Build New Bike or Buy New Battery ???

[HombreNuevoElectro]

Hi all,

I am new here and would like some of you opinions on what would be my best option.

I have recently got back out of the car and started back on the electric bike again. It is a bike that i have owned for almost two years and i bought it second hand. It is the Urbanmover 36 - 26v 9ah battery and i assume 250w brushless motor, although i am not sure which one. Here she is:

I have not been using it now for maybe 8 months and in that time i am embarrassed to say that i did not look after the battery (only a few charges), however i am back commuting again and i have noticed no noticeable change in performance.

Then bike is very solid and has been a good servant with very few punctures etc... and is still on original Kenda tires. Now of course has come the desire for more speed and more power.

So i was wondering what to do:

Option1: Sell the bike and build a new one
Option2: Try upgrading
Option3: Sell my bike and buy cyclamatic

Option1
For my build i could not get my mind off one bike in particular. The Saracen Pylon. It is on 50% off at winstanley bikes and free delivery to Ireland.

I was thinking here that maybe i could upgrade the forks, chainring etc... However the more i think about this bike the more i sadly realize that maybe it is just not suitable. No mount for racks and full mudguards, gearing all wrong, rigid forks,160mm disks etc...

What do you guys think of this bike?

With this options of was thinking maybe geared mac motor and a 36v or 48v 6.9ah A123 battery and i think that would seriously up my average speed to work. It work cost a fair amount of money also.

Option2

Now i have been checking my stats with my new wireless computer since i started back commuting. I have made 3 full commutes so far at 12.5miles each way.

Inward journey: Average 12.5mph
Return journey: Average 13.9 (with wind and hills in favour)

On a flat piece of road with light cycling it goes 15-16mph
On a hill it just crosses 20mph although i am then turning the top gear too fast so this is at the limit. TBH travelling at 20mph on a hill is really very fast for a bicycle and i think it would be dangerous to use any more than this. What i want is a higher average and quicker journey times.

Yesterday i very scientifically kept my eye for the green light when charging. The green light came on and about 2hrs50min of charging on my 2ah charger. So assuming the charger was put in 2ah then the fully recharge cost 5.7ah and this means that is used 12wh per mile on my way home. Does this sound correct? Does anyone know a way to measure this accurately.

Now the Beastamatic thread has given me inspiration. If i could get a 19-20mph average i would be very happy. So i would probably wait until my battery died for this as it would be a sin to discard a perfectly good battery.

So my thinking would be this.

Took off the casing this morning and controller is very similar to cyclamatic.

It is 7a(continuous) 14a(max) and very similar size to cyclamatic

1. Maybe add some solder to the shunt with my current 26v 9ah battery.
2. When my battery dies purchase what i think is a direct replacement from here Battery & Charger Only, , PowerSmart Electric Battery & Charger - 36V Li-ion 3.3kg Best Can Up to 2000 Cycles

This should certainly up my average speed but to what and is it a good choice for reliability.

Also i would need maybe to buy a watt meter but would probably need help from you guys with this. Dev's thread is excellent and i would probably go with his meter but would need more help to wire it myself.

Option 3

Sell my bike and buy cyclamatic. Then i would have a new bike. But TBH maybe this is not a good option because it is very similar bike to mine and i think maybe the quality is less. I did not have any of the problems with my bike that users of cyclamatic have found.

Also i would need to upgrade the battery immediately.

So i would like some help from you guys.

Could anyone recommend me some new bikes that would be best suitable for conversion? At good prices?

Thanks in advance
John

 

[Deleted member 4366]

I think you've weighed up everything pretty well. You're obviously a good student. Now it's time to graduate.
One point that needs clearing up. You can get the Cyclamatic to go a lot faster, but it's not a good idea to do it continuously. Over-volting a 250w motor is alright for short bursts of high speed or maxing out downhill, but if you really want to average 19 to 20mph, then you'll need a much stronger motor. If I put a bit of effort in and turned everything to max on my BPM setup, I might be able to average 18mph with my 36v battery. With my 44v lipos. I think about 20mph. However, I don't pedal so hard now.

Don't take any notice of wH per mile results. They're only a measure of how hard you pedal and what setting you have on the motor power. You can't make any realistic comparisons between bikes. Once you go up to 500w and above, wH/mile has more meaning because most of the power comes from the battery, not the rider.

I would say forget the idea of a Beastamatic because you already have something that is similar to a Cyclamatic (in principle), so you could achieve the same thing with a more powerful battery and more amps from your controller. If you solder the shunt, you have to be careful not to exceed the BMS max amps otherwise, the battery will cut out everytime you go up a steep hill. Do it a bit at a time.

Personally, I don't like that Saracen - no gears, no suspension - OK if you're young, fit and compliant, but it'd shake me to bits. Some people go for speed by starting off with a high speed road bike because they wear Lycra and can already ride it fast and just want a bit more help for higher average speed. An over-volted motor could help them, but, If you're not one of them, then you need real power to go fast - and proper air suspension makes the ride so much more comfortable. However, there's several members on this forum who are quite happy riding round on their bone-shaking Kalkhoffs and the like - mind you, they don't seem to want to go very fast: I don't blame them. Different people have different ideas of what they want. For me. I like to pedal along all day at about 15mph with hardly any effort and when the hills come I watch the speed go down to about 13 mph and the amps go up to about 25 and the pedalling effort doesn't change. That's why I'm biased to the BPM motor. The MAC won't be a lot different and the Ezee motor isn't far behind (if any). In fact many of our USA friends ride around on their Ezee motors at 20mph, so that is another option.

Anyway, only you can decide. It looks like you know what's what.

 

[NRG]

Wh are a good rule-of-thumb way of comparing ranges for you and your route, they are not too much use if comparing against another rider but 12Wh / Mile is not untypical from some reports on the forum. To measure consumption better you need to add a Watt Meter between battery and controller...

I don't like the look of the Pylon either, I think you could do better but I don't know the cost involved and if you are planning on trying the shunt mod then I would advise to use a Watt meter. The Bafang 250w is OK for 20~22mph and will last well if you don't go mad with the amps, they do make more noise though when the amps raised. I ran mine at just over 20amps for about a 1000miles and it was OK but I've lowered it now to around 17amps or so, I've not really noticed any difference climbing hills....