mikeridesbikes wrote:
Gatineau Gator wrote:
Hi fellows, Sorry, I did not pose my inital question very well.
To expand on my intitial question, I notice the QR PRSIX2 DISC tri-bike uses the crankset FSA SLK Light 52-36. Is 52-36 considered the correct crankset for tri-bikes? I notice at the website the
FSA SLK Light there are different sizes of cranksets. What advantages and disadvantages do the different sizes provide to a tri-bike?
Thank you in advance :)
GG Depends a lot on how strong you are as a cyclist and how hilly your routes are. I actually just got some 55-42 Q-rings for my TT bike which should be in tomorrow- that's definitely not for everyone though. I'm a strong cyclist (~300W, >4w/kg FTP in aero) with a fairly low cadence (hard for me to get much over 90 rpm in aero), so I found I was spinning out a 53-11 on anything more than a 1-2% downhill. Since I'm a strong climber, a 42-28 should still get me up short hills without going too deep and allow me to climb longer grades of 7-8% with no problem. But big chain rings on the front aren't for everyone- really only for those with very high w/CDA even more than w/kg. If you naturally spin a higher cadence and can comfortably get over 100rpm, you probably won't need the bigger chainrings as much either.
Personally, I would rather have a wider range on both ends of gearing than be limited on either end- I like pairing bigger chainrings with larger cassettes on the back, so that you can stay in the big ring longer (front shifts suck with cable TT shifters) and still climb decent grades. I'm not at all a fan of the new SRAM AXS gearing for TTs- the small sprockets on the back where you'll spend a lot of time on a flat course are very inefficient from a friction perspective (not to mention the cost of even force eTap). There's a lot of ways to skin the cat to get the gearing you want, so it just depends on what you're preference is and what type of rider you are.
Depends on personal preferences, I guess. I’m rarely below 100rpm in cadence, if I Can avoid it, so usually i’m actually pretty comfortable on a compact chainset. However much I like the looks of a Big chainset, if I Got a 58/44 or something like that, I’d rarely use the Big ring.
But in general, I would advise on getting several cassettes, depending on whatever profile you’re riding, wether it’s Racing or training. For a flat race 11-25 or 12-25 (i would prefer the 12-25, unless the 11 is absolutely needed), for a hilly race, I’d go standard 11-28, for purely uphill something that ends with 32. The chainset I would choose, would be the one where the fourth low cog on the Big ring would equate to my estimated avg speed for the race. Unless it’s a straight Road in one direction, my experience is that you’ll almost never race at your avg speed, always higher or lower.
And why the fourth low cog? - because you have a small chainring too and to add flexibilty up and Down without too Big jumps between them. Even though a straight chain Line is more efficient, it’s not more efficient, if you havent got the gear you need. I’d say for anyone averaging less than 20mph on the flat, just put a single 44 or 46 chainring on a 12-25 cassette. No, it doesn’t Look sexy