Custom Fighters - Custom Streetfighter Motorcycle Forum banner

Batavus Starflite

7K views 26 replies 9 participants last post by  excellrec 
#1 ·
I've been working on modifying a Batavus Starflite for a few months. My documentation has been less than stellar, but I figured I would start a post and maybe that would help. Someone gave me a Starflite like the one below:


I tossed most of the parts and started with the bare frame (no pic). So far I have:

-added a top bar and chopped some unnecessary bits off
-made triple trees and bar clamps
-made adapters to go from the tiny head tube diameter to large enough diameter to fit the smallest all balls tapered bearings
-Made a swingarm with bearings (stock these things had literally nothing for bearings in the swingarm)
-resprung some small Marzocchi forks and mounted them up
-fit a mono-shock, which is being replaced with a yss mono for a grom (the one pictured is way too soft)
-modified the hell out of the motor

This brings us to about here:



I made a front headlight setup that pivots on the bottom and mounts to the bottom triple tree:




Made an adapter hub to mount a disc brake rotor to where a drum brake used to be:





Now I've waiting on a different caliper to come in (the Brembo I had gotten won't work unfortunately) so I can finish the front brake setup.




I still have to make the intake/reed setup for the motor and then make a pipe tuned to this motor.

Lastly, I am working on fitting a variator to this thing but it's been kicking my ass. Packaging it all is hard, but the worst of it is trying to extend the crankshaft to take the front variator pulley. Failed twice already, thinking on it some more...
 
See less See more
10
#3 ·
Caliper came in today, off a 2007 EX650 ebay tells me. Should be plenty to stop this little Batavus. With caliper in hand I whipped out an adapter to go from the forks to the new caliper:


The back side of the caliper was too thick and interfered with the wheels, so it needed to go on a diet. After trying to clamp it in a mill for ~30 minutes, I took a stab at it with the band saw:



Did a pretty good job of it, took about 2-3mm off. I suspect/hope it's not enough to cause any problems:



Mounted it up on the bike. Looks a bit ridiculous, and it is. Should be good for stoppies:

 
#9 ·
#13 ·
You can get into the 'mini' machines for really cheap and they take up only a little space. I use a little harbor freight 7x10 lathe for 90% of lathe work I do and I only paid $200 for it on craigslist. The taper on the back of that drum->disc adapter was turned on it. I also have a Sieg x2 variant (http://makezine.com/2011/11/23/the-sieg-mini-mill-one-manufacturer-many-brands/) mini-mill that I use quite a bit. It uses r8 taper tooling as well, which is what Bridgeport mills and my Tormach use as well. So you can buy tooling for it and use it on bigger machines if you ever want to upgrade. These little machines are pretty cheap and well-suited for the size of most things done for a bike.
 
#14 ·
I still plan to do my mbx. Did some price search. Without wheels and pipe i can get it done around 50€. Plus cylinder and piston sent to germany and back, plus scooter pipe for el cheapo for performance. But i want 12" wheels and those are pricey to score
 
#15 ·
Despite working some most days on the project I haven't come as far as I'd hope, but there is some progress.

The biggest challenge has been trying to variate a motor that wasn't made for it. It's going to require welding on an extension to the crankshaft, turning that down, and hoping the whole thing stays true in the process. I was battling with figuring out how to mount a stock Ruckus drive face with the splines. I tried several modifications, including trying to weld the awful cast aluminum to a non spline mount adapter, bolts, pins, etc. and it all failed. I decided to make a new drive face altogether so I could use a pin type mount. Here is the old vs. new:




That slot in the back of the new one will be used to stick a big square piece to drive off the crankshaft. It should be more than strong enough for this wee little motor.

I was also battling figuring how to massively increase the reed and intake on this little motor. I had jb welded up around the cases where the intake goes into the cases and hollowed that out until the walls were just thin enough to still mount an intake (no pics unfortunately). I then had to figure out how to mount the relatively massive reed block compared to stock. I decided on doing an external housing and put together the bottom pieces into the comically large intake now hanging off the motor:



I'm pretty sure I'm losing some gains from the larger reed block where it necks down into the case, but I figured I'd rather end up having to choke off too large of a reed block than potentially having one too small.

The last thing I'd been struggling with was how to package the driven shaft of the variator onto the stock frame, reasonably in line with the swingarm/rear sprocket. I decided it would be easier to just gut the stock motor mounting area and replace it with aluminum plates:

Part I tore out:




Sealed back up:



I made one side of the new mount plates tonight:



You can also see the driven variator shaft carrier I made with those little clamps I made to mount to the new aluminum engine plates. The clamps will be nice because I can adjust lateral position of the driven shaft to dial in belt and chain alignment:



Other than that, I also managed to ride a Moto Guzzi through Italy and visit the Ducati Factory/Museum:





If you've a chance, I would highly recommend riding in Italy!
 
#16 ·
Still working on this thing quite a bit. Nothing terribly interesting though. Most of my efforts have gone towards figuring out the CVT conversion. A couple of lessons I've learned though:

1: Make sure the proper sized belt exists before fabricating a CVT, or anything

2: If you need spline shafts, grab something off the shelf and build around the shaft

3: Making spline shafts is a pain in the ass

Though those three points should be self-explanatory, allow me to elaborate.

I fabricated everything for the CVT stuff and I can't find a damn belt for it ANYWHERE. I have some belts that I might be able to make work, but this will likely be a process that continues for awhile.

The issue with the splines/shaft is that I need a shaft from driven CVT to sprocket. Nothing with the exact dimensions I need exists to the best of my knowledge. This shaft is real tricky because it has to size to 4 different sized bearings and then has splines on either side. A real nightmare of a thing for a part-timer like me to get right.

Here's a picture of the pieces:



The middle part is a bearing carrier that mounts to the engine mount plate I made. The one end is driven CVT side from a Ruckus, and the other side a 20mm sprocket from.. something. I've had three tries at the shaft thus far. The first two didn't make it past sizing to bearings since I figured out the lathe I was using was mis-aligned and cutting a taper enough to ruin bearing fits. I've got my third attempt in photo's here and this one has all 4 bearing fits good and one spline end correct:




While I was busy congratulating myself on getting the splines just right, however, I noticed that the last lathe operation I did was wrong, rendering this shaft a failure. Now I have to order more 4130 or 4140 and take another crack at it. I've respect for machinists that do this type of shaft work regularly. It's a tricky business to get multiple tight tolerance operations all on one little part. Screw up one of them and it's back to the drawing board over and over again.
 
#20 ·
I appreciate the interest! I'll update soon. I'm good at making progress but not so good at documenting it. Got it moving under its own power now, but a lot of fine tuning to do yet. I'm learning that when you get off the beaten path of ready made parts and assemblies the difficulty goes up exponentially. For example, it took me about a day to figure out a spark plug that would be appropriate -- one that isn't so long it interferes with the piston, made for the right temps, that fits the boot, and that is in stock locally. Etc. etc.
 
#22 ·
Alright, updates.

First, I had designed an ideal pipe for this engine but my friend had one that was very close that he would trade me for fixing something on his bike. So, I took this pipe and did a sectioned header to fit it to the motor:



It's in kind of a weird place but I think if it bothers me enough I can move the side bleed to the rear of the expansion chamber and it would look more traditional then.

I ended up redoing my intake because I wasn't really satisfied with the first one and I think the reeds were just a bit too big. I got a slightly smaller reed block from an MB5 and made a steel intake this time. The carb sits in not an ideal position but It's tucked in as far as I can get it, and I can still get enough lean angle to reach the edge of the tires with it here (as long as I don't hit a big bump!).



I was trying to use a cheap-ish CDi but was having problems with it misbehaving and being junky overall. I got an HPI unit that can allow me to adjust curves later on if need be. It comes with pre-set timing curve. Will see how that works out. Had to machine it a bit to get it to work, but seems alright now.



Seat pan with risers built. Plan to put minicell foam pad on it. Electronics hidden beneath, basically just distro block, voltage regulator, and a couple switches (lights and ignition).



Bars with throttle, brakes, controls etc. Pretty sparse. Have a RPM/Temp gauge that I need to mount yet.



CVT is operational and seems to be working fine. Found a series of belts with the right angles, and lengths down to as short as 10", in 1" increments. Fortunately the CVT auto-tensions itself pretty well, so getting the belt in the ball park lengthwise is not works pretty well. Can also shim the drive side faces to bring them closer together to get the belt to grab initially if things are too slack.

This reminds me, I was battling with interfacing one of the CVT drive side plates to the crankshaft. Based on advice that the stock Batavus crankshafts are not very hard, I ditched the stock crank altogether. It now has a Tomos A55 crank, which has a longer stroke, and required some different seals and bearings. This crank had a spline end where the CVT drive goes, so I machined the spline section out of a stock A55 clutch and pressed it into the drive face I made to make the CVT drive complete. The webs of the counter weights on the A55 crank are the same width so it matches the Batavus bottom end well. This also alleviated another problem -- the con-rod on the Batavus crank only allowed clearance for a bronze bushing to the piston pin. These are notorious for melting at high RPM's. With the A55 crank I am now running a Wiseco needle bearing which should be fine up to 12k. The longer stroke coupled with the bigger bore from the aftermarket piston gives the motor even more displacement (I haven't actually calculated it). I had to make a large (~30mm) spacer under the cylinder so the stroke piston wouldn't hit the head. Compression should be around 11-12:1, with a squish band of ~.5mm and PSI tested around 160-ish. There are some drawbacks in terms of port timing. I wasn't able to get an ideal blowdown for the port timing I'm running, but you are kind of stuck with what you get on 2-strokes. Barring making my own cylinder, I have to make these port timings work.



One issue at this point is the narrow clearance between the head and the front tire after I managed to get the CVT and everything packaged, and increased the cylinder height to match the increased stroke. If there is zero rearward flex of the forks under braking there will be no interference if the forks bottom out. That is, however, unrealistic. I've some ideas in mine but frankly I'm not interested in fixing this until I get some other things straightened out.



*edit* for some reason the above image is not showing, but it's just a picture of the front and rear sprockets.

Herein lies where I made a big, stupid, mistake. When I calculated gear ratios I figured I'd get in the ball park by using the stock Ruckus main drive ratio as a guide (because I used a variator from a Ruckus). I had looked on forums and discussions mention ~3:1 gear ratios. I went on that and geared to approximately 3:1 and figured I could adjust with cheap and readily available gears that fit the drive/jack shaft I made (Finally got that made and hardened!). Upon initial testing, however, it was clear that the RPM's weren't getting high enough to begin engaging the CVT. Also, there was almost zero torque from start. I initially worried about the engine port and ignition timing making the engine to anemic to torque up to speed... until I sat down and actually calculated the gear ratios. It turns out the Ruckus actually runs two step-down gears in the final drive, and one of these step downs just isn't talked about in the forum posts. So, I am currently geared to begin CVT engagement at around 70MPH, and to top out 12k RPMS traveling around 350MPH. Since that's a little too optimistic, I need to gear way down. I'm considering trying to get 10:1 in the rear by using a 10t in the front and 100t in the back. I have a 10t for the front but will need to machine the 100t. That's what I'm working on today...
 
#25 ·
I had a 105t cut for the rear and have a 10t up front now, so the gearing is set for ~60mph at 12k crank speed. At some point, I set a goal of top out at 60mph. With the main mechanics sorted, I'm beginning the process of closing in on more power with the potential for more risk of catastrophic failure (e.g. upping compression, leaning the jets, advancing the timing). Hit 52mph with it yesterday and it seemed to hold fine. The handling of it is fantastic, tight and turns in sharp and crisp. I've ridden lighter bikes before but this is an entirely different animal. Makes a Ninja 250 feel like a behemoth. My friend made an impromptu video of it. Please ignore the little quirks here and there. I just got the main mechanicals sorted and waited on addressing all the little things (e.g. chain clearance, wiring clean-up, etc) until I knew the major parts were staying how they are.

https://www.youtube.com/watch?v=0jYMgoZ5bO0&t=22s
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top