Roadies_Rok

I just bought a Litespeed Arenberg circa approx. 2002 or so and I am making adjustments to my new bike to better set it up to suit me. The bike has a full Campy Centaur (which I understand was also Daytona) 10-Speed group and I want to change the large front chain ring from the 53T which it now has to a 50T which is better suited to the riding I do and I am having a heck of a time finding a chainring. I will add that to the best of my knowledge the Centaur chainring has a 135mm BCD.

Is there indeed a 50T chainring available in a 135 BCD for my bike? Does Campy make one? Is there an aftermarket manufacturer making Campy compatible chainrings for a 135 BCD. I have looked on several web sites and so far I am not having a lot of success.

Also, the cassette and chain appear to be fine and are shifting well. They were dirty especially the cassette but I cleaned the cassette and lubed the chain and it is doing well. I understand that aftermarket cogsets like SRAM and aftermarket chains like KMC and SRAM will work on my Centaur 10-speed setup. Is this correct? Is a special lockring tool needed for the cassette or will the Park FR-5.2 lockring tool work? Thanks everyone.

Andrew R Stewart 

I know of no optional rings that fit the 135 pattern with a 50T count. (Not that I am any 135 ring expert). However for a bit more there is a solution that also opens up your future choices. Change out the crankset to one with a more available bolt pattern, will require a new BB. As the LH shifter is an Ergo with no specific indexing issues most any ring to ring spacing crankset will be compatible.

I run a few different mid 1990s Shimano triples (and use to run a few doubles) with Ergo (G spring loaded) shifters with no issues. My large rings are either 46 or 48T with middles of 34 or 36T. I have both 8 speed and 9 speed speced frt ders.

This is the beauty of the original Campy ergo design, wide compatibility for the front. Andy

70sSanO

It is not a 50t, but with a few more donuts you can make it feel like a 50t...

https://www.ebay.com/itm/Vintage-Spe...QAAOSwSz1ezWge

I saw a 49t, but not sure if it would be compatible.

John

Andrew R Stewart 

https://www.peterwhitecycles.com/ta-...s.php#nerius10 Have you looked at Peter White's TA offerings? Andy

blamester

Might be easier to a get cassette with bigger sprockets and change the gearing that way. If they can be got. Or custom build one.
So a 50/11 is quite close to a 53/12 for example.

CyclingFool95 

I use a Stronglight Impact compact Crankset. I used to use it with 8 speed Chorus, now with 10 speed Chorus. Requires a JIS BB spindle. A Shimano UN-55 works well and is cheap.

Drew Eckhardt 

Yes

Campagnolo made them for triple cranks, although alignment between pins, ramps, and truncated teeth with your 39T ring could impair shift performance.

Specialites TA sells 135mm BCD 50T rings.

https://www.peterwhitecycles.com/ta-...ings.php#vento

Stronglight may too.

Cassettes don't interchange. Campagnolo has 8-spline freehubs while Shimano uses 9.

While you could use a different chain you don't want to. Campagnolo uses harder steel so they're longer lasting than all other brands except Wippreman.

I get to 4,500 miles without reaching 1/32" of elongation over 11". I replace my chains at that point due to slower shifts to my big ring because lateral wear has increased flexibility. Probably not coincidentally, that matches the Campagnolo specified between rollers measurement limit.

I have 25,000 miles on my current cassette but expect to replace it with my next chain.

You need a Campagnolo pattern tool like the Park FR-11. IceToolz makes one with 1/2" square drive for a torque wrench. While the same spline count with apparently matching major and minor diameters, Shimano cassette tool splines are narrower and you don't want to chew up your campagnolo lock rings.

I still run 10 speed because Campagnolo does not make 11 speed with 13T starting cogs, and no one sells an attractive carbon fiber 110/74mm BCD triple crank that would make 11 speeds with a 12T first position cog work better for me than 10 and 13T.