Sugino Cycloid
 

Cleaned up the crank on an '85 Nishiki Cresta GT, all looks good and it appears to have had relatively light use. Anybody have any experience or opinions on Sugino's version of oval rings...the Cycloid? Interestingly, the large ring is silver (and round), while the two smaller rings are anodized bronze, like the rims are.

Should the arrow on a chain ring point to the crank arm or away from it? I know I should have noticed this during dis-assembly, but apparently I am not that smart!

The triple is a 48/40/28, and the freewheel is a Suntour Pro-Compe 14/17/21/26/30. The freewheel cleaned up nicely, spins quiet and smooth, and shows little wear. The bike is destined to be a commuter in Seattle, so I'm hoping this gear range will work well.

http://i.imgur.com/5AvwIFd.jpg

http://i.imgur.com/N8fHMZq.jpg

http://i.imgur.com/Euo5nkD.jpg

http://i.imgur.com/dIOhPto.jpg

http://i.imgur.com/qYTHDjl.jpg

http://i.imgur.com/zRTCPml.jpg

http://i.imgur.com/KvvLYoi.jpg

http://i.imgur.com/W7vGpnl.jpg

Looks like a PO did away with the cycloid version of your big ring. See this link. Regarding the arrows, these are interestingly different than bio-pace rings. I just checked a bio-pace triple I have, and they have a little protruding "key" between the bolt holes that is to be lined up behind the crank arm. Someone probably knows better than I do, but logic would dictate here that since the arrow is on a bolt hole (rather than between two bolt holes), that it should be placed on the bolt hole that is in line with the crank arm.

Since this might be your next question (I've asked it myself): http://www.bikeforums.net/showthread...Can-I-mix-them

Good luck with your rebuild. I have a buddy who LOVES his Nishiki Cresta, and I like anything with the phrase "GT" in it--esp. bicycles and cars! Like to see a photo when it's all back together.

I have an 89 Schwinn Impact with a Sugino Cycloid triple 28/38/48. The big ring is also a plain round ring and was specified that way in the catalog. While I like Biopace, I don't care much for the Cycloid, even though it is said to be a Biopace copy. It seems to me like the transition is much more abrupt with the Cycloid.

Well, there you go. Guess they made it in two versions (all three ovoid, and with a large round)? I checked on velobase and couldn't find a mixed one.

I have riden these and really did not like them they tend to give a feel like your riding over washboard road on flat ground. On the bikes I have rebuilt with these I changed them out for normal round Sugino chainrings.

I am currently restoring an '85 Nishiki Cresta GT and I pulled the Cycloid rings off as quickly as I could. I even tried to sell them to my local bicycle co-op (which is what I do with any parts that I have no use for) and they found them novel, holding them up to the light and commenting, loudly, on their oddity. After their trip down memory lane, they tossed them back in my pile and stayed far, far away from them. I am replacing mine with regular, round Sugino rings (as soon as I can find some for a fair price).

I forgot to mention the proper psition for these chainrings. Which would be at the bottom of a recycling trash bin get some round normal chainrings they bolt right on to these cranks and good used ones are fairly cheap. If you can't find some PM with the BCD's teeth size and I will sell you couple at a good price

Best picture I have of a cycloid from a Nishiki I sold a while back. Hope this helps out.

http://i482.photobucket.com/albums/r...y/DSCN0580.jpg

Dang, Matt, you seem to have all the odd sh_ _ I'm in need of...we could have combined shipping!

Thanks for all the replies, especially the negative ones which make me rethink what's going on this bike. I'll send you a PM, Matt, to see what you have in a 40 and 28 size. The distance between bolts on the small one is 44mm, on the 40 teeth ring it is 65mm. Sorry I don't know how that translates into BCD!

Question for everybody: With a Suntour Pro-Compe 14-30 freewheel and a 48t large ring, would using round 40t and 28t rings, as original, still be a good choice?

Thanks again!