Viewing 17 posts - 1 through 17 (of 17 total)
  • Shimano road/mtb shifting compatibility
  • timbur
    Free Member

    Afternoon all,

    I'm building my old Roadrat up for my dad as he wants something a bit faster than his MTB but with the capability of venturing off into the woods as he does a lot with the National Trust.

    Can anyone help me in the shifting department? I've got a Truvativ triple road/cx crank I was going to throw on it with a Ultegra triple road mech. Can I use MTB 3 speed bar top shifters as I don't want to put drops on it. Obviously I won't get the half shifts you get to trim the chainline but will this be a problem?

    If not what 9 speed options do I have?

    It's meant to be a cheap build as well :O)

    Cheers

    Tim

    cynic-al
    Free Member

    I think mtb shifter needs mtb mech and vice versa, certainly was previously.

    Mister-P
    Free Member

    If you want to run a road triple with flat bars the way to do it properly is use SL-R440 9 speed flat bar shifters with an FD-R443 triple flat bar specific front mech.

    Fresh Goods Friday 696: The Middling Edition

    Fresh Goods Friday 696: The Middlin...
    Latest Singletrack Videos
    Mister-P
    Free Member

    You could of course use MTB equipment with a 48/36/26 chainset to get a bit higher gearing.

    timbur
    Free Member

    All sounding expensive :Oo

    Bugger.

    one-eyed_jim
    Free Member

    If you want cheap, look for an old friction thumbshifter on eBay. Fancy ones fetch a lot of money. Those from the lesser groups often work just as well, and sometimes go for peanuts, especially if it's just an odd left-hand one.

    They may not be quite as ergonomic as Rapidfire, but they're infinitely trimmable. It just depends whether the looks put you (or your dad) off.

    breatheeasy
    Free Member

    As road triple is something like 30/40/50 and the trekking/mtb version is close (ish) at 26/36/48 I'd say try a cheapo mtb front mech with your road chainset first.

    Yes, it will no doubt offend half STW and probably not be 100% perfect shifting but it's probably your cheapest option to start.

    If your dads gonna just bomb round in one chainring then it's probably a nobrainer.

    I've ran double mechs on a compact when it specifically said it wouldn't work and I'd die horribly and to be honest it's pretty good so I've just extended the logic a little here….

    PeterPoddy
    Free Member

    Now, here's me thinking if it's 9sp, it's 9sp and that's it, road or MTB, and it all works together?
    Certainly downhillers use MTB shifters and roadie rear mechs….. I can't see why front shifting would be any different. Surely the chain is the same, so the chainring spacing is the same, so the shifters will be the same?

    timbur
    Free Member

    PP – road shifters have a half shift every gear to take up the trim. Not sure why that's the case on road bikes and not MTB's but hey ho.

    Saying that I've not ridden 9 speed road stuff, only 10 speed so I might be talking out of my hat.

    Tim

    timbur
    Free Member

    I've got a triple crank and triple road mech so that's good. However I don't havea flat bar shifter which is what's going to cause the issue.

    I could throw the groupset from his MTB on I guess. That would do it and keep the cost to a minimum.

    PeterPoddy
    Free Member

    PP – road shifters have a half shift every gear to take up the trim

    OK cool, I didn't know that. 🙂

    But the chainring spacing is still the same, yes? So there's no reason you can't use an MTB shifter is there?

    TomB
    Full Member

    I've got Tiagra 9 speed drop bar shifters running an XT mech on my road bike, so I would think the rear will be compatible the other way round.

    vinnyeh
    Full Member

    It should be ok, though might be a bit stiff on the upshift- I've got an Ultegra front mech and XT shifters on my Maverick (they pretty much require the road mech), and it works ok, though it's not as slick as the front shifting on my other bikes.

    breatheeasy
    Free Member

    Hell, just chuck everything on from the MTB.

    Mister-P
    Free Member

    There is a difference in the amount of cable a road STI pulls compared to an MTB shifter so the front mech won't index properly. You can get away with a double road chainset and front mech with an MTB shifter as you can sort of set it in the middle. Triples are not as forgiving.

    MTB-Rob
    Free Member

    thought Roadrat was single speed?

    Anyway another thing to check is the cable routing! as 99% of road front mechs are bottom pull, so if cable comes form the top you well need to a wheel thing to clamp below the mech to convert the cable into bottom pull.

    timbur
    Free Member

    Roadrat's do EVERYTHING!

Viewing 17 posts - 1 through 17 (of 17 total)

The topic ‘Shimano road/mtb shifting compatibility’ is closed to new replies.