# '68 Dnepnr motorcycle with sidecar



## zapyourrideguy (Oct 25, 2012)

Just started work on this.
It has a motenergy 1003 should be the double brushes.
I have 2 modules from a BMW I3 that I am testing. I gave it a spirited tool around the neighborhood, maybe 20 minutes, and there is a faint electrical smell coming from the motor. Are these things temperature protected at all? I am familiar with brushed motors I used run the ADC 8" in a civic (since gone ac-51) I know they get hot. This is direct drive (4.3 to 1) so maybe all the low speed take offs??
The bike is also probably at 700 lbs Is that too much for this motor?
Thanks for any info


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## Big Malky (Nov 6, 2016)

Hi am interested in your conversion as thinking of doing this with a Ural outfit.
How did you get on and where do you get parts from?
Thanks


Sent from my iPad using Tapatalk


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## Functional Artist (Aug 8, 2016)

zapyourrideguy said:


> Just started work on this.
> It has a motenergy 1003 should be the double brushes.
> I have 2 modules from a BMW I3 that I am testing. I gave it a spirited tool around the neighborhood, maybe 20 minutes, and there is a faint electrical smell coming from the motor. Are these things temperature protected at all? I am familiar with brushed motors I used run the ADC 8" in a civic (since gone ac-51) I know they get hot. This is direct drive (4.3 to 1) so maybe all the low speed take offs??
> The bike is also probably at 700 lbs Is that too much for this motor?
> Thanks for any info


Yes, a 4.3:1 ratio seems too low for a 700 lbs. vehicle

What is your top speed?


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## freetones (Sep 21, 2017)

Nice bike!


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## zapyourrideguy (Oct 25, 2012)

As far as parts I have just ordered head bearings and brake cable from east highway a speciality parts house in Estonia.
They seem responsive to questions and they have parts diagrams to order from which is pretty cool.

As far as gearing, It seems to have good starting torque and it's scary to take past 45 mph so I don't know how fast it would go. I have added a fan to the front of the motor and it is keeping it much cooler. I was toying around with the idea of putting a simple reduction gear with either a chain or a belt with a 1.75:1 ratio or so and some way to disengage this belt in case of runaway motor condition.


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## zapyourrideguy (Oct 25, 2012)

Well an update on my motor. It turns out that my motor was timed wrong for direction of rotation CW. This is something that I should not of missed as I am a Honda Civic converted EV owner/builder. I know the ME-1003 is still maybe marginal for my rig but I can't spend the dough on an AC-20 that I know it wants.
I've had the comm turned and getting new brush set. 
My question today is design questions about a gear reduction. The bike was direct drive with a 4.6:1 reduction to the wheels through a shaft drive.
I was going to do a simple 2:1 gear reduction by raising the motor and using as small a #40 gear on the motor shaft as I can get away with and a larger (2x the teeth) gear below it in a pillow block bearing with a chain.
Is #40 enough? do I need to do 2 strand chain? Will this take the RPM's?
will I need 2 bearings? The drive-shaft end is on a u-joint, I believe, as it flops around when motor is disconnected. There is also a rubber isolator that was connected between the motor and final drive.
I tried to figure out the design parameters on-line but I am not getting very far.
Any help is appreciated


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## electro wrks (Mar 5, 2012)

Yes this is a common problem with this set-up. Not enough gear reduction and no way to increase it. The motor turns too slow, draws too much current and overheats. You'll need to make some kind of jack shaft, and add another reduction step in the overall ratio to get the motor speed up and the current draw down. You're right, the floppy drive shaft and U-joint will need to be well supported in bearings on the motor side of the U-joint to handle the side load from the added chain or belt drive.

It looks like you have plenty of room for this. Plus, then you can adjust the size of the pulleys or sprockets to dial in the best ratio.

The jack shaft really should have 2 bearings. But, if they are large enough, they don't need to be very far apart if the load is not overhung very much. Flange mount or pillow block bearings are some of the easiest to work with:https://starsinphotos.files.wordpres.../12/s-8604.jpg http://www.fourwheeler.com/how-to/10.../photo-05.html
These type of bearings have a spherical outer race that makes them self-aligning, so no precision alignment is needed. Use the diameter of the motor output shaft, but the next convenient diameter larger, as guide for the diameter of the jack shaft and bearings.


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## electro wrks (Mar 5, 2012)

Mounting the jack shaft to the U-joint will probably require some machine work. You should be able to use stock pulleys or sprockets on the other end of the shaft. Ways of mounting parts to the shaft, from worst to best are: (1) set screw(s) over keyway only (2) set screw(s) over keyway with a bolt or nut screwed in or on the the end of the shaft, clamping the part to the shaft and bearing (3) use a tapered bushing to mount the part. 

Be sure to include slots in the motor mount to adjust the tension of the chain or belt.


You asked, I think, about #40 chain and sprockets? That size would work. But you're right, it's a pretty high speed application. It will be noisy and you'll have trouble keeping lube on it. Ripperton on his race bike with a similar chain set-up uses an O ring chain with some success. A toothed belt set-up might work better, but they're several times more expensive.


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## timbillyosu (Apr 9, 2018)

zapyourrideguy said:


> Just started work on this.
> It has a motenergy 1003 should be the double brushes.
> I have 2 modules from a BMW I3 that I am testing. I gave it a spirited tool around the neighborhood, maybe 20 minutes, and there is a faint electrical smell coming from the motor. Are these things temperature protected at all? I am familiar with brushed motors I used run the ADC 8" in a civic (since gone ac-51) I know they get hot. This is direct drive (4.3 to 1) so maybe all the low speed take offs??
> The bike is also probably at 700 lbs Is that too much for this motor?
> Thanks for any info


Bike looks great, Zap! I'm thinking about doing something very similar. Did you just mount all of the batteries in the sidecar? What size batteries are you using?


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## zapyourrideguy (Oct 25, 2012)

2) bmw I3 packs mounted in sidecar boot 60 ah at 96 volts


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## zapyourrideguy (Oct 25, 2012)

Here is an update on the motor. The Motenergy 1003 was timed incorrectly for reverse rotation. I got the comm serviced and a new brush set, and all is happy now. With the addition of a fan on the motor now blowing out the front of the motor, reverse rotation means the internal fan is blowing out also, the motor stays cool. Even after a hard run the motor is barely warm. bike performs very well. The I3 packs have 2 cells that are lower than the others. I wish I had done a capacity test on every cell, but was too anxious for the ev grin. In spite of the 2 lower cells. I am getting about 20 miles range before the lowest cell hits 3.5 resting. this is charging conservatively to 4.05 
Does anybody have a discharge graph for these I3 batteries? I wonder if I can let those two cells drop off a bit more or am I already on the cliff edge?


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## zapyourrideguy (Oct 25, 2012)

I have contacted EVWest about a belt drive reduction for my bike. they referred me to Rainbow Precision and mentioned NRG belt and pulley products. The shortest center to center distance available is 6" in a continental silent synch set-up. I have room for more like 4" center to center 
So question would be: could I do a straight gear to gear set-up? If so what are the engineering issues with such a set-up? It would need constant lubrication?

Or multiple V-belts?


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## electro wrks (Mar 5, 2012)

In post 11 you say every is fine. In post 12 you're asking about reduction gearing for the drive set-up. What's going on?


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## zapyourrideguy (Oct 25, 2012)

electro wrks said:


> In post 11 you say every is fine. In post 12 you're asking about reduction gearing for the drive set-up. What's going on?


Great question. On the flat it works fine. I thought for climbing hills and motor longevity I would do the reduction. I just looked at the numbers for the AC-30 motor I am going to put in place of the ME1003. HPEVS said that the obsolete AC-30 has similar power numbers to their current AC-35. If this is the case then I probably don't need to bother with reduction. 
ME-1003 315 in/lbs torque (is this ft/lbs if divided by 12?) 
AC-35 128 ft/lbs torque
ME-1003 11.5 KW continuous
Ac-35 28 KW continuous
What do you think?
Thanks again for your input.


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## electro wrks (Mar 5, 2012)

You're encountering the conundrum alluded to in post 7. Beyond not having enough reduction, with the current(no jack shaft) set-up, there's no easy way to adjust the set-up to dial in the best reduction ratio for a given motor, vehicle weight, or driving conditions. I suspect most OEM bike makers, in spite of their best design calculations, still have to dial in the reduction ratio that's best for their bikes, by doing road tests. 

The AC30 will have plenty of power for starting off. The power required to sustain higher speeds or climb hills may not be available (and/or the motor might be stressed by it drawing excess current) because the motor won't be able to operate at the higher RPMs where this power is available. Then again, this motor is oversized for this application. You might get away with it, and be satisfied with the performance. If not, you should have a backup plan with a jack shaft design. 

Gears are impractical in this application. Try to increase the motor shaft/drive shaft center to center distance so a belt or chain drive could be used.

Here's a video (if you can stay awake watching it!) of someone who burned out a ME1003 and switched to a AC20 on his bike:
https://www.youtube.com/watch?v=ct_fieej254


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## zapyourrideguy (Oct 25, 2012)

The AC-30 and 1238 controller is in with direct drive! I decided to try without the reduction. Performance is good. I have my grin back. It seems to pull fine but I have not been able to test it on any steep hills. The controller body stays cool but the built-in heat sink does get hot. I will be adding cooling fins if not a chill plate with pump etc. 

It is very nice to have reverse and regen braking, I don't have to worry about the Dnepr brakes not working that well. 

I initially could not get the programmer to connect to the controller to set parameters for the controller. We discovered that I had run the spyglass line along side my DC-DC converter which was so noisy that it prevented communication to the programmer. I should know this stuff having done this several times before (Zilla, Ac-51/1239, etc.) I just re-routed the cable clear of everything and it worked.
Thanks to Frodus for getting me going.


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## zapyourrideguy (Oct 25, 2012)

I can't believe its been 2 years since I posted this. Finally getting back to installing a jack shaft for 2:1 reduction, using advice from electro works. I will put a few drawings up.
I am planning on welding a large plate (white foam core mock up in photo) that will run from the engine bay floor up to the top frame bar. This moves the motor 5.5" up and to the center and approximately 4" forward for room for the jack shaft bearings and sprockets. I will run chain first. My question this time is how thick a steel plate should this be? The original plate that will be used for one of the jack shaft bearings is 1/8 or 3/16" steel with gusset plates on each side. the front bearing will be a pillow block (set on a shelf welded or bolted to the new plate) because of clearance with the motor and the rear bearing will be flat on a steel plate with slots in the original motor plate for adjusting tension. I was going to weld two bolts that make for adjusting tension and alignment for the pillow block bearing as well. I would also support the front of the motor from the frame above. Motor is a HPEVS AC-30.


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## electro wrks (Mar 5, 2012)

How close to burning out the motor did you get before deciding to move to the jack shaft gear reduction option? If you build the jack shaft with a over hanging shaft (like the motor output shaft), it will easier to change belts, if you ever go that route. Flange type self aligning bearings would probably work better for you: SKF

And, you do need 2, that's two, bearings. One will not work, as you will painfully find out if you ignore my advise again. The flange bearings have the advantage of being able to mount them close together, with through bolts going through the mounting holes of both bearings, maybe a spacer, and the support flange. The diameter of the shaft and the bearing spacing will have to be figured out. The motor has a 1 1/8" diameter output shaft? Maybe try a 1 1/4" jack shaft with the bearing centers(where the balls are) spaced at least 4" apart. This is just a guess. To be sure, you will have to get this properly engineered and /or keep a careful eye on the bearings for signs overloading.

Proper engineering again will determine the thickness of your motor and jack shaft support flanges. Bracing at right angles to the motor and jack shaft flanges is more important than the thickness of the flanges. If there is bracing between the flanges, make sure the bracing on one side is removable for easier access to the chain or belt.This bracing keeps the flanges from bending towards each other, under load. The loads can be considerable. More than one jack shaft has been ripped out of its mountings when the loads were not properly calculated. Keep a close eye for excess flexing in your mounts. If you ever anticipate using a belt drive, make sure the mounting slots in you motor mount flange are extra long. You can use an idler, but adjusting slots in the motor mount flange, if you have the room, are a lot simpler means of tensioning the drive. Some oversized holes in the jack shaft bearing mount(s) would be useful in centering the drive shaft. I would not depend on moving the jack shaft around to tension the drive.


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## zapyourrideguy (Oct 25, 2012)

Thanks for your reply, electro wrks I don't think I am anywhere close to burning up this motor, as you yourself said performance might be adequate, (which it is on the flat). I also monitor motor and controller heat closely. But it could definitely use more torque for hills and the calculation I made is it is currently geared for 100 mph. Even the little me1003 actually did okay with this gearing. I have attached some diagrams of the jack shaft plan. The jack shaft I was planning on is 7/8" which matches the drive shaft and I have the 7/8" fitting from the Me 1003 motor shaft to the elastic coupler. I hear you about the ease of adjusting tension with motor instead of jack shaft but I'm afraid I don't have the room. The drive shaft has a u-joint at the final drive and then this elastic coupler so there is room to deflect the drive shaft a bit (1/4-1/2") as the jack shaft is lowered to adjust tension. so both bearings will be adjustable. 

I wanted to follow your advice on starting with a chain but I want to end up with a belt like a gates Poly Chain GT. 
You said that I should have this engineered, any suggestions on finding an appropriate one? Thanks again for your ideas and advice.


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## electro wrks (Mar 5, 2012)

A minimum of `~1 1/2" of adjustment is usually required for the cog belt drives like this that I've setup. This is partly because of the limited length range of belts available. You have to work with what's offered. Also, at least one of the belt sprockets will have flanges you will need to slip the belt over. Your non-overhung, both sides of the sprocket bearing support design could make changing the belt a real chore. In a perfect world, the jack shaft would easily slide forward out of the way of the belt after the set screws or clamps are loosened on your coupling, the sprocket, and bearings. In the real world, rust, metal burrs, grime will make it so the shaft will need to driven with a hammer and punch or pulled out with a slide hammer.

Trust me, the belt drive double overhung jack shaft design is so much easier to work with.


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## brian_ (Feb 7, 2017)

zapyourrideguy said:


> ... I want to end up with a belt like a gates Poly Chain GT.
> You said that I should have this engineered, any suggestions on finding an appropriate one?


The Gates Poly Chain GT Carbon Belt Drive Systems manual has just about everything you need to know about using these belts.

If you plan carefully (so your shaft spacing is right for the specific pulleys and belt that you choose) you don't need much adjustment, but you do need some to account for imperfect construction, belt stretch, and ease of installation.


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## brian_ (Feb 7, 2017)

(duplicate post deleted)


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## electro wrks (Mar 5, 2012)

Brian is right about the shaft spacing related to belt and sprockets tooth count. But in that pesky real world again, even if you have fixed on an ideal ratio with a chain drive, you may not find a combination of acceptable belt and sprockets tooth counts that allows the set up to work with your limited belt tension adjustment. In case this happens, you should have another backup plan for using an idler. I haven't had to use one yet. But I would think it should be a fixed(rather than spring loaded) one that could handle the heavy belt tension during regenerative braking.


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## brian_ (Feb 7, 2017)

electro wrks said:


> ... in that pesky real world again, even if you have fixed on an ideal ratio with a chain drive, you may not find a combination of acceptable belt and sprockets tooth counts that allows the set up to work with your limited belt tension adjustment. In case this happens, you should have another backup plan for using an idler.


Absolutely - the manual helps with selection, but there are only a finite number of available combinations.



electro wrks said:


> I haven't had to use one yet. But I would think it should be a fixed(rather than spring loaded) one that could handle the heavy belt tension during regenerative braking.


I agree - these belts don't stretch much, so an idler (or adjustable drive or driven component) should be rigidly clamped in place after tension adjustment, to work in both regenerative braking and driving in reverse.


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## zapyourrideguy (Oct 25, 2012)

My thought in the original design was that the motor sprocket would be my way of getting the belt on. I re-drew diagram with the double overhung with 2 pillow-block bearings in front, as you suggested. I have preselected some drive belt solutions to give me the center distance measurement. I attached my current choice.


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## electro wrks (Mar 5, 2012)

I guess this would make putting on and taking off the belt easier. Although, I don't see it. My suggestion is to mount the two closely spaced bearings, supporting the drive shaft sprocket shaft, on the other side of the sprocket. This leaves space in front of the sprocket to pull the belt through. It looks like my design would have to have the motor mounting flange or plate removable (bolted-in, like the motor) to gain access to the drive shaft sprocket. Or, you may be able to cut a large enough opening in the plate to pass the sprocket through.

On your drive design report I see the install/take-up range distance is only 1.41" instead of the 1 .5", I estimated. My bad. The 25 tooth drive sprocket is near the lower end of the tooth count you want to use to minimize noise and belt wear. Just a few more teeth on this sprocket would reduce the noise and possibly let you use a narrower, cheaper belt and sprockets. Also notice the force pulling on the shafts is ~600lbs. This info will be useful to determine the bearing loads.

What does ~1950 RPM on the drive shaft translate into vehicle speed?


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## zapyourrideguy (Oct 25, 2012)

I will need 2500 rpm on the driven sprocket 5000 on driver motor sprocket to reach 50mph 
thanks for the link to the gates manual. In the manual as well as in using the design software they seem to limit rpm to 4000 rpm and in other places in the manual it indicates 5000 rpm. Perusing the manual. It looks like I could use a larger driver sprocket with a workable center distance.
On flopping the bearings to the other side the only way to create enough space would be to keep moving the motor plate forward to allow space to pass sprocket and bushing over end of shaft. On that subject, I could not find any info on the overall width of sprocket assembled with bushing. Does the bushing nest in to the sprocket? 
The chain sprockets that I already purchased slip on and gates sprocket would be taper lock. It doesn’t seem too hard to thread the shaft through the bearings and sprocket. Am I missing something? And thank you both for your responses.


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## brian_ (Feb 7, 2017)

zapyourrideguy said:


> I will need 2500 rpm on the driven sprocket 5000 on driver motor sprocket to reach 50mph
> thanks for the link to the gates manual. In the manual as well as in using the design software they seem to limit rpm to 4000 rpm and in other places in the manual it indicates 5000 rpm. Perusing the manual. It looks like I could use a larger driver sprocket with a workable center distance.


My impression from the manual is that the charts and tables cut off at the high speed end to avoid violating a 6500 ft/min linear belt speed, but if you calculate specific combinations - or find them in the software - you can get combinations at moderately higher shaft speeds which stay within that 6500 ft/min limit. Bigger sprockets are better (to reduced belt tension required and to bend the belt less), but a potential problem with enlarging sprocket diameter is increasing linear belt speed to an excessive level.


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## electro wrks (Mar 5, 2012)

AIR the 6500 ft/min limit is a max for regular cast iron sprockets as the Gates manual states on page 102:

"Centrifugal forces developed beyond this speed may prohibit the use of stock gray
cast iron sprockets. For rim speeds above 6,500 feet per minute, contact
Gates Power Transmission Product Application for other alternatives." 

The sprockets are sometimes made of other materials. Sintered steel, ductile iron, stainless steel come to mind. These sprockets usually have higher rim speed and RPM limits. Unfortunately, these limits are not listed in the catalog, that I've been able to find. The RPM limits are printed or embossed on the sprockets themselves. So, you'll have to do some looking and hunting or contact Gates or a supplier.


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## zapyourrideguy (Oct 25, 2012)

Doesn’t appear that I would be anywhere close to 6500. More like 4500 rpm. Any thoughts on assembled width of sprocket and bushing?


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## electro wrks (Mar 5, 2012)

zapyourrideguy said:


> On flopping the bearings to the other side the only way to create enough space would be to keep moving the motor plate forward to allow space to pass sprocket and bushing over end of shaft.


To get around this, you could make the motor mounting plate removable, as I mentioned before, to get good access to the sprocket and bearings. So instead of welding the plate directly in place to the motorcycle frame, weld in some mounting points on the frame that the plate bolts to.



zapyourrideguy said:


> The chain sprockets that I already purchased slip on and gates sprocket would be taper lock. It doesn’t seem too hard to thread the shaft through the bearings and sprocket. Am I missing something?


As I mentioned before, in the real world, rust, grime and metal burrs(like from set screws) can make it very difficult to remove bearings and sprockets from a shaft.Taperlock type bushings are usually an exception to this problem. This could make a normally simple belt change a very difficult, drawn out process. With a removable motor mounting plate, as described above, you would only need ~1/2" clearance in front of the drive shaft sprocket to twist and slide in a new belt. This could be done without moving or removing the motor plate, sprocket, shaft, or bearings.


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## electro wrks (Mar 5, 2012)

zapyourrideguy said:


> Doesn’t appear that I would be anywhere close to 6500. More like 4500 rpm. Any thoughts on assembled width of sprocket and bushing?


Sprocket rim speed is different from RPM. Calculate the rim speed the same way you calculate the vehicle speed from the RPM and diameter of the rear tire. Just calculate it in feet per minute, instead of miles per hour.


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## brian_ (Feb 7, 2017)

electro wrks said:


> AIR the 6500 ft/min limit is a max for regular cast iron sprockets as the Gates manual states on page 102:
> 
> "Centrifugal forces developed beyond this speed may prohibit the use of stock gray
> cast iron sprockets. For rim speeds above 6,500 feet per minute, contact
> ...


Good catch. 

When I found the belt speed limit it wasn't in context with that note, and I didn't search the rest of the catalog for the explanation... apparently I should have.

It didn't make sense to me at first because centripetal acceleration isn't just related to speed (if using tangential speed, it's the speed squared over the radius), but it looks like the pulley is approximated as a ring with the centre just locating against side force and taking torque, so the hoop stress in the ring is proportional to tangential speed squared, independent of radius (because it's proportional to the product of the squares of angular velocity and radius, and tangential speed is the product of angular velocity and radius). Convenient! I had incorrectly assumed that the limitation was the belt, not the pulley.

While it technically makes sense, I was surprised by this limitation... in automotive applications 5,000 RPM is routine and shaft speed typically isn't an issue for pulleys, most of which are cheap and simple stamped steel. Of course for a toothed belt the pulley can't be stamped, and cast iron is dense (increasing the hoop stress). A suitable grade of aluminum is the obvious solution.


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## brian_ (Feb 7, 2017)

zapyourrideguy said:


> Doesn’t appear that I would be anywhere close to 6500. More like 4500 rpm.





electro wrks said:


> Sprocket rim speed is different from RPM. Calculate the rim speed the same way you calculate the vehicle speed from the RPM and diameter of the rear tire. Just calculate it in feet per minute, instead of miles per hour.


Right - 6500* ft/min*, not 6500 RPM.


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## zapyourrideguy (Oct 25, 2012)

Here is a revised plan. I am going to see if one of the jack shaft bearings will fit between original motor plate and the elastic coupler.
This will achieve clearance to change belts. I am also seeing if I can mount motor with slotted mount holes so the motor can move up and down for adjustment. It is 115 lbs so tough to move.


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## electro wrks (Mar 5, 2012)

You'll be much happier with this set-up. You should keep the clearance between the front of the drive shaft sprocket and the motor mounting plate to a minimum, just enough to slide the belt through. This will keep the motor sprocket as close as possible to the motor output shaft bearing, reducing the load on it (minimum overhang load). If you opt for this design, you'll have to make the motor mounting plate removable or make sure there is an opening in the plate large enough to slide the drive shaft sprocket through, and access its Taperlock bushing.

Belt velocity should be very close to the rim velocity. Formulas for calculating this are on page 110 of the manual. AIR the max rpm of this motor is moderately low, 6-8k rpm? You will probably be alright with the cast iron sprockets-but you should confirm you are below the max 6500 ft/min rim speed. I'm working with motors running 10-12k RPM, and having serious design issues trying to keep the sprockets below their RPM limits.

You can use the formulas on page 107 to calculate the bearing loads for your set-up. It's basic teeter totter/ lever arm stuff. Being so close together(you should try to make them as far apart as practical), the bearing and shaft loads will be quite high. This means the shaft diameter and bearing size will need to be larger than you might imagine. Bearing suppliers will rate their bearing load capacities based on the RPM. This is where a good contact at bearing store or an engineer will be very helpful. Don't forget, these large loads will be transferred to the mounting plates, their supports, and the motorcycle frame.

You can weld threaded clips (sometimes just regular nuts will do) to the mounting plate that use jacking screws to move the motor to tension the belt. Threaded rod sections welded to the motor mounting washers will work in a pulling type adjuster.

Unfortunately, some set-ups can be very noisy. It would be a good idea to have a plan to completely enclose the drive. This will also keep dirt and rocks out.


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## brian_ (Feb 7, 2017)

electro wrks said:


> You can use the formulas on page 107 to calculate the bearing loads for your set-up. It's basic teeter totter/ lever arm stuff. Being so close together(you should try to make them as far apart as practical), the bearing and shaft loads will be quite high.


I had the same thought. Could the bearing on the output shaft side be spaced further back (to the right in the drawing) from the mounting plate, or is the rubber coupling location fixed?


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## electro wrks (Mar 5, 2012)

Just to clarify, z-guy, you write that you have an AC30 motor? Is that the size motor that's no longer available? 115lbs? Isn't that the weight of AC50 motors?


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## brian_ (Feb 7, 2017)

electro wrks said:


> Just to clarify, z-guy, you write that you have an AC30 motor? Is that the size motor that's no longer available? 115lbs? Isn't that the weight of AC50 motors?


Wow, it looks like the HPGC AC-30 is from so long ago that HPEVS (Hi Performance Electric Vehicle Systems) was still called HPGC (Hi Performance Golf Carts) at the time. If it's this old HPGC/HPEVS motor, it was apparently (and this is more forum rumour than factual information) an earlier version of the AC-31, which became the AC-34/35. The AC-34/35 (which are the same size but wound differently) are the same diameter as the AC-50/51 (which are again, the same size but wound differently) and an inch shorter, and lighter as a result. The AC-3X weigh 85 pounds; the AC-5X are 115 pounds. My guess is that the AC-30 would match the current AC-3X external dimensions and weight.

Given the entirely unoriginal naming system, and the existence of other "ACnn" motors unrelated to HPGC/HPEVS, it could also be an entirely different motor... except that it looks like an HPEVS motor and HPEVS seems to have confirmed that.


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## zapyourrideguy (Oct 25, 2012)

The rubber coupler is fixed without a lot of re-design there. To fit a bearing between the rubber coupler and the original motor plate, I will need to modify my cardon shaft slightly to allow the coupler to move back 1/4".

The motor is in fact an early AC-30 and I believe it's weight is 115 lbs. I bought this from Frodus and spoke with HPEVS about it before purchasing. Older formulation of metal in the windings or something, slightly less efficient than the newer ones.
Anybody know about the sprockets and hubs if they nest into each other? Tried to ask a distributor this question but got no response. This will tell me how much room I will need and how far forward to install new motor plate.


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## brian_ (Feb 7, 2017)

zapyourrideguy said:


> The motor is in fact an early AC-30 and I believe it's weight is 115 lbs.


Interesting... then presumably it's as long as an AC-5X.


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## electro wrks (Mar 5, 2012)

zapyourrideguy said:


> Anybody know about the sprockets and hubs if they nest into each other? Tried to ask a distributor this question but got no response. This will tell me how much room I will need and how far forward to install new motor plate.


If you mean the sprockets and the Taper-lock bushings, there is nothing in the literature I could find or in my parts bins to look at. The sprockets I do have, for 21mm wide belts(the next width down), have the bushings nearly flush with the backside of the sprocket. If this is also the case with the 36mm sprockets, you won't pick up any overlap room with the bearing. To be sure, you'll probably have to look at the actual sprocket and bushing you intend to use.

If you could move the motor further to the left in the frame, you might pick up more adjustment length for the motor mounting slots. I've usually found that I need more slot length than initially estimated.


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## zapyourrideguy (Oct 25, 2012)

Here is an update 
finally have the drive reduction in and it works great. Thanks to all who helped.
The bike is very quick and has good torque, I have tested a few times off-road once with the chain drive and then again with synchronous belt. Top speed is about 55 which is as fast as I want to go. 
the 2 sprockets are just about a degree out of parallel (Gates likes .25 degrees) so I will try to tweak that closer.






















I am going to take everything apart clean up wiring and replace that rear gear with a QD bushing. Since these photos I have added cowling over the belt and gear for safety.
Thanks again, especially Electro wrks, for your input.


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## electro wrks (Mar 5, 2012)

Glad it is working out for you. These belt systems are a real game changer for power transmission. To control and adjust the deflection and parallelism between the motor and bearing mounting plates, you could extend the bearing mounting plate up to hold a bolt or threaded rod or two that ties across to the motor mounting plate. Adjustment would be a matter of tightening or loosening nuts on the bolt(s) or rod(s).

Just keep an eye on the belt wear on the inside of the flanges on the sprockets, and adjust accordingly. 

You must have slotted the bearing mounting plate for adjusting the belt tension. Most shaft drive bikes don't have the clearance where the dive shaft goes into the swing arm to do this. I recall you wrote that there just was not room to move the motor up and down to tension the belt.

For reference, can you list the type and size of the belt and sprockets and the diameter of the counter shaft and bearings? What's the voltage you are using and how many amps are you drawing at your 55 MPH top speed?

Good work!


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## zapyourrideguy (Oct 25, 2012)

Used gates parts 1 1/8 driver sprocket and 7/8 driven sprocket: 
GATES 8MX-28S-21-1108 TIMING BELT SPROCKET 
Gates 1108 1 1/8 Taper-Lock Bushing

Gates 8MX-56S-21 Timing Sprocket 
Gates 2012. 7/8 Taper-Lock Bushing

Gates 8MGT-608-21 Poly Chain GT Carbon Belt
96 volts I will have to get back to you on amp draw.


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## electro wrks (Mar 5, 2012)

Just by eye estimates, the counter shaft (I guess I've also been calling it a jack shaft) bearing near the sprocket is subject to ~2X the belt tension. ~2 x 600lbs( I think I saw this belt tension load at max torque number somewhere in your posts, and it sounds about right) = ~1200 lbs. This may be too high a load for a 7/8" diameter bearing of this type. Keep an eye on the bearing by checking for excess wear and/or heating from an excess load. You may have to use a larger bearings and shaft diameter to correct this.

Also, flanged bearings are available with a double row of bearings in one unit. This would make your life easier, mounting and belt tensioning wise. AIR they are quite a bit more expensive than the common, regular, single row flanged bearings, like you are using. Some have nice preloaded tapered roller bearings. Again, you need to check the bearing load capacity (side load at the RPM used) to make sure you are working within the bearings limits.


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