[cderalow]

Looking to upgrade in the future from my current POS shimano crank to a road triple.

Is there a real difference between a '9-speed' crank and a '10-speed' crank.

ie: Shimano FC-4603 v FC-4503

[robkyle]

Why a triple chainring? Unless you're doing some serious hills or just not a very strong climber, you're probably better off with a compact double. Triples are much fussier to keep dialed in. And you'll need a shifter that can handle a triple. For most roadies a compact double is the way to go.

[cderalow]

Originally Posted by robkyle

Why a triple chainring? Unless you're doing some serious hills or just not a very strong climber, you're probably better off with a compact double. Triples are much fussier to keep dialed in. And you'll need a shifter that can handle a triple. For most roadies a compact double is the way to go.

... does not in the least answer my question.

the reason for a triple is that I frequently tow a trailer with 100+lbs of children in it, and need the granny gear. even going to a road triple will be stepping up from my current mtb triple with it's 28 small ring.

[carlharsch]

With a triple, the difference between a 9 and 10 speed would be 3 speeds, which you probably won't even notice. More important is the hub on your rear wheel and whether it supports the cassette on the rear. The rear hub/cassette gear teeth, in conjunction with the gear teeth on your crankset, have a lot to do with determining the lowest/highest gear you'll obtain.

What is your current gearing situation with your bike? And, what is your end goal for the change?

The 4603 is the newer version of the Tiagra, designed to be coupled with the 10 speed cassette. From first look, they appear to be the same, but I don't know if they are interchangeable with older hubs or not.

[cderalow]

Originally Posted by carlharsch

With a triple, the difference between a 9 and 10 speed would be 3 speeds, which you probably won't even notice. More important is the hub on your rear wheel and whether it supports the cassette on the rear. The rear hub/cassette gear teeth, in conjunction with the gear teeth on your crankset, have a lot to do with determining the lowest/highest gear you'll obtain.

What is your current gearing situation with your bike? And, what is your end goal for the change?

The 4603 is the newer version of the Tiagra, designed to be coupled with the 10 speed cassette. From first look, they appear to be the same, but I don't know if they are interchangeable with older hubs or not.

I'm currently in the process of swapping from 8 to 9 speeds, but the question arose due to the cost difference in the two tiagra triple cranksets.

i find the 4503 is $15 more than the 4603 despite being older.

so i was wondering if the '9/10' speed on the crankset mattered at all.


the reason for the crankset swap in lieu of just retaining my current 48/38/28 MTB triple, is to give me a slightly higher top speed, and to drop some serious weight with the square taper and heavy ass crankset

I'll be retaining a MTB rear derailleur and cassette, so I'll be able to run a 9 speed 11-34t cassette, with a 50/39/30 road triple (if I can find a 28 chainring to fit the bcd, i'd run 50/39/28 as my intended derailleur setup would support it).

my current rear hub (and future shifters) support 9 speeds.

[davereo]

A ten speed crank will work on a 9 speed bike. You need to use the proper chain to match your cassette spacing.

9 speed chain 9 speed cassette
10 speed chain 10 speed cassette

8,9 and 10 speed cassettes mount on the same free wheel hubs. The difference is in the thickness of the cogs and spacing. Ten speed cogs being the thinest.

[robkyle]

... does not in the least answer my question.

Try not to be a jerk. That was valid and pertitent information. Maybe if you had included your trailer explaination in the first place my response would have been more tailored to your needs.

[davereo]

The pitch on all the cranks regardless of speed is .5 inches. The difference will be in the thickness of the chain rings.

[bikertank]

I think the difference in 9-10 speeds depends on how well you utilize all or your chain rings - for me - using only the large chain ring it was VERY noticeable - because I didn't like shifting - it sounds like you will be using all three chain rings in a proper manner - so it shouldn't make much difference between a 9 or 10

[cderalow]

Originally Posted by davereo

The pitch on all the cranks regardless of speed is .5 inches. The difference will be in the thickness of the chain rings.

this is what I kind of anticipated. that the 10-speed rings would be slightly narrower to accommodate a 10-speed chain compared to the slightly larger 9-speed chain.


just wanted to make sure before I spent $100+ on a new crank.