DIY Shift Kit Project--'The Shifty Beast'

[lowracer]

Today I swapped the transmission output sprocket to a 10T (from the 12T).
I didnt start it up to test drive it yet, but definitely will this weekend.
I'm looking forward to the change in gearing & picking up a couple extra useable gears on the cassette.
Stay tuned
-Lowracer-

 

[lowracer]

Oh yeah! the 10T was the hot ticket
In 1st gear the 10T allows the engine to get on 'the boil' much quicker for great launches from a dead stop. I was able to get it up into 7th gear, but I didnt rev it all the way out & dont have the tach hooked up for top speed calculations. Here are the ratio's for each gear with the new gearing changes. I'm definitely sticking with the 10T.
- Tanaka 47r (~8750 max rpm under load)
- 26" mtb wheel
- 10T : 44T (44T/24T on front freewheel)
- 24T : 34T/11T cassette
1st - 34T = 31.15:1 ratio = 21.7 mph
2nd - 30T = 27.5:1 ratio = 24.6 mph
3rd - 26T = 23.85:1 ratio = 28.4 mph
4th - 23T = 21.1:1 ratio = 32.1 mph
5th - 20T = 18.35:1 ratio = 36.9 mph
6th - 17T = 15.6:1 ratio = 43.4 mph
7th - 15T = 13.75:1 ratio = 49.2 mph
8th & 9th fuhgettaboudit!
-Lowracer-

 

[Dan]

.........
8th & 9th fuhgettaboudit!
-Lowracer-

lol LowRacer.

and congrats on your success!

 

[lowracer]

Thanks Dan.
I may need to re-install the front derailleur for inner chain management for the 24T front chainring. I took it out for a spin & got about 2 miles away when I experienced 'chain suck'. I rolled over a bumpy section of road & dropped the chain. The chain came off the little ring up front & lodged itself below the exposed nylock nuts that hold the small chainring to the freewheel. I was using dead leaves to grab the chain, trying to keep the grease off my hands. After a few minutes of this, I grabbed the chain with both bare hands still unable to free the chain.
With my left foot on the right pedal & my right foot pushing off the ground like skateboarding, I pushed my way home.
I removed the right crankarm and rearranged the bolts and spacers to remedy this problem. Now the nylocks are on the outer portion of the freewheel and the smooth mushroom allen bolts are on the inside. I'll still going to install the front derailleur, adjusting it just off the inside of the chain to hopefully prevent another dropped chain.
-Lowracer-

 

[lowracer]

Today I set out to remedy the chainsuck problem I had.
The front derailler isn't going to work since the chain rides on the lowest part of the derailleur and it can't be moved down any more due to the bike frame design.
I installed a 27T chainring (bought but never used) inside of the 24T. It prevents the chain from going off the 24T and down onto the bottom bracket shell (see pic)
While I was at it, I also installed a new shifter inner cable & housing. I lubed the entire length of cable with a very thin grease (000). This grease was tough to find, I spent days trying to find it to lube the internals of the pocket bike 5:1 transmissions awhile back. It is very watery and perfect for slick shifting 9 speed derailleur cable.
What a difference the new cable has made. All shifts go off without a hitch (no ghost shifts).
-Lowracer-

 

[lowracer]

Here are a few more pics of the changes to the drivetrain
-Low-

 

[BarelyAWake]

Something you may be aware of but I figured I'd mention it anyway jus' in case - with the speeds we're running chain whip can be a real issue and what lube you use can make a huge difference. This is a new, high quality mutispeed chain with a medium/light lube yet if you watch the vid (partic 5-7 sec mark) you can see the chain slap around quite a bit (top/return in this example) https://www.youtube.com/watch?v=_GTS0xG8BPM

While I was using a chain wax I'm normally fond of for summer riding - it is formulated for motorcycles and a touch heavier than oils, after switching to a light machine oil most of the slap went away... anything thicker than that chain wax could most likely cause some problems. I suspect some of the derailleur failures folks have had were the result of binding links or gummy chains & not the derailleur itself as they haven't any real load on 'em.

Jus' a thought

 

[16v4nrbrgr]

I'm gonna try using White Lightning to see if I can keep my setup from getting the normal gunk light oils attract. I am kinda amazed that I was able to ride and up and downshift and it actually works, lol!

 

[lowracer]

BarelyAwake,
Thats for the input.
I know I have some White Lightning somewhere around here in all my stuff.
After the 1st chainsuck experience that lodged the chain into the chainring mounting hardware, I inpected all the links and found one where the link plate was coming off the pin. I've since removed the link and shortened the chain a few more links. 1st gear has the derailleur pulled forward a bit and seems to working well.
IMHO, These thin 7-8-9 spd chains on derailleurs are the weak link.
I'd like to find a 6 bolt brake, 135mm width, MTB rear wheel with internal gears. I'd run a std #410 bmx-track-fixie chain (same as what I run from the engine to the big chainring)...Nothing like a straight chainline.
Anyone know of such a wheel?
Thanks,
-Lowracer-

 

[lowracer]

Here is a Nuvinci rear wheel I found on eBay but $500...?
The hub without the spokes and rim is $199, then build up my own wheel.
I'll may just need to control my throttle hand better with the derailleur/cassette.
lol
-Low-

 

[5-7HEAVEN]

Thanks for props, lowracer.

You're running into the exact same issues I encountered @ the bottom bracket.

I also reversed the nuts and have the allen button heads on the inside. Then the right-side crank arm needs a LOT of clearancing to clear the outside flat nuts.

When the chain jumps, kill engine and stop immediately. Carry spare gloves to work on greasy chain. ALWAYS carry TWO spare chains and master links. Cut your chain to perfect length, then add a link. That way, you can repair the chain at least once before trashing it.

I must've gone thru at least 12 chains and 4 derailleurs and 2 cassettes.

Sometimes lifting the rear tire and spinning it backward will unsnag the chain@ the bottom bracket.

It helps to keep the chain on by rarely using first gear and the last two gears.

Yes, it'll be simpler and easier to maintain if you convert from cassettes to internal hub. Remember to keep your gearing low for best performance.

With the smaller 10t sprocket, you've JUSSSST begun to reach the "enjoyment" range. Keep lowering your gear ratio, and your bike will come alive!!!

 

[5-7HEAVEN]

Today I set out to remedy the chainsuck problem I had.
The front derailler isn't going to work since the chain rides on the lowest part of the derailleur and it can't be moved down any more due to the bike frame design.
I installed a 27T chainring (bought but never used) inside of the 24T. It prevents the chain from going off the 24T and down onto the bottom bracket shell (see pic)
While I was at it, I also installed a new shifter inner cable & housing. I lubed the entire length of cable with a very thin grease (000). This grease was tough to find, I spent days trying to find it to lube the internals of the pocket bike 5:1 transmissions awhile back. It is very watery and perfect for slick shifting 9 speed derailleur cable.
What a difference the new cable has made. All shifts go off without a hitch (no ghost shifts).
-Lowracer-

Thanks for the tip of running a larger chainring on the inside as a chain guide. I'm gonna do that. Do you think your chain will ever jump onto the 27t sprocket? I'm gonna use a 30t-36t as a guide and keep my chain adjusted tight. that way, chain suck should never happen again (altho I haven't had a chain suck in months, knock on wood).

 

[lowracer]

5-7,
I dont think the chain can jump onto the 27T since the 27T is a 1/8" & the chain is a skinnier 9 speed chain.
So far so good, but I'm riding it very gingerly, not trying to do high rpm until I know my new derailleur cable is done stretching.
After shifts, I get back on the gas nice and easy to avoid driveline lash.
I know this is going to sound contrary to my earlier rants about 'keeping it simple', but since having my new toy: aka: shift kit, 'The Beast' has never been more ferocious. I am seriously considering building a wheel with a Nuvinci hub w/ 6 bolt disc rotor.
How cool would it be to run a perfectly straight #410 track bike/bmx chain to the rear hub and have a CV transmission without a rear derailleur or cassette?
I already have a brand new rear wheel with a Sun Rhyno Lite rim that I got for $10. The Rhyno rim is my favorite & could be used to build up this new wheel.
Just need to do some more research on the Nuvinci (reliability?) and shop for a much lower price.
-Lowracer-

 

[unknownbmxa88]

i heard that motors eat those nuvicini hubs. i have also heard that they work sometimes...i do know that you cant shift under power.

 

[16v4nrbrgr]

You should try a Sturmey, they're pretty stout under power and easy to rebuild. The 3 speed ones under $100 are pretty dang good and will serve your purpose well.

I'm having issue with my new derailleur cable stretching and falling out of low gear, hopefully that problem stops once it take its final set. I got the 1:1 SRAM to avoid the derailleur skipping gears but I guess it needs to break in.

For 9 speed chains I went with that expensive Wippermann because they supposedly do twice the miles of a standard chain since the links are stronger, but also heard that KMC makes a decent 9 speed chain that lasts a long time. Chain stretch might be an issue but I'm hoping the derailleur will take up the slack so its unnoticeable.

 

[lowracer]

I had a sachs 3 speed internal with a 7 speed cassette on a Greenspeed trike a long time ago & it was a very reliable hub. Since then Sachs has been bought by SRAM and they still make it but call it DualDrive. If I go internal, I dont want a cassette. I've been looking online for an internal hub already built up into a 26" wheel w/6 bolt disc mount, but not much out there for cheap.
I'll keep the cassette & derailleur setup until I start breaking too much stuff.
-Lowracer-

 

[BarelyAWake]

I personally prefer the Sturmey Archer X-RD3 three speed internally shifted hub I have on another jackshafted build over the seven speed cassette I've referenced above, I didn't use it for that specific build for two reasons - the first being it's a hybrid with a hub motor so ISH wasn't an option, the second is perhaps more relevant to the topic at hand.

While the internally shifted hubs like the X-RD3 have been used with great success, they seem to be right on the edge of their preformance envelope with even the 66cc in-frame kits. Push it much farther with heavier loads, greater torque and/or aggressive usage and there is the potential for failure. This doesn't mean a cassette is any more durable or less likely to develop problems, rather in my experience the opposite may be true - it's that a cassette is far easier and cheaper to replace/repair if there is a failure, odds are it will still get you home even still.

It's a judgement call based on your build - the ISH is cleaner, easier to operate, chain maintenance/repair is simplicity itself and in general more reliable than derailleurs... but should it fail it tends to do so catastrophically and expensively, you're walking home, buying a new hub & building a wheel. With a cassette you're most likely just stuck in a gear but it'll limp you back.

This is all just food for thought, should I remove the hub motor from my hybrid I'll most likely replace it with a ISH... yet having said that due to the torque (four stroke), the application (trailer hauling) and the whims of Murphy - I'll leave the derailleur mount & keep a cassette wheel handy, just in case

 

[lowracer]

16V & BarelyAwake,
Thanks for the input. I'll probably end up running the derailleur setup until chain or derailleur problems begins to occur. In the meantime, I'll be hunting for a good deal on a Sturmey. Now that I've tasted the sweet Motorbicycling Bliss of multi gearing, I'm sold.
-Low-

 

[16v4nrbrgr]

I chose a derailleur for my latest build since I have broken Sturmey parts under massive electric torque, and saw that Hanebrink uses a derailleur on his electric minibike, so I figured I'd give it a try. I definitely like the wax chain lube it was easy to use and it makes installing the chain a clean deal. I'm a bit hesitant to raise the stall speed on my clutch, which needs it to get into powerband, because then it makes more power before engaging harder.

 

[unknownbmxa88]

anyone ever tried one of those 5 speeed stumney hubs?