Thoughts on Internal Shifting Hub?

[LRSimons]

I've been running a shimano 8 speed hub on a setup I got a few months ago. I try and baby the thing, but I know at some point its going to blow up on me. I think that the higher speeds its forced to deal with would be the death of it before engine torque, but I could be wrong. Wouldn't mashing on the pedals put more torque through the drivetrain than a china girl? I know most upgrade car drivetrain parts are rated for torque- but some have horsepower ratings as well.

Isn't the nuvinci rated for 7 horsepower? I wonder if a cvt style would be stronger or weaker than a planetary gears. The engine connected to my hub certainly isn't making 7. Id be happy with 3 lol.

Has anyone been running one of these for a while? Reliability?

Hope my ramblings make sense.


Logan

 

[panmines]

I am glad that you ask this because I had a brand new 34t 8-speed cassette bend on me in its highest gear. Cog sets definitely have their limits.

 

[lazylightning@mail.r]

Hi! Are you guys running jack shaft kits that send power to the right side and through the bicycle chain and cogs? I'm thinking of trying a jackshaft setup. Did a cog on your 8 speed cassette bend or did the whole set of cogs go crooked? Maybe there are certain brands and makes of cogsets that are known to be better?

 

[panmines]

Hi! Are you guys running jack shaft kits that send power to the right side and through the bicycle chain and cogs? I'm thinking of trying a jackshaft setup. Did a cog on your 8 speed cassette bend or did the whole set of cogs go crooked? Maybe there are certain brands and makes of cogsets that are known to be better?

Yes, my bike is jackshafted. It was only my largest 34t cog that bent and folded outward over the smaller ones. It was actually more of my fault because I took it up a super steep hill that I really shouldn't have and my bike being close to 100 lbs. probably didn't help it either . Interesting enough, I managed to bend it back straight with a pair of vice grips and you almost can't tell that it's bent. I do think the brand makes a difference because before this cassette (Sunlite brand), I was using a different wheel with a 7-speed Shimano mega range (14-34t) freewheel, and that thing lasted a long time and never faltered on me. Another thing I noticed is the 34t cog on the freewheel was more of a solid piece than the one on the cassette. One thing I know that would help prevent this is adding more space between the small and large chainrings in the chainset assembly. That way, the small chiainring will be closer to the center of the bike and hence more inline with your largest cog on the back wheel. Plus, spreading the two apart is something you generally want to do to avoid the chains from rubbing in your highest gear.

A jackshaft is definitely worth the money and you shouldn't worry to much about destroying your rear cogset unless you are looking to gear it way down like I did.

 

[LRSimons]

I'm running a jackshaft- think it's the middle priced shifter kit. As many others have said before, the jackshaft is a huge upgrade and reduces compromise. However, it is expensive and with the ~$200 (and knowledge) you can build a single speed to the same top speed/acceleration. Heck, with 200 bucks you can have whatever pipe you want, a fred head if you're so inclined, jag cdi, maybe just scrap the china girl and put a engine actually made of hard aluminum on. But IMO, the shifter bike will always be more refined.

panmines- Wondering about how your sprocket/ cogset broke as well. Was your gearing putting a ton of torque through the thing? Any teeth shear off, or just bent side to side?

Edit- posted a couple of seconds after yours went up. Questions answered.


Logan

 

[panmines]

I'm running a jackshaft- think it's the middle priced shifter kit. As many others have said before, the jackshaft is a huge upgrade and reduces compromise. However, it is expensive and with the ~$200 (and knowledge) you can build a single speed to the same top speed/acceleration. Heck, with 200 bucks you can have whatever pipe you want, a fred head if you're so inclined, jag cdi, maybe just scrap the china girl and put a engine actually made of hard aluminum on. But IMO, the shifter bike will always be more refined.

panmines- Wondering about how your sprocket/ cogset broke as well. Was your gearing putting a ton of torque through the thing? Any teeth shear off, or just bent side to side?

Edit- posted a couple of seconds after yours went up. Questions answered.


Logan

I was a real bummer to. Had just bought it the day before. If I money was no issue, I would put this thing on it:

It is a 11-48t 8-speed cassette made for e-mtb. It says in the description that it was made to handle the high amounts of torque of an electric crank motor. It is kind of cost prohibitive though. With this cassette, special derailleur and trigger shifter, the whole setup come out at $580 before tax.

 

[LRSimons]

Wow, that's expensive. Seems like the sprockets would be weak except for the largest and three smallest. Is it an electronic shifting setup? I remember seeing that on Top Gear, before Hammond stuffed it into railroad tracks.

 

[panmines]

Ha, I wish is could have saw that episode. And yes, I think this is an electronic shifting setup (motor is at the cranks, not in the hub). You're right, the in between cogs look very flimsical. I guess bike engineers want to keep the weight down on all components, but the cassette strength should not be compromised. I imagine that I would have to use the small cogs for cruising and only the largest one for serious hill climbing while using the in between ones for light duty off roading.

Do you (or anyone) know if there is a "one up" cog for an 8 speed cassette? The only ones I see are for 10 speed and above. It would be much more worth it to use a 11-34t cassette with a 40t one up cog rather than paying $390 for this one.

 

[Gino Pi]

the expensive one is made out of some material that wont bend, bottom line. too expensive for most of us, though.

theshimaino internal hub is said to be warrantied for life, i think. supposed to be stronger than the 3 speeds. its made with hard hard steel, i think. sealed for life. the shimano... not sure which one though... but 8 speed yeah.

i want to make a jackshaft bike. or... make what? i can do anything right now. dont like the width, though. i have a pk80 already. do i go JS.... get a 4 stroke kit?? put on a 50cc ktm clone??? i like good mpg. i wouldnt mind being able to push 50 on long flat runs... like by the beach... you know? and, i guess with the JS kit, you can start out without pedaling??? would be nice.

the cvt... should be strong like the 8 speed. from what i heard. one of the things i dont like about both of them, is twist shifting... not sure about other types of shifters avaialbility... but i have no space for a twist shift on my bar. cvt is supposed to be ideal... im not sure. i know for sure, its expensive as heck.

any feedback to help me understand what this JS kit all about, please let me know.... im trying to imagine... i want light. i want to make it quiet. quick enough that i wont be killed by every car. great mpg. what do you guys think??? i have the 26 inch steel frame, the pk80. need wheels... JS kit... or... what???!!

 

[panmines]

I think the Jack shaft can help you get most of the things you want. You will get better mpg because the engine will be spinning at a comparatively lower rpm in high gear than it would using a stock sprocket at the same speed. For example, if your going say 30 mph with a stock 44t sprocket, your engine is turning over at about 7000+ rpm . On the other hand, in your highest gear using a jackshaft, the engine is turning over at about 5000 because you'll be at a lower gear ratio. The lower rpm the engine is at, the less gas it will use, therefore, you will get better mpg. For the same reason, you'll be more quiet because your engine is not screaming at high rpm.

The main advantage of a js is you can get massive amounts of torque out of them while not giving up your high speeds. It is for when you want to go trail riding and a cruising on the open road with the same bike. Also, you don't have to worry about sprocket truing with the typical tag joint

The main disadvantages of them is they can be pricey and hard to install for 2 strokes.