"Suzuk-E" RM125 Conversion

[FrankG]

Hey All!

After a 6 month absence glad to be back and working inside for the winter...

This thread will follow the progress of a 1987 RM125 conversion...



The image above is how the bike looked when I recieved it earlier in the summer.



This is the easy part, stripping down the frame.



I really wanted to utilize the 6-speed tranny while dumping the ICE component to free-up space and drop a few pounds in the process.




The clutch basket "Drive" casting has been cut back and drilled to accomodate a 38 tooth drive sprocket that will be driven by the original MY1020 1200Watt motor.

The motor will be controlled be either a Ver 1.02c or V2.00 PicOx controller in it's stock winding, the motor will be re-wound in the new year either for higher RPM or torque depending on how the stock set-up will work. Ultimately I'm aiming for excellent hill climbing characteristics with a top speed of approx 30Km/h within the confines of 48V @ 75Amps peak.

The Dirt-E bike built last year has performed like a champ through the summer and has seen 100's of Km's logged by close to 20 different users... That build was based around a much older (heavier) bike with an even smaller MY1020 motor without any sort of transmission. The only complaint is that it tops out at 24Km on the flats and can't quite climb some of the steepest hills about the farm, though in all fairness it can cover the most common trails...

[drewjet]

Frank,

Glad to see you back. And really happy to see another motorcycle. I will be curious to see how the transmission works out. I agree that it is the one thing my bike is missing. I think even just a 2 or 3 speed would make a huge difference.

What batteries are you planning on? The frame looks a bit small for holding a decent amount of batteries, any plans to stretch it?

[FrankG]

Drew,

For now it's going to just be cheap SLA's (I already have them on hand)... The Dirt-E Bike typically covers 5 to 7 km of varied terrain or 9km of flat road riding. So I hope to get similar results with this build.

Once I have the motor mount finalized, I think that I'll be able to get away with cutting the frame tube that runs down from the head-tube and "y"s to the mid motor mount. The battery rack will replace that frame section structurally.

I've been trying to get pricing and availablity info from Firefly about their carbon foam Oasis batteries, but with little success. Thogh they currently are only listing a Group 31 sized cell that is way too large for this project. Firefly claims 4 (four) times the energy density of typical lead acid technology due to their anode & cathode being largely lead plated carbon foam. As well as higher sustained current delivery and a broader operating range in colder temperatures (not a concern in Fla for you, but I have just pulled the cells from 3 EV's for the winter up here...)

The cost of Lithium based technology is still too high for me at this point, and I can't help but feel that BMS is an added level of complexity that I just don't feel like dealing with at this point.

...fg

[PaulM]

Neat project!! I have an RM80 rolling chassis in the basement waiting for a conversion . . . . someday!

How are you going to keep oil in the transmission with the clutch cover missing? Or was it originally a dry clutch?

[FrankG]

yeah, about the oil in the tranny...

It was a wet clutch and there are numerous points of flow between the gear box and where the clutch was housed.

None of the bearings or fixture holes on the clutch side have seals, and I think that it would be very difficult to try and seal it up effectively, so the idea for now is to use one or two of flow points to spray either a lithium based grease or some similar foamy grease onto the drive train on a regular basis.

I can appreciate that this seems like a lame solution, but my rational is a) the removal of the ICE will have reduced the heat of the tranny quite a bit, and b) the load that the drive train will be under will effectively be a fraction of what the ICE was producing... Given that the "Current" power parameters I want to play with are 48V by 75A peak the heaviest load (including electrical inefficiencies) is 3.6Kw or 4 3/4Hp in very rough numbers... That is definately less than half of what a typical 125cc ICE can produce.

If this idea proves unworkable, ie; the grease is slung off the spinning gears due to centripidal force, and shifting becomes unreliable, I'll have to use some epoxy or JB Weld to seal the actual holes and lay in a series rubber seals over the bearings... The main issue there is that the bearins are pressed into the casting and I don't have the proper tooling to remove and re-insert them without damage at this point.

Alternatively, I have made a cover for the clutch side that would seal about 4/5ths of the gear-box, but would have to build up the front opening where the crank was cut away from the castings... This may prove to be the more realistic option, provided that the oil level is kept below the height of the clutch shaft.

[FrankG]

More pics n' progress...



Above the stock MY1020 (1200Watt) version is mounted to the tranny.

The motor mount is made from 18 or 20 gauge steel scabbed from a dead (late 1990's) Compaq DeskPro case, much heavier stock than what you'll find on the cheaper off-shore PC's these days...

The mount was actually from another project that just never came together the way I thought it would... It's not the best picture, but you can just make-out the motor drive sprocket - Home Made .

This setup was run for about half an hour intermittently, to align the sprockets and set the chain tension, just a single 12V 7Ah SLA was hung off the motor terminals.



It took the better part of a a day to re-assemble the PicOx Ver 1.02c controller and find the software to setup the controller... (See thread viewtopic.php?f=2&t=3463&st=0&sk=t&sd=a&hilit=picox for more details)

After nearly throwing the primary drive chain a fews times due to a flakey throttle I was able to tune back the controller to 20Amps and calibrated the PC display to an analog current meter in-line with the motor. At no load it's kind of fun to just rip through the gears and fill the shop with lots of noise, but the current draw doesn't hit much above 10 to 12 Amps as the throttle is cracked open. And the controller is reliably stuttering as the current hits 20Amps when the rear brake is applied.

Next on the list is to measure and document No-load RPM of the motor, install a speado on the rear wheel and check how close my calculated and measured ratios are to reality...

It has just been powered-up a few times and only for 5 minutes or so at a time, but I think that the motor mount will have to be revisited ie; rubber mounting and some sort of chain tensioning... Also there is about 180 degrees of slack between the tranny input shaft and output shaft that is making a lot of racket when ever the wheel decelerates or accelerates relative to the motor...

The transmission and motor drive are very loud... Like so loud I almost think that something is wrong, but everything meshes and shifts very smoothly, and there is no feel of grinding or mis-meshing gears as it's rotated by hand...

Once the above is worked out I guess it's on to start cutting the frame and making some decisions on battery placement (not necessarily in that order)...

[PaulM]

180 degrees of slack?? As in, if you hold the output sprocket (that goes to the wheel), the clutch basket (what's left of it) can rotate a quarter turn each way? Something is definitely not right there.

Contributing to the noise is likely the lack of oil and the openings in the transmission case to let the sound out.

[PaulM]

Just did a quick test on my wife's TTR125. If I click it into first and rock it back and forth gently (I don't want to rotate the crank), there is about 1 tooth of play on the countershaft sprocket (13 teeth). That also would include a small amount of backlash between the crank and clutch gear as well as between the clutch plates and the clutch basket.

[FrankG]

Paul,

I'll check to see if there is a difference which gear the tranny is in tomorrow... As well as exactly how much slack there is...

I knew what I was in for when I split the casings, and had the exploded diagram at hand to ensure that nothing was re-assembled in error... The other reason I feel confident that the transmission is re-assembled properly is that the in/out ratios progress incrementally from 1st thru 6th gear.

Already, I'm thinking that this will have to return to being a "wet" transmission...

[FrankG]

The link below is to full build details on this project to date... Lots more images and probably more narrative than would be appropriate to post on this forum...

http://www.theworkshop.ca/energy/suzuk_e/suzuk_e.htm

[FrankG]

The link below should be to a Youtube Vid of the Suzuk-E just posted... (first one I've done...)

http://www.youtube.com/watch?v=L1mSELOrJTg

Not sure how the [youtube] coding works so just set it as a URL for now.


...fg

[pgt400]

Wow, fab'ed your own sprocket! Never saw that before, you going to roll your own lifepo4's?

[drewjet]

Frank,

It's looking good. I can't wait to see part 2 and find out how fast it is before and after motor mods.

[FrankG]

Hey PGT400, naw I'm still stuck in the 19th century with Heavy Lead for this build anyway... Drew, If nothing comes up over the next week or so I hope to get a test ride in before we get much more snow.

But the Vid stuff on a build is a drag on time as I don't like to stop and repeat a task for the camera, especially as most of the stuff that gets shot is cut during the editing process.

Just got in from the shop tonight with little to show for a solid 12 hrs... But I did diagnose a problem (new to me anyways...) a defective hall sensor in the throttle. Since I don't have any spares anymore I opted to replace the actual sensor. But the replacement was whacked compared to the previous throttles I'd used in the spring when the PicOx controller was built.

So the bulk of the evening was digging out old notes and re-reading the web-site to figure out how the throttle gets read by the controller and rescaling it to work with the new Hall Sensor.

The batt frame is welded, but the space is a lot tighter than I thought, ideally a 2" stretch would the right thing to do, but that will either screw-up the tank to seat fit, or just the gas tank placement...

Paul M, you were right, the slop in the gear-box is nowhere as bad as I mentioned earlier, but the slop at the motor is close a full turn. The motor mount has been raised slightly with some rubber spacers, that tightened the chain considerably and cut the noise slightly... After checking numerous You-tub Videos of other Electrics mine doesn't sound quite as bad as I thought...

The Motor RPM reads a consistent 4100RPM @ 48V regardless of gear (no-load beyond the rear wheel) and the rear wheel is spinning within 2 or 3 KM/h of the calculated values of the spread-sheet (calculated at 4100RPM)...

But it does occur to me that the motor does need to have it's timing set as it was dis-assembled earlier in the year and just re-assembled for storage...

[FrankG]

It must be getting late as I just entered a few images and a link, went to preview and "Bang" I'm off the thread...

Regardless... the latest progress can be found at the link below, but here are some images for those with just a passing interest...

Assembled at the testing station...




Low tech stuff like a home made high current switch...



Even a safety feature... a 90Amp breaker array...



The PicOx controller got dumped as it was choking as it got tuned up toward 60Amps or more, locking-up unpredictably, potentially a dangerous feature, but really more annoyanying since the motor is just a MY1020 for now...