29"er DH: The Final Frontier?

Despite the many views purporting that 29″ers are not going to make a good down hill oriented rig, (And I have held that view myself), there are some who are willing to push the envelope of what is possible with the wagon wheels. Of course, it isn’t as easy as one might think. Frame design has to be very carefully engineered to keep the wheel base, bottom bracket, handle bar height, and chain stay lengths within reason. Not only that, but there needs to be components to match, such as tires, rims, and forks.

These things have kept most 29″er down hill rig dreams just that: Dreams. However; with the advent of longer travel 29″ers, the component manufacturers have started to address the needs of this sort of rig in a way that now makes a 29″er down hill rig even more feasible than ever before. That is not to say it hasn’t been done before. No, there are already 29 inch wheeled down hill rigs out. WaltWorks design comes to mind. However; a new design that is currently being tested is now probably the most promising design with big wheels yet. That is from the mind and hands of Devin Lenz and his LenzSport Bikes company. Check out this rig………

LenzSport prototype DH rig.

Here are some hard numbers on this proto:
* 175mm travel on both ends.
* 14.25″ BB height.
* 65.5* HTA.
* 17.25″ CS.
* 6 speed, 13-28 cassette.
* 38.5# as pictured.

So far the feedback has been very positive, but there are still some challenges ahead. If things get sorted on this front, it may well be the “final frontier” for 29″er bikes and will certainly be a surprise to those who for years said “it can’t be done”. Interesting times for big wheeled fans, to be sure!


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9 Responses to “29"er DH: The Final Frontier?”

  1. Sevo Says:

    “Yeah, but your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should. ” – Dr. Ian Malcom in Jurassic Park

    And I think that is the case for the 29er DH rig. We became so preoccupied with “When are we going to see a 29er DH bike” that we stopped to ask if we really need one. Or why we need one. I think Devin does great work, want to own one of his rigs one day (Milkmoney personally) and it looks nice. Even applaud him for catering to a niche as it’s what framebuilders like him need to do to and are supposed to do. He’s one of the best in many arenas, including this I’m sure. But I don’t think you’ll be seeing 29er DH rigs making the podium ever in the DH world in major races.

    I love 29ers, but honestly I’m in the market for a 6+ inch trail bike….I’m not even thinking of 29ers because I strongly believe it’s an area where 26″ wheels do it better for what I like to ride. That said I don’t know why anyone would want a 26″ hardtail unless they were 5’4″.

  2. Jeff Says:

    Someone will take a podium on a 29.. just to be the first. People always get what they want, correction, never underestimate the power of the dollar.

  3. Shop Mechanic Says:

    This is truly groundbreaking news. The geometry numbers are spectacular. 17.25″ CS is bang on for a modern DH bike and to pull it off with a 29″ wheel is amazing. Much shorter than many hardtails out there! All the other numbers look perfect as well (maybe 1/4 to 3/8ths of an inch lower on the bb height to put it more in line with the modern bikes especially given its shorter travel but this is minor). Even if you don’t think that DH on a 29er is a good thing or not at least now we have a bike where the concept can be adequately tested at the very least. Dirt magazine did an article about 2 years ago asking all the big time DH bike designers if they thought that 29″ wheels were the future of downhill and there were some very positive remarks on it as a possibility. So I think that the idea has a fighting chance in the marketplace if some other brands are willing to experiment with the idea. Big virtually high five to Lenz! Although I am wincing at the grip choice (hurts credibility, just being honest here).

  4. t0m Says:

    @Sevo- “But I don’t think you’ll be seeing 29er DH rigs making the podium ever in the DH world in major races. ”

    I’m not sure about that. Maybe not in the next year but at this point it’s damn near inevitable. If the 29″ DH race tire selection comes through, I have no doubt that the bigger wheel will carry its advantages to a podium. One other issue is getting top talent onto a 29er. The elite DH guys are a level above anything prior, and the merely good (privateer, small company) DH ranks rarely break through to the podium. The giant companies aren’t going to introduce a DH 29er. But it’s still coming. There will be a DH 29er on a podium in a major US race soon. 1-3 years. Then it’ll be big.

    The Lenz is nice. Looks like the closest to the mark yet.

  5. Cloxxki Says:

    From what I know about bikes, DH bikes, and laws of physics as we have no choice but to obey them, larger wheels DO make sence for DH.

    Let’s summerize what DH is all about, and how 29″ works for that in general.
    +- Hard pedaling, fighting the various drag factors (air, rolling resistance, roll-over resistance)
    +- Speed changes (often over-estimated IMO) : accelerating rider+bike weight = >200lb
    + Flight. Low and fast, with maximum control upon landing to then either brake or pedal hard.
    + Last-moment braking (brake traction and stability sought)
    + Cornering with minimal speed loss (cornering grip needed.

    The wheels being bigger, they might have increased air drag. That doesn’t keep people from using 29″ for the faster of XC events, though. To the contrary, it seems.
    Rolling resistance and roll-over both are huge in DH. just roll a DH bike down an XC trail. It drags. Damper rebounds… Rigid bikes can be rolled down slopes faster, to a point of bumpiness of course. Larger wheels and less travel, should even out, but nett a faster combination.
    29″ is associated with “heavier wheel”, and THUS (…) “slow” acceleration. I’ve always contested this, and taken the lead in many a race to support my words with factoids. Wheel weight is just minor over the whole, and the percental change fraction at that, let alone when factoring bike and rider weight. The reduced rolling resistance should be of greater factor, or somewhere in the “all else being of the same quality level” equasion, something went very wrong.
    Flight is subjective, My opinion (+) in listed. I’ve raced 4-cross (forced with 26″), and ridden the courses down on my XC 29″ers to come to that conclusion.
    Everyone who’s ridding a 29″er knows about braking and cornering traction. This alone, will be worth several seconds down a WC downhill.
    Overall control, precision and line fluidity, remain undiscussed here.

    I’d love to read those initial ride reports for the Lenz. Where are they?

    (disclaimer: I was on a mission to get a similar level 29″ DH t happen in 2003 or so, and miserably failed, didn’t get any help other than the prices for prototype production of frame. White Borthers was the only really helpful party.)

  6. Broke Cyclist Says:

    Push the edge of the envelope guys. Designing, testing and relooking how to do things improves the 29r product line. Success isn’t based on who makes the podium first.

    Folks also said for years that 29rs wouldn’t be successful nor accepted on the pro circuit either….a husband and wife team have proved the nay sayers wrong this year. The Europeans are starting to review 29rs in their mainstream MTB magazines so we have a foot hold starting in that market which is good.

    I’ll say this. They won’t be the perfect wheel choice for all things cycling, but I’m damn happy for what they do for me.

    I wanna read about a 7″ full carbon sub 32 pound 29r by 2011. Git at it!

  7. Lee T Says:

    29ers are awesome – period. So are Lenz and Curiak. I would like to see this experiment work – but if it doesn’t then 29ers will not be a failure, nor will Devin, nor Mike. If it weren’t for the big wheels, I might not be on the trails – 26ers sucked that much for me. So, if I can ever, at my advanced age and decrepitude, ride DH, I am sure this will be the way.

    But I don’t have to ride DH to know these 29ers are superior vehicles.

  8. optimus GRRR Says:

    Excellent way to work a Jurassic Park reference into a down hill 29er conversation.

  9. Nicholas Says:

    I don’t buy the short CS idea for a DH bike. It may be good for an east coast supertight trail but makes the bike way more unstable on a fast run- DH or not. Why woud this be any different?

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