I've got a Fuji Absolute 1.0 with a Shimano FC R553 triple crank.

It took me a while to figure out my crank arms are too long... 180mm,***(RE MEASURED: CORRECT LENGTH 175MM)*** and I'm 5 ft 7.5" with a 30" inseam. My Fuji Roubaix 1.0 is extremely comfortable and has 165mm ***(RE MEASURED: CORRECT LENGTH 170MM)*** cranks.

MY QUESTION:

What inexpensive Shimano cranks have arms that will bolt on to my current FC R553 crank? I don't want to spend the money to get a 105 setup, and I cannot find an FC R553 for sale with 165mm cranks. Looked at Shimano compatibility chart, but it didn't help.

I have found Sora and Tiagra triples with 165mm cranks, but don't know if they'd work.

Thanks!

FORGOT TO ASK: WILL I NEED TO CHANGE THE CHAIN? CURRENTLY RUNNING A SHIMANO 105...

You need a *standard* 130mm BCD Shimano Hollowtech 2 crank for a road bike... in your case, a triple if you want to swap rings. I'd just buy a new crank unless you find someone that wants to trade.

Basically, any standard HT2 road crank (with rings) will work with your frame and bottom-bracket, double or triple, black or silver.

Just buy a full crank with rings, unless you happen to find some compatible arms on ebay; it will still likely be cheaper to buy the whole crank with rings; then you have extra rings.

Post a link of what you found, if you want confirmation.

Shimano Tiagra 4603 165mm Triple 303950T Crankset SLVR | eBay

Thanks a lot for your response headloss.

Will the above crank work? Also, if I choose to use just the arms, will they bolt on to the FC R553? ( Seems they will, 130mm BCD)

Finally, will I be upgrading, downgrading, or maintaining quality with the Tiagra?

You'll need to replace the entire crankset.

Refer to this exploded diagram from techdocs.shimano.com and you'll see why.

While the left crankarm is a separate part and is easily replaceable, the right crankarm is not. It's a one-piece unit that also includes the spider that the chanirings bolt to, and the crankshaft itself, which goes through the bottom bracket and comes out the other side for the left crankarm to bolt to.

Any of Shimano's current "two-piece" or "Hollowtech II" road cranksets will work--from Sora all the way up to Dura-Ace--and most of the "non-group" cranksets like your R553. Claris group and below, and the non-group "Octalink" cranks, require a different bottom bracket than you have.

Alternatively, by changing the bottom bracket, you can use any crankset, even other brands.

Thanks tsl! Very informative and extremely helpful information.

I don't know... ... I found it odd that a mass market, off the rack, hybrid would come stock with 180mm cranks so I've spent too much of a nice Saturday morning chasing down bike models and Shimano crank specifications. As far as I can determine, the Fuji Absolute 1.0 has 170mm cranks and they are indeed FC553 road triples. I also found it odd that a road bike with racing pretensions like a Roubaix would come stock with 165mm cranks. Here I have less luck with obtaining hard numbers, the Oval 520 compact double that comes stock on that bike does not list a crank length. I would ask the o.p. to measure both their cranks again, using the center of pedal spindle to center of bottom bracket convention that is pretty much standard and report back.

Other may differ, but I for one switch back and forth between 165mm, 170mm and even 175mm cranks without any noticeable discomfort. I try to have 29.5" to 30" between the center of my BB and the top of my seat and I let the crank length sort itself out. I used to measure from top of pedal surface with the crank in alignment with the seat tube up to the top of the saddle. Keeping this dimension constant will somewhat compensate for different length cranks. FWIW.

H

Those will work fine. You can get them cheaper from another vender. Shimano Tiagra 4603 165mm Triple 30/39/50t Crankset Silver~ Bottom Bracket Not Included - AEBike.com

as tsl showed with the links, you don't really want to "use just the arms." But, you can save the rings from your original and use them down the road if/when the rings on the new crank wear out.

You already have a bottom bracket, so fortunately that's not an issue... just reuse the cups/bearings that are currently on there.

Quality is the same, both are using stamped rings (as opposed to a forged ring) which is true all the way up through 105 (105 rings used to be higher quality). Honestly, I don't see any reason to justify buying 105 over Sora, let alone Tiagra. Bearings are the same regardless unless you want to buy something aftermarket (independent of the crank itself), so bearing quality isn't an issue. If there's any difference besides that, it would be in the weight of the crank arm; I wouldn't worry about it. I don't think the crank arms get the hollow treatment until Ultegra anyways, but I could be wrong (hard to keep track from one generation to another without running off and researching it).

Thanks for the info Leisesturm! Fuji is notorious for outfitting the bike with components different than what's listed on their website.

My cranks on the Roubaix are FSA Gossamer, and are indeed 165mm. Strange but true...

Thanks for all the info and help headloss!

Many cranksets come with a new bottom bracket.

Forgot to ask tsl... will I need to change the chain if I go Tiagra? Currently running a Shimano 105 chain.

Chains are based on rear sprocket... which hasn't changed. Crank has the same number of teeth on the rings, yes? So, you shouldn't need to resize the chain. As far as tiagra vs 105 vs ultegra vs KMC vs SRAM vs whatever, it doesn't generally matter as long as it is made for the correct number of speeds.

So, no change is necessary. IF the rings are an identical size, no adjustments are necessary either.

If you remove the chain for any reason, make sure you put it back on in the correct orientation (only an issue for SHimano chains)... no reason to remove the chain though, and I wouldn't suggest it anyways.

And many do not.

I have yet to purchase a Shimano crankset that comes with the BB.

The reason is that Shimano has no way to know which BB your frame requires, so packaging BBs with cranksets would result in people complaining that they have to pay for something they won't use. Far easier just to sell them separately.

No.

The chainrings on both cranksets have the same number of teeth, so you won't need a longer or shorter chain.

As far as "compatibility" goes, all Shimano 10-speed stuff is freely interchangeable with other Shimano 10-speed stuff.

Some parts are also freely interchangable between different speeds. For example, I recently upgraded my 8-speed Sora bike to 10-speed. I replaced the levers (105 5603-series), the cassette (Ultegra 6700-series), and the chain (KMC DX-10 not even Shimano). Still running the "8-speed" Sora crankset, FD, and RD.

They spread a lot of FUD around hoping you'll fall for it and buy extra parts.

Leisesturm,

After re measuring as you suggested I found that my Fuji Absolute 1.0 has a crank length of 175mm (as verified on the Fuji website for "Medium").
You are right; it would be very odd for a mass produced bike to come with a 180mm crank.
Also, after re measuring the Roubaix I found the true crank length to be 170mm, not 165 as I previously stated.
Thank you for kindly reminding me how important it is to measure accurately.

Sorry that my misinformation caused you to burn your time researching this issue in the morning.

Just bought a new SLX crankset that came with a BB. BTW, the chain is 10 speed ("10S"), not 105.