6

Salsa Marakesh https://salsacycles.com/bikes/marrakesh/2020_marrakesh_sora is based in part on road Sora components and MTB Alivio components.

Let's focus on the front -- in my bike I have Sora brifters, I added MTB crankset (Acera FC-MT300) and I have MTB Alivio front derailleur (FD-T4000). To make it works I had to add jTek pull ratio converter. And with it, it works great.

And here is the Salsa -- Sora brifters as well, MTB crankset, MTB Alivio front derailleur. And that's it. No converter.

So my question is how can I simplify my setup (by removing cable converter) and make it work like in Salsa? The only difference I can see Salsa uses Alivio crankset, not Acera, and Salsa uses 48/36/26 chainrings while I have 44/32/22. I doubt the size matters here, but could it be upgrading to Alivio crankset would allow me to drop cable converter?

2
  • 1
    You're right to focus on the front - the back is easy. I've mismatched Sora and Acera at the back with no trouble at all (always Sora brifters but I've borrowed the RD and/or wheel from my MTB a few times). I'm starting with a Tour de Fer - Genesis's rugged tourer with Sora 50/39/30 at the front – Chris H Nov 18 '20 at 8:13
  • One hack is to forgo indexed shifting on the front, and use a friction shifter. You lose the detents, and employ skill to set the chain. There is no Trim, instead you just nudge the lever around should the chain rub. A lateral solution that I've used on a quad chainring bike. – Criggie Nov 19 '20 at 8:24
13

I sell that bike at work. The road/mountain FD mismatch functions very badly. We've had to replace the front derailleurs with road models. The total throw of a road shifter isn't enough for it to shift well and not have rub anywhere. It's terrible.

It can be made to kinda sorta work if you accept rub in the lowest gear. But, that shouldn't be acceptable. And the adjustment is totally finicky, i.e. the exact opposite of what one would want on a bike one may have to fix in the middle of nowhere.

There is no alternate cable mounting or trick. It's just a mistake on their part.

The really unfortunate thing about their choice to spec it that way is Shimano's latter-day road triple FDs, which are designed for 50/39/30, have no trouble performing acceptably with 48t trekking-style triples as long as the middle to large minimum tooth difference is respected. I believe the 22t total difference on a 48/36/26 pushes past the printed max total difference to do this on every pertinent model, so maybe that's why they consider it off-limits, but I've never seen that be an issue in practice, and if it was an issue, all it would amount to is chain rub on the bottom of the cage in small/small.

For a 44, you really need a mountain FD. The profile of a cage intended for a 50 will leave you with an overly large gap at the tail even with the FD down as far as possible, which in turn will cause iffy performance because of the limited contact made with the chain during shifts, as well as some risk of derailment from the excess gap.

There is a milieu of questions one can ask about making STI work with a road FD on various not-as-intended cranks and chainring combinations. These can be difficult to answer because in a lot cases the answer is it can function to some greater or lesser extent, but with a hit in performance, and whether the result is acceptable is up to the user. If you wanted to lose the adapter but give up the minimum on your low gear, you could switch your rings to 24-36-48, along with a road triple FD, and it would probably work okay as long as the rings were good quality and ramped, but it would be noticeably chunkier to shift, and it's pretty common to need a chain catcher in that setup. You may be able to get 22-34-46, or -48, to work okay, but both can have their issues too. It's a grey area.

1
  • 1
    Thank you very much, this is my experience as well -- I mean without jTek I could force it to work, but the tolerances were minimal and some combination of gears would rub anyway. One clarification, both Salsa and my bike use MTB (not road) FD, so the size of chainrings and the shape of the FD cage work as intended. – greenoldman Nov 19 '20 at 5:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.