My GSM / Muddy Fox eBike build

[davidg]

For the last 5 years or so I've toyed with converting an old Muddy Fox courier mountain bike into an eBike. I used to use the Muddy Fox every day but it had been languishing in the attic for the last 15 years. I'd thought about a simple hub motor but live in a hilly area and everyone seems to use big 1000 watt motors around here. Then the Cyclone came along but it looked just too complicated and funky. Finally the Bafang's caught my eye, a refined mid motor. A neighbour was selling eBikes and I borrowed a 250 watt mid engined Matra which I used to climb Alpe d'Huez and it seemed to have enough power.

However I still wasn't confident about wiring everything up. Finally, after getting a small bonus, I took the plunge and ordered the GSMoon kit from Woosh bikes. This is the latest revision of the motor with the new controller. Here is my build for anyone who is interested, feel free to ask any questions:-

 

[davidg]

Long commute into work today:-

https://www.strava.com/activities/630565535/segments/15404040986

22km

interestingly my non-ebike commute is a few minutes quicker

https://www.strava.com/activities/603514476#14709964666

which is probably because I ride around 25 - 30 kph normally so the motor is not being used on the flat and is dead weight - I'm probably getting more of a workout using an ebike

I didn't really buy it for commuting.

 

[anotherkiwi]

You are riding in traffic? I average about 25km/h (at least I did on my hub motor) but it isn't as flat around here. I am going to buy a mount for my GPS (a.k.a. smartphone) so will see how fast I go on my new steed. As it is more comfortable I have the impression that I am going much slower, no more spine jarring vibrations and bumps...

 

[davidg]

Not too much traffic, only when I get into town and then mostly on a cycle path. Ride home

https://www.strava.com/activities/631054548

came back along the tow path, which is very rough in places.

1 bar used on the battery for 45km riding, the motor isn't being used enough but is nice on the uphills.

 

[davidg]

As it is more comfortable I have the impression that I am going much slower, no more spine jarring vibrations and bumps...

I've just been (re)reading about your build. You are p;robably one of the people Woosh Bikes told me about who'd ordered the external controllered GSM in France. I'd noticed that Lipos are pretty cheap from places like HobbyKing but didn't want to make my life too complicated at first.

 

[anotherkiwi]

There are a couple of good reasons to use LiPos, price is one and lack of sag when climbing the other. They require a bit of discipline but the danger of using them is less on a bicycle than in a toy which is prone to crashing as long as you respect them and don't use them below 3.6 V and charge above 4.15.

I think that having the right charger(s) and good charging strategy can make them acceptable for a daily ride. If you buy quality ones when they are on sale it can be a very cheap source of energy even if they only last for 250 charging cycles. I can be around when they are charging so it isn't an issue for me.

 

[D8ve]

10s 16ah plus connectors cost me £110 but it's only 10c so I can't run over 160amps . I think my motor is set for around 14 amp anyway so I don't expect to much battery sag

 

[davidg]

I've been away a week but I've restarted the commute and just clicked over 225km. The motor is sometimes a bit slow picking up the slack when you've been bowling along at 30kph then hit a hill. I'll post some more thoughts later.

 

[trex]

I always try to keep the RPM on the high side by shifting to a lower gear before hitting the hill.

 

[davidg]

I will try that. I've been running things in really and getting a feel of the kit to date.

 

[anotherkiwi]

I have changed controllers and the motor seems to prefer the no name 14 A controller to the 09 bottle battery one. No more run on, more and smoother power delivery (a mystery - 14 A vs 18 A...).

And I have traded speed for comfort, I must be feeling my age! Top speed downhill is between 45 and 55 km/h but I am sitting up on a bigger bike so air resistance is playing a bigger factor. Overall on average I have knocked a couple of km/h off.

Climbing my big long hill yesterday I was in second instead of first, I am only just getting the hang of how it climbs compared to the hub motor. I have a derailleur issue which doesn't surprise me - it came from a wrecked bike with unknown history and I have put about 3500 km on the clock since then. It is very lazy changing between 3rd, 4th and 5th gears.

 

[davidg]

Went out on a longer climb today. 550 meters vertical. Battery was on 2 bars by the end on the display or 3 Leds on the battery.

Beat Simon Yates' time on the climb.

 

[davidg]

I've just charged the battery, took 2 hours 45 minutes but the young lad did about 10km on it when I got back riding round the square.

Here is the unboxing of the kit

darn, no idea who the young lady is !

 

[davidg]

I'm at nearly 400km now, haven't been doing my long commute due to a bad hip but the short one is 22km. I can to 2 short commutes and one long commute on a charge - that's about 80km but I guess the motor is not doing much work when I'm riding at 27-28km on the flat.

There is a bit of side to side movement on the bottom bracket now - I will have to see what needs tightening.

 

[davidg]

I clicked over 500km earlier in the week and now heading for 600km territory. Had a crank come loose one day, which is pretty common I hear do to the allen key bolts not tightening enough. Half of the riding this year has been in 30C + temperatures (afternoon commute home) so the motor doesn't seem to have too much problem with those conditions. Not many long climbs though and boy does the battery empty fast when you are pulling big amps.

 

[davidg]

My bike haulin' skis in the mountains:-

Battery is good for a 1000m climb but it is dead after that.

 

[Woosh]

Lovely pic.
Can you tell us where it was?

 

[davidg]

Lovely pic.
Can you tell us where it was?

Yes, that's in the French Chartreuse mountains. If you want any better pics in the future PM me. I'm on about 900km at the moment as I've not been cycling much over winter as the roads are heavily salted.