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  1. #1
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    New question here. 69 vs 70.5 head angle

    I need some guideance here!! I'm considering one of two DW link bikes, the mojo and the Pivot Cycles Mach 4, but I'm not sure about one thing with the mojo, and that is the slack head angle (69 degrees). The Mach 4 is listed to at 70.8, and I ride 90% cross country in Florida on some very tight twisty single track, which is my favorite stuff! My current bike is a Stumpie FSR which has a head angle of 70.5 with a 100mm fork, so I need something that will respond at least as well as that. I have considered putting a 120mm fork on the mojo, but I suspect that may create other handling issues. This has really been driving me crazy, so please help me here!
    Thanks, RT

  2. #2
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    Quote Originally Posted by Robert Thompson
    I need some guideance here!! I'm considering one of two DW link bikes, the mojo and the Pivot Cycles Mach 4, but I'm not sure about one thing with the mojo, and that is the slack head angle (69 degrees). The Mach 4 is listed to at 70.8, and I ride 90% cross country in Florida on some very tight twisty single track, which is my favorite stuff! My current bike is a Stumpie FSR which has a head angle of 70.5 with a 100mm fork, so I need something that will respond at least as well as that. I have considered putting a 120mm fork on the mojo, but I suspect that may create other handling issues. This has really been driving me crazy, so please help me here!
    Thanks, RT
    Consider that brake dive is greater when you have more suspension travel. So with more suspension travel you need a slacker topped out head and steering angle, because when braking the angle becomes steeper about 1 degree for every inch of brake dive.

    The common 140mm travel Fox fork produces the 69 degree head angle on the Mojo. Some riders use a 130mm travel fork on the Mojo to have less bob, less brake dive, and steeper, quicker steering with about 69.5 degree head angle while not braking.

    The Pivot Mach-4 is about 4-inch travel. The Mach-5 is over 5-inch travel, I think it is 5.5 inches. I test rode a Mach-5 prototype at Interbike in September, it had steeper head angle and quicker steering with a 140mm travel Fox fork than the Mojo. The overall ride is very smooth and efficent but felt firmer than the Mojo with the same RP23 shock. There is rumor that the Pivot production bikes will have special production shocks to be more bump compliant. The Mojo shock can easily be firmed up by setting the propedal on to have a very similar suspension feel as the Mach-5, but the Mach-5 cannot be made as bump compliant as is possible with the Mojo.

    The Mojo is a more versatile use design than the Mach-5, and excels in many uses from high speed XC to technically difficult AM.
    Last edited by derby; 12-28-2007 at 09:43 PM.

  3. #3
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    140-130 is not going to create 69 to 70.5, you need to probably reduce the travel to 110-120 to see that kind of result.

  4. #4
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    ok, but...

    Thanks for the input derby, but something in your reply doesn't sound right. To go from 69 degrees to 70 would require going from the 140mm fork to a 120mm fork (~20mm = ~1degree) so a 130mm fork would be around 69.5 degrees. Or is my math wrong?? Also, did you get a chance to ride the mach 4?
    Thanks, RT

  5. #5
    www.derbyrims.com
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    Quote Originally Posted by Robert Thompson
    Thanks for the input derby, but something in your reply doesn't sound right. To go from 69 degrees to 70 would require going from the 140mm fork to a 120mm fork (~20mm = ~1degree) so a 130mm fork would be around 69.5 degrees. Or is my math wrong?? Also, did you get a chance to ride the mach 4?
    Thanks, RT
    Yes, thank you I caught that error too and edited the post.

    I'm not very interested in bikes with less than 5 inch travel now that pedaling performance isn't reduced at all with longer travel dw-Link suspension. But I imagine the Mach 4 would be a great XC racer. It probably rides very similar to the Iron Horse Azure dw-Link, but lighter and more refined in metal work quality.

  6. #6
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    Caution;  Merge;  Workers Ahead! Yes but...

    Thanks for the info guys, but what I realy want to know, especially from you Derby since you've ridden both, is will the mojo handle the tight stuff I crave as well as the Mach 4, or will the slacker angle of the mojo always hold it back unless I put a 130mm fork, and is that advisable? I plan on racing next year and I won't have a chance to test ride either ones so thats why I'm being so picky (sorry). Derby, or anyone else please feel free to dive in with an opinion.
    Thanks, RT

  7. #7
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    Quote Originally Posted by Robert Thompson
    Thanks for the info guys, but what I realy want to know, especially from you Derby since you've ridden both, is will the mojo handle the tight stuff I crave as well as the Mach 4, or will the slacker angle of the mojo always hold it back unless I put a 130mm fork, and is that advisable? I plan on racing next year and I won't have a chance to test ride either ones so thats why I'm being so picky (sorry). Derby, or anyone else please feel free to dive in with an opinion.
    Thanks, RT
    How tight is your "tight stuff"?

    I ask because I find the Mojo to be incredible in slow technical terrain where you are moving the bike around in very tight situations. For this is the sort of terrain you find on the technical trails in the desert where you have lifts and turns piled on top of each other but the traction is perfect so it just relies on you keeping the pedals turning and putting the bike where it needs to go/be.

    I run a 160mm fork with a very short (50mm) stem - all the things that should slow down the turning capabilities of a bike - but the mojo just performs perfectly (at least for me and in my experience).

  8. #8
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    Quote Originally Posted by zzsean
    How tight is your "tight stuff"?

    I ask because I find the Mojo to be incredible in slow technical terrain where you are moving the bike around in very tight situations. For this is the sort of terrain you find on the technical trails in the desert where you have lifts and turns piled on top of each other but the traction is perfect so it just relies on you keeping the pedals turning and putting the bike where it needs to go/be.

    I run a 160mm fork with a very short (50mm) stem - all the things that should slow down the turning capabilities of a bike - but the mojo just performs perfectly (at least for me and in my experience).
    I think RT is interested in XC race use where short travel and steep head angle is quick handling in tight elbow to elbow passing situations, and climbing optimization, sacrificing less important rough trail and higher speed handling stability since they are so intensely focused and on top of the handling during a race. Some riders just prefer that feel all the time, and have adapted to exaggerating weight shift over rock obstacles and stretching more rearward behind the seat when descending moderately steep downhill.

    The Mojo is very light and super efficient pedaling and can be tightened up in suspension using a shorter fork and firmer damping to limit travel to quicken up handling to be an excellent XC racer. There are some owners racing the Mojo in XC, 24 hour, and Super-DH events.

    I'm not XC race oriented at all so I may not be the best to answer whether the Mojo is quick enough in handling feel. I'm more interested in rough and rocky terrain where a shorter stem and less steep fork angle is more confidence inspiring. If I have to get off and carry the bike over some areas, that's the trails I like the best.

    Mach-4 sounds like it is a "turn-key" high end dw-Link XC racer with a significant weight and finish quality advantage over the 3.75 inch travel Iron Horse Azure.

    At the time I rode a prototype Mach-5 in September, the estimated first shipping of production Pivot bikes was not scheduled until mid-summer '08 (often estimated milestone dates are very optimistic too). So that may a factor in deciding about a bike for this coming race season.

  9. #9
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    Very Tight stuff!!

    ZZsean, the tight stuff I spoke of is sometimes between two trees ~2 feet apart (24 in) and I'll rub my front tire on one tree while leaning into the turn( I'll do ~ 16mph there). If you don't have the right speed or lean wrong, you get to eat wood. Oh, BTW did I mention the 3rd tree!! that's almost in front of you, so the way the trail goes you've only got one way to go In fact I rode out there today and clipped the left side of my handlebar, which sent me right and I crashed into a small tree that I broke in half .Instant firewood!!! The hard way. (check out www.swampclub.org & go to the Boyette section)
    Derby, I think you are right about the Mach 4 and the comparison to the IH. But it sounds like with a 130mm fork on the mojo, it can do the job just as well (maybe better?). As it is with 100mm on my current bike, when I'm not knocking down trees, I will go thru almost all the travel especially in the rear, and it is pumped up to 200 and I weight 165 without wood on me .
    Time to break out the ice. RT

  10. #10
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    What about trying the Mojo with a Talas fork. That will give the option of 100, 120 and 140mm travel with a separate lockout. I have forgotten to extend and unlock the fork after long climbs and ridden for some time at 100mm locked out over all sorts of nasty terrain without even noticing the difference (obviously the blow-off valve must work). Maybe that makes me a poor and unobservant rider, but I doubt it. I am using wider bars than on my previous rides, but the Moj is definitely faster and safer through the tight stuff, especially if it is rough. Also I made a decision to use 2.0 Hutchinson Python tubeless to take advantage of lower rolling resistance for longer and tougher rides and the suspension has been great with awesome traction and the pedals almost seem to push themselves through obstructing logs etc at low speed. What I am saying I guess is the bike is really accomodating regardless of setup and terrain and that says a lot for both the DWL and the frame itself. I couldn't give a .... about the head angle - it is far slacker than my last dually, but everything better and faster

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