Forum home Mountain biking forum The Crudcatcher

MTB mechs ona road bike - will it work?

YeehaaMcgeeYeehaaMcgee Posts: 5,740
edited August 2012 in The Crudcatcher
So, I'm rather dissapointed with the crappy quality of roadie mechs, after only 260 or so miles the front mech has pretty much seized up, and the weak spring on the rear mech means I constantly have to adjust the indexing since the slighest cable drag messes it up. Seriously, it's like riding a bike from the dawn of indexed gears again.
The ones on the mountain bikes are as good as bulletproof, in all weather, all conditions, and covered in virtually any amount of mud.

So, I was thinking, since the roadie is a 10 speed, with a dual compact chainset, are there any MTB mechs that I could use?
Currently has Shimano Tiagra shifters and mechs.
«1

Posts

  • t.m.h.n.e.tt.m.h.n.e.t Posts: 2,265
    Any long cage 10spd would be suitable. http://www.chainreactioncycles.com/Mode ... elID=67252 for example.
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    Ok, cool. What about front mechs?
  • njee20njee20 Posts: 9,613
    No it won't, you need a 9 speed MTB mech, but then yes, any 9 speed MTB mech will work with 10 speed STIs.

    Suggest you've probably been unlucky though, the Tiagra rear mech on my winter bike is now 3 years old, I've cleaned the bike twice in that time, and it's spot on.

    Front mechs will be problematic, they're a very slightly different cable pull, and the radius of the cage is far larger. Suggest buying a new/better front mech is a better way to go.
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    Ah, censored . Cheers, Njee.
    My understanding is that Tiagra is roughly equivalent to Deore, is that about right? I am shocked at how bad th eshifting performance has been. I expected a little cable settling, but not this much.
  • t.m.h.n.e.tt.m.h.n.e.t Posts: 2,265
    njee20 wrote:
    No it won't, you need a 9 speed MTB mech, but then yes, any 9 speed MTB mech will work with 10 speed STIs.

    Suggest you've probably been unlucky though, the Tiagra rear mech on my winter bike is now 3 years old, I've cleaned the bike twice in that time, and it's spot on.

    Front mechs will be problematic, they're a very slightly different cable pull, and the radius of the cage is far larger. Suggest buying a new/better front mech is a better way to go.
    Why would you put a 9spd mech on a cassette with 10 gears? That would make 1 gear impossible to reach no?

    105 front mech would be the next upgrade point. Then Ultegra and Dura-ace
  • njee20njee20 Posts: 9,613
    Why would you put a 9spd mech on a cassette with 10 gears? That would make 1 gear impossible to reach no?

    No. On Shimano the cable pull is the same for 9 speed MTB and 10 speed road, as the cassette is the same width it's fine. It's only 10 speed MTB which is unique.

    On SRAM their 9 speed stuff is different to 10 speed road or MTB - which are interchangeable.

    Tiagra = Deore yes, then as above: 105, Ultegra, Dura Ace. 105 or Ultegra are noticeably nicer IMO, and front mechs needn't be expensive, may be worth getting an Ultegra one, that does seem bad though!
  • t.m.h.n.e.tt.m.h.n.e.t Posts: 2,265
    njee20 wrote:
    Why would you put a 9spd mech on a cassette with 10 gears? That would make 1 gear impossible to reach no?

    No. On Shimano the cable pull is the same for 9 speed MTB and 10 speed road, as the cassette is the same width it's fine. It's only 10 speed MTB which is unique.

    On SRAM their 9 speed stuff is different to 10 speed road or MTB - which are interchangeable.

    Tiagra = Deore yes, then as above: 105, Ultegra, Dura Ace. 105 or Ultegra are noticeably nicer IMO, and front mechs needn't be expensive, may be worth getting an Ultegra one, that does seem bad though!
    Thanks for clarifying :)
  • nicklousenicklouse Posts: 81,520 Lives Here
    shimano front mechs can work but the cages are often the wrong shape as the road rings are much bigger.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • njee20njee20 Posts: 9,613
    If only someone had said that already ;-)

    Are you sure it's not the cables incidentally? 260 miles really is terrible, that's 2 weeks of moderate riding. The (admittedly Dura Ace) one on my Madone is nearly 9 years old and I've never touched it.
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    The rear indexing seems to stem from cable issues - there's a little bit of censored on the cables, but nothing I would even have noticed on the MTB.
    The front mech has seized - it actually requires considerable effort to move it inwards (towards the smaller ring) even with my hands.
    It's only about 2 and a half weeks old. The LBS told me to bring it in 6 weeks after buying it to get a routine service, re-check spoke tension etc. But at this rate I can't see it being rideable in that time!
  • njee20njee20 Posts: 9,613
    That's definitely not right, suggest there's sommat else going on there!
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    I can't see any defect with it, or anything jammed. The annoying thing is, I only use the small ring for one particular hill right near the end of my 17 mile ride home from work - I can just about get up it in the 52-tooth, but it requires almighty effort, which I usually havent got the energy for at that time!
    And, because it's that one hill where it sees use, I've often forgotten about it until the last minute when I think "OH BOLLOCKS!"

    Interesting abotu the 9-speed Shimano stuff working fine. I'm surprised that all the Shimano road mechs still have that odd loop of cable, and haven't adopted the Sachs style shadow arrangement.
  • Chunkers1980Chunkers1980 Posts: 8,035
    Adopt it and put a medium shadow mech on (9spd of course)

    Seems odd about your front mech, as it's summer. I'd give it a good soak of WD 40 over night and take of and clean and put some proper lube on the pivot points.
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    Why a medium cage? the one that's on there now is a short cage (naturally).
  • nicklousenicklouse Posts: 81,520 Lives Here
    to the LBS and get them to sort the brakes as well.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • njee20njee20 Posts: 9,613
    and haven't adopted the Sachs style shadow arrangement.

    Mainly because of cable routing on road frames, having the loop means it works with anything, more awkward if you need a straight entry. That and roadies are immensely adverse to any change!

    Can't get short cage Shadow mechs (other than Saint?), only GS (mid) and SGS (long).

    As an aside, it'll almost certainly be a 50t ring unless you've changed it.
  • Chunkers1980Chunkers1980 Posts: 8,035
    Why a medium cage? the one that's on there now is a short cage (naturally).

    As what's actually available, not much call for short mechs in xc mtbs.
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    Ah, yes, you're right, no short cage XT - but there is a Saint.
    Nick - you can hear my brakes squal from there? :lol: - I filed the pads, they were ok.
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    Adopt it and put a medium shadow mech on (9spd of course)

    Seems odd about your front mech, as it's summer. I'd give it a good soak of WD 40 over night and take of and clean and put some proper lube on the pivot points.
    Summer :lol: Yeah, whatever!
    Actually, whilst I've had the bike, it's not been too bad. The weather was cataclysmic last week, so I did't ride after Tuesday.
    Which is what's bothering me. I've just been out to give it a clean with some WD40, the only thing I have to hand at work (It's a slow day at work thankfully, after the stressful chaos earlier in the week), and it's now a bit more free moving, however, there's not much crud on it, certainly not enough to warrant concern.
    There's more censored on an MTB mech within the first 30 feet or so of an off road ride, and I've luckilly never had one of those seize on me until they're rusted to all hell and back.
    Most strange.
  • Chunkers1980Chunkers1980 Posts: 8,035
    I was meaning more that there will not have been grit, you live in Wales, so rain is given ;-)
  • njee20njee20 Posts: 9,613
    Good point, could there be a sheep stuck in it?
  • cooldadcooldad Posts: 32,904
    In Yeehaa's case, more likely to be stuck in a sheep.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    cooldad wrote:
    In Yeehaa's case, more likely to be stuck in a sheep.
    That's be the mountain bike, you dumbfukk.
  • cooldadcooldad Posts: 32,904
    Who's talking about bikes, dumbass.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    You think I can simultaneously ride a sheep and a bike?
    Dumbfukk moron.
  • cooldadcooldad Posts: 32,904
    Nope, but you can get off, get off, get on, fark off.
    Dumbass Lola.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    I think you have a thing about me. This is Lola.
    lola_character.png
  • mrmonkfingermrmonkfinger Posts: 1,452
    Ah, censored . Cheers, Njee.
    My understanding is that Tiagra is roughly equivalent to Deore, .

    Tiagra is roughly equivalent to a censored , in my limited experience of having one set and then replacing it, for similar reasons of crappy shifting.

    105 and upwards I have had no problem with, several current sets of 105 kit in our house are now 6 or 7 years and 1000's of miles old and still work very nicely.
  • rglinianyrgliniany Posts: 753
    the bike i bought had flight deck tiagra 9 speed..... they shift super smooth and have had no real issues... just need to sit and index them good and proper as the guy i got it off didnt do much in the way of upkeep..... but being in the sunnier climate of australia it seems you need to worry about grit and suchlike a whole lot less... i reckon you got a dodgy batch chainset....

    on the brake front
    i found that bbb techstop pads....(can be found at ribble) slow me up a treat....miles better than the standard pads. just saying.

    hope the issue gets sorted quick for you
    It's a boy , It's a boy , I Shouted Running Into The Street With Tears Running Down My Face.....

    That's The Last Time I Holiday In Thailand

    URL Pinkbike
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    No problem with the FSA chainset apart from flex, but I'd expected that with anything after riding Saint cranks and small chainrings on the MTB for so long.
    Brakes are fine, they just needed some filing to get some toe-in.
    Indexing isn't really the problem with the rear mech, it's just friction making it slow to move. It eventually gets there, but it's nowhere near the machine-gun changes of Shimano XT.
    Isn't flight deck a cycle computer thing? What's that got to do with Tiagra?
Sign In or Register to comment.