# Considering upgrading bike crank



## Brian_D (Sep 28, 2010)

I'm slowly upgrading my components on my bike. Currently I have all Shimano 105 group except for my crank. Currently I have a Shimano Sora 2203 Triple (52-42-30). I searched around on Ebay and can't seem to find a single 105 or higher triple that's 52-42-30. They all seem to be 50/48-39-30. Is there such a thing as a 105 or higher triple that's 52-42-30? 

Can I just go with a 50/48-39-30?

I currently have a 12-23 9-speed rear cassette.

Another question, while I'm thinking about it....is there really any performance advantage going from a Sora crank to a 105 or better? 

Thanks In Advance.
Brian.


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## scottzj (Oct 4, 2010)

Is there a reason why you have to go to a triple? I dont have one person in the club I ride with that has triples. The reason asking is there is so much more to choose from if you ventured away from that. Just a thought, but good luck on the search for which you like.


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## wim (Feb 28, 2005)

*Some thoughts.*



Brian_D said:


> Can I just go with a 50/48-39-30?


Sure. There's not all that much of a difference between what you have now and a 50-39-30 triple. Keep in mind that a 3-teeth change in the front roughly equals a one-tooth change in the rear, so the 52 > 50 and the 42 > 39 difference equates to about one rear shift. If you find the 50 x12 is not large enough for you, you could always get a cassette with an 11T smallest cog.

There's no real performance difference (= speed) between Sora and 105. But it's nice to have all the parts on a bike belong to one particular group, so it might make you feel better about riding your bike. If you want to call that a "performance advantage," why not.

The Ultegra FC-6703 triple comes in 52-39-30, but that's a lot of $$$ to spend just to get the 52 large ring.

FWIW, the triple is unfashionable right now, mostly for reasons having nothing to do with performance. I think it's good to have two closer-ratio chainrings with a granny ring in reserve rather than the "compact compromise", but that's just me. People seem to love their compacts.


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## Camilo (Jun 23, 2007)

Couple of thoughts.

Since you are running a 9 speed bike, look for the 9 speed triple cranks: 5503 and 6503. They will be, IIRC, 53-42-30. I see them on Ebay all the time, and if you look at completed listings the Ultegras aren't going for a lot of money.

On the other hand, if you are "stuck" with a 50t big ring, just switch to a cassette with an 11t small cog and you'll get the same high end with the 50X11 as you have now with your 52X12, actually a little higher. 11-23 cassettes are common. Your lowest gear wouldn't change - would still be 30X23... if you need lower, you could go to 11-25, also common in 9 speed.

Finally, you might be able to change the big ring from 50 to a 52 - I believe they make 52t rings in both 130 and 110 BCD (the spec which tells you which rings will work with your crank's spiders). I don't know if this is possible, but something to check on. Decent quality rings are not horribly expensive.


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## TomH (Oct 6, 2008)

Brian_D said:


> Another question, while I'm thinking about it....is there really any performance advantage going from a Sora crank to a 105 or better?


Not even remotely. We're talking zero difference in performance.


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## Brian_D (Sep 28, 2010)

Thanks for all the help guys! Y'all answered my questions perfectly.


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## TomH (Oct 6, 2008)

I would consider a compact as well. 

You can use 10 speed cranks on everything.. The rings are a little narrower, but they'll fit every chain type. The wider old cranks might not fit 9 and 10, so its best to stick with 10s cranks.


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## kmunny19 (Aug 13, 2008)

TomH said:


> Not even remotely. We're talking zero difference in performance.


likely true that most riders won't feel a performance difference. however, there's likely to be a quality, durability, and longevity difference. I'd recommend planning to upgrade the crankset when the current one starts to warp, shave teeth, repeatedly require tightening, basically come apart. It may take some time, but until then, a true performance difference isn't too likely noticeable, or enough to merit switching before needed. I've never had a sora crankset, but I'm guessing it will be easier to break than a 105.


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## red elvis (Sep 9, 2010)

i've read from another thread that there is really not a lot of difference in performance between the 105s and ultegras so maybe just keep the 105s and save your money. but unless you really wanna spend your money for your bike, i suggest to go with the dura ace, the fsa slk light crank set or sram red.


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## Drew Eckhardt (Nov 11, 2009)

If you actually need the 30x23 and/or want a high gear like 52x12 I wouldn't switch to a compact since that's going to get you something like 12-13-14-15-16-17-18-19-21-23-26 or 11-12-13-14-15-17-19-21-23-26 with noticeable gaps in your cruising range on the big ring around 18-20 MPH.

If you can live with 34 x 12-13-14-15-16-17-18-19-21-23 which avoids the spacing issues I'd still skip the compact. I made a mistake switching to 50-34 x 13-14-15-16-17-18-19-21-23 after wearing out by 50-40-30 triple and realizing that my 8 speed era low gear of 30x21 was the same as 34x23. There are terrain/wind/fatigue combinations which result in a lot of double front shifts due to limited overlap between the rings, and the double shifts are slower than triple/conventional double setups due to the spacing (the rear derailleur takes up to five lever activations to get to the next gear).

53x39 x 12-13-14-15-16-17-18-19-21-23 works better with more overlap and a small ring useful for flattish situations without killer head winds, but gives a low gear about like 30x18.

All of this really depends on your local terrain, weight, fitness, preferred cadence range, and what happens when you ride outside that cadence range (it's silly to spend a lot of money on bike parts that don't feel good, and some people's physiology gets them dropped when they have to ride too hard at too low a cadence).


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