Chilli Pepper Posted March 30, 2006 Posted March 30, 2006 Apparently my bike setup is quite wrong for me. Current setup: Shimano 105 tripple crankset (52-42-30), 12-25 cassette, 170 crankarm.My length: 174cm. Frame size: 54cm Scott Speedster S4.I've been advised to change to the following:53-39/38 crankset, 11-25 cassette, 172,5 or 175 crankarm.Anybody out there who agree/disagree with reasons? I desperately need/want to improve my current cycling performance.
Mickey Posted March 30, 2006 Posted March 30, 2006 The 170cm cranks sound definately to short, I would advise changing the cranks to 172.5 not 175 ?
Wonder Woman Posted March 30, 2006 Posted March 30, 2006 Well, I can tell you now that you cassette is fine. You would never use an 11. I can't imagine the triple crankset being too wrong, you will just spin a little more. I think more likely is your frame too big, your stem too long, saddle height and position will make a lot more difference. smileys/smiley4.gifMy opinion though....Who actually told you your setup is wrong. Why not go to a professional and see what they saysmileys/smiley2.gif
pastapouch Posted March 30, 2006 Posted March 30, 2006 Chilli, chill, you look perfect on the bikesmileys/smiley2.gif and just maybe the cranks are a bit short
DRIVETRAIN Posted March 30, 2006 Posted March 30, 2006 smileys/smiley4.gifGo see Wendel Bole at the cycle hub ..call him on 011 432 2280. he did my set up and I'm happy with it."DTsmileys/smiley4.gif"
Wonder Woman Posted March 30, 2006 Posted March 30, 2006 He did mine too, and I'm snug as a bug...okay until I'm dying up some hill.
Gumpole Posted March 30, 2006 Posted March 30, 2006 Apparently my bike setup is quite wrong for me. Current setup: Shimano 105 tripple crankset (52-42-30)' date=' 12-25 cassette, 170 crankarm.My length: 174cm. Frame size: 54cm Scott Speedster S4.I've been advised to change to the following:53-39/38 crankset, 11-25 cassette, 172,5 or 175 crankarm.Anybody out there who agree/disagree with reasons? I desperately need/want to improve my current cycling performance.[/quote'] Get yourself measured by someone like cyclelab! Your leg length not total length will determine crank arm length. I would guess a size 56 bike would be better. The 11-25 cassette will be important if you can sprint at over 60km/h but for people like me it is wasted. Loosing the triple will mainly just save you a tiny bit of weight (and look a lot better smileys/smiley4.gif)
Velouria Posted March 30, 2006 Posted March 30, 2006 The thing that grabbed my attention was the short cranks. I would go for 172.5 since you are quite tall. Therest just sounds like people trying to make money out of you. There isa very small improvement by changing cassettes. I think changing thecrankset will require you to change your style of riding quiteconsiderably - no more granny. If you find you are unable tokeep up with the bunch because you run out of gears, then changing thecrankset is a good idea, but if you like spinning up hills andpedalling the light gears at high cadence, then keep your current setup. Don't take any of this too seriously - I just ride bikes, so this is all just my rather limited opinion...
Chilli Pepper Posted March 30, 2006 Author Posted March 30, 2006 I've decided not to do the cassette.I'll change the crankarm to 172.5 and the crankset.I've got a problem with running out of breath before I run out of power - working bigger gears seem to be easier than spinning up hills, and I run out of gears and get dropped by the bunch on the straights. I can't afford any of it really, but can definitely NOT afford another bike, so will have to change this one's setup as far as I can.Can I keep the 9spd shifters, chain, derailleurs and cassette, but upgrade the crankset to 10spd? I'm really still very new to this - and all the cranksets on the web seem to be 10spd?!
CVANC Posted March 30, 2006 Posted March 30, 2006 Can I keep the 9spd shifters' date=' chain, derailleurs and cassette, but upgrade the crankset to 10spd?[/quote'] YES
Poison Ivy Posted March 30, 2006 Posted March 30, 2006 The thing that grabbed my attention was the short cranks. I would go for 172.5 since you are quite tall.Hi Chilli, I agree with the above, I've changed last year to 170mm cranks, but I'm about 9cm shorter than you (1.65m) and the shorter cranks work much better for me than the 172.5's I've had.Go for that measurement at Cyclelab. You won't be sorry. You will not believe what difference a good and propper bike set-up will do for your riding
Austin Posted March 30, 2006 Posted March 30, 2006 We have used the 10sp cranks with the older 9sp chains, etc on our old TT bikes with great success. I have a 2nd hand Dura Ace 9sp 172.5mm crankset you can buy for cheap!The only REAL change needed I would say is the crank arm length. In the Alps my guys ride 50 in front and 12 at the back and they come right.
Gumpole Posted March 30, 2006 Posted March 30, 2006 I cannot believe that a 52-12 wont suffice unless you are an elite male sprinter! I also dont think you will feel the difference between 170 and 172.5 cranks. I am 183cm and went from 170 to 175 and didn't really notice any difference.* with the 52/12 at 100rpm you will be going 55km/h, at a leasurely 75rpm still 41km/h. if you wind it up to 150rpm... 83km/h!
linnega Posted March 30, 2006 Posted March 30, 2006 As far as I remember the 105 groupset has a triple specific front derailleur, so you may need to change that or you could find your chain being dropped too frequently. The shifters for the front derailleur should be changed but don't need to be if you get a new front derailleur. The chain length may need to change, although moving from a 52 to a 53 up front should mean no change is necessary. Get a non-Shimano crankset and you will be better off as they are compatible with 9s or 10s drivetrains. Just check that the crankset you get fits your Shimano splined bottom bracket!Some other advice from Uncle Al Ardizone on Shimano 9s/10s:I'm a compatibility freak. I spend way too much of my time trying to figure out what works with what. My latest quest has been to determine how much (or if any) of Shimano's new 10-speed stuff can interface with its great 9s stuff. What a mess.<?:NAMESPACE PREFIX = O />Shimano created some of the greatest drivetrain compatibility of all time with its 9s system. You can mix and match nearly all 9s road or ATB parts to get whatever gearing you want. Like a road triple crank with 30/39/53 rings mated to an 11-34 cassette and XT rear derailleur with so you could climb Everest and speed down the Chinese side, bullets a-flyin'. But 10s has virtually shut the door on custom gearing while providing very limited choices to boot. Now, what about the new Shimano Compact crank (FC-R700)? Compacts do give lower gearing for fit cyclists with legs of steel. But that 34x27-tooth bottom gear isn't low enough for weenie-legged recreational riders (like myself) with a Walter Mitty Complex. There's a reason I ride in the valley and not out of it.Will Shimano's compact crank work with 9s stuff? The bad news is it's a dedicated 10s crank and the only way you're gonna use it on your 9s is to replace the chain and front derailleur with 10s. The derailleur is fine but I think Shimano's 10s chains would be better used for necklaces. I destroyed two of the $50 ones installing them with the correct chain tool. It wasn't the first time I'd installed chains during 40 years of wrenching, it just felt like it. Broken or twisted 10s chains are not uncommon from poor shifts or simply generating too many watts.A couple other issues to think about when considering 10s stuff:---The 10s STI brake/shift levers are 2-cm longer on the hoods than the 9s. If you ride on the hoods a lot be sure to factor that in to your bike fit. Credit for this insight goes to fit guru Richard Schwinn of Waterford Precision Cycles. You'll have to shorten your stem if you're happy with your current position, or get a frame with a shorter top tube. Whatever it takes; 2 cm is dramatic.---Don't buy a Shimano 10s-dedicated wheel if you run a 9s system. The hub won't accept a 9s cassette. Fortunately, most other aftermarket wheels are 8-9-10s compatible.Bottom line: Don't assume that going to 10s is the next nirvana. Ask yourself if you really need it. Trying to mix and match 10s with 9s could drive you to drink. If you go there, be absolutely sure you're getting compatibility advice from someone who really knows their stuff. This sounds too much like the GM business model of planned obsolescence. What were they thinking?RoadBikeRider newsletter 23/3/2006
linnega Posted March 30, 2006 Posted March 30, 2006 I'd go with Austin's 9sp Dura Ace crank. Good quality crank that will fit your BB without a problem. I'd still go for the double specific front derailleur as the cage is narrower.
Chilli Pepper Posted March 30, 2006 Author Posted March 30, 2006 Thanks everyone - What a lot of information! I'll try to assimilate everything and make a decision accordingly. smileys/smiley20.gif
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