Ok 2nd derailleur failure...

[dchevygod]

I have 4.25+ hp running thru an 8spd cassette. When everything is new it runns great! Kinda like a 125cc dirt bike!!! So I get confident in power shifting and pulling the front wheel up in 1-2-3 gears, then parts start to wear and skipping/dropping of the chain happens. Even if I notice strange skips and shifts and slow down to a crawl the derailleur will now start kicking the chain and destroys the derailleur. After 3 progressively stonger sram 8 spd chains and 2 decent quality shimano derailleurs. Im just done with all the wear and adjustments.

It's time for a sturmey 8 speed hub! I know im going to be pushing the stress limits of said hub but it has to be stronger than what I'm using. 14t engine drive sprocket off of a 5:1 trans, to a 72t secondary on the crank, then a 27t to the 11-34 8 spd cassette. As I said though the gearing is on point, it's a stress failure on chain and derailleur and a little too kwik wearing out new 27t 8spd sprockets.

I know I can make a good chain retention device to really help with chain jump. But that still leaves me having to replace chains or derailleurs all the time. Im going to go with a straight chain line and a spring tensioner by the top of the crank sprocket to the IGH. I think if I always shift easy I'll be OK

Any thoughts? Other than telling me to get a more expensive hub. I like the SA w/1:1 in first gear. So I can still wheelie LOL. I could be happy with the 3 spd and I may try that first so if im not and still want the 8 speed the 3 speed will go in my 2nd Schwinn electric to gas scooter conversion.

 

[wheelbender6]

I have heard that a 3 spd hub is adequate. Plenty of 3 speed Sturmey Archer hubs available used.

 

[Street Ryderz]

I have 4.25+ hp running thru an 8spd cassette. When everything is new it runns great! Kinda like a 125cc dirt bike!!! So I get confident in power shifting and pulling the front wheel up in 1-2-3 gears, then parts start to wear and skipping/dropping of the chain happens. Even if I notice strange skips and shifts and slow down to a crawl the derailleur will now start kicking the chain and destroys the derailleur. After 3 progressively stonger sram 8 spd chains and 2 decent quality shimano derailleurs. Im just done with all the wear and adjustments.

It's time for a sturmey 8 speed hub! I know im going to be pushing the stress limits of said hub but it has to be stronger than what I'm using. 14t engine drive sprocket off of a 5:1 trans, to a 72t secondary on the crank, then a 27t to the 11-34 8 spd cassette. As I said though the gearing is on point, it's a stress failure on chain and derailleur and a little too kwik wearing out new 27t 8spd sprockets.

I know I can make a good chain retention device to really help with chain jump. But that still leaves me having to replace chains or derailleurs all the time. Im going to go with a straight chain line and a spring tensioner by the top of the crank sprocket to the IGH. I think if I always shift easy I'll be OK

Any thoughts? Other than telling me to get a more expensive hub. I like the SA w/1:1 in first gear. So I can still wheelie LOL. I could be happy with the 3 spd and I may try that first so if im not and still want the 8 speed the 3 speed will go in my 2nd Schwinn electric to gas scooter conversion.

Just stop power shifting and do your wheel standing once engaged in the desired gear!It's not a trans with syncronized shifts your draging the chain across the tops of the teeth with 12 times the normal power running thru it!If you go pounding thru the gearing on a Strumey Archer hub you WILL grind the s**t out of the gearing in there too and they aren't cheap like a freewheel or cassette and derailer!

 

[gary55]

Speed shift in a car and miss a gear spun bearing. Speed shift with a derailleur eventually trash a chain or cog, same with a internal. So do you wana have a little bit of pricey fun or subdue your shifting and make things last. I'm into the later, but their ain't no harm in having fun if you can afford it.

 

[5-7HEAVEN]

Your bike's been down for quite a while.

Like Street Ryderz said.

I had a CY460 like yours.
I ran it thru stiff gears and a shift kit like yours.
I powershifted it like you.
I also broke a number of clutch springs, chains, cassettes and derailleurs like you.
When the clutch spring broke the second time, I gave up and replaced the 460 with a 3.5hp Tanaka 47R engine and pipe.

I haven't broken anything in years.

Bu then, I no longer powershift.

Word of advice?
Stop manhandling your 460, and it might stop breaking parts.

 

[dchevygod]

LOL 5-7. Yes is has been a struggle. But i cant put this little beast in a cage! Gotta let wild animals roam free. Ive just been busy with a new job and absent from the forums. Ive fixed this thing 6 or 7 times now and replacing derailleurs and chains is nickle and diming me to death.

Thanks for all the response guys. I've learned not to power shift at any speeds above 5 mph. I just like to hit first and let her eat from a stop.

 

[5-7HEAVEN]

I know the feeling.
It was very difficult for me to run the 460 without stomping on it.

I dream of running the 460 again...two of them.

Not so much for twice the power.

Two would be more reliable.

 

[dchevygod]

I totally feel the dual engine you are shooting for. If I wanted/needed dual... They would be axle mount on the front and rear, single speed @ 20:1 with 2 wheel drive and some beefy off road tires of course a dual pull brake handle or cable splitter to pull the throttles evenly or unevenly if the front wheel gets crazy lol.

 

[dchevygod]

Speed shift in a car and miss a gear spun bearing. Speed shift with a derailleur eventually trash a chain or cog, same with a internal. So do you wana have a little bit of pricey fun or subdue your shifting and make things last. I'm into the later, but their ain't no harm in having fun if you can afford it.

Really my problem is that all the vibration my high rpm "14,623 at a 56 mph wot in 6th!" causes, power shifting or not, makes the chain slack "that is inherent to a derailleur setup" it actually makes a visible wave pattern. Its a tripp to look down for a second and have to double take because of the "chain dance" wave pattern. That just kills a derailleur in no time at a cruise not even WOT!

My thought is. If I have bigger/stronger/smoother high quality chain with a straight chainline, perfect length and a spring tensioner that prevents torque from jumping the chain off the front sprocket on a beautiful piece of bike tech. It will be near bullet proof from the failures I have seen beating on mine like 5-7 and a few others just have to point out. I can still smash it in first just because 1st gear is 1:1 and the other 7 are overdrives that need a settling time before shifts. The S/A 8 spd will be very close in the final ratios to the shimano cassettes I run currently and I will change pedal cadence to better suit my ability to assist. Then I can avoid power shifting to save a $275ish wheelhub at all costs!!!

 

[5-7HEAVEN]

I hear you, man.

My 460 used to do that to my rear tire, when I ran friction drive.

Every square inch of the tire had chunks of rubber tread missing.

I ran several engines on friction drive. The 460 was the only one that did that.