Test Pilots: What's your status?

PJD- Excellent work!!

I did consider that the tire may not be absolutely round after making my post. Marking the rim, which should be concentric, is better thinking on your part.

I also think the tire may show its out of balance condition more effectively if one of the shocks is disconnected at the wheel/swing arm end.

To re-enforce a point, the tire /rim is marked at the heavy point and the weights are slowly moved to the opposite/light side.

I really enjoyed getting your post that you tried my method and were successfull!

Here is a possible cause of the front handlebar shimmy on these bikes:

My bike has a very slight shimmy if I hold the handle bar lightly with one hand. Not bad at all but it should not do it.

When I first got my bike I did a number of measurements. One of them was to make sure the front wheel was centered in the front fork.It was not and still is not. It is offset about one eight of an inch to one side.

On consideration, I believe this causes the front tire to want to pull very slightly in one direction. When it does the castor effect causes the wheel to want to run straight. The two forces wrestle with eachother and this causes the wheel to swing back and forth like on a hospital gurney. Hence the shimmy.

PJD also noted that his front tire had worn unevenly and had started to ride like a knobby tire. Uneven tire wear is caused by alignment issues and that is an additional symptom that would be caused by the wheel not being centered in the fork.

Other people have posted that the cause may be a loose headset. I think if the wheels were properly aligned the bike would not shimmy on smooth pavement even with a loose headset.

Comments?

LCJUTILA wrote:

On consideration, I believe this causes the front tire to want to pull very slightly in one direction. When it does the castor effect causes the wheel to want to run straight. The two forces wrestle with eachother and this causes the wheel to swing back and forth like on a hospital gurney. Hence the shimmy.

Excellent insight! I was considering everything else except that. A caster wheel whose center line is not aligned with the steering axis WOULD go into shimmy oscillation.

My front shimmy is not severe, but I have found it very annoying.

The wheel could be re-centered by changing the spacers either side of the axle bolt 1/8" longer one side, 1/8" shorter the other. Either find appropriate length and diameter spacers in a good hardware store, or grind one down 1/8", add 1/8" of washers to the other. The brake caliper assembly can probably accommodate this much change in the wheel center, but if not, spacers could maybe be put on the brake disc or caliper mounting plate.

Alternatively, the wheel could be properly centered if the outer races of both bearings are driven completely to their machined seats. but if the inner race spacer tube (needed to keep the axle bolt from applying a thrusting force on the bearings and binding/ruining them) is a bit too long, the bearing won't drive down their seats, resulting in off-center wheel.

To what side was your wheel the wheel off-center? I'll going down to check mine now.

Oh, and regarding spin-marking the inside web of the wheel, it would indicate the opposite movement as marking the tire, ergo the light, not the heavy side. Disconnecting one shock is a good idea I didn't think of.

--------------------------

Edit:

I'm back.

Measuring from the fork tube to the rim, the difference between right and left is 3.5 mm - lower on the left - so the off-center amount would be half of this to the left - just a bit more than 1/16 inch to the left. This does not seem to be enough to be having an effect (asymmetry in the tire section could be more than that) but maybe it is. I forgot that the spacer on the right is integrated with the speedo drive housing. It could be ground down 1/16", then a washer added to the spacer on the left side. It's worth a try and won't hurt anything.

Hi all,

I've been a Test Pilot since Dec 14, 2011.

Here's my status:

Model: Current Motors C124
Delivery date: December 14, 2011
Rider profile: Medium build (5'10" and 165 lbs;).
Mileage: Closing in on 4000 miles on the odometer
Typical daily mileage: 19 miles
Longest single trip: ~36 miles
Return on investment: Great so far since I use it on my daily commute. Haven't put any money into it yet (but see below)
Maximum range (estimated): 40 miles.
Typical charge pattern: Charge nightly.
Issues:
1) Initially had some problems with loose mirrors but CMC helped me sort that out. Also had a problem last winter where the motor wouldn't work below a certain temp (think it was 32F) - but a software update fixed that problem.
2) I have an ongoing issue with the 15Amp slow fuse (located in the left side access panel) burning out every few months or so. I'm on my 4th fuse. Not a big deal but clearly something is not quite right.
3) I also have a large wobble on the front wheel if I relax my hold on the handlebars so I was interested to see the discussion in this thread about that issue.
4) Hit a big pothole once and bent the back wheel rim so that the tire blew out. After searching in vain for a mechanic who would attempt a repair on my bike (nobody wants to touch the rim - I guess for fear of shattering it). I eventually just asked one to lend me a hammer and I was able to very slowly and carefully hammer the rim back into close enough alignment that the tire would hold air. Have been riding a few months now with it with no issue but I should probably try and replace the rim. Haven't asked CMC directly about it.
5) Locks - poor quality and fit. My back seat catch doesn't work anymore and I basically have to pound the seat with my fist to get the side catch to grab - both basically need some re-aligning. And I've had frustrations with the key turning the lock for the charging panel.
6) Head and Tail Lights, as many have pointed out are dim. Just living with them for now.
7) I do, however, have a recent issue with the right turning signal. When I activate it, I can hear the clicking and the light on the mirror housing works. The main front and back signals don't, however and the dash indicator light also doesn't work either. It isn't the bulbs because a couple of times it they have started to work again. Seems like a loose connection somewhere perhaps... Any ideas?

Overall Impression: For a test pilot bike, I've been extremely happy with the C124. It's been very reliable and CMC has always helped when asked. I've been busy with kids, work, remodeling our kitchen, life - you know - so some issues that I could ask CMC about (replacement rim, turning signal) I just haven't gotten around to yet. I was disappointed when they raised the price to what I think is beyond the sweet spot for this bike. Granted, I haven't seen or tried a newer production bike but to me, a price of ~8k would be in the right range. If they had a nicer body (better fit and finish, etc.) then I think 10-11k could be justified but they have been held back (in my opinion) by the less than stellar off the shelf frame/body.

I really do hope that CMC can survive in this (tough) early adopter market because I think their approach is generally right. And I have really appreciated their personal approach and attention to detail.

Cheers,
Jeff

We got a fix now for that blowing fuse. We have slowly been performing updates on customer scooters (between the other mountains of work that we're trying to get done), and the fuse holder has been one of the updates. You'll cut out the old fuse holder, and solder in the new fuse holder and fuse. I'll send one out next week.

By the way, check this out. Go pass all the Romney junk, to "Pick of the week":

http://www.technewsworld.com/story/What-Mitt-Romney-Could-Have-Learned-from-EMCs-Joe-Tucci-76651.html

Hi Terry,

That's a great article - thanks for sharing it! And thanks for the update on the fuse too. I'll look forward to changing out the holder.

Any ideas for the turning signal problem? It's weird the it only affects the right side and I still hear the clicking noise. Three of the four lights that normally flash are not working (front, back, and dash signals) but the one on the mirror front does still work. A couple of times over the last few days they all worked again but then stopped. The left signal works normally.

Cheers,
Jeff

Signal bulb problems are usually related to bad grounds in the sockets or corrosion anywhere in the circuit. Check the sockets and connectors for oxidation and clean them with fine sandpaper - assuming these are plain automotive bulbs and not LEDs.

It may also be related to moisture that may have entered the blinker relay. Was it raining heavily before the problem first occurred?

I would suspect from your comments about the steering shifting and the bent rear wheel, those are the source of the wobble. There should be zero shift in the steering head under braking. If you go on line and look at the manuals for any big brand of bike you will see reference to checking the steering head bearings quite soon after purchase. Usually in about 600 miles. You need a wrench that is made with a "tooth" on it to engage the nut notches (spanner wrench), not a punch and hammer, and a big wrench like a cresent wrench. Tighten the bearing really snug until the forks do not want to move and rattle the front end to make sure everything seats. Jumping on the throttle and then the front brakes in about 5 ft will rattle it good. If you hear a click you know that is the issue. Then back off the tension until the fork moves freely and lock the top nut down. Some try to just tighten, but not make sure the slack is out of everything. You cannot be sure that way.

The bearing cups are not delivered polished and they wear in also. The result is despite some people on this site saying that they have never checked the heads in their life and refuse to do so, you should. It is not as has been said just Mftg CYA. Things just wear and move.

Racers can tell you that things that move or are not right at the rear often feel like a front end problem. That bent wheel might effect the tire shape, or maybe the swingarm got tweaked. You can rig up a flat surface, levels and check.

If it persists, I have had some Chinese brands come through the shop for repairs and after failing to be able to fix the front, opened up the steering head and found 1 or 2 balls missing from the bearings. The balls are not held in the race by any rigid structure, but just set in there during assembly until they are firmly clamped down, so it is possible that in assembly some fell out. This is unusual, but I have seen it. That "shifting" as you say, is what it looks like when a ball or two are missing.

Tires can cause a wobble, but you do not have a lot of mileage on the bike for that. Might check against some different road surfaces.

I will assume you have checked the steering head or triple clamp bolts for tightness.

The front forks come apart. You can buy different strength springs for the legs, you can change the viscosity in the fork oil for more dampening. Usually a few shims for a preload is all that anyone needs or wants. Be warned, those forks want to come apart with some force and are a pain to reassemble. Best let a shop do it.

Enjoy your bike.

DH Zehrbach

Thanks for the suggestions about the turning signal. I'll have to do some checking and report back. I'm pretty sure there wasn't rain before it started happening but I have certainly been through my share of it so some corrosion somewhere I guess is likely.

Cheers,
Jeff

After almost a year of trouble free riding, something odd happened.

The first, possibly related incident was on about Nov. 24, while riding at night, all lighting/accessory power suddenly went off. I still had traction power, but (as expected if there is no 12V power) no regen. It was a street-lighted road, so I kept riding slowly - mostly coasting downhill, wondering what the driver behind me was thinking about this guy riding a scooter with all lights out. Then after perhaps 30 sec to a minute, the lights came back on. This problem has not repeated itself since.

But then yesterday, I discovered it was not charging correctly - It would switch to balance mode normally, but run for only a minute on balance mode, then go to balance charging timeout (2 short flashes). I broke out the notebook pc and cable and checked the BCU configuration. Sure enough, the setting for charge timeout was set to 1 (minutes) instead of the normal 360 minutes. Not knowing what other setting may have changed, sent a "restore factory defaults" command. The charge timeout setting was restored to 360, and the charging then finished normally.

So, the question remains, what could have caused to stored setting value to change?

And another issue, when are we test pilots going to get a comprehensive manual on the BCU software and explanations of the various settings?

John Harding, are you still out there?

Paul D.

IF the 12 volt and drive systems are interconnected, and the latter relies on the former working properly, wouldn't the DC/DC converter (and related connections) be the first thing to check?

IF the 12 volt and drive systems are interconnected, and the latter relies on the former working properly, wouldn't the DC/DC converter (and related connections) be the first thing to check?

The bike control unit (a programmable controller that manages all the scooter functions) is what actually turns the accessory power on and off.

The key switch presumably powers up the 12 volt DC-DC converter, which powers up the BCU, then after a few seconds of time for BCU to boot up and the programming to load, the BCU turns the lights and horn power on, and also makes the throttle operable. The throttle itself does not directly command the motor controller, it interfaces with the BCU, then the BCU alters and/or disables the throttle signal for a lot of conditions, like high motor temperature, battery pack SOC, kickstand down, etc. The BCU in effect serves as a gate-keeping "nanny" between the operator and the basic scooter functions - like allowing it to run at all. It is my least favorite feature of the scooter as earlier versions of the programming would stop the scooter in the middle of the road over the most trivial of malfunctions - for example an erroneous battery pack temperature reading. John has since improved the programming so you now just get a warning light signal for many of the former "shutdown" conditions.

Then, to complicate things more, there is also a separate 24 volt power supply to power the Kelly motor Controller. It stays on all the time, except when a "winter switch" under the seat is flipped off. The Kelly can also be set up to be powered by the full pack voltage, but the 24 volt power is "preferred method".

the only interface the 12v system has with the controller is that the 12 volt brake light circuit also provides the regen and controller power shutoff signal.

After a bit of winter weather, we had a little bit of spring weather and rain, washing away both the snow and road salt. closer to normal, but dry weather has returned - so I am riding almost every day again. But I have been watching a failing cell no. 19, and it has finally failed to the point that the scooter got a low-voltage cutoff condition from this cell, just as I was leaving work. Rode home in reduced power mode - thankfully on a route with no steep hills. It goes 40 mph max on the flat in this mode.

I've left a voice-mail message with Terry, but no reply so far. I don't know if the pack is in warranty or not. I'm pretty sure the particular cell that went bad was replaced once before. Someday, the QC of Chinese lithium cells will improve...

I think they may all be at the auto show in Detroit. It's in full-swing now through the 27th and Current Motor Co. has a booth at the show. If you "like" them on FB, you'll get their feed of updates.

From my perspective, that is not good news. I'll be down for more than 2 weeks!

I'll probably just shell out the money and buy a cell or two from Elite Power Solutions - $95 ea.

Edit: Terry called - a cell will be sent out after that are back from the show. The break from winter weather is about to end, so I'm not in much of a hurry to fix it.

Follow-up:

The new cell was installed and when weather permits, It is running fine.

Terry is working on a new very useful improvement that I've been thinking about as well - the ability to charge the CuMoCo Scooters at a J1772 EV charging station, which I am starting to see a few places even here in the rust belt. For now, it may take the form of an external box with a J1772 socket at one end and a short cable with a standard US 3-prong extension socket at the other end. I presume that sending 220V through a US-style 120 volt plug and socket would be against electric building codes but it should be perfectly safe, and legally speaking, a vehicle is not a building! The alternative, having to put a chunky 220 volt 4-wire electric dryer or range plug on the scooter would be rather awkward. Better to just find a place to mount the J1772 socket in the scooter. In my case, I'll have to remove the (110 volt mains-actuated) relay I'm using in place of the charging door switch, and go back to the door switch.

My bike is running great and I am working on a bigger, more aerodynamic windscreen for it that is at a greater rake and fits my sillouette. I am hoping this will cut down on helmet windnoise at highway speed and increase efficiency.

Any ideas or caveats?

You want to reduce wind noise; it's real easy. Do what must motorcycle groups suggest - use ear plugs. Take a good ear plug and cut in half. Put half in each ear. Works wonders to cut wind noise and you still hear what's going on around you. By reducing the size of the plug you get two benefits: it doesn't interfere with your helmet and its actually easier to insert/remove.

A good quality, properly-fitting helmet shouldn't produce a lot of wind noise even with no windshield. The problem is usually air getting in around the visor.

I have a modular full face helmet that flips up in front. There are lots of seams that create the wind noise. I think a raked windscreen that is shaped to my sillouette will be more aerodynamic than the wind spilling around the small windshield and hitting my body and helmet for a second time before heading past. They say the coefficient of drag for a motorcycle and rider is the equivalent of a brick dragging a parachute and any improvement would increase range and efficiency measurably at highway speeds. My bike can go about 70 mph so drag is a concern.

When I tuck behind the wind screen noise drops off to close to zero. Very pleasant but not a good position for comfort or control.

"My bike can go about 70 mph so drag is a concern."

Drag is a concern (especially for battery-elctric MC's or scooter) at much less than 70 mph too. As you wrote, the aerodynamics of any 2-wheel vehicle is poor. Assuming a generous CD of 0.8 (i.e 80% of the aerodynamic slipperiness of a brick broad-end to the wind) and a frontal area of 9 square feet (.85 m^2), the drag at even just 45 mph (70 kph) amounts to almost 4.5 horsepower. Raking the windshield back would help some, but removing the windshield altogether (which I did last summer), would probably help more.

And regarding the electric plug issues for 220 volt charging, I didn't realize that there are a number of US plug/socket types the same size as a 120 volt plug or socket that are approved for 220 volt service - the NEMA 6-15 or NEMA L6-15 (twist locking type) for one. So this is not an issue. I still think the J1772 socket being built into the scooter would be more elegant.

I'm surprised there has been no talk on the much more active Vectrix forum on adapting our scooters for J1772 charging. I guess one problem is that J1772 is strictly a US, not an international standard - although I assume at least Canada will adopt it too.

So, the good news (for me) is that I bought a plugin hybrid, a Ford C-Max Energi. It's great going to work in the winter in a heated cabin, with no risk of slipping on wet pavement, and still be driving with just electricity. The bad news (for Current) is that I bought a plugin hybrid, so my scooter use is going to drop noticeably, especially in poorer weather.

But that means I now have a J1772 charger for the car. Two in fact, I have a 110v charger that came with the car, and I'll be buying a 220v charger and mounting it on the wall sometime shorty. So putting a J1772 socket on the bike is going to make charging more convenient (though I will have to figure out which vehicle gets connected overnight so it'll be ready in the morning).

I wonder if having a J1772 socket on the bike will mean it can charge at faster rates if the power is available?

MikeB,
I'm interested in what you find out to terms of max safe charging current. A local battery distributor was destroying GBS cells within a month by charging/discharging cells near 3C. I contacted Elite Power Solutions and their only response was to charge no higher than C/3 (13.3A on 40AH or 20A on 60AH cells) for longest cell life.

So I gave up my dream of charging at 30A off J1772, and am using only 14A.

MikeB,
I'm interested in what you find out in terms of max safe charging current. A local battery distributor was destroying GBS cells within a month by charging/discharging cells near 3C. I contacted Elite Power Solutions and their only response was to charge no higher than C/3 (13.3A on 40AH or 20A on 60AH cells) for longest cell life.

So I gave up my dream of charging at 30A off J1772, and am using only 14A.

Our CHL battery can bear 2C constant charging,see 30minutes quick charging video on 50AH battery http://v.youku.com/v_show/id_XNTEzODgyMzIw.html

http://v.youku.com/v_show/id_XNTEzODgyNjc2.html （100A,30minutes quick charging )

and 150A constant discharged no more than 10 degree temperature raised.

See www.erider.cn

Mike,

The JI772 is not "smart" and it is not a charger. It is simply a fancy 240 volt AC extension cord with redundant electric shock, tamper, and-child proof features that assure the plug is only energized when it is plugged into an EV and the EV signals it to "charge me". It also communicates its maximum amperage capacity to the vehicle so the vehicle knows how much it can draw. All the "smarts" must come from the charger in the EV. Details here:

https://en.wikipedia.org/wiki/SAE_J1772

So in the case of the CumoCo, the J1772 makes no difference as to charger output unless you change to a more powerful charger too. My existing old-style charger (with the fan) charges at about 9 amps or so. It would be nice to have a more powerful charger - but it would probably be difficult to physically fit it on the scooter. The circuit on the EV that produces the "connected" and "feed me" signals is simple - just a diode, 2.7K resistor, a 1.3K resistor and a relay connected to the existing charger on/off signal from the BMS. Or, in the case of a simple adapter box and cord, a SPST switch the user throws once the J1772 is plugged in.

BTW, I'm up to 7160 odometer "units" (about 6300 miles) on my scooter.

IBScootin,

Have you adapted your scooter to charging on a J1772?

The advantages of using the J1772 is simply that it gives me an option other than "sneak charging" from an 120 volt outlet in a parking garage or the side of someone's building or planter-box. (My range is good enough that I have yet to have had to do this, but I came close once) And, it also shows the public that those charger boxes we are starting to see are actually getting used by someone. I have yet to see and electric car or plug-in hybrid anywhere in my area. As far as I know, My two scooters are still the only EV's in Allegheny County (Pop. 1.2 million), PA.

Mike,

The JI772 is not "smart" and it is not a charger. It is simply a fancy 240 volt AC extension cord with redundant electric shock, tamper, and-child proof features that assure the plug is only energized when it is plugged into an EV and the EV signals it to "charge me".

Yea, I'm aware that calling it a charger isn't quite correct, it's an external device designed to provide power to the onboard charger. However, that said, CuMoCo chose a charger that expects 110v power at no more than 15a, using a standard extension cord. If they move to a J1772 plug, they could choose a charger capable of accepting higher wattages. If they do that, then the battery becomes the limiting factor.

CHL, please don't insert your advertizing spam in this thread. Current Motor Company has already made a decision on battery chemistry for the bikes they are building, and we're not going to second guess that here. Just because we bring up batteries as a topic, doesn't mean we're making some sort of purchasing decision.