T3 Rebel ATV rear end work.

[Brainsquishy]

Today we took off the T3's rear axle and sprocket. Found the three threaded holes used to adjust the chain which are hidden by the sprocket. Drilled a hole in the sprocket to access the holes. Pretty soft metal and bent bolts. Did it just in time!
Also put a grease fitting into the center bearing area.
Lots of pics and will post later.

Going for beer now...those darn beer loving buddies of mine again!

[waynev]

Don't 4 get the wings ! !

[Brainsquishy]

OK, so here are the pics so far:

A shot of the rear end ready to be worked...."get a good look city boy!"







This is a shot of the left side of the aluminum bearing chassis and the three threaded holes in its side. I think they are M-10 1.0.



This view is through the bearing chassis. you can see the steel centre tube. There is a space between its outer dimension and the inner dimension of the aluminum bearing chassis.







Here's a pic of the axle and the four bolts which hold the sprocket on. As you can see, we have some bent bolts here. I will be replacing these with some more sensible ones. They will be longer and then I put a lock nut on the other side of the sprocket to prevent future issues, because I intend on making this thing wheelie!
A note on the axle. You can see the two points the axle actually contacts the bearing chassis. They are the grey bands. The OD of the axle is slightly bigger at these points. This os where the centre tube (spacer) touches it. That means the is an air space between the two and a spot I want to fill with molybdenum sulfide grease to repel water. More on that shortly.



I then measured the spot where the sprocket needs the hole for the chain adjustment procedure. One hole slightly larger than the bolt hole. Now I will be able to insert a bolt or screw driver and roll the atv backward to tighten the chain after loosening the clamping bolts. Also, the clamping bolts where bent so I will be replacing them as well. Canadian Tire should have that in stock.


I didn't want to let this out, but yes I do have three hands. :oops:

Now we drill for the grease fitting. I decided to put it at the top of the bearing chassis when the biggest part of the eccentric is pointing straight out the back. When I tighten the chain, the chassis will roll downwards and still leave the grease nipple accessible.
There are two layers to drill through. First the outer aluminum housing, then the centre spacer tube. I drilled into the centre tube because it will be the only access point to fill the space between the axle and the centre tube. Remember that little space I mentioned earlier.






Here you can see the centre tube moving out of position as we drill into it. No big deal, it will align again as we re-insert the axle.



The finished grease fitting. We bring in 10,000 long shank grease fittings at a time into the shop regularly, so that's the one we used. 1/4-28
I was using the two screw drivers to practice turning the bearing chassis.



...more to come as we get the new bolts and find out why the rear brake stopped working on the last time we had it out. Also looking for a smaller sprocket. Need more speed as its geared way too low right now. I'll check at a couple of local shops for a decent match.
8O

Now, out for wings and waynev suggested.

[Weldangrind]

Too bad you ended up with two left hands and only one right (no offense to our Southpaw members).

I'm quite envious of your eccentric rear axle (loved the Cars reference; one of the most memorable lines for me ). Can you remove the spacer? If so, it would likely pay to drill a few holes in it. If I'm understanding correctly, the zerk is threaded into the outer housing, and grease has to then find its way into the hole in the spacer. Before grease can fill the spacer, the air needs to escape.

The axle housing in my Beast has a stepped edge for the bearings, so I deleted the spacer. Can you do that?

[Brainsquishy]

I think the spacer is stuck (for lack of a better word) between the two sealed bearing units. We did get one hole in the spacer, but I think the grease will fill it if enough pressure is used (more or less). The ends should let the air out. I doubt they are perfectly sealing the thing up. For what we did here, its not too bad I think. I used marine bearing grease with anti-washout properties to fill it after assembly.



Oh, here is the new sprocket hole which lines up with the chain adjust holes. I used this screw driver to turn the thing. Just stuck it in and rolled the machine in reverse.
NOTE: I have the performance shocks on mine and I don't know if that makes a difference, but I need to make the chain kind of tight because when i sit on it, the chain loosens, not tightens like my chinabike.



The best thing about these forums is its almost like open source code for chinabikes, everyone improves it as we go along. I'm sure the next guy digging into the rear end will do something better than me...
...kachow! I love that movie! Great ending.

[Weldangrind]

Great tip on the marine grease! Hadn't thought of that.

Uhh, he did what in the cup?

[Brainsquishy]

Originally Posted by Weldangrind

Uhh, he did what in the cup?

HA!

[Brainsquishy]

I just saw this on the Giobikes.com site. It's the new 2010 200cc GIO BEAST ATV Limited Edition.

This time they drilled the holes to tighten the chain.





I'm going to try and make a new rear bash plate out of aluminum or steel. I just got a CNC PlasmaCAM cutter in the shop and need a good project to take up my non-existent spare time. I'm going to cut a new rear sprocket as well. Just need to get a good picture of a smaller one and blend the image of the interior area of my existing one. Awesome shop machine!

[Weldangrind]

Originally Posted by Brainsquishy

This time they drilled the holes to tighten the chain.

You're ahead of the curve.

Originally Posted by Brainsquishy

I'm going to try and make a new rear bash plate out of aluminum or steel. I just got a CNC PlasmaCAM cutter in the shop and need a good project to take up my non-existent spare time. I'm going to cut a new rear sprocket as well. Just need to get a good picture of a smaller one and blend the image of the interior area of my existing one. Awesome shop machine!

Get 'er done! Can the new toy do 3D with billet stuff? It would be really cool if you could plot the existing bashplate and let the machine go (assuming you're talking about the rear axle bash plate).

What material would you use for the sprocket? I'd be interested in purchasing one if not prohibitively expensive.

I have plenty of that non-existent spare time also.

[waynev]

For our #40 chain microsprint sprockets i used 1/4" 6061 aluminum and cut them on a CNC router, i then anodized them and they held up quite well, not sure if they would take the abuse i give to my beast though.

If you need sprocket drawings let me know, in mechanical desktop there is a sprocket tool so i can draw them up in about 1 min, can you use .DXF for you new CNC plasma ?

[Brainsquishy]

Originally Posted by Weldangrind

Can the new toy do 3D with billet stuff? It would be really cool if you could plot the existing bashplate and let the machine go (assuming you're talking about the rear axle bash plate).

What material would you use for the sprocket? I'd be interested in purchasing one if not prohibitively expensive.

I have plenty of that non-existent spare time also.

I don't think it can do the 3D style your mentioning. It can cut up and down profiles like corrugated steel etc., but I'm learning this all from scratch. (scratching my head!)

The bashplate first on the list is the one you mentioned for the rear axle. I think the rest of the machine needs some plates as well, so I'll cut them out as I progress. I can get plenty of steel at various gauges so it doesn't really cost anything. Aluminum is harder to get for free. As an "entrepreneur" (defn: "he who does lots of things with not money and no net") I need to be cost sensitive, hence the chinabikes! I think I will need to cut out pieces then weld them together to make a 3D puzzle.

I will cut the sprocket out of steel, then make holes in it to reduce the weight. Same with the bashplates I guess.
The chain is a 530#90t, says the gio site. The sprocket would be cheap. The cost of the free steel and the electricity and compressed air to cut it out. The slight bevels at the teeth will need to be ground with a grinder or wheel by any new owners. Shouldn't take more than a few minutes to do.

I will need to pull my gear off the T3 again and scan in my desktop scanner. That way I can get the axle and bolt hole layout. I then scale it to the exact measurement and remove the outer portion of the gear on the software. The actual outer teeth is where I'm lost. I just need a drawing (yes waynev, the .DXF files should work.) with an outer exact dimension.
Once the drawing is finalized, I can cut them till the cows come home.

I don't know how many teeth to lose to get more speed out of the T3. Any suggestions?
I am going to put a performance exhaust on it and re-jet in the near future, so I can translate the new found power into useful forward motion. Its geared very low right now. I forgot to count the teeth today, but will do it tomorrow and post.

The machine is totally cool though. Got it cheap and it will pay for itself with just 6 product orders.

http://www.plasmacam.com/indexfla.php

This isn't mine, but it looks almost just like it.


Next machine is a Turret Lathe. Can get them cheap these days. Need to knock out one more supplier.[/url][/i]

[waynev]

Not sure if you need to scan your sprocket, if the GIO site is actually right than the " GIO Rebel T3 200cc ATV Rear Sprocket Specifications: 530#34 /φ40/4-Φ8.1/ 60 " sounds to me like it's a 34 tooth sprocket 530 size chain with a 40 mm bore and 4- 8.1mm holes on 60mm spacing. I can draw this up very quickly if you like and send you the .dxf, i will have to check the chain sizes i can draw in MD, i know i can do #50, will have to see how much different 530 is, PM me your e-mail address and i'll send you the .dxf.

[waynev]

Does this look about right, this is 34 teeth with the bore and bolt circle from the GIO site.



See EZ PZ.

[Weldangrind]

Wow. 8O That's really cool Wayne.

Brainsquishy (I was going to call you BS for short, but that didn't look right),
Check out the ratio chart from JT: http://www.jtsprockets.com/fileadmin...tgearratio.pdf

I don't have a specific recommendation about ratios, but Spud mentioned something about the number of drive teeth vs. driven teeth. I don't remember the specifics, so perhaps he can chime in. What I've heard is that you should never go below 12 teeth on the front sprocket, because the chain will be forced to articulate around a circumference that's too small (you don't want to gear down any further, so a smaller drive sprocket isn't what you're after).

[SpudRider]

Nice job, Squish! Thank you for posting the great writeup, and the excellent photographs.

I understand you are currently employing a 34T rear sprocket, and you are going to report the size of the countershaft sprocket as soon as you have time to count the teeth. Do we know which model sprockets your ATV employs? Also, do you plan to fabricate both sprockets, or just the rear sprocket?

Spud