2nd Build Full Suspension KTM Clone, SBP Shift Kit

[Wild Bill]

Doug, I bought a spare clutch since the shoulder bolts threads were messed up on the original and I wanted to have a spare in case it strips later on and on the spare clutch I used the spring washers that I showed in the earlier post and I use the thin shims to adjust it so I dont have any free play in the shoe when bolted up and yet very little to no preload on the spring washers. The coil springs have preload and I suspect that they will have a higher rpm lockup that we dont want but if you try the coil springs please let me know if they start to grab right off idle because thats what we want. Those coil springs may work great but I suspect they will lockup a little higher than we want.

Also you have to pick up the rear tire and see if the clutch is dragging at idle, that we dont want. My bike when the engine is cold drags just barely so after I start it when its cold I hold up the rear tire a few seconds and blip the throttle a couple times and then its fine and doesnt drag at all.

Oh ya the second clutch had a different stack than the first so they arent consistent from the factory I guess.

 

[Wild Bill]

Well I have finished the 1st gallon of 20:1 break in fuel and everything has been great so far. When it comes to fuel mileage this thing is a pig! I ran out about 1 mile from where I parked my truck and I found out just how heavy this thing is by having to pedal into the wind......phew!

I still need to make a chain tensioner for the right side jackshaft chain, a tensioner gives me more time in between chain adjustments. I have a problem of the chain adjustment not lasting long because Im too afraid to wrench down the muffler clamps on the jackshaft mount real tight to the seat tube and kinking the tubing so the chain doesnt stay adjusted up for a long time but thats ok. I would rather adjust than crimp my frame! On my other bike the tensioner I made gives a while between adjustments.

I replaced the plastic derailleur cogs with billet aluminum ones and lubed the shifter cable and readjusted the derailleur, earlier in the day i had to play with the shifter cable because it started to skip in a higher gear and I have seen that before in the other bike and it was because the cable needed to be lubed and it causes the derailleur to stop at the wrong point because of the dragging cable. It shifts smooth and reliable again.

The disc brake wheels came today but the street tires wont be here till tomorrow so thats when I will setup my disc brakes.

My son and I are planning on going to the motorized bicycle race at The Grange June 1st and I wasnt too sure I would have this thing done in time or that it would work at all, but now it looks good to go! My son will run the other bike in the china girl class and I will run the KTM in the mid class.......WOOOOT! Its been a long time since I have raced anything with an engine, and the last bicycle race I was in was back in 1977 (sponsored by Bobby Encinas and Shimano) so this is gonna be great!

 

[16v4nrbrgr]

Lol, mine eats gas too, I ran out a couple miles from home and got a stiff neck for weeks from pushing it home lol.

Keep us updated on your R&D findings, I'm really interested because I am in a shifter/Cagllari build an my KTM chopper has a sprocket that looks like it belongs in a sawmill! It would be nice to be able to use a jackshaft to shifter setup if there are components that have been proven to hold up to it.

 

[maniac57]

If you slide another chunk of seatpost into the tubing where your clamps attach, it will improve crush strength and generally reinforce everything. Just find out how long you need to fill the tube and still allow seatpost adjustment.

 

[Wild Bill]

If you slide another chunk of seatpost into the tubing where your clamps attach, it will improve crush strength and generally reinforce everything. Just find out how long you need to fill the tube and still allow seatpost adjustment.

I have been trying to find some tubing the right size without buying a seat post to hack up but I may have to do just that.

 

[Wild Bill]

I made the right side chain tensioner so that will hopefully buy some time in between chain adjustments. Also the universal rear brake adapter came so put on the new rear wheel/disc brakes along with the new pavement tires and number plate for the June 1 race at The Grange. I have run about 1 3/4 gallons of fuel so far and I am trying to keep the miles down before the race so I dont break it or wear it out before then. I did flood it by leaving the gas on with a full tank and bouncing down the road in the back of my truck and boy it was hard to get fired back up even with a new plug and kicking it over without a plug to dry it out. It is tough to get the plug out because the plug is very close to the top tube and I have to take out 2 motor mount bolts and tip the motor sideways a little. So a plug change can take a couple minutes.

 

[unknownbmxa88]

check out my vid of my bike http://youtu.be/YKg-3RN-wDI

 

[Wild Bill]

Unknownbmx, Very good!! love the sound. Seems to accelerate pretty well, nothing more fun that shifting gears!

 

[Tyler6357]

Hey Bill
This is the most awesome build!! It's really a dream motor bike. Now that you have had it running for awhile, I would like to know what you think of that KTMC 50? Is it worth $500? Also, you said it was wider than the china girls, How wide is it? Also, how much does that KTM pipe add to your torque? Is it a mostly high, mid, or low end torque upgrade? Also, how is the vibration on that GT LTS frame? Also, thanks for posting your build and videos here, it sounds soooooo gooooood!!

 

[Wild Bill]

Thanks Tyler, all I have to compare to as far as motobikes go is my china girl GT LTS and there is no comparing the two. Its like comparing a UFO to the Wright Brothers plane. IMO it is worth the $500 especially when you consider you can sink $500 into a china girl and still not have as much power.

The engine case is about 7.5" wide at the case not counting the kick start shaft. You have to mount the engine up kinda high to clear the pedal arms since the case is more narrow lower on the case. The shift kit comes with a wider pedal arm spindle but it could stand to be even wider still since I had to grind a little off the right side arm. I could have mounted the engine about another 1/4" to the left and not needed to grind any.

The power of the pipe feels more top end but you have to remember that in my application I have lower gears in 1st, 2nd, 3rd than if it were a single speed so it has more bottom end than a single speed would have, it accelerates very well thru the bottom end and hits a power band like a two stroke dirt bike on the top end. But you also have to remember that the clutch is set to grab at a very low rpm to make use of the ability to shift, where the single speed has the clutch setup at a higher rpm to get into the higher power to pull a much taller gear ratio. Its really a blast to ride!

As far as the vibration I would say maybe a little less than my china girl. And it sounds much better in person that the videos, it really sounds like an 80cc or 125cc dirt bike and sounds much better than my china girl.

Since you are in Santa Barbara if you are going to the June 1 race I should be there and you can see and hear how cool it sounds going thru the gears.

 

[16v4nrbrgr]

How well are all the shifter components holding up Bill? I am getting antsy to build my shifter bike now since the gears make a little power do a whole lot!

 

[database00]

great build, looks like your about a week ahead of me now. I just got all my light so I can start adding those on for turning and night riding. Our bikes are getting pretty similar lol. but your motor is alot lower then mine. Im a little jealous I have alot of chain to move around and get hit when changing my gears. I still need my tensioner. Did your motor come with an electrical stator for lights?

 

[Wild Bill]

16v4nrbrgr, So far the only thing I have seen is the first gear sprocket was bent slightly but that may have come from the period of time I rode it as a pedal bike before I put the engine on it. I found that about 2 weeks ago and I straightened it out and it has not bent again since. I have been full throttle on just about every ride for the last couple weeks but I still roll the power on kinda smooth after each gear change. I have hit approx 50 mph several times on a local hwy where the traffic flow is 50-55 mph. The real test will be the June 1st race day where I hope to put a lot of track time on it. So far it has held up very well with no failures.

On race day I plan to start out fairly easy on it while I get used to the track since I have never raced there before and every practice session before the first heat race I will step it up just a little. I will push it a little more each race as the day moves on and in the main I will let it all hang out but I still wont shift under power but I will be more aggressive on applying the power. I just dont want to end my day early if I can avoid it.

 

[Wild Bill]

Database, I dont think it has a light circuit built into the stator. I am a firm believer in chain tensioners on both the jackshaft chains. Be real sure your rear derailleur is adjusted right and it wont jump over the first or last gears into the spokes or frame, I have had that happen on my other build and it wiped out a rear wheel.

 

[database00]

50, nice, I havnt had mine past 40. I still had power just hard to find a strait away, and if i hit bumps right now I break chains. so I need a good chain tensioner before I really hit mine hard. Wish I could go to cali to race you lol

 

[16v4nrbrgr]

Cool glad to here it's working out Bill, I think as long as you don't thwack the power on hard it should work out well, shock loadings what kills all the bike stuff it seems. I too wish I could race with you this June, but I can't afford it really at this time. :/

 

[Tyler6357]

Bill
Thanks for answering my questions, I should say that I'm still rather new at building. Me and a friend have built 2 bikes together and have been out riding them around SB, but I am inspired by your build. I will have to think about doing a bike like this. I've got a few other projects going right now (a motorhome and a boat). If I can get some stuff done on my motorhome in time I would love to take it to Grange on June 1, and putt around the track on my 66cc china girl, I've never been to the track before and it would be super fun to run that track but I just don't know if I will be able to get the stuff I want done in time. Anyhow, If I can make it, I'm sure I will have no trouble identifying your kick-ass bike and will stop by to hear it live.

 

[SpecializedMountainMoto]

Where do u get the mx style handle bars?

 

[Wild Bill]

LOL I just answered on the other thread. I found those on Ebay. They are Junior BMX bars.

 

[SpecializedMountainMoto]

Did u use bmx stem or shims?