I have a Razor Ecosmart Metro. I am using the scooter in training my dog for sleding (dog pulls scooter along flats, downhill and up hills with motor assist). My course includes flats and hills. The problem is that the dog has more stamina than does the scooter. I don’t need high speed, but I need more range and more up-hill ability. The training course has several steep hills that are too steep for the scooter in its stock configuration. The scooter will power uphill if I walk along side, but I can’t ride it up some of the hills.
After searching the web and your site, I plan on making the following modifications:
Add a 12 volt battery in series to go to 48v
Change motor to your 48v-1000w MOTOR part# mot-481000
Change controller to one of your 48V 1000W controllers (which one do you recommend?)
Change to your 48v THROTTLE THR-75
(Will your 48 volt charger part# CHR-48V1.6AXLR plug directly into the existing charger port and charge the batteries configured for 48 volts?)
Also, I will be adding front brakes and I think I will need your front brake lever LEV-30R.
As far as the up-hill situation goes, I plan on making the battery-motor change and then decide if I need to change the gearing.
OK, given all of that am I thinking in the right direction for this project? Everything I have read on the web leads me to believe that you folks are THE AUTHORITIES in this area, so please give me your thoughts.
OK, thanks for the good news about the easy rear sprocket modification. That means that I can order your SPR-2580 rear sprocket and mount it directly on the stock Razor EcoSmart freewheel. So, I will be ordering that sprocket and the SPR-2580-Guard.
Now, as to determining the correct chain length, maybe you can do me a favor. After installing the 36 Volt 1000 Watt motor item # MOT-SD361000 that I got from you folks, I have been using the stock chain that came with the scooter. While your description of determining the new chain length when installing the 80 tooth rear sprocket is very straight forward, can you make the determination for me?
You folks sell exact replacements for the stock EcoSmart chain, so you might already know how many links that chain has. You also know how many teeth the front sprocket has since you supplied the 36 Volt 1000 Watt motor item # MOT-SD361000 that came with a front sprocket. With that information I am sure that you can determine the correct chain that I will need with the SPR-2580 rear sprocket.
I'm asking this favor because I'd rather not make a mistake counting links (I know it is pretty easy) and end up giving you the wrong information. Also, since we are getting a lot of use out of the scooter now with the new motor, I'd like to keep the scooter together until I have all of the parts in hand to make the sprocket/chain swap all at once.
Thanks for all of your advice and support. Our project would not have gone together so well without you folks
The SPR-2580 sprocket will bolt directly onto the freewheel, however, we do not have an EcoSmart scooter here to determine if an 80 tooth sprocket will clear the frame. We have a way of doing this which is shown in the drawing below.
The outside dimensions of the original SPR-2565S sprocket and of the SPR-2580 sprocket are listed on our #25 Wheel Sprockets page. The difference in outside diameters between the two sprockets can be determined and then divided by two to figure out what size to cut the cardboard to so the clearance can be checked.
Our parts list shows that the original Ecosmart chain has 86 links and its original wheel sprocket has 65 teeth. The MOT-SD361000 motor comes with an 11 tooth sprocket. If Razor has recently changed the EcoSmart's wheel sprocket or chain size then calculating a new chain size using this data will yield an inaccurate result so without counting the chain links and wheel sprocket teeth please use this information and calculation at your own risk. Using the data from our current EcoSmart parts list here is the result we got.
Chain can be broken to even numbers only so for a 95.59 link result we would round it off to either 94 or 96 links depending on if we thought that a tighter or looser chain would work best.
Please let us know if you have any questions.
You folks are the best. Thanks for the rapid reply and the handy hints.
OK, I made a cardboard tab and taped it to the stock sprocket. There is clearance for an 80 tooth sprocket, so I have gone ahead and placed my order for both the SPR-2580 sprocket and the 96 link heavy duty #25 chain.
I will let you know how things work when the parts arrive.
That is great to hear that the 80 tooth sprocket will clear the frame. We are looking forward to hearing how these parts fit on the EcoSmart scooter after they are installed.
OK, back again.
The 36v 1000amp motor and 80 tooth rear sprocket has done the trick. Now we can pull VERY long uphills easily. The temptation is to fully open the throttle, but that is like tromping on a gas pedal - only so much fuel can be converted into forward motion, the rest blows out the tailpipe. Same thing seems to occur with the scooter going up hill. We find that we only need to apply the amount of throttle rotation necessary to maintain forward thrust. Opening up the throttle may make the scooter go marginally faster up steep hills, but doing so really eats up the battery charge. Pulling the same hill with just enough throttle to keep going greatly prolongs the charge life.
Ok, a couple of questions.
1) Do you offer a cog for #25 chain that could slip onto a standard bicycle multi-speed (shimano type) type hub? Now that we can go up steep hills, we need to be able to modulate down hill travel. I'm thinking about having the rear wheel rebuilt using a bicycle disc brake hub that would have a freewheel designed for multi-speed sprockets to be slid onto it. Some folks make single speed bikes by using no-tooth spacers and a single toothed sprocket. By judiciously applying the spacers it is possible to get a nice clean chain line.
If I can get a #25 sprocket to fit on a standard bicycle hub designed for use with disc brake, I would have a lot of options for fitting up a rear disc brake. I'm afraid that the standard Razor drum brake will burn out quickly given the current course over which the scooter is run. We start out at 780' elevation and run down about 1.5 miles of gravel road dropping to about 120' elevation. Remember that we are training a sled dog, and the coasting scooter can over run the dog on long down hill slopes.
I have not mentioned it yet, but I have changed out the front fork to take a 20" wheel and have installed a Vee brake for extra stopping capacity. The fork also has the option to mount a disc brake. BTW, the 20" wheel greatly reduces the twitchy character of the Razor on long down hill runs on gravel. However, with the larger front wheel and substantial front braking ability while riding on down hill gravel roads back brakes are really necessary.
So, the question is what do you guys have available that could let me use my 80 tooth #25 sprocket on a standard bicycle hub setup? Or, do you have some other rear disc brake suggestion?
2) I have found that the throttle that I got from you guys has a cable that is about a foot too short. I ended up getting some 5 conductor cable, cutting into the throttle cable and splicing in an extra foot in order to reach the control box. Though that modification worked, I am not very happy with the kobby patchwork extension and the 10 crimp-on connections necessary to get the throttle to plug into the controller. Question - do you offer a throttle that would work with my 1000 watt motor that has a longer cable? For your reference, the throttle cable length should be about the same length as the throttle cut-off cable on the brake lever.
Looking forward to your feedback
Great to hear that the scooter is working so well for going up long hills now.
We do not carry and cannot get sprockets for #25 chain that will fit onto a Shimano type splined wheel hub. However, if you can find a 16 tooth bicycle chain sprocket that fits onto the hub then the existing wheel sprocket that is bolted onto the freewheel right now can be taken off of the freewheel and bolted directly onto the 16 tooth bicycle chain sprocket.
If you decide to use a bicycle wheel hub that has a threaded side for a freewheel then we carry a 16 tooth sprocket with 1.375 x 24 TPI (ISO) bicycle hub right-hand clockwise threads that the original #25 sprocket will bolt onto which is our item # FWM-180 sold on our Freewheels Clutches page.
The THR-1000 throttle that you ordered shows as having a 62" long cable. We do not carry any other twist throttles with 36 Volt battery indicators that have very much longer cables, as the longest cabled ones we carry only have a 64" long cable.
We do carry throttle extension cables that will neatly and cleanly extend the length of the THR-1000 (or any other) throttle cable. These are sold on our Extension Cables page. We also carry the Black Plastic Connectors, Cable, and Connector Crimping Tool to make these throttle extension cables yourself.
Please let us know if we missed any questions or if you have any new ones.