In the begining...

Avolio G

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#1
New to the forum and considering my first build. I'm curious as to what any/everybody might thing of the bike I am hoping to start with.
The basics that I have...
Frame - '96 Kona Cinder Cone size small 14"
Shock - Marzocchi Atom Bomb Z2 60mm travel, Coil and Oil
Head Set - Chris King
Stem - Diamond Back Billet
Bars - BMX style handle
Drive - RaceFace cranks, single speed 34/19
Brakes - XT side pulls - front and rear
Wheels (F) Rolf Dolomite or Alex 18, (R) LX/Mavic
Kona wo motor.jpg

I was a bit worried about being able to squeeze a motor in the triangle but I think after mocking it up with a friends parts motor, it will work. I think it will need an offset intake and I will need to grind a little from the mounts.
Kona w motor.jpg

Does anyone have an opinion about using a light butted cro-mo frame?
I have a little welidng experience and own a small mig and have considered adding a few gussets in some corners.
I'm not sure of a direction to go other than the obvious... keep it light simple sort-of motocrossish.

Again, I am new to this, and looking for suggestions and input before I move forward.
My current plan is to pickup a basic 66/80 kit and see where it takes me.
Thanks for taking the time to look.
MF
 


Frankenstein

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#2
Well everything seems good at a quick glance, butted and cro-mo is probably as good as you ask for too, the frame will probably outlast you if it doesn't end up being crushed at some point. Make a point of not crushing yourself either and wear a damn helmet.
 

FurryOnTheInside

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#3
I would change the wheels to something much heavier and with 36 spoke disc compatible hubs before starting, personally. I don't ever want to try the rag joint!

I would pick a lower rise bar, too; but that's personal preference.
 
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Timbone

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#5
I wouldn't weld into that CroMo steel frame (especially if it's FluxCore) unless it's absolutely necessary.

The weak spot in the entire system is the rear wheel. My experience and experiments have shown me that a "normal" 3/8" bicycle axle is not adequate for long term durability. That's a tough hurdle to surpass and I am working on an improvement. I think 1/2" axle is almost mandatory for safety. Everything falls on the rear axle.

So, in lieu of a new design, a normal bicycle rim will not stand up to the stresses. Get a bicycle rim designed for downhill racing. They can take it.

As for the rag joint, done right they can be s good cheap alternative to the clamshell adapters. But $ for $, a good fitting hub sprocket adapter will save you tons of problems. Still, even with thread locker, you must check the bolts often - they can come loose!
 
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Frankenstein

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#6
Oh and I forgot to mention it but you reminded me, he shouldn't even have to weld a gusset anywhere on the frame, it really should stand up to the challenge unless he gets as crazy as some of us do with getting max power from a motor.
 

Avolio G

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#7
It's taken a minute. Thanks to everyone who took an interest. The build is moving forward, all be it a little slower than I maybe thought it would.
First off, I received an old touring bike, I robbed the rear fender to modify for the build, also the matching chain guard. Switched out the front rim (more spokes), Conti town and county tires, different crakes and gear ratio(a perfect fit, no need for a tensioner), and I have already 86'd the gel seat pad.
IMG_20171010_001315.jpg

Finally got an engine kit last week. Came as expected. $125 delivered, seems all intact, probably in the same box it came over from China in. It's a good thing I've seen a few different bikes and feel that I am fairly mechanical. I could have sworn the seller said there was some documentation that should have been in the box.
As I thought, it is a pretty tight fit. The following pics were taken after I cut 1cm from the rear mount block and filed about 3mm, adjusting the front mount.
IMG_20171017_020042.jpg

IMG_20171017_234220.jpg
IMG_20171017_020055.jpg


Real tight indeed. You can see the first thing I had to tackle, there is certainly no room for a carburator. I tried an offset, no luck. The angle was way off. The carb was no where near level.
So what does someone who sees himself as being crafty do??? Builds a custom one of course.
IMG_20171022_000022.jpg

IMG_20171022_000042.jpg

Went to the local big box store and picked up some 19mm steel tubing and some 1/8 inch strap. Bent the pipe, a little heat and some persuation with the ball peen, drilled the plate and stuck it together with bronze braze. Got it all cleaned, heat stained and clear coated tonight.
IMG_20171023_234730.jpg

IMG_20171023_234810.jpg

IMG_20171023_235827.jpg

The intake is about 5 1/2 inches long. And can be shortened about 1.5 inches if needed. if I shortened it I will not be able to access the idle screw because of the seat tube. I have also started to look for a place to attach the cdi. Any opinions??? Up front under the tank, or back on the seat tube???

Next thing I need to do to get a little closer I'd modify the exhaust. The left pedal does not clear it. Hit about dead center of the muffler. Anyone had good luck bending them? I would like to get it to line up with the down tube if possible. I may have to make several small slices, bend and weld. I plan to build a full custom exhaust after I get a chance to break it in. I will have plenty of time, I won't be riding much during our Michigan winter

Hope this was not too long.
Looking forward to comments, ideas and insight.
 

FurryOnTheInside

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#8
Looking great so far! :)

Intake length is from the front face of the carb slide to the rear face of the piston, 7-7.5" for best grunt according to a couple of sources so I think you probably have it about right. :)
The carb will need to be secured against the seat tube with a strong cable tie to prevent the vibrations from cracking the brazed joint, I reckon.

I read that a shorter spark plug cable is better, and the CDI likes to be kept cool but idk how much difference it makes.
Certainly the cable and boot from the kit is not high quality. A replacement wire and NGK boot is inexpensive enough to be well worth getting.

I had the left pedal hitting the muffler too. I just had to elongate the holes in the flange so I could rotate it slightly, then also dent the side of the muffler just a bit, which worked fine. :)
The muffler needs support to prevent it cracking off, just like the carb.
 

Steve Best

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#9
Your build looks great. That Kona should be a tough bike, no worries.
I didn't like a long intake, it cut from rpm too much for me, but you clearly have the skills to experiment with that.
 

Avolio G

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#10
Well I have not posted much about the Cinder Cone since I started. Was a lot of fun cruising around this fall. May have been riding it a little hard for the break-in, but it all seemed to stay together.
Per my first post I took care of that exhaust. Again a little heat, some leverage, and the occasional love tap with the hammer got it tucked under the frame and out of the way of the pedals.
IMG_20171025_233616.jpg

I also had some challenges with the stock chain tensioner. I modified it, adding a pivot and turnbuckle for adjustment. It held up pretty well.
IMG_20171106_005456.jpg

Then 3\4 flat bar ended up getting twisted like a pretzel. I replaced it with 1 inch aluminum c channel, a little lighter and a whole lot stiffer. You can see it in some of the next pics.
I did not care to leave the fuel filter loose in the breeze so I created a mount for it from some copper pipe straps. Holds it place real nice and I'm not worrying about kicking it or catching it on anything.
IMG_20180205_175230.jpg

I am working on two more mods right now. It's been real cold here in Michigan, so not much riding for me.
First a chopper style seat with sissy bar. I've created it from seat stays from some bike I picked up during bulk trash clean up this past fall.
IMG_20180205_175117.jpg

IMG_20180205_175401.jpg

I've lost the quick release rear wheel.and went with a bolt on. Way easier to center the sprocket with 36 vs 32 spokes. Plus it gives me a place to mount the vertical braces for the seat. Those too were salvaged from one of the donor bike, front fork blades.
I've started the seat pan, need to score some foam and I think I will be good will shopping for some knee high leather boots to upholster it with.
I'm also starting to work on an expansion chamber. Once the seat is done I plan to do a little port work, based on some of the great threads, articles, and info I have gathered here and elsewhere. Then with numbers in hand I hope to build something similar to Jaguar's torque pipe.
Does anyone have any opinions on that?
With the small frame and tight spaces I'm not sure it a bolt on will fit without nearly as much work.

Always looking to hear what others think. I will post again when a few more thing fall in to place on the bike.
Cheers!
 

Timbone

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#11
It has been a long, cold Winter. Not a whole lot of riding even a few hundred miles South.

Your bike looks great - some really good fabrication there.

I welded up a Jag pipe on my next to last build. It made a big difference, especially on the low end. As soon as I get a good weather day, I'll cut and weld up all the pieces to lock it onto my latest build.
 

Frankenstein

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#12
It has been a long, cold Winter. Not a whole lot of riding even a few hundred miles South.

Your bike looks great - some really good fabrication there.

I welded up a Jag pipe on my next to last build. It made a big difference, especially on the low end. As soon as I get a good weather day, I'll cut and weld up all the pieces to lock it onto my latest build.
Cold enough he switched from a yard background to a tarp and a cement floor one. Come to think of it my bikes are in the basement don't know why I stopped using my porch. Hmm..
 

FurryOnTheInside

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#13
Well I have not posted much about the Cinder Cone since I started. Was a lot of fun cruising around this fall. May have been riding it a little hard for the break-in, but it all seemed to stay together.
Per my first post I took care of that exhaust. Again a little heat, some leverage, and the occasional love tap with the hammer got it tucked under the frame and out of the way of the pedals. View attachment 80826
I also had some challenges with the stock chain tensioner. I modified it, adding a pivot and turnbuckle for adjustment. It held up pretty well. View attachment 80828
Then 3\4 flat bar ended up getting twisted like a pretzel. I replaced it with 1 inch aluminum c channel, a little lighter and a whole lot stiffer. You can see it in some of the next pics.
I did not care to leave the fuel filter loose in the breeze so I created a mount for it from some copper pipe straps. Holds it place real nice and I'm not worrying about kicking it or catching it on anything. View attachment 80829
I am working on two more mods right now. It's been real cold here in Michigan, so not much riding for me.
First a chopper style seat with sissy bar. I've created it from seat stays from some bike I picked up during bulk trash clean up this past fall. View attachment 80832
View attachment 80833
I've lost the quick release rear wheel.and went with a bolt on. Way easier to center the sprocket with 36 vs 32 spokes. Plus it gives me a place to mount the vertical braces for the seat. Those too were salvaged from one of the donor bike, front fork blades.
I've started the seat pan, need to score some foam and I think I will be good will shopping for some knee high leather boots to upholster it with.
I'm also starting to work on an expansion chamber. Once the seat is done I plan to do a little port work, based on some of the great threads, articles, and info I have gathered here and elsewhere. Then with numbers in hand I hope to build something similar to Jaguar's torque pipe.
Does anyone have any opinions on that?
With the small frame and tight spaces I'm not sure it a bolt on will fit without nearly as much work.

Always looking to hear what others think. I will post again when a few more thing fall in to place on the bike.
Cheers!
What's your plan with those head nuts? :) :) :)
 

Avolio G

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#14
Right now they (the head nuts) just replaced the acorns. I put the screws in to keep things from getting into the coupler nuts. I may use one of then to mount an exhaust bracket to.
 

FurryOnTheInside

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#15
Right now they (the head nuts) just replaced the acorns. I put the screws in to keep things from getting into the coupler nuts. I may use one of then to mount an exhaust bracket to.
Ahh, I see. :)
I just wondered because they look like mine that I used for the head mount. :oops:
 

Avolio G

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#16
I've seen your build pics. It may be where I got the idea to use the coupler nuts. Mostly I just thought the acorns looked cheap. If I do not use them for exhaust I would like to find/Fab the correct length hardened cap screws.
Did you find a real advantage to having the extra motor mounts?
My engine seems rock solid with just the two mounts. Both of which I took the time to grind an exact fit to my frame.
 

FurryOnTheInside

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#17
I've seen your build pics. It may be where I got the idea to use the coupler nuts. Mostly I just thought the acorns looked cheap. If I do not use them for exhaust I would like to find/Fab the correct length hardened cap screws.
Did you find a real advantage to having the extra motor mounts?
My engine seems rock solid with just the two mounts. Both of which I took the time to grind an exact fit to my frame.
The acorns are just too cheesy! :)
Idk how much difference it makes to the torque required when you use longer nuts, though. (I used normal length grade 10.8 nuts to secure the head and the stud couplers are just snugged on top.)

Idk how much difference it made. I do know that my frame flexes a certain amount under my bodyweight, under any stresses in fact, all frames do. I made it before I had my engine running so there was no need to see how much worse it would be without it. I know that I read posts recommending foam handlebar grips and big sprung saddles and I just can't relate to that (but I did other mods to reduce vibration).
 

Avolio G

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#19
Beautiful weather here in Michigan. It's about time. Been working on the bike, seems like a long winter.
Broke it all down for some paint and polish. Keeping with the classic chopper theme that has developed, went with black paint. I think it is set off well with the silver (polished Al and stainless. Used Dupli Color and sprayed it with the paashe.

IMG_20180419_235558.jpg

IMG_20180419_235536.jpg

I also driller the 44t sproket. Lost nearly 1/4 lb, about 112g.
IMG_20180422_005049.JPG


I also did a bit of engine work. Ran pretty good at the end of last year,but what else do you do into the winter.
Widened the exhaust by about 3.5mm, the intake by 2mm and Cleaned up the transfers. Made sure all the ports had a nice smooth edges.
(No pics of the port work)
Modified my Piston slightly by drilling 2 small holes on either side of the exhaust port. Drilled larger oil holes for the pin. Cut, beveled and sanded any sharp edges alonghe skirt. And polished the crown to 1500 grit.
IMG_20180410_200621.JPG


I also drilled the clutch.
FB_IMG_1524012145437.jpg


Finished the engine up with some high temp paint.
IMG_20180422_011107.JPG


Also...
ScoredSco NGK cap and Bosch wire.
New rear side pull rear brakes.

Seems to have worked out, ran real strong today. Back to running 20:1, at least one tank with the mods to the cylinder.

Still need to cover the sear. Just duct tape so I could get out and ride.
IMG_20180421_235128.jpg

IMG_20180421_235052.jpg


I have some closed cell foam and a leather jacket to finish the seat.
I have also started pie cutting some pipe and preparing for a custom exhaust. We'll see how my expansion chamber com together. Of it works as good as the things I've done thus far, ilI' be stoked.
 

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