Originally Posted by
Jeff Wills
It's an unusual combination because it probably won't work well. For the chain to upshift from the granny to the middle reliably, the chain has to get caught by the middle without coming into contact with the outer ring. The 50-36-28 might work... the 50-34-30 probably won't. With the latter combination the chain will shift from the inner to outer chainring, bypassing the middle.
IMO, it would be better to install a larger middle chainring, something appropriate for the majority of your riding. I've been pretty happy using a 38 or 40 tooth middle chainring with a 11-34 or 12-34 9-speed cassette. With a 48 tooth outer I'm able to to do most of my riding on the middle and outer rings. I have a 24 tooth inner ring for when stuff gets super-steep.
110mm bolt pattern rings are available from Origin8:
https://www.amazon.com/Origin8-Alloy...dp/B002G363XM/
I haven't tried them so I don't know how well they work. Like RCCARDR, I have a box full of used chainrings in various states of wear.
Originally Posted by
rccardr
I was trying to stay away from suggesting actual ring sizes, but my experience has been similar to yours.
A 50/34/24 did not shift well for me. Lots of skating up and down, not very reliable from ring to ring even with correct chain line and several different triple FD's.
Migrated to a 48/36/24 (12 tooth spacing) and that has worked well on several bikes. Right now only have one bike with a triple- the 83 Davidson Discovery- and that shifts well with that combination.
Jeff, thank you for your advice on the 50/34/28! I like your suggestion of a 48 outer, but I'm somewhat limited since I have a 7 speed 14-28 freewheel. I spend most of my time on the 50/18 or 16. The 50/14 is usually plenty, although I do spin out occasionally. I would love to upgrade my wheels to a cassette so I have more options, maybe someday.
rccardr, I appreciate you confirming what Jeff suggested, and thank you for your recommendations. Both of you have been very helpful, and I am glad you guys took the time to respond. I have one last question. You mentioned 12 tooth spacing as being your preference. Is having at least 12 tooth spacing more important between the inner and middle chainrings? I have friction, so I was thinking I would just adjust as needed. Although, I haven't seen any with a 34/28, so based on what you've told me, I need to toss that idea. I have seen some 36/28 as Jeff said, but will need to look into how well that works.