Hello all help a noob first e bike ;_)

The 53T is nice, but for me it offers no chain guard. Would it work with a 44T derailleur? So many bikes use them, it would be good to know.
I use my gears somewhat, but my front changer failed on my maiden voyage. I think I use the rear from 13T to the mid 20s. If I run out of power I may flick the chain off the 52 to the 42 but the 34 is just silly. I have a feeling that with the front derailleur working, I would rarely use the rear. Just going 42/52 most of the time.

I'm pleased to hear the shimano 8 is stacked higher than the 7. I have a 7 on my cst and needed to make a spacer around 5mm thick. Seeing the epochs 7&8 look identical, had me wondering what the cst expected me to fit lol. You sure don't need close ratio's with an ebike.

Where are all the 5 speed options. 5 is ample. 5 well spread gears like 11-36 if a derailleur can hack it. It's not to tall between gears if you have a motor. With 7 speeds, I'm changing up at a frequency close to 1 a second. Making me very aware that I'm using gear sets designed for non assisted use. 5 in the back, one in front, nice weight saving with aero advantage. Minimal kit for the 'I don't pedal' crowd.
 
Hello all

Ive recently built my first ebay ebike kit, the seller says the battery is - Samsung 2900mAh Cells
- 12A Rated Current

1) its in a conceled black metal box, is it safe to open this box up and confirm the cells?

2)i was hoping to only charge once a day as i comute 7.5 miles each way and if i charge twice a day ie each way will this half my battery life? I dont want to be buying a new bat every year.

i had 1 out of 4 bars left this morning so pedalled hard up hill in fear of having to ride the rest of the way to work.with no charge lol.

3) if i am going to charge my bike each way 7.5 miles what is the highest amps i could mod my controller to run with the battery cells i have? Currently have a 22amp controller.

I try and pedal along and keep a steady 20mph all the way to work apart from paths and built up areas.

my motor is a 1000watt and battery is 48volt 10ah i weigh 12.5 stone.

thanks for any tips.
 
Chalo said:
Since Shimano stopped making 11-34 and 11-28 7-speed freewheels a decade ago, all the 11t freewheels I have seen have been ultra-nasty low quality units that fail early and often (e.g. DNP Epoch). Please report if you've found something decent.

Switching to a crank with a 52t or larger ring is a mechanically much more effective way to get tall gearing. 53/14 gearing on a fat tire 26" bike takes you to 30mph at 100 pedal RPM. Over 30mph, pedaling adds enough aero drag that it doesn't net you much added speed. Better to level the pedals, pull your knees in tight, and crouch (unless you have to fake-pedal to stay out of legal trouble).

11t sprockets are not only inefficient and prone to skipping, but they wear out your chain quickly-- which in turn wears out your other sprockets. I just locked out the 11t sprocket on my new 9-speed cassette because it's the only part of the bike that doesn't work worth a damn, and because I don't need it.
Click to expand...

I believe that you're talking from experience of bikes without hub-motors, where maybe the stress is much higher. Myself and many of my friends and UK Pedelecs forum members have been using DNP free-wheels for many years. None of us have ever experienced any noticeable wear or failure. They're not exactly expensive either in the unlikely event that you did have to replace one.

If someone is a sporting cyclist and likes to pedal hard, a hub-motor that takes a freewheel is probably the wrong choice anyway. They might be better off with a cassette motor like the Q100C or Bafang CST, or maybe a crank-drive system.

As far as I can see, most people want a motor so that they don't have to pedal hard, in which case a DNP freewheel is more than adequate and probably better than the one they already have even if it's not as good as the no longer available Shimano one.

Fitting a 52T or 53T crank is also not without problems. On MTBs, there often isn't enough clearance from the chainstay, which means adding spacers behind the BB on the drive side, which then means you need a longer BB and your chain is no longer on the ideal line. Also, as already pointed out, it's difficult to find a chainguard for 52T.

I have found that my ideal combination for pedalling a bike with a rear hub-motor (freewheel type) at 20 to 25 mph, considering low price, functionality and durability, is the 48T Shimano M590 crankset and the DNP 11T/30T freewheel.
 
Hi doggydowg. Here are some brief answers to your questions.

1) Sure, I don't see why not. Make sure you have disabled the self-destruct function first though.

2) Lithium batteries will give the longest service life the sooner you are able to charge. Charging twice a day will prolong the life of your battery. Discharging to 100% is a sure fire way to shorten the life of your battery.

3) You already stated that your battery is rated at 12A. Running it with a 22A controller will not be doing your battery any favours. I would say you are already over the recommended discharge rate.
 
12 amps rated current is a bit small for a 22 amps controller. This is typical, they compete for price by undersizing the battery, and they know you will need a battery every year.

So what can you do about it? ride slower.

FWIW, you will likely use less than 12 amps, if you keep your speed below 32 kph on the flat parts. Pedal hard up the hill, because you will likely be pulling about 18 amps then. If you can still make 20 kph up the hill with less than full throttle, do that.

Lastly, are you sure its rated 12 amps? Or is it 12 amp hours in size?
 
Motor or not, it's still true that an 11t sprocket will wear your chain faster if you pedal hard. Some do pedal hard for a few feet leaving the stop sign, and that can wear the chain fairly quick.

for sure, you will notice some clicking when using a 7 speed freewheel, and an 8 speed shifter. This will be worst if you index the shifter to run best on one end of the cluster. So if you index to run smooth on the small gear, it will index poorly on the largest one.

Adjust your 8 speed shifter to run perfect on the gear you will use the most. Most of us only use 2-3 gears once you have the motor. It will index ok enough on three gears.
 
Thats good news that i can charge both ways and it wont decrease the life of the battery. if I wanted to run 30amps
Or what ever my 1000watt motor will take what battery and budget for ready made should i be saving towards for when this battery gives up?

My battery is 10ah and the seller said it was rated to 12amp but without opening it i wont know what it is.

ive read the faq in this section and most of it just went over my head, so all the people that do shunt mod on controllers run better spec batteries then me?

If it makes any difference I only traval 7.5 mile and dont exceed 20mph but do like the idea of getting there quicker especialy crossing busy roads etc or getting out of a sticky situation.
 
I still have no clue what you have really. What voltage? Most 1000w kits run 48v, so I'm assuming you have that.

Cruising 20 mph takes 400-500w for most people. So that's about 10 amps, (if 48v) and safe for your battery if it only allows 12 amps continuous.

If you want to do the shunt mod, you will need to increase the size of your battery, so each cell sees les amps. If you ride fast, it will take a lot more than 12 amps.

Pedaling hard the first 20 feet at stop signs will also help lower your amps.
 
Hi its 48volt motor, I am charging both ways so every 7.5 miles and according to my batery gauge which I know wont be that acuret I use between 1 out of 4 bars and 2.

I can ride to and from work on one charge but probably am dangerously low on battery power.

I was contemplating building a 2nd ebike and a guy from ebay has been advising on parts to build a fast bike he recommended these,

https://www.hobbyking.com/hobbyking/store/__16227__ZIPPY_Flightmax_8000mAh_5S1P_30C.html

Il start another thread asking about this but this is probably where I am heading towards, I probably did make a bad choice in the kit but it was only £460 and I have already racked up 106 miles in just under a week that otherwise would have been in a car and sat in hours of traffic so the kit will soon pay itself off lol.
 
You don't need a new thread.

I've ran Zippy/Turnigy RC Lipo over 5 years and will never buy/use Zippy brand again. I'm also suspicious of 8Ah bricks - when it comes to RC Lipo I want the freshest stuff produced in the greatest numbers. Not some oddball low production count stuff.

Personal favorite is Turnigy 4S 5Ah 20C Hardcase assembled in 12S, 16S, 20S configuration(s). Of course, 16-20S requires controller upgrade. Install a decent BMS and use a bulk charger.
 
Thanks YKICK

What is wrong with the batteries that were suggested to me out of intrest?

I am looking at buying a crystalyte hs3540 a 70amp controller and getting a 72volt battery, the link that I posted above apparently all I have to do is buy 4 packs of them and connect red to black wire on the 4 blocks, buy a ballencer charger which I wasn't sure of which one and a normal bulk charger same again?

That seems too easy, if I was to buy a cycle analyst 3 would that remove the bms aspect so resumably it can keep and eye on the voltage to make sure I don't run too low?

Also the seller of the hs3540 has offered to fit a thermistor in the hub so I can keep track of the temps im assuming this will just plug straight into my ca3?

Does the above kit look like a good wknd toy im in no rush to build my second ebike so I will ask lots of questions and reaserch this on more, thinking of selling my scrambler to fund this project although money isn't realy an issue ;)

thanks for imput.
 
Maybe nothing's wrong with them but based on my experience I don't trust Zippy brand. Sorry, I don't have any experience with Cystalyte motors/controller. I try to speak about things I've personally witnessed and used. I've never used the 8Ah bricks so maybe they're great but I'm also fairly certain they're not produced at the rate and numbers 5Ah pouches are produced.

Relying on any pack voltage based LVC (CA, controller) is foolish and asking for trouble. When a single cell drops above/below accepted voltage range cells will likely suffer from the imbalance. What's needed is a BMS or alarm which monitors individual cells and either shuts everything down and/or alerts you to a problem before it becomes a danger to yourself and others.
 
It's sort of just that simple. Unless you screw up and burn your house down, or weld your hand to a connector. But for a high performance bike, RC packs do have the c rates to handle your controller. The problem is, they are so cheaply made. 20c zippies, with a real world practical c rate more like 5c, won't cut it for a performance ride with 70 amps controller. You need better grade packs, 30-40c turnigy, or better. 8 ah of 20c zippy will sag like grannies tits when you open up that throttle. Fine for a 20 amps commuter, not fine for a flyweight motorcycle.

72v 8 ah will be very fun to ride, but you won't go all that far on that size battery.

Once you start to boogie around at 60-80 watt hours per mile, a 576 watt hour battery like that won't last very long. Theoretically 8 miles, but since a lipo pack gets wrecked fast if you discharge it too deep, you will have a practical real world mileage from that pack of about 5-6 miles at full speeds.

You do need a CA, or other decent watt/voltmeter on a lipo pack. You need to know what's happening so you don't screw up. Screw ups can cost many hundred dollars. A voltage read out is the bare minimum.
 
Thanks for the replys so turnigy batterys is the way to go, that's good to know as that would have been about £2-300 wasted lol.

Can I buy off the shelf bms for turnigy batterys, I have absolutely no idea about any of this stuff by the way I tried watching a video on how to build batterys and watched some kid stripping apart laptop batterys for 20 mins and soldering them altogether, id be buying it pre solders and hopefully ready to plug in if at all possible?

Ive tried searching for 72volt battery packs in this country and I cant find any maybe for liability reasons or im just looking in the wrong places ( I live in Enland)

I wont be flat out everywhere you just couldn't get away with it where I live, there are some single track country roads I could open it up for about 2-3 miles the rest would just be poodling about 15-20mph so im hoping 8ah would be enough in any battery technology as im hoping to do away with wanky panier battery they a pita and make my bike handle like a shopping trolley.

Im going to google the turnigy battery packs for today, maybe I biter the bullet and pay someone off this forum or from china to build me a complete battery with bms built in with a charger etc what kind of cost would I be looking for this if this is evan an option?

Thanks guys
 
Maybe a reasonable way for you to get into the RC Lipo game is to assemble a small "range extender" pack? That way you're not relying on it as much but gets you accustomed to purchase, cell qualification, series/parallel wiring, connectors, charging schemes, alarms, etc.

Many of us have been buying BMS from bestechpower and installing them to help make bulk charging a little safer. But without some previous RC Lipo experience It's not particularly easy to wire up, understand and employ a BMS out of the gate. That's why I wonder if a small "starter pack" could help you get up to speed with the usual RC chargers and cell alarms until you better understand how to construct a BMS protected eBike pack from RC Lipo bricks?

Small steps...
 
Ykick said:
Many of us have been buying BMS from bestechpower and installing them to help make bulk charging a little safer. .
Click to expand...
How do you actually buy/order one of these BMS's from bestechpower? I was on the web site, but don't see any prices or ordering instructions.
 
Thanks YKICK

Small steps indeed sounds like I need to do an electrical course to build this battery lol, I can do basic soldering, but better then that my mates old man used to do small pcb board solering etc for a job I once got him to solder a bigger resistor in my ecu on a car to raise the rev limiter.

With some help from you guys perhaps he would be able to assemble the battery pack to save me potentially burning the house down or welding my hands to a battery lol.

From what ive seen on hobby king the packs can be bought all assembled in shrink wrap with just a red and black wire coming from each block, what exactly do I need to do from here with the turnigy packs then?

Just to add I don't expect to be breaking any world records Id be happy getting anything above 35mph I doubt id be able to build anything exceeding 35mph and don't realy want to go over 40mph if that's evan achievable as lets be honest it is a pushbike at the end of the day, ive ridden fast motorbikes but to be honest evan at 30mph this seems much more fun and relaxed and loving the fact there are bus lanes and bike lanes that I didn't evan realise were there. Normaly I sit in traffic for 45min just to get 2 mile down the road im now getting to work in 30-45 mins ;_)

Got a bit off topic there keep the info coming ;_)
 
Hello all

My 1000watt rear 9c hub kit has lasted 400miles all spokes were loose one is snapped off and i have a massive buckle so bad ive had to remove rear breaks which isnt safe.

Can a normal bike shop get the buckle out or will it need lacing into a new rim?

If im going to get it laced into a new rim should i get uprated spokes from a motorbike if they work.

My rim is 26" what size would the new spoke be and any good places to get them from im assuming this wont be an off the shelf part in a normal bike shop lol.

My bike has the battery mounted on a panier rack so this is how the problem has come around, I have a spoke tool now and plan on transfering the kit onto a bike with no rear suspension so i can mount battery in the triangle.

Thanks
 
Lots of threads about spokes and rims, poke around and you'll find all the info you need about those and how to get the parts you need.

As for your existing rim, you might save it but if it's bent that badly it may take so much tension on spokes around it to fix it that they may break early because of it, especially on a hardtail, which will probably be much harder on the wheel than the one with rear suspension was.
 
There's a good chance that it'll pull straight when you tighten the spokes. You need to check your spoke tension more frequently to avoid all that. You can normally hear them creaking or clicking when they need attention.
 
If you really bent that rim, pulling it straight again with too much tension on some of the spokes will only cause more problems. Broken spokes, spokes ripping holes in the rim, etc.

Try it, no loss if it will pull straight again. But if it doesn't straighten easy, you need a new rim, and I'd advise a new set of all spokes too.

And, learn to rough tune your wheel. Just keeping it more or less tight and straighter will help a lot. You don't have to get the wheel perfect, but just straight enough and all spokes about the same amount tight to help. But don't overtighten, if you must, then the rim is roached.

If you still take it to a shop, they might charge you less if it takes them just a few min to do the final tweaks, vs a full tune up.
 
Since you have rim brakes you can usually keep the rim relatively straight (once it's repaired) using the brake pads as a guide. As mentioned, check the tension regularly.
 
Did you just buy and use a front kit?
No bike shop round here will touch a hub motor. It is just too heavy for their little weak wrists, or something like that. A build is about £35 though, if you provide the parts and find somewhere capable.
A reasonable double walled rim is quite cheap. Chainreactions ask about £25 for a sun rhino lite. A common rim of known dimensions, with a common sized motor, could make spoke choice a simple matter of copying somebody else. Spokes will be £20 as a custom size. You will have change from £100
 
If you get it rebuilt, get it built into the widest rim you can safely squeeze between your brakes. It'll handle impacts better and be able to support more weight.
 
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