Dual Suspension 'Roo'

[Theon]

Suspension feels good, there is plenty of final welding to do, but I've mocked her up again to get the position of the top/pivot mount on the suspension and to get a feel for it.
It kinda feels like a BMX monster truck, I will likely need a better shock for the rear, but I've got 6" or more eye to eye to mount a better unit, not sure now on the 20" wheels, it's got a good feel on the 26's, would be nice to have both.
It looks as though my KTM Fatty pipe will fit also, with a bit of a tweak.

it won't do pic's again?

 

[Theon]

I tried her on 20" wheels and she looked 'Top heavy', been for a pedal on her and it feels great, My next challenge is Disc brakes, and getting enough space between a 44t rear sprocket and a 160mm disc to fit a caliper, looks as though a 1/2" would be perfect.
But need some disc brake hubs, If I have to I will take the wheels from the Goat and put it back on V brakes, It would be a shame.
Will see what I can find.

 

[Theon]

I went back to Cairns yesterday and bought a n old GT Richochet for $100.
It has centerlock discs, nice rims and a reasonable set of front shocks.
Seems a nice old bike to strip, and I may have to put it back together with an old set of wheels and Vee brakes.
I have my knobbies mounted and swapped the gear set from 8 speed to a 7 speed with granny gear.
It looks as though mounting the sprocket on a rag joint will be easiest, and give me the clearance I need for the disc brake. However I will look into mounting the sprocket to the center lock.
There is a little more welding to do on the frame with engine and exhaust mounts, so far frame seems strong and I'm looking forward to my new engine arriving some time next week.
Will try and get a few more photos up this morning.

 

[Theon]

After realizing that my new centerlock wheels are 32h a rag joint wasn't an option, so I decided to mount the sprocket to the disc mount.
I drilled out the studs that hold the disc to its mount, drilled out disc and mount to 6mm, and drilled the sprocket also to 6mm to match the spacing.
I thought about making a spacer ring, but ended up just using 6mm nuts to space the sprocket and disc.

 

[Theon]

Still a little more welding to do, but I have the bike working well on pedal power, It rides nice.
My new motor is still in the post somewhere, but everything takes a little longer to arrive up here.
I bought a can of metallic charcoal paint for her, I'm not going for a flash paint job, this bike is my bush basher.
Next step is to make a caliper mount for the back brake, and to squeeze a carby in there.

 

[HotRodRob]

Coming right along nicely Theon. You're gonna be spoiled with that dual suspension. I no longer cringe when I go over bumps and pot holes. My back can handle longer rides now too. I'll be checkin back in for sure. Keep up the good work mate. What carby are you gonna use? What are your plans for exhaust?

 

[Theon]

Good questions Rob, I'd like to try this new motor stock before testing mods.
And just peddling this thing off a few small drop offs, I am impressed, however a dampened rear shock would be better as it can have the tendency to bounce you off of your seat on a decent pothole, but still better than no shock.
Carb, I have limited room for a speed carb, however may just squeeze one in with a custom offset manifold. I'm leaning towards using a 15mm barrel carb, would really like to put a reed valve in there also, so the barrel carb or walbro will likely be the best fit.
Exhaust, again will start off with standard pipe, but I have already started trying to get a KTM 'Fatty'/Pro pipe to fit, and it looks as if it will with a bit of a cut and twist and a different header.
I found a standard bicycle caliper in my junk pile that just squeezes between disc and sprocket today, giving a neat installation,
New motor will be here any day, But I really need to find the time to finish the frame and give it a quick coat of paint.
It's school holidays now, so between work and kids...

 

[Theon]

My Roo has arrived!
So I did have a longer than anticipated wait,
However, this thing is obviously 'handcrafted'.
It appears to have been test run.
Everything about this engine kit so far (it is mounted but not yet tested) has been spot on, to many details to list, but the fins on the barrel have been given a touch up and look neat.
It has 306 S/S head fasteners with helicoils in the cases,
All Allen head fasteners,
Nord lock washers,
Everything is greased properly,
Discreetly laser cut 'decals'.
High performance and reliability Mag coil.
Quality plug cap and lead.
Good quality chain,
44t and 39t sprockets,
6mm studs on the fuel tank,
NGK plug.
Speed carb,
ect., ect.
If you are looking for a Quality engine kit, without all the mucking around of putting it together your self, http://screamingroo.com/online-store/category/engine-kits/
I have not been 'rewarded' for this review other than the quality of what I have received.
I've basically just got to try and fit a carb in there somewhere and I'll be giving it a good thrashing!

 

[Theon]

A couple of photos of the test installation.
will put up some more detailed photos at some stage.

Tomorrow I should be able to get a carb on her and go for a spin.

 

[Theon]

I got up early this morning,
with a mission, to get a carb to fit on my new bike.
I gave up, and so borrowed the 'twin's' from my Softail,
They may become permanent, as they should be able to feed my Roo a healthy diet, and look mean.
So otherwise I've left the motor stock for now,
Installation was drama free, with the only 'moddifications' other than the carbs being a slight twitch of the exhaust to clear the pedals,
I gave the exhaust a slight match porting, but was a much better size opening than any of my other standard pipes,
The chain guard needed clearancing for the heavy chain.
It's a beautiful day, we've had a bit of light rain yesterday, but sunshine today, All that's left to do is trim the steering tube and take her for a test run.
It's just still a little early here for noise.
I also have the missing pieces to my case induced Mongoose, so hope to get it running very soon.

 

[Davezilla]

Looking Good!!
That's gonna be a really nice ride once you're done and that engine looks great with the twin carbs on it

 

[Theon]

It runs nice, idles slow and sweet, loves to rev and has a very 'linear' power delivery that makes you want to 'see what this thing can do'.
I thought it best to return home and stick a Taco on her, as I should be kind to it for a short period.
It does not have the low to mid grunt that my Goat does with the reeds and pipe, there fore not as much fun off road, but much better on the road, smooth and revy.

 

[Theon]

Cheers Dave, Wait till I get this pipe on her.

 

[Theon]

I've already wrecked the front rim on my new bike,
Got it caught in a cane rail track crossing, I don't think the rim can be straightened, and am considering ordering a pair on 24" rims that are on Ebay.
The tyres I want are $50 each!, but have a cheap set of 24" tyres to go on.
But a good excuse to strip the bike down and finish of the frame.
This is a very high revving motor, I was hesitant at first to see what revs she'd do, and by the time I was giving the bike max revs it was dark and I couldn't read the taco, then I buckled my rim, very impressed with the top end , very smooth and didn't seem to have a max revs.

 

[Davezilla]

Good to hear you got a good reving engine in that one but I'm sure it really bites that you wrecked the front rim... I guess this is the best time to break it all back down for painting tho since you'll be waiting for new rims to come in.

I'm in the same boat with mine where I'm so close to finishing it the way I want but I also know it all has to come back off so I can finish up a few welds and then paint the frame. It is rideable now but with some of the welds just tacked into place it's not something I would rely on or ride more than a few hundred feet away from the house. the short rides I have taken it on up the street did let me know the engine is pretty much spot on with good aceleration and I can feel it wanting to go faster but it's far from broken in still

 

[mapbike]

Nice looking Bike Theon, I'll be watching to see the finished product.

Map

 

[Theon]

Cheers Guy's,
This motor comes recommended with a 39t sprocket and after giving it a good strapping on a 44t, I'm keen to try it on a 39.
I didn't get the low to mid grunt from this motor that I do from my reed valve motor, however top end is really good, and I feel is better suited to road bike, The Goat has a much lighter frame, Much better brakes and now has a reasonable set of road tyres and a 39t sprocket.
So the plan is to put my new Roo in the Goat, leaving it stock for now, well, we'll see, I am tempted to give the motor a little more compression and have a bit of a play with the transfer ports, but I want to do this motor step by step, so I can see the improvements of each mod, however I am aware that certain mods work best in combination, and I am aware that Dino when building this motor has put a fair bit of development in to getting it to work so well, he has obviously found a good 'balance' of power, reliability, and Cost.
The Twin carbs seem to be working nice, with plenty of throttle in reserve, the motor was doing amazing revs and not even WOT. However a big Walbro is probably what I will have to use due to space restrictions, and maybe wanting to run a muffler where the left side carby is.
It has a strange dual personality, where it is very quiet and a little 'tame' until you get the revs up, Then the 'Turbo' kicks in, the exhaust note changes to a louder and more aggressive note, and takes a fair bit of backing off, to get the motor to 'calm down' again. Dino has obviously 'sacraficed' a little low down to get this motor to run sweetest in the higher revs, I'm not sure that I should mess with it to much. I even like the nice quiet low speed operation, and am putting a fair bit of thought into the exhaust, the Exhaust I built for the Goat was aimed at low to mid, and I will have to try it on the Roo, it may improve my low down, and I can't see how it can hurt my top end over the standard pipe.
I have found a cheap set of reasonable 24" Rims, and have decided this way on my 'Dirt bike', which will get the Phantoms bottom end with the Goats Top end and reeds. I am starting to get a bit of a shopping list for my 'Dirt Bike', and would like to do it right, so may have to take my time with it.

 

[Davezilla]

Sounds good... Definitely take your time with it and it'll come out nice in the end...
As for that Roo engine, I'd probably not mess with it too much if it's running the way you like it, but I'd definitely map out the porting and record all the port timings in case you need to go back to the way it was when purchased or if you ever need to replace a jug or piston if the piston is indexed as well.

 

[mrfubs]

NICE! This is coming along really well! you did a very nice job on fabbing up the rear, i do have a question though. Did you cast that intake manifold your self? it looks like a alloy

 

[Theon]

Thank's Mrfubs.
The new Roo motor is now residing in the Goat, with the torque pipe and chainsaw Weber, it is obviously more of a fast/street motor than a Dirt bike motor and I think it suits it's new home.
I have ordered a set of 24" Rims for the dual suspension bike and striped the her for final welding and painting.
It will get the reed valve motor, possibly with the twins feeding the reeds? as I liked the way they looked.
The manifold is welded scrap steel and some of my welds were that bad that I ended up welding over it that may times, it took a fair bit of grinding, and so ended up with that cast look. The manifold fits the Soft tail nicely, and I'm still deciding on trying to make another for the reeded motor, as it was quiet a feat to get it to fit so well with both carbs level and in line.
But I'm not sure that my $15 barrel carb is giving this motor everything it wants? However does fit nice, maybe with a UFO style filter and was giving me good throttle response.