Compact Crank Question



drbaize

New Member
Jul 6, 2007
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I have a Centurion LeMans that I purchase in 1984/5. The bike has index shifting and I like the ride, however I would like change to a compact crank and have been looking at Truvativ Touro Compact Crankset. I understand that this will require a new bottom bracket but am a little confused as to what else I will need to do and a I also don't know much about this particular crankset except the price is right.
Thanks,
Dan Baize
 
drbaize said:
I have a Centurion LeMans that I purchase in 1984/5. The bike has index shifting and I like the ride, however I would like change to a compact crank and have been looking at Truvativ Touro Compact Crankset. I understand that this will require a new bottom bracket but am a little confused as to what else I will need to do and a I also don't know much about this particular crankset except the price is right.
I believe the particular crank uses an ISIS BB. If you plan to do the installation, then you will need an appropriate BB tool which can accommodate the ISIS Bottom Bracket (I think it is the Park BT-2 ... early ones with the same desigination won't work, so be sure your shop knows you are going to use it for an ISIS BB).

For the amount of money that the Truvativ Touro Compact appears to cost (~£54 + ISIS BB, ~$80CD + ISIS BB, etc.) I think you may want to consider a Shimano FC-4550 9sp Compact Crankset 50/34 which uses the "external" BB. The price with BB will be about the same if you can get it off of eBay ... perhaps, a little higher, but not by much OR a little lower! Yes, you will need a dedicated "tool" to install the BB cups.

A "compact" FSA MegaExo Gossamer crank + BB should definitely cost you less than $100US (adjust prices, according to where you are) if you get it off of eBay.

UNLESS you can get the Truvativ crank + ISIS BB (113mm-OR-shorter spindle) for under $60US (I was going to say $50!), I wouldn't bother with it.
 
alfeng said:
I believe the particular crank uses an ISIS BB. If you plan to do the installation, then you will need an appropriate BB tool which can accommodate the ISIS Bottom Bracket (I think it is the Park BT-2 ... early ones with the same desigination won't work, so be sure your shop knows you are going to use it for an ISIS BB).

For the amount of money that the Truvativ Touro Compact appears to cost (~£54 + ISIS BB, ~$80CD + ISIS BB, etc.) I think you may want to consider a Shimano FC-4550 9sp Compact Crankset 50/34 which uses the "external" BB. The price with BB will be about the same if you can get it off of eBay ... perhaps, a little higher, but not by much OR a little lower! Yes, you will need a dedicated "tool" to install the BB cups.

A "compact" FSA MegaExo Gossamer crank + BB should definitely cost you less than $100US (adjust prices, according to where you are) if you get it off of eBay.

UNLESS you can get the Truvativ crank + ISIS BB (113mm-OR-shorter spindle) for under $60US (I was going to say $50!), I wouldn't bother with it.
Thanks, I will check on E-Bay, the freewheel has seven sprockets will a 9 crank work?
 
drbaize said:
Thanks, I will check on E-Bay, the freewheel has seven sprockets will a 9 crank work?
Yes, the 9-speed crank/(chainrings) will work with your 7-speed "chain"/drivetrain.

The ONLY thing (after you install whichever new crank you get) that you may have to do is to adjust the front derailleur's stops ... AND, of course, lower it if the outer chainring size is different.

FWIW. My old, SEDIS "narrow" chain is dimensionally the same as an 8-speed SHIMANO chain, or vice-versa ... a spitting image ... an exact copy. So, the 8-speed Shimano chain will be a good replacement for you(r bike ... or, any other 5-/6-/7-speed drivetrain) whenever you replace your chain.
 
alfeng said:
Yes, the 9-speed crank/(chainrings) will work with your 7-speed "chain"/drivetrain.

The ONLY thing (after you install whichever new crank you get) that you may have to do is to adjust the front derailleur's stops ... AND, of course, lower it if the outer chainring size is different.

FWIW. My old, SEDIS "narrow" chain is dimensionally the same as an 8-speed SHIMANO chain, or vice-versa ... a spitting image ... an exact copy. So, the 8-speed Shimano chain will be a good replacement for you(r bike ... or, any other 5-/6-/7-speed drivetrain) whenever you replace your chain.
Thanks,
Harris Cyclery has the Shimano 4550 that I would also need to by bottom bracket for, they also have a Stronglight with 36/50 that it looks like I could use the existing bb, any thoughts? I have never heard of Stronglight.
 
drbaize said:
Thanks,
Harris Cyclery has the Shimano 4550 that I would also need to by bottom bracket for, they also have a Stronglight with 36/50 that it looks like I could use the existing bb, any thoughts? I have never heard of Stronglight.
Stronglight is (or, was) a very good brand ...

AND, I would reckon that the odds are VERY high that the particular crank requires a CAMPAGNOLO-compatible, square taper BB spindle ... not the one that you may have on your bike if you have a SUGINO or SunTour crank, but one that is both symmetrical AND shorter (i.e., 102mm ... intended for Record & Chorus cranks). Maybe not.

The last time I looked (not that recently), a USED, square taper, 102mm Campagnolo BB seemed to be almost as expensive as a new one -- consequently, YOU WILL WANT TO KNOW WHAT BB THE STRONGLIGHT CRANK IS SUPPOSED TO BE MOUNTED ON BEFORE YOU BUY IT! There are longer, 111mm square taper Campagnolo BBs which were intended for the Centaur/Veloce/Mirage cranks.

Unfortunately, you probably won't be saving any money if you get the Stronglight crankset.
 
drbaize said:
Thanks,
Harris Cyclery has the Shimano 4550 that I would also need to by bottom bracket for, they also have a Stronglight with 36/50 that it looks like I could use the existing bb, any thoughts? I have never heard of Stronglight.

Agree with alfeng that your best deal is the Shimano 4550 or the Truvativ (or FSA) rather than the Stronglight, although Stronglight is a good brand.
 
John M said:
Agree with alfeng that your best deal is the Shimano 4550 or the Truvativ (or FSA) rather than the Stronglight, although Stronglight is a good brand.
Thanks,
I will check into the bottom bracket for Stonglight then make my decisions.