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  1. #1
    mad aussie
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    Titus X rear derailleur compatibility issues

    I found a couple of issues putting together my X. I am running SRAM XO running gear. A 34 big cog will not work with an XO rear derailleur when in the big ring due to the backward slant of the dropouts, the inner cage hits the 34 cog when shifting back down even with the B-tension bolt wound in as far as it will go (and yes my chain is not too short, and is even longer than I would normally run, and its a long cage derailleur). Its a bummer because this would be a combination that you would use for a 2x9 drivetrain and I was looking at running SRAM XX on the bike at some point. In addition the chain rubs on the right rear dropout when in the 11T cog, this involves removing material from the dropout to make it clear the cog. When talking to competitive cyclist they say this is common with the light rail rear end and they have to do the dremel trick with all the bikes they build.

    I called Titus early this week, they said they mostly run Shimano on their bikes and werent aware of this issue, but would check and call me back, but I havent heard from them since.

    What gives Titus? Somebody didnt do their homework and this is seriously disappointing in a $2300 frameset! On the plus side the bike does ride very well, pedals well with no propedal but I do find these issues annoying.

    Kevin

  2. #2
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    Flying Wombat, I think Titus seriously needs to redesign the dropouts on the X for several reasons.

    1) There is a possible shear tear out fatigue failure problem because of poor hole location of the replaceable derailleur hanger hole. (This hole location is a poor choice for Horst Link bikes because of the bending moments on the Horst Link caused by maximum chain tension and maximum acceleration of the rear wheel. Titus needs to move the hole back to where it was or place it behind the axle.)

    2) Their looks to be a stress riser problem where the carbon seat-stay enters the aluminum dropout causing the carbon seat-stays to break.

    3) And now your problem where the dropout doesn't appear to properly fit the SRAM cassette and long cage derailleur.

    With all this being said I am sure Titus will have all these problems addressed by 2009 interbike. (Hint, Hint!)


    Sopwithcamel

  3. #3
    Hueston Woods Trail Crew
    Reputation: Bikerbob.com's Avatar
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    Will investigate

    Quote Originally Posted by Flying Wombat
    I found a couple of issues putting together my X. I am running SRAM XO running gear. A 34 big cog will not work with an XO rear derailleur when in the big ring due to the backward slant of the dropouts, the inner cage hits the 34 cog when shifting back down even with the B-tension bolt wound in as far as it will go (and yes my chain is not too short, and is even longer than I would normally run, and its a long cage derailleur). Its a bummer because this would be a combination that you would use for a 2x9 drivetrain and I was looking at running SRAM XX on the bike at some point. In addition the chain rubs on the right rear dropout when in the 11T cog, this involves removing material from the dropout to make it clear the cog. When talking to competitive cyclist they say this is common with the light rail rear end and they have to do the dremel trick with all the bikes they build.

    I called Titus early this week, they said they mostly run Shimano on their bikes and werent aware of this issue, but would check and call me back, but I havent heard from them since.

    What gives Titus? Somebody didnt do their homework and this is seriously disappointing in a $2300 frameset! On the plus side the bike does ride very well, pedals well with no propedal but I do find these issues annoying.

    Kevin
    I am building a medium X this weekend and will look at your issue. I normally wouldn't use the big/big combo, but I know it is used by racers sometimes.
    I plan to use an X9 but should be the same. Let you know what I discover.

    Also, I have contacted Jeff and Chris at Titus about your issue.

  4. #4
    mad aussie
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    Thank you Bob for your help here. Yes I know you shouldnt big/big under ideal circumstances, but in a race situtation if you hit a short rise when hammering in the big chainring you will shift down and get out of the saddle to maintain momentum, especially if you are running a 2x9 with a 44/29 front combo. It clears just fine in the smaller chainring or if running a 32 small rear cog.

    Kevin

  5. #5
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    Similar but different FYI. Shimano low normal xt rear works very poorly. Makes huge contact with the rear dropout in lower gears with b tension maxed. Shadow xt looks to be the ticket. No problems with chain/cassette clearance. This on on an 08 racer x.

  6. #6
    txn
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    chip

    It sounds like your rear-d isn't set up correctly on your racer-x. I've been running low-normal on my 07 ML2 without issue. It will bang the dropout on a big hit, but that's a known issue. When properly tuned it shifts great and does not rub the dropout.

  7. #7
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    Txn, thanks. Mine shifted great but there was minimal clearance when in the larger gears (small cogs, had it backwards above). It would not hit until the trail got rough, but the clunking got old quickly and the the derailleur and drop out were beginning to be marred. Supposedly there is a way to modify the spring tension beyond the b tension adjustment screw, but I was unable to find this. At first maxing b tension worked but then the spring seemed to weaken and the derailleur was back to tucked right up near the drop out. Installed a shadow yesterday and looks like it will do the trick. It looks as if it was designed for full suspension bikes. Seems to shift well with the dual control levers. Not sure if I will like the reversed shifting pattern, but had grown very tired of the thwacking noise on my regular trails. It would be interesting to see if a modified hanger with a greater rear biased angle to the b tension stop would help. I like dual control a lot. The flick up, to shift into a lower gear from out on my ergons is a nice climbing feature. Hopefully I can adapt to the down motion now.

  8. #8
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    34 cog on FTM light rail

    What goes for the X also goes for the FTM
    Large FTM - usually run 11- 34 rear cassette - yes I know shouldnt really need such a big cog but I guess we are a little different down under !
    Mounting X9 long cage RD had exactly the same prob - had to change to 11 - 32

    Nice to hear some changes maybe on the cards - ? will Titus do deal to retrofit back to 09 FTMs and Xs ?

  9. #9
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    mw04snow........ This will be a good test to see how well Titus responds to rider feed back. The changes we are asking for here aren't huge. But I will add that the rear dropouts are the toughest part of the mountain bike to design because of all the requirements and specifications they have to meet.

    Sopwithcamel

  10. #10
    K n e e m o i
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    Long cage X.0, PG991 chain, 11-32 XT cassette.

    No problems
    "Prison sports are really fun. I get used as a frisbee, a dartboard, and a second base!" - Kneemoi

  11. #11
    mad aussie
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    "Long cage X.0, PG991 chain, 11-32 XT cassette.

    No problems"

    Its fine with an 11-32, its the 34 that causes the derailleur to catch. A 34 is a common combination with a 2x9 drivetrain. Currently I have it set up with a triple and a 11-32 and its fine. The 11 rubs the dropout in the stand, but after a little dremel work with sag it runs smooth.
    On the bright side I rode the bike 30 miles today and I have to say the thing that stands out is how the rear suspension doesnt stand out. No boborama without propedal that saps small bump sensitivity, no mid stroke wallow, no end stroke harsh ramp up, no stiffening under braking. It just works consistently and unobtrusively letting you focus on riding the bike.

    Kevin

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