# eBike First Load Test



## eRev (Jan 10, 2009)

Life is way too busy sometimes to keep focus on competing hobbies, so after 2-yrs of putzing I've finally bagged the first representative load-test and the results are spot-on what I'm looking for:

http://machdiamond.smugmug.com/Motorcycles/eRevMW-K75-Conversion/IMG3198/1229299000_zc7KJ-X2.jpg

http://www.youtube.com/watch?v=IY679FUy0ZI

Today was a mile-stone - she is already licensed - just needs some DOT bits and then we'll see... /Steve


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## RIPPERTON (Jan 26, 2010)

Nice work Rev
got a few more shots of the bike ?
and what cells did you use.


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## eRev (Jan 10, 2009)

RIPPERTON said:


> Nice work Rev
> got a few more shots of the bike ?
> and what cells did you use.


Hey thanks RIPPERTON.

The primary pack is comprised of (22) SE65Ahr cells:
http://machdiamond.smugmug.com/Motorcycles/eRevMW-K75-Conversion/IMG1989/752330877_Ls3W2-X2.jpg

Here's a better view of the drive-line bits - she's seemingly hitting the performance numbers calculated:
http://machdiamond.smugmug.com/Motorcycles/eRevMW-K75-Conversion/IMG2289/843442350_fAdb8-X2.jpg

http://machdiamond.smugmug.com/Motorcycles/eRevMW-K75-Conversion/IMG2349/853550583_cXTQb-X2.jpg

/Steve


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## RIPPERTON (Jan 26, 2010)

Nice
Is that the bikes gearbox still in there (gear stick)
Your belt is an over drive, is that cause the BMW diff is about a 5 to 1 reduction ?
Can you feel any torque reaction in the bike as you accelerate ?
ie does the bike want to lean over ?


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## eRev (Jan 10, 2009)

RIPPERTON said:


> Nice
> Is that the bikes gearbox still in there (gear stick)
> Your belt is an over drive, is that cause the BMW diff is about a 5 to 1 reduction ?
> Can you feel any torque reaction in the bike as you accelerate ?
> ie does the bike want to lean over ?


Yes, the OEM gearbox is retained and the drive system is setup to work best in forth gear which still requires the belt overdrive to properly match the gearbox input speed.

Compare to the ICE version where torque reaction is felt, the electric system has reduced inertia, so no the torque reaction wasn't felt under acceleration, but I have very little run time to fully evauate this effect - it is certainly reduced form the OEM setup.

Of note - my design is intended for surface street commuting only and I'm content with having some losses with the driveline than a more optimized approach such as a chain drive would allow - even if I missed my range target by a significant amount it still becomes a viable mode of travel.

Is it just me or is it normal to be thinking of the next generation (meaning employing improved concepts) before the first has proven itself?

/Steve


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## RIPPERTON (Jan 26, 2010)

I would have left the gear box in there too just to find out what the optimal overall reduction was and then remove the gearbox and redesign the belt and pullys to give that same overall reduction. Im guessing you will be able to move the belt/pullys rearward and make more room for batteries or also move them rearwards.
Can you tell us what the overall reduction is from motor to wheel and what your top speed is.


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## eRev (Jan 10, 2009)

RIPPERTON said:


> I would have left the gear box in there too just to find out what the optimal overall reduction was and then remove the gearbox and redesign the belt and pullys to give that same overall reduction. Im guessing you will be able to move the belt/pullys rearward and make more room for batteries or also move them rearwards.
> Can you tell us what the overall reduction is from motor to wheel and what your top speed is.


Hey RIPPERTON - you are a caliber above my head - wish I had more time also to consider something besides keeping the EV implimentation simple - design goal was to keep it off the hwy at a pittiful 57mph to gain moped insurance rates and I'm not sure, but approxiamting a 7mph loss on account of back emf is about where I had it in my test - it is what it is and she runs rather effortlessly in the fun zone, so it should work good for the daily short commute - just wondering if the belt "whine" will grind on me over time.

Besides, I disagree on removing the gearbox - the housing is a structural member and the futz factor again is not worth the bother - I rather spend the energies on something different or some level of augmentation like regenerative motor braking - currently using an Altrax.

The eBike is a diversion right now - my real passion is amateur rocketry. I need time to absorb your project RIPPERTON - gave it a brief a day ago and I'm jealous already then again I'm just a hobby whore.


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## eRev (Jan 10, 2009)

*DOT Bits Installed*

Still looks fugly, but it works for the intended purpose:

http://machdiamond.smugmug.com/Motorcycles/eRevMW-K75-Conversion/eRevDOTp1/1254715010_LpjdbwL-X2.jpg

http://machdiamond.smugmug.com/Motorcycles/eRevMW-K75-Conversion/eRevDOTp2/1254715076_fFhbwZ9-X2.jpg

http://machdiamond.smugmug.com/Motorcycles/eRevMW-K75-Conversion/eRevDOTp3/1254715146_78t8QdD-X2.jpg


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