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  1. #1
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    G2 29er to Monstercross?

    In the process of seeking a good drop bar on-and-off-road bike (as in both in one trip, frequently). What I'm basically aiming for is a road cockpit and an XC wheelbase.

    I already have a drop bar setup on a Surly Ogre and am not 100% satisfied. What I think is the problem is that the MTB top tube forces the stem to be so short that it doesn't handle like a drop bar should. But I wouldn't want a shorter wheelbase because I'm as tight as I can afford with toe overlap, and I feel like too much weight is already on the front wheel.

    I've asked a few questions, possibly come across as dumb, but have a very specific one here. Would a small (15.5) Trek/Fisher G2 frame be a good fit for a drop bar conversion for a medium-large fellow? I ride a DB Overdrive L for XC, and with the stem turned down and the bars shortened a couple inches it fits me like a glove. My Ogre is a M and as I mentioned I think the top tube is too long and the toe overlap too tight for a drop bar, for me at least. Also think there's too much weight on my hands. So that means slacken the headtube, hence the G2. A Salsa Fargo was on the radar, but I suspect for my tastes there will be too much weight on the front wheel and not enough toe room. So basically this would be a slacker Fargo. Also for reference, I ride a 56 road bike.

    Is there something terrible waiting for me if I take a small G2 frame, add an extra-long seatpost, use a Surly fork from Ogre or ECR (ECR being higher offset of 47mm), and size the top tube and stem like a road bike? I believe the wheelbase would be just a little longer than my Ogre, so it's not as though I would be arched far over my front wheel (that's kind of the idea.)

  2. #2
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    Do you already have a small g2 frame? If not, this sounds like it could end up an expensive experiment (not that there's anything wrong with that). Your reasoning seems pretty sound for TT sizing, though I'm not sure I understand how a slacker headtube angle will take weight off your hands.

    The only terrible thing I can think of is that a lot of the trek / GF frames have had issues with the seat tube cracking above and around the ST/TT junction. With an extra-long seatpost it seems like you could have more leverage at that point and cause cracking a bit more easily.
    Yeah I only carry cans cause I'm a weight weenie.

  3. #3
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    That's good to know about the seat tube. I think that pushes me over the line into not doing it. Thanks very much for the info.

  4. #4
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    I thought about doing something like that a while ago. I even bumped into a guy with a dirt jumper set up as a touring bike. Weird, but he liked it.

    It sounds like a cool experiment. If you want to control the cost, start with an inexpensive frame or one you've got. Why were you interested in the G2 specificially?

    Are you looking for a MTB with dirt drops kind of an attitude or something a little more road? I've really only done the latter...
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  5. #5
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    One way in which you could look at this problem is to lay it all out on paper. By this I mean, you measure yourself up as a stickman - centre to centre - foot to knee, knee to hip, hip to shoulder, shoulder to elbow, elbow to hand. Ok, then scale a drawing of the bike - contact points only needed - saddle, pedal, h/bar. Play around with it on paper or computer program, and look at yourself on your road-bike relative to the MTB by over-laying them. You will see a lot when you do this. Another way is to get someone to photograph you at equal distance side on, on both bikes so that you can look at how you are positioned and move on from there.

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    If I don't make an attempt, how will I know if it will work?

  6. #6
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    Re: G2 29er to Monstercross?

    Quote Originally Posted by BATRG3 View Post
    That's good to know about the seat tube. I think that pushes me over the line into not doing it. Thanks very much for the info
    I'm not sure how much of an issue it was - I was still ready to trade a cross bike for an old rig after reading about it but that fell through. Definitely worth keeping in mind though especially if buying a frame.
    Yeah I only carry cans cause I'm a weight weenie.

  7. #7
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    A dirt jump frame may not be a horrible candidate, with the only downside being the short BB drop. Short chainstays and long front end are desired here. I'm actually not too attached to a single wheel size here, so if there were something dirt cheap in a 26 I would be ok trying that out with parts from the bin. An AM HT frame in a smaller size would be great except for the price and being heavier duty and slightly less utilitarian than I really need. (I'd like at least minimal rack/fender mounts.) But with the overextended seat tube, a heavy duty frame may be the ticket. (Sure beats custom, especially for resale.)

    I am aiming for a mostly road style on the bars. The main thing I'm going for is to keep the cockpit of a road bike but stretch the front wheel forward without lengthening the top tube much, which means slackening the head angle. What I meant with having too much weight on the hands is that it was too long still, and was visualizing slackening the head tube at the same wheelbase for a shorter top tube. Sorry that was a little convoluted.

    Comparative photos would definitely be a good idea, given that I have an XC and road bike for reference, each of which I consider a good fit.

    I had thought of taking a cruiser or comfort bike and using an offset seatpost to move the seat angle up and shorten the top tube, but then the chainstays would be ultra-long and I suspect I would feel more impact from the front end, which is the opposite of what I'm aiming for.

    As far as the seat tube cracking on the G2, I'm not so much concerned in the scenario that I get one in my own size and used for its intended XC purpose. It's just that I would be taxing it even further with an extended seat post, and that's just too concerning if there are already issues.

  8. #8
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    Have you pulled the trigger, I would love to see your results, I was also thinking of doing the same thing, if I could get my hands on a cheap xs 29er frame. but my reasoning were it's impossible to get a 135mm rear disk ready cx frame for less than 100.

  9. #9
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    After learning that some G2s had an issue with seat tubes cracking, I decided that this was just pushing it too far.

    An AM frame would seem like a perfect fit, but too expensive just to experiment like this. A 26in DJ frame seems like something to hunt for on the cheap, but the high BB would still throw me off.

    I think I'll be spending more time trying to learn to live with the short reach and stem on my drop bar Ogre. A Fargo is dang close to what I think I want, just too short in the front and long in the back.

  10. #10
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    Taking a look at other available frames, it almost looks like a Surly 29+ frame could be perfect, but far too expensive to just monkey with. It would be great to have 29+ as a consolation price, but then I would need a M or L frame, not a S. I'm thinking again about the small G2, wondering if getting a beefy enough seatpost would address my concern there.

  11. #11
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    Looking at the 650 Tomah, it doesn't look like a bad candidate either, if we're open to other wheel sizes. Unlike the G2, a size L has the short top tube I would want (roughly a 57cm), with a typical size L XC wheelbase and a seat tube in my height. Could even swap out with 700C wheels if I wanted to go narrow and keep the geo.

  12. #12
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    Quote Originally Posted by BATRG3 View Post
    Looking at the 650 Tomah, it doesn't look like a bad candidate either, if we're open to other wheel sizes. Unlike the G2, a size L has the short top tube I would want (roughly a 57cm), with a typical size L XC wheelbase and a seat tube in my height. Could even swap out with 700C wheels if I wanted to go narrow and keep the geo.
    thosw tomahs are quite reasonable on ebay , like 150 shipped, you will be better off putting 700c tires on 29er rims, most 700c wheels have a thinner hub.. Which I have done, 700x38 on 29er wheels, and it fits in a 26" frame. (montague mountain bike) which I would assume has tighter clearance than a standard 26" frame.

  13. #13
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    Quote Originally Posted by BATRG3 View Post
    After learning that some G2s had an issue with seat tubes cracking, I decided that this was just pushing it too far.

    An AM frame would seem like a perfect fit, but too expensive just to experiment like this. A 26in DJ frame seems like something to hunt for on the cheap, but the high BB would still throw me off.

    I think I'll be spending more time trying to learn to live with the short reach and stem on my drop bar Ogre. A Fargo is dang close to what I think I want, just too short in the front and long in the back.
    I think you might just get away with a DJ frame as most are built around a good length A to C measurement to accommodate the suspension .

    Therefore if you reduce the the A to C measurement it would in effect steepen the head angle but also have the added bonus of lowering the "high" BB as everything would rotate around the rear axle with a rigid shorter fork (This is all assuming you're not wanting to run a 100MM+ suspension fork of course) .

    Is this something you have considered ?



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