Originally Posted by
squarenoise
I have a Miyata 1000 as well and very curious to see how different the 610 feels. The stock chainrings on my 610 are 52/46/28, but I plan on switching to 48/36/28 and If I feel the need for more speed, I have a 50t to try out.
I see you replaced your rear derailleur. Was that a preventative move or did the original Mountech actually fail on you? I've read they can collect a lot of grime and are a major pain to service, but work well if maintained?
When changing rings, for good shifting I wouldn't want the chainring size difference between the bigger two rings to be any bigger than the size difference between the two smaller rings.
Actually better when it's the other way around, especially with older, plain chainrings w/o pickup pins ( and why half-step chainrings give better shifting to and from the middle ring).
Mine came from Goodwill with the Shimano derailer shown, I added indexed 6s levers mounted on a Huret clamp, using something like 10-24t coarse-thread screws, and using LocTite.
I had the 1st-gen Mountech on my '84 Stumpjumper Sport, and the big top pulley clogged up with mud early on. It was a lot of work to rebuild and I later replaced it.
Bad design because the very large diameter bushing surfaces caused high friction and rapid wear.