cs1

I came upon this on ebay. https://cgi.ebay.com/Jeep-Rubicon-Spo...QQcmdZViewItem
If you look closely, you can see the worm gear on left rear. The drive shaft goes through the seat stay to the top tube into the fork. Ingenious but heavy I'm sure. Anyone actually ride one?

Tim

Ted Danson

i dont understand what it does? pushes air to your fork? whats the point of having a giant piston running through the frame of your bike?

streetlightpoet

There is a company called Christini that makes the same thing. I haven't had a chance to ride one, but I would trust them more than a Jeep branded one.

rbrsddn

I don't know if Christini still makes 2wd mountain bikes, but they developed the drive for the Yamaha 2wd dirt bike I read about a year ago or so.

streetlightpoet

Their site still lists them, 2 full suspension models. I don't remember if they had a hardtail or not.

indygreg

Lets say you could do this for a reasonable price and at a reasonable weight and it actually effectively put power down to both wheels . . . (just for sake of arguement)

I am not sure what the upside is at all. Having power to the front wheel would make it less stable in ice and snow. The best thing you can do in a car to gain steering on ice is to not apply power. In a well designed car, AWD or 4WD takes power away from the wheels that are slipping.

If were on ice or snow and had the front wheel have power, that would break it free. At that very second, you are on the ground.

It is not as if when you ride you always get stuck and just sit there and pedal the rear wheel to no avail . . .

Chris_F

Yeah. Plus, how much torque will that thing transfer from the front to rear (or visa versa) when you're not pedaling? Unlike a single wheel drive in just about any AWD configuration I've seen wheels tend to "share" torque, unless some sort of open diff is used. Doesn't sound particularly stable.

streetlightpoet

From my understanding the front only gains power once the rear slips, and while they claim that it's good with snow/ice I think the real strength is in steep climbs being able to stand up and not worry about the rear slipping out.

pyroguy_3

It's good for sandy, loose conditions, apparently. Also, has anybody ever tried to ride their bike on ice? It is the exact opposite of easy. I'm pretty sure that if my bike had had power to the front wheel I might not have fallen over so damn many times. The front wheel just sort of shoots out from underneath you. There was actually a question about awd in MBA this issue.

streetlightpoet

I remember more than a few bruised hips from my days riding in ND.

Chris_F

I made one attempt to cross one frozen puddle on my bike. I now get off and walk on ice instead of riding it. How do you even ride effectively on ice? Do you use studs? I was using my regular old summer tires and I don't see any conceivable way I could possibly have stayed upright on the bike.

Bruce_B

Looks like it just adds weight and complexity for no good reason.

cs1

It's not a piston, It's driveshaft that goes through the frame.


Tim

01amberfirewv

They had one on display at the last camp jeep I attended but I didn't get a chance to ride it. I don't think I would want one but would like to take one for a test ride. If I go to camp Jeep this year I will have to try one out

pyroguy_3

With a very good center of gravity. You cannot try to turn or lean or else the front tire washes right out from underneath you. After about 6" of snow one day last winter, the bike/walking path I take to campus had been trampled down into a sheet of ice with lots of bumps. I do have a Panaracer Fire FR on my front wheel, which is very knobby, so that helped a little. But yeah it's basically coasting over the ice while keeping dead center over the bike with very little pedaling. I am going to throw some studs into my old tread-worn front tire for this winter though.

BearSquirrel

a) The Jeep AWD IS the Christini bike with a different sticker.

b) Full studs like a Nokian 296 make riding on ice just like riding on slightly damp singletrack. The problem is getting OFF the bike.

Svr

Yep, and they've been trying to sell the idea of an AWD MTB for the past fifteen years or so. I'm sure it'll catch on any year now....

Cyclist30907654

Lee McCormick has an excellent review on this

leelikesbikes.com

rbrsddn

Word. I took this pic last Feb. on my first ride with the Nokians. I got off the bike and went down hard! Amazing traction on sheet ice when safely back on the bike.

cs1

Kind of like a 29'r.

Tim

indygreg

This is just incorrect. Power to the front wheel would not add stability on ice, in fact the opposite is true.

Take a front wheel drive and stop on a snow or ice covered road with a slant to it. Apply power. The front end goes down the direction of the slant, with gravity. Take a RWD and do the exact same thing, the rear goes down the way of gravity.
Now take front wheel drive car and gun it around a turn . . .it will push, or in simple terms the front will lose traction. Do the same with a RWD and it will get lose, or the back end will spin around.
This is not saying one is better or worse in the snow. Front is generally better, but the main advantage is that about 65% of the weight is on those wheels to help get traction.

Now on a bike your front wheel just cannot lose traction or you go down. In a turn in soft stuff you have a shot at staying upright if the rear slips out. You have nearly no shot if the front does the same.

This is a gimmick, pure and simple. Bikes are not cars. People are so brainwashed about AWD that everyone demands a SUV with it when they live in an area that gets about 3 inches of snow a year. This bike maker is playing off of that . . . AWD must be better.

pyroguy_3

So you mean, if the front were starting to slide to one side(assume a positive vector), and you applied force in the opposite direction (a negative vector), also known as pedaling with an awd bike, you wouldn't be able to counteract the force. Damn, seems all my physics just went out the window? What are you assuming the wave functions of your wheel's molecules are all jumping to a state of being where the tire doesn't pull you back into straight? For the life of me, I can't not remember a time when trying to get up a sandy hill on an ATV with RWD that didn't result in the front end drifting. Even riding a bike on the beach, on relatively hardpacked sand was a fairly difficult task. Now, throw the transmission into AWD, and bammo the front end tracks better. I'm not disputing that your explanation is wrong, just that mine is correct with respect to a bicycle. As for the weight being in the front of a car, next time you're on ice lean over your handlebars and start pedaling really hard to see if it works the same on a bike. I bet it wont.

cs1

Thanks for all the great info so far. I didn't know Christini was the actual mfg. Here's what I found out after that. https://www.christinibicycles.com/bikes-fullsus.php

Tim

Chris_F

Do they make clipless compatible crampons?

rbrsddn

I'm going to screw some sheet metal shoes into the Lakes if we get a storm like that one again!