Anyone run a road derailleur on a 1x9 mtb setup?

[Reposter]

Sorry if this has been covered in the past, but an internet search has opinions all over the place; nothing solid.

Running a single chain-ring up front, is there any merit to the idea of using a road mech/cassette at the back? (general XC/trail, singletrack riding).

The idea would be to save a few grams and achieve slicker shifting, but more just to try 'something different'.

Cheers all.

 

[Tazio]

It will limit the size of your gearing at the back, but should be fine if you are running a cassette that is around a 28 max.

 

[Reposter]

Plugging some numbers into Sheldon Brown's gear calculator, it looks like there's not a huge difference between a 12-27 road cassette and, say, an 11-34 mtb, paired with a 34t ring up front.

 

[cyfa2809]

I run a road cassette on my dh bike.

An x9 mech though.

My mate had similar setup with 105 mech.
No trouble.

Im not sure how the opinions would be divided on this? :?

Your idea is spot on - perfect. Few less links in the chain, lighter mech and lighter cassette. Go for it.

 

[Reposter]

Thanks, I think I will.

Mid-high end road parts seem to be cheaper than their MTB equivalents, too.

 

[Tazio]

I completely missed the bit in the original post where you mentioned using a road cassette!

I run a 11-24 road cassette on my 1x7 bike with 34 up front, perfect as it's just my tootling around town bike.

 

[Dickyboy]

Plugging some numbers into Sheldon Brown's gear calculator, it looks like there's not a huge difference between a 12-27 road cassette and, say, an 11-34 mtb, paired with a 34t ring up front.

Not a huge difference in numerical terms - but think of the percentage terms 34t to 27t is a 25% jump in gearing 26" to 32"

 

[Reposter]

X MPH at X RPM I was comparing. You're right, though, there's likely more "real world" difference than the numbers indicate.

Still umming and erring about this. Few more parts to buy before I need to commit to a mech/cassette, so we'll see.

 

[cyfa2809]

Buy a cheapie setup if your unsure before diving in.

 

[cannondale king]

i used to run 1x9 with ultergra rear mech and 11-25 cassette on my trials bike and then 11-28 1x9 same thing ultegra rear mech on my old gt zasker worked fine with 32t front chainring on the xc bike and 28t chainring on the trials bike