1) Spokes
The factory fitted spokes are 110mm long when measured from the inside of the elbow:
But if you are going to fit an MTX-33 rim you will need to measure the internal diameter of the new rim. If it is more than 2mm larger than the GM rim you may need to use longer spokes.
For example, if the internal diameter was 10mm larger, you would need spokes at least 5mm longer than the existing ones.
The threaded end of the spoke should ideally end up just below the head of the nipple when the spokes are properly tensioned:
You might also need to add a bit extra as the riveted holes will not allow the nipples to be pulled as far into the rim.
To calculate the additional length you will need to measure the length of a nipple, and then insert it into the rim and measure the length of the nipple which is still protruding. Add 1mm to this measurement
(to allow for stretching under tension) and then deduct it from the overall nipple length to determine the additional length of the spoke that should extend inside the rim.
So if the nipple is 16mm long, and only 10mm sticks out of the rim when it is fitted, you would deduct 11mm from the original 16mm to determine that the spoke needs to have at least 5mm of its overall length hidden inside the rim.
I much prefer to ride with thinner spokes and would even use 14 gauge spokes if it wasn't for the large holes in the hubs. The thinner spokes have more give in them and are therefore better at absorbing impact forces instead of simply transmitting them directly between the rim and hub.
A correctly fitted quality spoke should be more than adequate for most hubmotors, there should be no need to increase the thickness of the spoke diameter.
I know its in the uk, but Graham @ www.tillercycles.co.uk will cut custom spokes, payment by PayPal and I guess if you email him, he will tell you if he will send to Sweden.......
Go for the Sapim 13/14g strong spokes....very strong (1400N/mm2) and butted...rated for 1.6 million revolutions.
If there is a slack at one spoke it will eventually lose its head or just unscrew.
If your spokes are all breaking on the elbow section like this:
it's because the spokes are failing due to metal fatigue caused by the constant flexing of the elbow as the spokes are not correctly supported at the flange end.
I suggest you read the following posts to find out why this happens, and how to prevent it from happening again:
Why spokes break.The best way to prevent spokes from breaking.2)Regen
The regen setting will ultimately be set to suit the preference of the rider. If regen is too strong you simply reduce it and vice versa. I have mine set to max because I have a lot of steep hills and I don't usually go too fast because I usually have the dog with me and I try and keep at a pace that suits her without having to wear out by mechanical brakes
(and rims).
Unless you regularly brake at very high speed you are unlikely to be pushing too much regen current into the battery, especially with a 48V battery.
3)Current Settings
Unless you definitely need to keep the output within legal limits I would set them as high as they will go.
I think 30-35Amps is probably the most that will be drawn from the battery, even though the controller is set to its maximum
(70Amps is as high as my settings will go).
The battery's
BMS should automatically prevent excessive current draw and keep it within the battery's output capability, but if you find that it occasionally cuts out, it might be worth reducing your current settings slightly until the cutting out is eliminated.
My original Magic Pie would draw a maximum of 20Amps before I modified the shunt on the controller, which tripled the power to around 60Amps. It ran very nicely at this level for almost ten months until I tweaked it a bit too much and eventually blew the controller.
But I can confirm that is was a lot of fun while it lasted.
Alan
