Adjusting wheel diameter + system freeze problem

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brace
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Last seen: 13 years 11 months ago
Joined: Wednesday, June 4, 2008 - 06:47
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Adjusting wheel diameter + system freeze problem

Hi.

I traveled 500 km so far with my Bionx bike and I am very satisified with it. I have 2 issues:

1) I set the wheel size to 2199 (700c wheel, as described in the user manual). Anyway it looks like the distance I ride is overestimated in the odometer (and therefore the speed). I made a check on a 13.4 km road. I know that that particular road is 13.4 km long, by measuring it with my car and also by using google earth to calculate the distance. Both cases 13.4 km (so I would say it is 13.3 - 13.5 km). When riding the bike (I made the road 2 times, in both directions) I always have the same result: 14.4 km. So it looks like the Bionx overestimates. I also measured my wheel. And with a a measurement I had 218 cm, quite consistent with the 219.9 cm that I inputed in the Bionx console. So assuming my wheel is 2190 mm I should the the following:

Inputed wheel size = (13.4 * 2190) / 14.4 = 2038 mm ? (so 2038 instead of 2199)

I think I should, anyway I'd like to know if anyone has found the same problem. I say problem since the wheel circumference is ok, but anyway I have "higher distances".

Since the speed affects the speed limiter too, I'd gain some km/h and still being legal.

Please correct me if I am wrong.

2) Twice I had this problem: while pedaling suddenly the display moved to a "freeze" status and the kit didn't work anymore. No assistance, no response from the console, in one case the kit moved to "generation" mode so it was also difficult for me to push the bike. After several attempts I found the solution: disconnecting and reconnecting the console by temporarly unconnecting the the cable (about 15 cm from the console). That connection is quite "floating", I didn't secure it to the bike, so I feel like it is likely that hitting a stone with the wheel can make it disconnect.

Does anyone of you have the same problem? May be this can be caused from that connection to "disconnect"for a fraction of a second. In this case I could just use some tape to make it more secure, but I am not sure this is the way to go. I had this problem twice in 500 km, so it is quite difficult to reproduce.

Thanks.

nasukaren
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Last seen: 14 years 3 months ago
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Re: Adjusting wheel diameter + system freeze problem

The problem with measuring the wheel with no-load is that you will always over measure because the weight of you+bike+batteries tends to compress the wheel slightly on the road. So it's best to fine tune by doing what you are doing -- calibrating against a known distance. Play with the wheel diameter in mm. by subtracting small amounts until the odometer matches reality.

K

Working on a Piaggio Boxer (mo-ped) EV conversion: http://gpsy.com/ev

brace
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Last seen: 13 years 11 months ago
Joined: Wednesday, June 4, 2008 - 06:47
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Re: Adjusting wheel diameter + system freeze problem

Thanks for the comment. I will for sure adjust the wheel size until the odometer behaves well.

In the meantime if someone can also comment on the "freeze" problem I'll be happier.

sandorszabo
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Re: Adjusting wheel diameter + system freeze problem

You don't mention the voltage of your system, so I'm not sure whether this is relevant. But I, and one other poster, have noted that the connection between the accelerator and the controller can loosen. This caused my setup to go into regen mode. It hasn't happened since I reconfigured the attachment of the cable to the handlebars.

brace
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Last seen: 13 years 11 months ago
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Re: Adjusting wheel diameter + system freeze problem

I have the PL-350, so 36V.

I also had the regenmode inserted in one case, in the other no. Probably this is a random factor, since the disconnection brings the system in an unexpected state that can give random results.

Anyway since you also had the loosen connection, probably all I need to do is to fix this somehow. The reason why I left this loosen connection was in case of a bike accident, to avoid that the cables can be damaged. Anyway the likelihood that this happens is very low, while it is not impossible to have disconnections as I experienced.

Thanks.

alan in tempe
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Last seen: 5 years 11 months ago
Joined: Saturday, April 4, 2009 - 09:53
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Re: Adjusting wheel diameter + system freeze problem

A few months late replying, but I just found this place!

I got a PL350 last September, and have about 1900 miles on it now, doing 10.3 miles each way to work, mostly flat, except for some pedestrian/bike under or over passes. Mine freezes frequently. Bionx says to send it back for warranty, but it is not worth the hassle of shipping and being without for a few weeks, so I put up with this otherwise excellent system. I converted an old Univega Alpena mountain bike, putting on 1.75" road tires and fenders.

Caution: minutiae of freeze details in this paragraph! I get freezes about every eighth ride, on average, unless I check the total mileage (one press on the chrono button), in which case I usually get a freeze on the following ride. I have had two freezes on the same ride twice. If I have the back light on when it freezes, it stays on. The speed is almost always (more than 9 out of 10 times) reading 18.3 MPH when it freezes, but has been various values between 17 and 19 MPH, but nearly always 18 something. There seems to be no correlation between the freezes and things like actual speed (I don't believe I usually ride at 18, but ride 19-20MPH when I am in a hurry or want more exercise, or 15-17MPH otherwise!), bumps or vibration, temperature, or assist levels (occurs on A2, A3 and A4, although I rarely use A4). My trip ODO loose around 2 miles (1-4) with each reset, and I assume the total mileage is similarly reduced, but I am not sure. I am pretty sure there is no mileage lost at the time of the freeze (from the few times I was sure of the mileage just prior to the freeze), only after the reset. Rarely does the freeze occur during heavy assist, and never (so far) during braking/regen.

The reset is simple: quickly unplug and re-plug the controller cable at the controller. I usually do it while continuing my ride, but will stop if in traffic or wearing gloves. I'm considering finding a matching pair of connectors, and creating a 2 inch long "patch cable" to put in-line with the cable. This would have a momentary press-to-open switch with which to break the one or two leads needed to do the reset (with the rest of the leads connected straight through. Now all I need is part numbers for the connectors and identify which lead or leads need to be momentarily broken.

-- Alan

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