Carrera crossfire/vulcan tuning

Ricky 88

Finding my (electric) wheels
Apr 10, 2018
11
1
31
South east
Sounds interesting, what was your total spend on it? Might have to do this when my warranty run's out
 

anon4

Esteemed Pedelecer
May 9, 2017
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Sounds interesting, what was your total spend on it? Might have to do this when my warranty run's out
About £75. That was for controller and display, new crankset and a thumb throttle which hasn't arrived yet. I also bought connectors for the motor wires
 

anon4

Esteemed Pedelecer
May 9, 2017
527
79
27
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Been riding some more, some notes:

Battery drains a little quicker, but I have been abusing the throttle as it can winch me up mild inclines by itself so that's expected

Make sure to buy a small controller, mine is 8.8/5/3cm and it only just fit inside the box

Cable ties. Lots of cable ties

Speedo is definitely wrong, I have a theory as to why. It looks like the black wire and white wire come from a single wire inside the insulation. As both are plugged in it may be scrambling the data, need to test with the white unplugged.

I think my old bike was a little faster hot of the charger, but this maintains nippy speeds throughout the charge, I think cell quality is a factor here as the voltage is very stable

If you don't plan to reuse the original controller then cut the wires as long as possible. I created more problems by trying to make it reversible, the wires are short and I've already had to redo a connector as it got pulled off due to lack of slack

Make sure to get a controller with self learn as mine spun backwards at first.

Hill climbing is godly, better than before as I get full whack no matter what my input.

Anyone wants any help converting give me a shout
 

egroover

Esteemed Pedelecer
Aug 12, 2016
371
202
52
UK
What top speed are you getting on the flat? Be interested in how the suntour (bafang apparently) is wound as I know its very torquey and great on the hills, but wondered on top speed now it's been unrestricted
 

anon4

Esteemed Pedelecer
May 9, 2017
527
79
27
GB
What top speed are you getting on the flat? Be interested in how the suntour (bafang apparently) is wound as I know its very torquey and great on the hills, but wondered on top speed now it's been unrestricted
My speedo is completely wrong unfortunately. I'd guess it's capable of 20+mph as it's definitely going significantly faster than the 17mph cutoff it had before. Hot off the charger maybe 22mph. The Vulcan is such a stable and safe ride it's hard to judge speed so it makes me grateful of hydraulic brakes when it get it wrong haha. I'll try to get a bike computer or something to test and calibrate it properly
 

anon4

Esteemed Pedelecer
May 9, 2017
527
79
27
GB
Also it's virtually silent at higher speed so you get some funny looks seemingly freewheeling uphill lol. Flat out on throttle I'm getting just under 20 miles range with the amp limit set at 16.
 

anon4

Esteemed Pedelecer
May 9, 2017
527
79
27
GB
Just a heads up. The cutout fault still exists with new controller. This confirms that the BMS is tripping somehow. It's infrequent enough on mine not to bother me though
 

Mawds

Finding my (electric) wheels
May 7, 2019
5
0
Hi, this is exactly what I want to do to my Crossfire E. You completed your project about 8 months ago, can you give an update on how it’s run since then and would you do anything different. Thank you.
 

anon4

Esteemed Pedelecer
May 9, 2017
527
79
27
GB
Hi, this is exactly what I want to do to my Crossfire E. You completed your project about 8 months ago, can you give an update on how it’s run since then and would you do anything different. Thank you.
It's been a blast! I have since upgraded to a 48v battery and KT 20a controller, this makes the thing fly, unfortunately it stopped working, think the controller was just a dud though. The motor wire was looking worse for wear so I bought a new one along with a cheapie controller from Amazon while I wait for my KT 20a. It's running great with this tempory setup, hoping the controller was just a dud as the KT 20a is fantastic when it works, so much torque. It has light outputs so I also have front & rear light plus horn wired in, I also added a cutoff brake as the motor can try to keep moving when you stop sometimes. I would definitely consider going 48v, the original setup I did here works just fine though, depends just how far you want to take it.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
7,702
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West Sx RH
The 6 fet s/w KT's do suffer from getting HOT, my one and I know AK had a similar issue with thermal cut out's. Long term heat etc must have an effect on the component parts, esp on longer ride out's involving quite a bit of climbing.
I did add an extra heatsink and a pair of 5v fans run off a pair of 18650's in P, now on my 700c Boardman have upgraded to the slightly larger 9 fet S/W KT.
 

anon4

Esteemed Pedelecer
May 9, 2017
527
79
27
GB
The 6 fet s/w KT's do suffer from getting HOT, my one and I know AK had a similar issue with thermal cut out's. Long term heat etc must have an effect on the component parts, esp on longer ride out's involving quite a bit of climbing.
I did add an extra heatsink and a pair of 5v fans run off a pair of 18650's in P, now on my 700c Boardman have upgraded to the slightly larger 9 fet S/W KT.
Would it tell you if it was thermal cutout? I ran mine naked on the frame and the outer shell stayed pretty cool. Sometimes when it cut it would say error 6 which is a short, either it was a dud or my motor cable was. China ems seems to be giving my replacement a grand tour of China, tracking is all over the place lol
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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06 is phase short/error which if not a wire issue is a fet issue.
Fets act as a switch an can latch on and off, when they get hot the circuit is closed causing a temporary short, once cooled down enough the circuit opens again.

I in your case maybe a fet simply failed so you still got error 6, you can test for failed fet by simply probing between black to each phase.
All readings should be the same and in the range of 7k - 14k or 15k ohms.
Also test between Red and each Phase for any anomaly any that read 0 means a blown fet.
 
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anon4

Esteemed Pedelecer
May 9, 2017
527
79
27
GB
06 is phase short/error which if not a wire issue is a fet issue.
Fets act as a switch an can latch on and off, when they get hot the circuit is closed causing a temporary short, once cooled down enough the circuit opens again.

I in your case maybe a fet simply failed so you still got error 6, you can test for failed fet by simply probing between the red wire to each phase and black to each phase.
All readings should be the same and in the range of 7 - 14 or 15 ohms.
Ok thanks for that, I'll see if the new one behaves
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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If a controller fails usually the two most common reasons are wrong polarity or fet failure. Fets work like a switch and need low voltage to open the circuit to allow power to flow, when one fails voltage fails to flow & like a switch it remains off/closed producing the short. Heat also affects them as they are temperature rated over temp results in temporary short until they cool down this also triggers the switching action as the resistance due to heat becomes greater. Heat eventually can lead to fet failure in time.
Battery power isnt't required for testing as voltage is not being tested but just continuity/ohms.

If a controller fails it is hard or nigh on impossible to test where or what though the fet test is easiest to carry out.
 

anon4

Esteemed Pedelecer
May 9, 2017
527
79
27
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If a controller fails usually the two most common reasons are wrong polarity or fet failure. Fets work like a switch and need low voltage to open the circuit to allow power to flow, when one fails voltage fails to flow & like a switch it remains off/closed producing the short. Heat also affects them as they are temperature rated over temp results in temporary short until they cool down this also triggers the switching action as the resistance due to heat becomes greater. Heat eventually can lead to fet failure in time.
Battery power isnt't required for testing as voltage is not being tested but just continuity/ohms.

If a controller fails it is hard or nigh on impossible to test where or what though the fet test is easiest to carry out.
Happy to report replacement is working a treat, the fun never ends for me though, my throttle snapped on the way home and a puncture patch failed as I was fitting the new controller lol. It's so much more powerful than the brainpower one I was using and it's nice to have my integrated lighting back
 

anon4

Esteemed Pedelecer
May 9, 2017
527
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Ok well I managed to get a cutout today from a dead stop, it is nowhere near as sensitive as the old one was but its present. I'm thinking it's a thermal issue as you say as it got pretty warm for not a lot of runtime. I run it in open air but it is warm today. Is there anything I can do besides reducing the current to prevent damage as it seems to be a progressive fault, initially running it starved in a bag may have contributed to the first ones demise
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Adding a heat sink may help a little with the fins being cooled by air flow, with warm ambient temps though that might not be enough.
The next option is to have a 5v mini fan attached to said heat sink and run if off a 18650 ether 1 or 2p. 5v fans only use about 50mv so a 18650 will run for days.
 

anon4

Esteemed Pedelecer
May 9, 2017
527
79
27
GB
Adding a heat sink may help a little with the fins being cooled by air flow, with warm ambient temps though that might not be enough.
The next option is to have a 5v mini fan attached to said heat sink and run if off a 18650 ether 1 or 2p. 5v fans only use about 50mv so a 18650 will run for days.
Surely this still isn't right though, does this mean it's going to fail again if this is happening? Definitely seems like a flawed design unless my motor is just a poor match
 

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