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Discussion Starter · #1 ·
I have a Litespeed Niota (aluminum) that I am thinking of converting to a 69er. I have not tried either a 69er or a 29er, but I do get the feeling that a bigger front wheel is more of an advantage than 29er on the rear. I also don't really have the money to spend on a totally new 29er, and I love the dualie ride, so I am not interested in a cheap rigid bike, or heavy cheap dualie.

I am running a Fox RLC Talas on my Litespeed, set at full travel (135mm). I am considering getting a 100mm Fox RLC FIT, and just swapping out the fork and front wheel. This fork should put the headtube at the same height and angle as the current setup. There also seems to be toe clearance, but I haven't checked it with the fork collapsed.

I asked a former racer freind about it, and his reply was that the 69er was an answer to a question that was never asked. I recall way back when that CannonBall had a bike with a 24" rear and 26" front, making all the same claims as the 69ers, better climbing and better rollover in the front. I think they made it for about a year. It seems like a great idea, and even MX bikes have larger front wheels. UInfortunately I don't have any gear to borrow, and I am kind of a high end dude, so crappy stuff wouldn't be a fair assessment. Should I do it?
 

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Generally speaking it is difficult to build a 29er out of a 26er. I know people have done it, but it is going to throw all your geometry angles out of whack. While it is true that the 100mm 29er fork may have the same A to C of the 135mm 26er fork, you need to also factor in the larger wheel. The front end will be raised approximately 1.5" (38mm) just from the larger wheel. So that combined with the increase in trail from the 29er wheel is going to make it feel at least 2 degrees slacker. And I suspect that the Niotas head angle of 70.5 is based on a 120mm fork, so in all you are going to be increasing front end height by 53mm, basically changing the head tube angle to about 68. Its also going to throw your seat angle way out and make it difficult to get the seat properly placed. This isn't to say you can't do it or you can't ride it like that. But it is going to ride strange with geometry that out of whack. I am no expert on this stuff, so someone please chime in if I am off with my numbers.

I am not trying to discourage you. Just giving you some things to think about.
 

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Discussion Starter · #4 ·
I don't assume the 100mm 29er fork has the same axle to crown as the 135mm 26er fork, i assume it is shorter by the height difference of the wheel. if what you are saying is true, then you are right, it will handle like a garbage truck. does anyone know the AtoC of the Fox FIT RLC 29er fork?
 

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OK, so I built a 69er out of my old Woodstock 505 hardtail; it originally had a HTA of 71.5 with a 100mm fork, now with a 100mm Manitou 29er fork and 29er wheel it is slacked out by my measurements to about 68.5.

I read all the posts saying the thing would handle like a wheelbarrow, but then I put a 60mm stem on it with wide bars and it handles great, it's a lot of fun.

It's certainly NOT as fast or doesn't climb like my full sus 29er but it's still a pretty nice bike built as a 69er.

So, maybe a slack HTA bike isn't as bad as everyone here often thinks.....
 

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shreddr said:
I don't assume the 100mm 29er fork has the same axle to crown as the 135mm 26er fork, i assume it is shorter by the height difference of the wheel. if what you are saying is true, then you are right, it will handle like a garbage truck. does anyone know the AtoC of the Fox FIT RLC 29er fork?
The A to C of a Fox 100mm 29er fork is approximately 500mm, which is the equivalent of most 140mm 26er forks. An 80mm Fox is 480mm A to C, so that would work well assuming you are willing to lose that much travel. I actually know these numbers because I have been toying with the idea of a 69er myself. But finding the right frame that won't get too messed up geometry wise is the hard part.
 

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gdlals said:
OK, so I built a 69er out of my old Woodstock 505 hardtail; it originally had a HTA of 71.5 with a 100mm fork, now with a 100mm Manitou 29er fork and 29er wheel it is slacked out by my measurements to about 68.5.

I read all the posts saying the thing would handle like a wheelbarrow, but then I put a 60mm stem on it with wide bars and it handles great, it's a lot of fun.

It's certainly NOT as fast or doesn't climb like my full sus 29er but it's still a pretty nice bike built as a 69er.

So, maybe a slack HTA bike isn't as bad as everyone here often thinks.....
You've found what manufacturers apparently found a short while ago. I think we all realize a bike is the sum of its geometry numbers and not just one, but it's been interesting to see head angles drop on just about all MTB's, and yet retain good handling. Just raising the front with a tall fork and/or wheel may or may not work ideally, but in many cases it results a very workable and fun bike.
 

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Discussion Starter · #8 ·
Thanks LJS, I found the info I was looking for on the Fox Fork Help Site

http://service.foxracingshox.com/consumers/index.htm

all the fork specs are in here. i figured that a 35mm shorter travel fork would accomodate a 29" front wheel and have the same headtube height and angles. I didn't realize that the 29er fork is longer to begin with (DUH!) so you are correct, an 80mm travel Fox fork will give me the same height and angles, but I doubt going from a 135mm to an 80 is going to be something I will like, especially with 5" travel at the rear, and I doubt the advantages of the bigger wheel will over come the loss of travel. I would have to set it up much stiffer, which would change it's manners considerably. I think I will bite the bullet and purchase a 29er SS, and give it a shot. The SS won't make me miss the rear suspension so much, since you spend a majority of time out of the saddle.
 

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I've got an Iron Horse Warrior full susp 26er with a Manitou Splice fork (130mm travel). I find for shuttle run type riding (all i use it for anymore) I'd like a slacker front end. I looked at putting a 145mm travel Nixon fork on it but the Splice actually is longer crown to axle.

I also have a craigslist special 29r hardtail with a Tora front fork. It has crossed my mind to put the Tora and 29 wheel on the front of the Iron Horse. I run my seat way back anyway so I can move it forward (should I want to). For laughs I dropped a 26" wheel on the back of it. Didn't ride half bad. I put the 29 rear back on and have been riding it "stock" since though.

My other train of thought is to install a 650b front wheel on the Warrior with the existing fork. The Warrior is a weight pig and the Splice is a low end fork. Turns out weight wise the fork is not bad. It actually works pretty good too. I suspect the 650b will clear the fork crown as is (no travel limiter required), I have to check if it would clear the arch though.
 

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Discussion Starter · #10 ·
i do have the Fox Talas on the Litespeed, and I know it will clear the 650b, so perhaps my best bet at an improvement will be to go with the 650b front and dial the travel down a bit to get the correct geometry. the only thing holding me back is the sweet set of crossmax wheels i already have, and i hate mismatched wheels, which means a new set of wheels.

what are the best 650b rims for a 180lb hammerhead on rough nj trails?
 

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TNC said:
You've found what manufacturers apparently found a short while ago. I think we all realize a bike is the sum of its geometry numbers and not just one, but it's been interesting to see head angles drop on just about all MTB's, and yet retain good handling. Just raising the front with a tall fork and/or wheel may or may not work ideally, but in many cases it results a very workable and fun bike.
I think the Blue Pig has done a lot to change public opinion on slack HTA's especially. I've never ridden one, but on paper the bike looks fabulous and the reviews are great. It certainly takes some of the apprehension out of building your own franken-bike when you already know Ragley has figured out the slack HTA and fun trail bike concept.....
 
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