cannondale adventure 4

[silverfizzy]

Can I use a front hub motor if I use torque arms on both sides. The forks are tridium and aluminum alloy. The rear derailer is 8 speed so I would prefer to add a 500 watt front hub motor and 36v lithium battery on the cannondale rack already installed. I have this bike in a 15 inch frame which fits me perfectly. Any help would be greatly appreciated, thanks guys.







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[bigisland]

I would say IMO Yes, the motor will be putting some stress on your telescoping fork. How much depends on how much torque is applied to the axle, and this is determined by how much power your motor has and at what rate you apply it at to over come loads and how large those loads are. In a high power situation you would not configure a design like this, But I think that unless your forks are total junk they should be able to handle it. I would say you primary concern should be well made torque arms that tightly hold the axle in position, any looseness that is present, or develops can cause you dropouts to be enlarged by a shifting axle. If you will be fabricating your torque arms you could easily accomplish this, but if you need to work with whats out there it may be more challenging to find parts you can work with. Look at all the examples on the forum and plan your attack. I am doing a similar bike at the moment, Trek Navigator, but I am doing rear wheel I am going to play around with 2 of these $12 Fixed angle torque arm for 14mm axle at http://ebikessf.com/node/177 and cut and weld as needed, because I didn't want to cut and file axel holes.

 

[dogman dan]

If this is your first ebike, the answer is you'd be an idiot to put a motor on alloy front forks.

Almost as dumb, to put it on the alloy rear dropouts of the cannondale if it's your first try.

I put up a thread on how to install a motor on alloy front forks a few years back, but the pics have dissapeared. I got er done, but it took three sets of forks to find one that it would work on. It's for experienced ebikers only. In a great many cases, once you install a motor, the forks get sticky and won't work right at all. Currently the fork I'm running only functions if I am coasting.

Can't say it enough times, to do your first install on steel. Once you have experience, even if just from lots of reading here, then you can go to the alloy bike.

You simply can't appreciate how fast a wheel can rip itself off the bike, till you have experienced it. Go with the rear motor, but put it on a steel frame MTB that has a 1 1/8 headset that can take a decent shock fork.

If you must use the cannondale, then go rear, and read a LOT of build threads very carefully. Then determine if your particular bike is a good one for installing a custom made torque plate or not. You need a certain amount of flat area around the rear dropout for attaching the torque plate. A great many bikes don't have that space there, making a torque plate very difficult to design. You could easily spend as much on torque plates as you would on a used steel MTB.

Your 8 speed chain and derailur will work fine on a 7 speed motor hub, you just reset the derailur to hit the stop before going into 8th gear. 9 speed is where the difficulty begins.

 

[bigisland]

If this is your first ebike, the answer is you'd be an idiot to put a motor on alloy front forks.

I think this depends on your technical abilities as to if you went to MIT it wouldn't matter if it is your first build, weather or not it is feasible is another story (can be done but a motor on the end of a telescoping fork, is from a design stand point awkward). But I always like to minimize my risks, and remember accidents are things: you thought wouldn't happen, you didn't expect to happen, you didn't know could happen. And that a lot of stuff, unless you are very experienced at what you are doing. My first answer to your original post was just in reference to if it was technically possible, but if you can personally do it? only you know your abilities, and Dogman's reply illuminates this and the feasiblelity of implementing that configuration.

 

[bigisland]

If this is your first ebike, the answer is you'd be an idiot to put a motor on alloy front forks.

I think this depends on your technical abilities as to if you went to MIT it wouldn't matter if it is your first build, weather or not it is feasible is another story (can be done but a motor on the end of a telescoping fork, is from a design stand point its really incorrect because the torque being applied to your lower fork tubes is going to interfere with their liner movement, but is this going to cause your forks to fail?). But I always like to minimize my risks, and remember accidents are things: you thought wouldn't happen, you didn't expect to happen, you didn't know could happen. And thats a lot of stuff, unless you are very experienced at what you are doing. My first answer to your original post was just in reference to if it was technically possible, but if you can personally do it? only you know your abilities, and Dogman's reply of his hands on experience is invaluable in illuminating this and the potential difficulty of implementing that configuration.

 

[neptronix]

Rear is the safest. What do your rear dropouts look like?