T, can YOU spin it “effectively?” Yes.

Do you need it? I don’t really know.

And yes, I do think that a 56-11 is, “a ridiculous gear ratio!” But then I can budge it and may just be horribly jealous! :wink:

Good luck this season and congrats on the District win.

Last thought:

POWER isn’t pushing a big gear, it’s pushing a big gear FAST.

17

"Your cadence is in the 80s I assume? that’s still over 50kph for 50km, which is impressive, but if you do 90+, you should have a crack at Boardman’s absolute Hour record, it’s only a couple of revs away. "

…too funny!

Naw, I have no delusions of ever being at that level, thanks. Too old, massive lack of talent.

I don’t TT at a particularly high cadence. Road race cadence for me will average in the mid 90 rpm range, but I’m faster in TTs at 80 or below.

After years of trying to convert to high cadence TTing, with poor results, one season with a power meter and Cyclingpeaks helped me realize that that was a massive waste of time - for me. I figured out what my sweet spot was, and bought a bigger chainring :0).

For a TTT, though - yeah, 50kph isn’t too far off the mark. Depends on the course.

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18

"Again, my replies were a bit “tounge in cheek.” Sorry if I offended. "

  • No, no offense taken. Not at all.

"Now, while I do believe that there are a VERY SMALL number of people on this board who can, “use these gear ratios to EFFECT.” Read again, “to effect.”

I also believe that the actual NEED for a 56/55-11 or 12 is highly misunderstood. I really wouldn’t want the average or, even above average triathlete thinking, “Man, old Fred’s pushing a large pizza and he’s fast. I need a pizza for a big ring too.” "

  • Don’t forget, there are many, many posters on this board who aren’t riding Tris - although this is a tri board, it doubles as a gathering place for TT afficianados, and that can change things around quite a bit… and you did mention something about “…a TT of any length…” didn’t you?

"So, 55-56T, can YOU spin it “effectively?” Yes.
Do you need it? I don’t really know. "

  • Yes, I do (insert emoticon)

"And yes, I do think that a 56-11 is, “a ridiculous gear ratio!” But then I can budge it and may just be horribly jealous! :wink: "

  • now we’re on to something! :0)

"Good luck this season and congrats on the District win. "

-Thanks! Good luck to you, too.

“POWER isn’t pushing a big gear, it’s pushing a big gear FAST.”
http://forum.slowtwitch.com/images/clear_shim.gif

  • You know, I hear this all the time. Too bad it isn’t true.

People get really hung up on this, but it’s very, very simple. As K.Willett says, “fast is fast.” 300 watts is 300 watts, whether you pedal 20rpm or 120rpm to produce it.

Power is power, independent of cadence or gear ratio. Analyzing pedalling cadence may speak to issues of efficiency, metabolism, and other related topics, but it doesn’t tell you anything about how fast you’re going.

If a rider can do X wattage for 60 minutes at 75 rpm, and X-20 wattage for 60 minutes at 90 rpm, she is going to be faster at the higher wattage, period. It’s that simple.

What *isn’t *all that simple is why a rider might be faster at a certain cadence range, and how you figure out what that cadence range is - that’s the fun part.

PS -

I love compact gearing, BTW, and I run it on my road bikes - so I have people making fun of me for the puny gearing on my road bike, and the giant gearing on my TT bike… too funny…

.

19

I just bought the FSA K-Force ring and returned it as soon as it arrived. The thing feels like it weighs about 2 pounds vs. my Shimano TT chainrings that are light as a feather. The K-Force ring has more of the opening closed in, so presumably has better aerodynamics, but it weighs about as much as an entire DA crankset!
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20

Hey CB do me a favor. Put your 54T D-ace ring back on. If you can really spin it out in the 11T for the length of ANY TT, come back and I’ll answer your question.

Why would it be an issue whether or not you can, “spin it out in the 11t for THE LENGTH of ANY TT … ?” As I see it, the issue is to always have a gear available so you’re NEVER spun out … so you can ALWAYS be applying power. If there’s even a little bit of downhill grade, I can easily roll a 55x11 … especially since I run 650 wheels.

The question of whether or not someone can “spin it out” strikes me as ridiculous. Where is there a law or rule that you shouldn’t have a gear on your bike any larger than what you’d need for a totally flat 40k TT? How stupid.
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