Ultegra 6700 group set
Small chainring in front is a 30t (50t/39t/30t)
Large cog if the cassette is a 32t
So, better to reduce the size of the front chainring
OR
Increase the cassette size and make the derailleur reach using a Wolftooth derailleur extender etc?
What would integrate best and result in a better result?
First hand experience from anyone who has done this would be vastly appreciated.
by Nugginz
7 Comments
I should add, the climbing gear is for fully loaded wild camp touring in the hills of Wales and Scotland so I really need that granny gear, don’t judge!
The cheapest and best option IMO would be to install a 9-speed mountain derailleur and a 36t cassette.
Specs for your rear derailleur are here: https://si.shimano.com/es/pdfs/si/5X90A/SI-5X90A-002-ENG.pdf
Your 32T cog is already 4 teeth above nominal capacity, dunno how much more you could actually get with the wolf tooth. Unless you find a reference of someone doing exactly whatever you want to do, I wouldn’t bet on much. Unless it’s not actually 6700, in which case you’ll have to figure out what it is and look up the specs.
Since you have a triple, it must be FD-6703: https://si.shimano.com/en/pdfs/si/5LX0B/SI-5LX0B-001-ENG.pdf
Unless the FD is actually 105 (FD-5703) rather than Ultegra… The Ultegra one states it needs AT LEAST 13T difference between the biggest and middle chainrings, but you’ve only got 11T, which is the 105 spec. Please check!!!
For either spec, you can’t get a smaller inner chainring without shrinking the others, so a new crankset/chainset is probably needed. Good opportunity to think about your bike fit / crank length…
I would suggest figuring out what the lowest “highest gear” ratio you’re willing to end up with is, and getting a new set with that as your biggest chainring, with the smallest whatever is the 22T or 20T spec below that. If you’re not much of a roadie/race cyclist, this probably doesn’t matter though.
Even if you do have the FD-6703 working with 11T difference between intermediate, I would not assume that it working for 50/39 means it will work for something like 40/29, and so would recommend buying a set that is within spec.
If you’re not at all concerned with your top speed / highest gear, then just figure out what you can buy for the other two that’s in spec for 24T. Probably not much need to look at smaller than that, but 22T is an option I guess.
Probably a good idea to go check the exact model numbers and then report back!
What is the (I know) about? Croix de fer has a bad rep?
I run a 48-36-24 crank pretty much everywhere. I think lowering your 30t inner chainring to a 24-28 tooth range is your cheapest simplest option. I don’t think you’d have too many chain wrap issues (chain being too slack) unless you shift into the tinies diameter gear combos.
30t granny can be swapped with a 24t granny, both are 74mm BCD. This will exceed your chain wrap capacity even with a MTB RD but if you are careful about cross shifting and only use the lowest rear gears while in the granny, then it won’t matter in actual practice.
If you need a lower gear than 24t back to 32t, then I’d consider getting a different crankset entirely, maybe something like a 44/32/22.
You could move to an 11-36t cassette as well (along with a MTB RD) but that’s going to exasperate the risk of bad cross chaining, as you’d have to resize the chain for the worst case scenario big-big combination, and that makes the chain longer, which means even more slack to take up, which means fewer usable gear combinations in the end before the chain goes completely slack.
There is absolutely no reason to use a Wolf Tooth Road Link and even larger cassette here unless you decide to drop the 3x and switch to a 2x or something.
buy a grx400 rear derailleur and you can get a 11-40 cassette