#219 Chain Front Sprocket Suppliers?

drewjet

drewjet

10 kW
Joined
Jan 23, 2008
Messages
821
Location
Orlando, FL USA
Ok, you guys convinced me of going to 219 for it's superior chain selection and rear sprockets. I got my 3220 coming from Astro-Bob. Now I need the front sprocket for a 3/8 bore

http://www.cometkartsales.com/store/sprocket/dd.htm

These seem to be the only front sprockets I can find. I think they are a tapered bore and too large.

Anyone got a source?
 
10t - too large? Or you mean the bore?
Down to 12t straight bore here: http://www.gokartgalaxy.com/engine_sprockets1.htm (scroll down)

Also, Gary will have some machined - once I get around to modelling them :)
 
Miles said:
Also, Gary will have some machined - once I get around to modelling them :)
Click to expand...

Yes, a 12T to start. I don't think we want to go below 12T because even my 11T #35 sprocket makes quite a bit of racket, mainly starting out. This is due to the... wait for it... chordal effect ( yes, Miles, I remembered... that's two-in-a-row... :roll: :mrgreen: ), which basically means that the fewer the number of teeth the chain has to get around, the harder it is and the more noise it creates. It doesn't matter what size/pitch chain or sprockets.

Anyway, I'm going to get some steel 12Ts made, with hardened teeth and a 3/8" bore. It will have a hub with two setscrews.

-- Gary
 
Gary, You are the man, and my God what a memory, Chordial, who wada thunk it.

Gary I would really like one of those spocket adapters as well, any chance of getting one? How long before you think the sprockets will be ready?

Next question, best chain? Is O-ring chain more effecient? Best place to get it from?
 
Does #219 come in colors, cause I want hot pink!! :lol:

Actually Gary I will take 2 please, if you are taking orders.

Interesting question about the O-rings, anybody have an answer? Miles? Matt? Physics?

I would think the inefficiency of a chain comes from the action of bending around the small sprocket, so the Chain with the least resistance to bending wins? :?
 
etard said:
Interesting question about the O-rings, anybody have an answer? Miles? Matt? Physics?
Click to expand...
I've no experience with them. I guess they'd have more drag (less efficient) but significantly longer life under adverse conditions.
 
Hi Gary,

GGoodrum said:
Yes, a 12T to start. I don't think we want to go below 12T because even my 11T #35 sprocket makes quite a bit of racket, mainly starting out. This is due to the... wait for it... chordal effect ( yes, Miles, I remembered... that's two-in-a-row... :roll: :mrgreen: ), which basically means that the fewer the number of teeth the chain has to get around, the harder it is and the more noise it creates. It doesn't matter what size/pitch chain or sprockets.

-- Gary
Click to expand...

I think the RPM is a major factor. I think D is using 11t and I think his bike is pretty quiet. The difference is that on his bike 11t is the second stage after a belt first stage reduction so the RPM is much less.
 
etard said:
Does #219 come in colors, cause I want hot pink!! :lol:



Interesting question about the O-rings, anybody have an answer? Miles? Matt? Physics?

I would think the inefficiency of a chain comes from the action of bending around the small sprocket, so the Chain with the least resistance to bending wins? :?
Click to expand...

I've seen people doing back to back dyno's to show that a fresh O-ring chain has more frictional loss than a "race" chain that is not sealed. Even right out of the box, when they are so stiff to bend you can stand 3ft straight up and they stay, there was no detectable difference on the dyno, and this was by people trying to prove that the racing chains made gains. I think this is because they can use superior types lubrication inside the chain that couldn't be used without the O-rings to seal it. In an application with lower stress loading, I'm not sure if it would make more of a difference. Once an O-ring chain has been run for an hour or two, it feels pretty supple. They last forever. I don't think you could wear one out on an E-bike driving around the world. BTW- I would recomend "X" rings, or "quad-rings" over O-rings.

Best Wishes,
-Luke
 
Gary- You are the man for having sprockets made! You know I will be getting some from you :)
 
My guy got busy with a big order for Boeing, but it has been a couple weeks, so I will check with him and see when he can do the 12t #219 motor sprocket. He has the CAD files that Miles sent me.

-- Gary
 
I am getting ready to bore the taper out of the sprocket I bought,
If I can help any one out let me know.
Looks like all the straight bore one are 3/4" through. We may need some step down adapters, again If no has any yet I can run a few to cover some commom shaft sizes.
 
Thats 2 adaptors? .75" reduce to 8mm VI?
 
To use one of Matt's single-stage drives with a #219 final stage, I would only need a ratio around 3.5, e.g 22T driving 77T.

I've noticed there is a large gap in the range of available tooth counts, I haven't found anything between 18 and 72.

Can anybody help with this?
 
Gary,

These would be a great item to stock - 8mm and the 10mm for larger bore, in #219 I would go 9,10,11,12,14 if you don't want to run that many then 10, 12 and 14 or just 10 and 12t in 8/10mm with set screws.

Id take 10 of them (10x in each 8 and 10mm so 20 units) upfront if needed to cover costs of initial production, I'm sure other would too... my 8mm 10t I had made by a local machine shop and it fits my Tower Pro or one of the Axi's I have nicely - I just got it back yesterday (took a week cause I was an on the side project for the machinst) and it wasn't too bad on the cost but it took me near a month to find someone to make it locally and I couldnt' find a non tapered 9 or 10t 8mm to fit the motor from any vendor online.

-Mike
 
I've noticed there is a large gap in the range of available tooth counts, I haven't found anything between 18 and 72.
Click to expand...

I noticed that also, they may have to be custom made if you wanted a 50t or 60t or similar. I think the reason is that Kart riders only need certain sizes and anything else wouldn't sell so it doesn't get made.

just to think out loud with some numbers...

using astro 3210 10 turn - 135 Kv
at 48volt = 6480 rpm
if you wanted to go almost 35mph you'd need 450 rpm for 26" wheel.
thats 14.4 : 1 ratio
or 2 stages at about 3.8 : 1 each
12t - 72t = 6 : 1 ratio, may be noisy with 12t
18t - 72t = 4 : 1 ratio, which may be a bit quieter

I guess my tentative vote then is for an 18t 8mm bore sprocket :mrgreen:

I was considering a 3/4 bore sprocket from here http://www.gokartgalaxy.com/engine_sprockets1.htm and machine a bore reducer, but if Gary has a sprocket made 18t with 8mm bore I would definitely buy from him.

Here's a page with some sizes, and they have 66t listed as the smallest available http://www.pegasusautoracing.com/kart-sprocket-pitch-diameter.asp , but when you go to their sprocket selection 72t is the smallest they stock.

edit: duh, I forgot to factor in the geared hub, so I probably would want the 12t :roll: I guess the more sizes available the better :D
 
This is about going single stage.

128t rear, 12t front. Something along those lines.

128t extron sprocket in 219 pitch is actually a pretty small diameter sprocket, and it would be very light.

Each stage means throwing away a few % power, and adding complexity and weight. Getting it done in one stage is what its about IMO.

Keep in mind, the 130KV motor is terminated in delta, so if you tease the leads apart and terminate in wye, your 14:1 reduction needs become 8-9:1. Also, 35mph top speed would be kinda lamers :)
 
wow Luke, now you got me thinkin again :)

128t rear, 12t front. Something along those lines.
Click to expand...

are 128t sprockets available or are you talkin custom made?

128t extron sprocket in 219 pitch is actually a pretty small diameter sprocket, and it would be very light.
Click to expand...

a 103t is about 10in so 128 would be about 12-13in?

a 48v 10 turn in delta 12t - 128t is 10.66 : 1 ratio giving a top speed of 47 :shock:

with the sram dual drive in top gear we're talkin top speed over 84mph :shock:

I must be missin somethin here, I like the single stage idea, but not sure how it's possible w/o breaking the sound barrier

I don't know much about wye mode, do you plan to run your motor in wye most of the time? are there drawbacks to that? if not why aren't they wired for wye by default?

sorry to bombard you with questions, but I'm really curious about this. If I could pull off a single stage build I'm all for it :twisted:
 
Wye mode is fantastic for ours uses with RC motors. Generally picks up a couple percent in efficiency as well.

They don't use wye from the factory because it requires making 3 solder connections. The way they like to do the motors requires zero solder connections, they just run the leads outside the case and bundle them up with heat-shrink and call it a day.

1.73 is the multiplier to go from wye to delta.

A 130kv becomes a 75.1kv motor when you re-terminate the windings to be paired in wye rather than delta.

Makes things a lot more reasonable to fit the reduction we need, and it should make for a quieter drive setup with a tiny bit better efficiency (less heating = more power potential :p)

It's a win-win IMHO.

And yes, a 128t extron would be custom, which they claim to offer as a service. I'm thinking extron sprockets with an inside made to bolt right onto the outside of the ENO bolt/flange freewheels.
 
Just as something to think about, your example above where you want a peak speed of 35mph, if you terminated the motor in wye, you would just need an 8.3:1 reduction.

That would be a 100t rear with a 12t front, which are completely reasonable sprocket sizes.


If Gary makes just 12t sprockets, we can tune the ratios we want easily by picking whatever rear sprocket size best suits our needs.
 
dude, I just became a fan of wye :D it sounds great! Is there a way to solder these connections on my current 3210?

If not I'm going to request the 6 wire thing on my next motor in the astro group buy deal and go wyeeeeee :mrgreen:

edit: ok the initial excitement has worn off and I did some more calculations and it seems for my riding style a 2 stage reduction in delta is the way to go. otherwise I will need a huge chainring to pedal comfortably. also my bike has no shocks so over 35mph seems a bit fast to me. I still like the idea of having 6 wires though in case I want to experiment.

sorry to get off subject, back to 219 sprockets :D
 
on a side note of delta/wye configs, I modded one of my cheapo motors and yes it did reduce the speed and increased the torque but ( for reasons i didnt bother investigating due to my gearing is ok in delta ) ran hotter under load.
 
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