Originally Posted by
stilllearning
Hi,
This topic has been discussed numerous times, and I have looked through the various threads on lowering the gearing, but I need some clarification on a couple of things.
Here is what is on my 86 IM now:
50/34 with a 7 speed 14 – 28
Shimano 600 FD/RD
The current set up works well, but I want lower gearing for some of the steeper climbs. I could use a 7 speed Shimano Megarange, but that jumps from 24 to 34, and I would lose the 28, which is fine for a lot of my climbing. So, it seems the least expensive way for me to lower things is to go with a triple crank.
What I have learned will work:
A 110/74 BCD triple that is square tapered, or a 110 BCD Sugino or Sakae double drilled w/74 holes.
I’ve read that those triples need a BB that is a 3U 124.5mm measuring 32-52-40.5. Thanks to Sheldon Brown’s site, I now understand what those numbers mean.
Here is what I need clearer information on:
Are there other makes of triples that would work with my 7 speed?
If so, would those need a different BB than the 3U 124.5mm?
How difficult is it to find the 3U 124.5 BB? I've looked around a little, but haven't seen any.
I’ve read that the 600 FD will work with a triple, I’ve also read it will not. Which should I believe?
Is my 600 RD okay for a triple? If not, I have a Suntour V-GT Luxe I could use.
Will my shifters, currently set up as friction, work with a triple?
I’m sorry if these questions have been answered before, but after going down the rabbit hole of all the possibilities, I think I have finally settled on something that is doable for me. This forum has been a fantastic resource already, but any extra advice anyone can give me will be greatly appreciated!
Brian
The 600 FDs I have shift triples. I think I had a how to on this thread at the start of the virus crisis that determined the 600 RD would run a 28T sprocket, but not a 30.
Just my opinion, but a triple and a 12-28 7 speed is a great combo to run. 2t jumps through the 18. 3t between the 18, 21, 24 and a 28t as well. You don't have to have a long cage RD. That's a sweet combo.
For those that say, "I don't need an 11 or 12t sprocket," it works great with the middle ring. I think the main advantage a triple has over a compact is it gives you more options to jump around and find a gear that works on days when something is off.