Hi All,
I'll be following up with another chapter in the blog but for now I wanted to let you know that the Bridgestone electric mountain bike got it's new Alltrax controller today.
First thing I did when it arrived was to quickly re-read the programming instructions. Fortunately I received my USB/ Serial programming cable in the mail today as well. It took me a while to find the right XP driver for this cable but finally got that together.
Programming the Alltrax 4824 is very straight-forward and the free software they provide on the Alltrax site installed and worked nicely.
I set the Maximum Output Current to 60% to start off.
Set the Under Voltage for 23.8V
Set the Over Voltage for 30V
I left the throttle up and throttle down rates at default and turned off the Brake Current.
Set Top Speed at 100%
Hit the SET button and the Alltrax indicator light confirmed that the controller was reset.
I studied the bike for a while looking for the best place to put the controller. It's much larger than my previous controller but I finally found a good spot near where the other had been. The wires all reached there so I used some strong wire-ties to anchor the controller to the bike. Made the connections, added a 150A fuse and tested it ... it all worked.
I spent some time getting the wires secured with wire-ties, looked everything else over and took the bike outside.
I flipped the ON switch, gave it a little throttle and noticed that it accelerated smoothly and got up to about 20mph with ease.
After several trips around the block, I headed down the road and got it up to 22, 23, 24, 25 and it topped out at 26.2mph! There was a slight wind blowing and it must have been at my back so I cruised at around 20-22 most of the trip and at about 2 miles pulled over to see how things were doing.
The controller was still cold, no detectable heat at all. The motor was slightly warm but not anywhere near hot enough to keep me from leaving my hand on it for a long while.
When cruising, I noticed that after about 2/3 throttle, there was no more acceleration even if I gave it full throttle, so I will assume the Maximum Current Output was holding it back as I had set it to do.
I continued on down the road and came back home then did a few more loops around the block and went on down the road on the same route that I had gone before.
I checked the temps again at the same spot as before and nothing was any warmer than last time I checked.
Headed home, around the block a few more times then headed in.
I think I went around 10 miles total today.
I checked the battery voltage and they were each at 12.67 volts. Before leaving they were about 13.4 volts.
My current reduction ratio is 10:1.
Conclusion:
I think I'll get good range with this setup.
I can definately feed this motor more juice by increasing the Maximum Output Current without fear of hurting anything.
The controller perfomed flawlessly and didn't even begin to heat up at all.
I'll be changing the ratio in the future to around 10.5:1 and also upping the Max Output Current.
I haven't weighed the bike yet but with the Scott motor, jackshaft assembly, gears/ pulleys, chain, 8-9Ah batteries and the Alltrax controller it is definately not a lightweight.
It handles well on narrow dirt paths and on loose gravel road sholders so it doesn't seem to hurt it's performance much if any. The center pull brakes work fine and as long as I keep the throttle ramp-up speed gentle, I think it will be a great bike.
Lifting it into my truck will be another story I'll have to figure something out for that. Maybe even take my canopy off since the opening is too low for my handlebars.
Bike's on the charger for a longer run tomorrow.
Dave,
Sounds GREAT!!!!!!!!!!! I would suggest when you make changes make them 1 at a time so you can tell what they are doing to the bike. In the case of upping the current and changing the ratio if you do them together you might see something different than you would doing them 1 at a time. By making 1 change at a time you will know how it effects the bike and performance which will give you a better understanding of which change is best. As an example after the gear ratio change you may find it helps with acceleration but did not effect top speed which tells you the motor can spin faster. In this case I would try to drop the ratio a little more to see if I could improve acceleration without giving much up top speed. Changing the current will lower your range but the gear ration change may increase the range so if you do both you may end up with a net gain of 0 range change. Well you get the idea.
Good Riding,
Chas S.
My Bicycle Pages
Good plan Chas.
I've got a synchronous belt and pulleys that I'll be putting on next week.
Currently:
Current reduction is 10:1
New reduction will be 10:15:1
Optional reduction can be 12:1
I'll work with these first before making any controller changes.
I'll get some pics of it all soon.
Thanks for the input!
Dave
MB-1-E
Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'
Dave B
MB-1-E
<a href="http://visforvoltage.org/book-page/996-mountain-bike-conversion-24v-3-4h... - Bridgestone MB-1 Mountain Bike</a>
Dave,
Good to see you on the road. Great speed. How is the handling. On my Raliegh I never liked to go much over 20 mph, the bike got a little loose and skittish on the steering on higher speeds. My only question is motor temperature combined with ambient air temperature, flat or hilly terrain. You have caught up to me on your progress now, I really think both of us need to be in the 10.5 to 11.5 ratio.
Up good grades I do 22 mph, on the flat 25 to 27, down hill up to 29 mph, I have never cracked that 30mph barrier, only problem I have is motor heat.
Chuck
[b]AGM BATTERIES[/b]
Chas and Chuck,
I have an embarrasing confession to make. Boy do I feel stupid.
Today when I went to reset my odometer it was set on K/hr instead of M/hr. I clocked my speed today and got up to 20 mph. Sorry for the mis-information, guess I was caught up in the moment, the other 6 mph must have been pure adrenalin ... :D I did get going 30 mph today but that was down a slight grade. No wobbles or problems at that speed. But it is a little bit hair raising.
Now that we have that straight, my motor is not getting hot at all. Controller actually stays cold. I'm sure I can push more current through this motor. I figure that even though motor rpm is directly related to voltage that more current will help keep the motor in it's efficient rpms.
The top third of my throttle doesn't have any effect to speed me up. I need to read up on the programming a bit and experiment to see what helps.
Tomorrow I'm going to put on the larger rear sprocket just to see what it does for hills and to my top speed. I forgot before, but my brother has an old friend that has a small machine shop. I called him and he said he'd help me with boring out the synchronous pulleys.
I need them bored, but I may actually end up using the v-belt configuration since it gives me the 12:1 ratio.
I never realized how many variables there were to finding the sweet spot ... I've got a long way to go and may never be able to do 22 up grades. I think that extra 1/4 horse may be helping you there.
So far I have been real conservative on the controller output and settings, I want to work out the mechanical end and get it tweaked. Then I'll tweak the controller settings to get the most out of the motor.
I think you're right though, we both probably need the increased ratio.
Hey, I'm glad to report that everything is holding up very well and your advice for putting the motor right next to the frame saved me from a whole other set of problems. It's just a matter of trial and error to get the rest set now.
Part of my ride today was up and down some (high tension) power line roads, lots of ruts, medium bumps and winding around but the bike did real well on them. Mine is a hardtail so I do have to use my legs and arms as shocks but it manouvered great.
I took the bike part way down the steep road that fried my last controller and had to help by pedaling comming back up but no overheating at all.
Good luck to you both on your E-adventures!
Dave
MB-1-E
Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'
Dave B
MB-1-E
<a href="http://visforvoltage.org/book-page/996-mountain-bike-conversion-24v-3-4h... - Bridgestone MB-1 Mountain Bike</a>