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Drop Bar MTB drive train options

2oldnslow2oldnslow Posts: 313
edited December 2010 in MTB workshop & tech
Hi,

after a number of years riding exclusively on the road I recently had 2 weeks in Cyprus with a hired Orange Gringo MTB and thoroughly enjoyed exploring the island off road. So much so that for my next holiday there I'd like to take a bike suitable for day long rides both on and off road. I was looking at a Salsa Fargo until I came across the Singular Gryphon and thats what I plan on buying in the New Year.

The Gryphon like the Fargo is a rigid 29er based designed to use an off road drop bar and I'll go with either a Salsa Woodchipper, On-One Midge or Radly Luxy. Rooting through my parts box I've found pretty much a whole 9 speed drive train I'd like to use comprising of 9 speed Dura Ace STI's (7700 series I think) 9 speed long cage Dura Ace RD (7700GS) and a Middleburn RS7 chainset. The chainset is currently fitted to my SS road bike and running a 50T ring but I would either fit a 24/26 inner 36/38 middle and use a cx chainguard in the outer ring postion or change the spider to a duo and going 27/39.

I think the Dura Ace mech should be good for up to a 28T cassette but I'm wondering if I could push it to a 32? The hills in Cyprus are decidedly alpine in places. In any event a new MTB rear mech will do the trick if I can't use the existing DA one so I'm not overly concerned there. Would a shadow rear mech do the trick?

As for the front shift I understand using road STI's with an MTB FD is a problem so am I best going for a new road FD if so would one designed for a compact c/set be best? I've seen the SLX M665 which is designed for small ring double chainsets would that be an option? I don't have a clamp on FD at the moment so will have to buy new anyway but working in the Middle East all my shopping is on line so I need to make sure I get what I need and will work.

I'll be using Avid BB7 road mechanical discs 185F 160 R and for wheels I was thinking Stans Arch on 32H Hope hubs DT comps or supercomps any comments? I'm about 85kg but ride light and in any event this is more off road tourer/gravel grinder than full on MTB so I won't be throwing myself down any massive drops. Might stretch to DT hubs or happy to take suggestions. Budget is flexible.

Thomson seat post and stem my trusty Arione and I should be good to go but any ideas suggestions would be much appreciated particularly with respect to the front shift.

Thanks in anticipation.

Posts

  • nicklousenicklouse Posts: 50,675 Lives Here
    Front mech for 2 rings it does not really matter. you have enough clicks on the shifter to get it right.

    rear mech MTB version needed.

    for buying questions try the buying section :wink:
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Sorry to sound a bit obtuse, but aren't you just describing a 'cross bike?
    Commute: Langster -Singlecross - Brompton S2-LX

    Road: 95 Trek 5500 -Look 695 Aerolight eTap - Boardman TTe eTap

    Offroad: Pace RC200 - Dawes Kickback 2 tandem - Tricross - Boardman CXR9.8 - Ridley x-fire
  • well in as much as it's a drop bar bike running 2 chainrings

    but if you take a peek here http://www.singularcycles.com/gryphon.html it's definately more off road biassed than an average cross bike mind you I've taken a genuine cross bike to the top of Skiddaw so I guess it's not exactly black and white.

    What I want to do is use road STI's but have gears that will get me up the sort of hills you get in Cyprus where I plan to move in the near future. Could use a road compact chainset and 11-27T cassette, but 34/27 with 29 inch wheels isn't going to cut it slogging up 10 km of 9% dirt road. At least not with my legs. Hence my thinking 24/36 or 26/38 on the front with a 11-28 cassette using road front and rear mechs changing to an mtb rear mech if I need to go bigger than 28 on the back. My only slight concern was the front shifting but with only 2 rings and a 12 tooth difference just about anything should work I guess.
  • The RookieThe Rookie Posts: 27,802
    If you are worried about climbing why not get

    11-28T rear cassette (Shimano and SRAM both do it as well as the like of BBB and Suntour) 22-36 front to keep the lowest granny?

    2x10 setups have upto a 16T jump between front rings so you should be able to get a mech that will do that 14T.

    Simon
    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
  • nicklousenicklouse Posts: 50,675 Lives Here
    but on a 29er would not the 36-11 (10spd) work better?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • well 22 inner is out on my RS7 chainset as is because with a 74/110 spider 24 is the smallest chain ring I can fit. On a 29 this gives about a 25 inch gear. That's roughly the same as a 24T sprocket on the 22T granny of a typical MTB triple. At 61 even though I'm fit I need lower if I'm going to be riding up hill for an hour or so which in Cyprus is likely on most of my rides. Just checked on the Middleburn site though and the CD spider will take down to a 20T inner so that could be the answer thanks. 11-36 would be fine except my shifters are 9 speed. So I think I'll go 22-36 on the front as suggested 12-28 on the back. A low of just under 23 high of 87 should be enough and I can always get fitter.
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