Help! Tilting trike - getting it going again (newbie questions)

[vfr400]

You need to do the voltage test first with the full and empty battery because you might still be limited by the controller.

Which cell-pack did you buy so that we can assess how hard you can push it?

 

[beanisboy]

Got the one you suggested - label above.

Ok will do the voltage test then and see. Phew - this is tricky!

 

[vfr400]

Phew - this is tricky!

You're learning all the time, though. it's not at all tricky once you understand it all.

The battery is good for at least 20 amps. Your present controller is 15 amps, so you can get 30% more torque, but that won't improve the speed unless the results of your speed test show otherwise. It's now a case of how much you want to spend. I can make that bike to 30 mph and steam up any hills.

 

[beanisboy]

Still a bit unsure about what it means if it slows down by 10% at lower volts.
I've been trying to run it down but it was at 40v now its at 39 after a good few miles. Will keep riding tomorrow. It's not slowed down yet (though still at a measly 8mph).

For my dad it's not about speed really, it just needs to get up steep hills. Do I need a better hub-motor for this? I was wondering if 500w and a nw controller would do it

 

[Nealh]

The controller software could be limiting the speed to 8mph if the original bike was sold as a disability trike.
Is an lcd display being used ?

 

[vfr400]

You must do that speed test. It will show you what's limiting the speed. Until you know what it is, you can't improve anything.

 

[beanisboy]

will do

 

[beanisboy]

The controller software could be limiting the speed to 8mph if the original bike was sold as a disability trike.
Is an lcd display being used ?

there is no lcd but i did think this. also wondered if 20" wheel would make a difference

 

[wheeliepete]

What's the voltage like on your old battery? If it's fairly low you could use it to compare motor speed, rather than having to ride 60 miles at 8 mph to flatten your new battery.

 

[wheeliepete]

I think it's very likely that your controller is speed limited, as this is a much cheaper option for the manufacturer, than having a bespoke slow speed motor built.

 

[beanisboy]

i destroyed the old battery to fit the new one inside the case!
still trying to run it down!

 

[beanisboy]

i destroyed the old battery to fit the new one inside the case!
still trying to run it down!

 

[beanisboy]

Ok - the test has been done and it's not good news

At 36v I got to a staggering top speed of 7.3mph
at 33.9volts i got to 6.2mph
and when it dropped to 33.3 i got to 5.3mph

I am assuming this indicates that it is the motor wheel that is in fact a problem?

My main issue is the wheel is 20" and I can't find any 20" motor wheels.
I am wondering if I should buy a whole new trike with knackered battery...

 

[vfr400]

Can you tell us the metric size written on the tyre next to where it's written in English?

Motor speed is proportional to voltage, so 48v will give you nearly 10 mph.

Invalid carriages are only allowed to go 8 mph on the road and 4 mph on the footpath, which I guess is why they used that motor.

 

[beanisboy]

54-406 in metric
20x1.96
like a bmx wheel

Its not really speed its power I need - and i've already upgraded the battery as a 36v.

Are there any 20" wheels out there? Or will I have to buy a hub and rebuild it?

 

[beanisboy]

also what wattage wheel can i upgrade to with the new 25amp 36v battery I have?

 

[vfr400]

You could try a shunt mod then. Take the end-plate off the controller, where hopefully you'll see the shunt grinning at you and begging for a drop of solder. It looks a bit like a thick staple. The idea is to add some solder on one side about 25% of the entire length, which will increase your power by 25%. You can't go any higher than that. There are other things you can do, but they all involve spending increasingly more money. Try the solder first.

If you're unsure about where the shunt is, show us a photo inside the controller.

I'm pretty sure that your present motor can give you the power you need. it's the controller that's limiting it at the moment.

 

[beanisboy]

ah, I thought that the test chows that it's the motor that's limiting the speed?

I can try the shunt mod, and 25% is ok but as i said its really gonna need more than that as currently its just weak as hell, if i get 7mph on the flat its like 5mph on a tiny tiny hill.

I'm considering whteher its better to scrap this trike, and just move the battery to a new project.. Will try shunt mod tho

 

[Jimo]

If all else fails I have a Batribike 20 tilting trike that runs perfectly that it for sale, see Batribike trike 20 (with full details) elsewhere on this forum.

Jim

 

[beanisboy]

Can anyone suggest what type of controller and/or motor I could buy for this 20" wheel?
If my vattery is 25amp and 36v can I use a 500w motor? I am after the most torque i can get for steep hills