Morini j-shaft gearing options?

I have read and seen a few people on here using the 5.8hp and the 9.4hp Morini motors with jackshafts. It seems like all of you are using internal shifters like nuvinci or a nexus. Some have blown up these internal shifters.

I am curious as to why no one has used the conventional cassette setups? What is the failing point?(if any)

Is it the derailer? cassette? freewheel hub?

If it was derailer or cassette that would fail, would the bike work fine with a standard freewheeling hub and a single sprocket?

If the freewheel hub was the main fault, you could not have a cassette meaning no derailer, but you could get a single speed sprocket that is non-freewheel. Keeping in mind that the cranks have a freewheel on the front sprockets, would this setup work? Is there something horribly wrong with this idea?

I am asking anyone who has experience with the sort of power these motors have and understand the stresses that will potentially arise in certain areas.

One reason I have for asking is because gearing would be CHEAPER! Single sprockets for bicycles are cheaper than MB ones and just as or more accessible.

Another reason is the build I am going with is on a GT-LTS. It has an intricate rear shock system with odd pivot points making a device to take up chain slack more difficult. (see EZ's summer build) He made his a hardtail because of it. With a jackshaft it should be easier to get a tensioner that hangs off the derailer hanger to pick up the slack like it would normally.

I have been thinking about these things for a while and thought I should ask some people with experience, who may have never thought about it before.

Ill be starting a thread on my build as soon as it really gets moving along to document the process.

Thanks for reading!

--Fizz

Easy Rider said:

I think it would work but use a scooter racing chain.

Click to expand...

What exactly are you saying will work? I asked quite a few things. I think you mean that the suspension would work on an LTS with a jackshaft, correct me if im wrong.

I am more interested in what could be used for gearing on a morini. All the builds I have seen use an internal shifting hub. I am wondering why no one has used a cassette/freewheel? Is it because the cassette wont do the job with that much power? or has no one tried gearing with a cassette/freewheel?

BTW, Where did you purchase a scooter racing chain?

What are you using now camlifter? If you took the nuvinci off your hotrod, what are you using now?

What is the max torque at the rear wheel? I found a hub that can take a rated max input of 100Nm... a bit pricey tho; Rohloff speed hub Might see if i can rig up a cassette out of single speed sprockets that support #41 chain... i will just buy a beefy. Ill see what i can rig up. Ive been looking into shimano alfine hubs but cant get a rated max input rating. no one supplies that technical data. Have you found anything?

I called Nuvinci today to ask them what the limit is for their new N360 model. They said they havent done the tests for it yet, although this one is rated more for mountain bikes, whereas the N171 is rated for cruisers. Im assuming this meant it could take more of a beating. I asked them if the N171 would take a 9.4hp motor, they told me their tests show that it would... I also told them yours blew up. They said it shouldnt have, although there is no warranty for motor use... Were you particularly rough on your Nuvinvi hub?

Did you roll the gear changer while giving the motor gas or did you let off the gas?

Did you get the developer kit nuvinci or just standard bicycle one?

so if the springs were stronger there wouldnt be an issue?

Interesting...I am looking into the developers kit and the 360n models for the nuvinci. I noticed on this page, about the developer kit, that the hub can be made to take 10,000rpm. I called today to ask them about this, the tech guys were already gone for the day so the lady took down my questions and said she would have the tech guys email me. The developers kit seems interesting, you can set it to have automatic shifting... hehe, find the bikes power band and set the hub to it! If it can take the power, I am EXTREMELY excited.

I saw the same thing big dude.It states at the bottom to call in for a high speed custom configuration. So I thought i might as well call in and inquire. Turns out they no longer do the custom configurations and the developer hub just is not strong enough to withstand the forces.

With that being said, they did mention that they had a new model of hub that is not out for commercial purchase at the moment that would be able to take the force of the 9.4hp morini. Just have to wait it out...