|Replacement Chainrings ??||dirthead|
Aug 2, 2002 11:21 AM
|I will be making a 75 mile ride over very hilly terrain this fall. I currently have a Shimano Dura-Ace drivetrain with 12-27 cassette and 53/39 chainrings. To aid in climbing and allow me to spin at a higher rpm, I was thinking about replacing the chainrings on my crankset with a 52/38 combination. It doesn't seem that Shimano offers chainrings of this size. What are the best aftermarket chainrings that would be available in this size range? Where would I find them on the internet??
Thanks in advance!
|re: Replacement Chainrings ??||JimP|
Aug 2, 2002 11:46 AM
|The last 38 tooth ring I saw was a SuperBe Pro. That didn't work very well because the bolt pattern caused the chain to touch the crank spyder. I see only a couple of choices - change the derailure and cassette or change to a triple front or both.|
|re: Replacement Chainrings ??||Rusty Coggs|
Aug 2, 2002 12:27 PM
|Shimano makes a 52 and there is a 38 in a 130BCD by SuginO available from www.excelsports.com I'm usin one of the 38s and it works ok.|
|Found 50/38 Chainrings||KillerQuads|
Aug 2, 2002 12:24 PM
|I lowered my gearing on my commuter bike by changing the 52/42 rings on my Ultegra crank for 50/38 rings to go with the 24/13 7 speed cassette (old Ultegra 600).
I found the 130 mm Shimano compatible chainrings at WWW.BikeMan.com
They were supposed to be Sugino, but were only stamped with the tooth size. They were good quality with cutouts in the arches and good fit. No problems with spacing, spider or chainring bolt contact with the chain, or shifting (on my 7 speed setup). There are no ramps or rivets to aid up shifting, but it shifts great regardless.
I once had to modify a 5 speed old Campy crank by filing the inner ring at 5 points were it contacts the spider to make it shift well with a 7 speed chain. I think your Dura Ace crankset will be narrow enough in the spider ends so you will not have to do this.
You will have to lower your front derailleur to match the 50T ring. I don't think you will notice much difference between 39T and 38T but a 50T will lower your top end for better spinning. I think bikes with a 53T front and 11 or 12 small cogs are over geared. For a 53T, I like a 13 small cog.
|agree with Killer||Qubeley|
Aug 2, 2002 4:14 PM
|I too feel the 53-11 is too hard, that of course is just my personal experience. Even in sprint, I can only use up to 53-12/13, and I can hit 40 mph on those.
I just changed my big ring from 53t to 50t, and felt I have more gearings that I can actually use. You really didn't lose much by go down to 50t, since 50-11 has similar gain inch as the 53-12 combo.
The 50t chainring I got is FSA Pro Road, in black, has pins and ramps. They are the same rings come with their carbon cranks. Man they look sharp! The 50t chainring is very hard to find, best way to get them is go to your LBS, and have them order it for you. Shimano 50t is only available either as Dura-Ace or 105, no Ultegra. My LBS only charge me the cost for FSA, and I paid $25, sweet.
|re: Replacement Chainrings ??||sam-g|
Aug 2, 2002 1:18 PM
|Try Peter White Cycles for unusual sized chain rings. He carries the largest range of TA Chain rings in the country. I purchased a set of TA 50/36 matched and pinned rings for my Ritchie crankset which have worked out very well. I also seem to remember a TA set designed for Shimano cranksets.
|TA Specialities chainrings!||Bikez|
Aug 3, 2002 8:03 AM
|Places like Parker International, and Branfordbike sell the TA Specialities chain rings; they range from a 38t to a 57t for Shimano&Campy! Plus they're also anodized in several colors :^)|| |