One step away from buying - Oxydrive CST HT 13Ah or Woosh


Oct 31, 2014
Hey all,

I'm new to the site and have been doing some research over the last couple of weeks for a conversion kit and find myself hovering over the buy buttons but wanted to post in this site just in case there's a better option.

Firstly a bit of background and intended use.

I'm a cycle courier and deliver 300+ letters 5 days a week (on average but going up to 600 ish on a very busy day). I cycle an average of 30 miles a day over a mix of flats/hills and there's a lot of stopping and starting, which is sometimes up a hill with headwinds. Not a day goes by (or probably an hour!) where I need to deliver to several houses that are 5-6 houses apart. The quickest way is to hop on, pedal a few times, stop and hop off. Although this is quicker than walking it means more energy used and more strain on the body and the bike.

Cycling is the only way I get around in the city, shopping with panniers etc but that probably only adds a max of 15 miles to the week, making the average distance about 165 miles per week.

The bike I want to convert is a Carrera Subway (18" frame, 26" wheels) that's nearly 4 years old and I think it's about 18-20 Kg. I'm in my mid 40's and weigh about 64 Kg and on average I carry an extra 6-8Kg each day for work, more when I do my shopping and most of this now goes in the panniers bags.

So the idea is to convert this bike to make my life easier :)

Good & bad points of kits

Oxydrive: The 350w motor is good and bad due to current legislation but if this kit will do I what I need, I may be willing to take the risk. It's £300 more but anyone can do the install. I was hoping to take my bike to my local shop that has always done a good job (the best in town!) and get them to do a full service and fit the new kit. This would be the quickest way of me getting it back on the road.

Woosh: Has the bigger battery so should give power for longer? if so that's good. The motor has less power (although I don't understand the difference with CST 250W & BMP 350W) but legal and It's £300 cheaper but does it require a registered e-bike mechanic to install it or would any normal qualified mechanic be able to do it? I haven't asked at my shop yet but if they can't do it I have to consider the cost of getting the bike to and from there and it will increase the time for me to get back on it.

What I hope it will do is allow me to travel the same distance or more and use a little less of my own energy. I would rather be in a higher gear on the flat and mid gear for hills. Ideally I would be able to accelerate (not pedal) from stationary up to about 5 mph for approx 400-600 meters, at least 100 times and for the battery to last all day!

Am I asking too much?

One of the things I haven't determined is whether they have regeneration? Braking or back pedaling. Does anyone know that? With all the stopping and starting, regen' would be a big thing in prolonging power would it not? I know I wear down a lot of brake pads!

When it comes to accelerating for short distances, it seems that it should be ok on flat or downhill but not uphill as it could cause overheating and I could live with that (cycle up and work my way down delivering).

Getting to 15 mph on flats or slight slopes isn't a problem, so will I get to 15 mph quicker? Some of the hills I go up make me drop into the lower gears and my speed goes down to 8-10 mph so if I use the same amount of energy pedaling will I be able to get to 15 mph?

Although my current distance is about 30 miles a day, if I can do my deliveries quicker and not be as tired I can then do deliveries in different areas to help a colleague or something. So if the statement of "up to 50 miles (standard mode)" on the Oxydrive site is true, I would more than likely do 50 miles as this would prolong battery life when recharging.

I've typed a lot (thanks if you got this far lol) as I said I've done research but there's a lot I don't know. I'm going to visit Onbike for a test ride of some of their bikes and I have next week off work so really wanted to have my bike kitted out before I go back.

I'd like to know your thoughts and any advice.



Esteemed Pedelecer
Apr 24, 2013
a couple of things, I know v little (just bought a kit which hasn't arrived yet), but

1) that bike weighs about 13kg apparently, that's pretty good.

2) oxydrive do a bafang cst 250w with an 11ah battery, which - you'll want to check if this is true - may be essentially the same motor (the bafang cst 250w is wierd, i've ordered one from china, it seems to be a 350 with 250w painted on it). if it is the one you need, oxy might be willing to sling in a higher capacity battery if you negotiate it with them.

3) are you self-employed? if you're employed, or if you're self-employed but are treated like you're employed (which can mean the relationship is treated in law as one of employment, in case of serious disputes), then i'd avoid a nominally 350w motor because your employer has a duty to make sure you have a safe system of work, and one which doesn't meet legal safety standards is by definition not safe. their insurance would also be invalid - as against you or a member of the public claiming off them, so they'd have unlimited liability. actually if you are self-employed, and part of your contract is to carry public liability insurance, you'd be in breach of your contract because you'd have invalidated your insurance.

are you near enough to woosh to call them and arrange a test ride on some of their different setups maybe? i know how easy it is to just order a kit, i got gripped by the urge and fortunately i didn't follow it straight away as i nearly got the bbs01 which i later learnt wouldn't suit my dodgy knees.

the woosh battery and other equipment which comes with the 250w kit looks really nice. so one thought is that if if the motor blows up because it's not suited to your ride, you maybe could order another motor cheaply from china (greenebike and bmsbattery seem to be more trusted than the other companies on these forums) and whack it in.

but yes they do have a rule about getting a mechanic experienced with ebikes to fit the initial kit.
Last edited:


Hi Tezdread,

Welcome to the forum.

Cyclezee supply and or install 3 brands of kit, eZee, Ansmann and Heinzmann.
From what you say, I'm guessing that the eZee kit may be within your price range.
In any event, you might want to take a few minites to see what we have to offer.
The following link will take you to the relevant section of our website


Esteemed Pedelecer
May 15, 2011
with the mileage that you have to do, forget the Woosh CST, big motors like the Ezee and the BPM are much harder wearing.

Oxygen Bicycles

Trade Member
Feb 18, 2010
Hi Tezdread,

I'm Andrew from OXYDrive and apologies for using Oxygen account since the business transfer have not set up yet a separate account for OXYDrive kits.

There are a couple of things I would like to clarify as I see you kind of confused at the moment.

The CST 13Ah kit:
runs on the classic Bafang CST motor which is large diameter hence it has more motor torque and has Samsung 13Ah battery that uses 50cells Samsung 18650-26F. We recommend it more for off road users or in the very hilly terrain as it's a better hill climber. This is indeed 350W but as it's sold out of the box it is set up to comply with legal requirements anyway down to 250W and 15.5mph with limited current on the controller.This upon request can be removed to allow more power for off road users. The current limit on the controller will not allow the motor to get more power anyway without changing settings in the software.

The CST 11Ah kit:
runs on the smaller 8FUN cassette motor which is equivalent of RM G01.D250. It's a smaller diameter, bit less torque too and has a 11Ah Samsung battery that uses 50cells Samsung 18650-22F

I wouldn't say that the CST 13Ah kit will consume more battery juice as it's all down to the controller that allows appropriate current that is delivered to the motor. Naturally if you program the kit for off road purposes the more power will be used and range will ultimately drop down.

Please also know that there is no golden rule that every user will cover 50 miles on the 13Ah battery. The range is always dependent on the number of factors and the quoted values of 50 miles is based on the realistic range that majority of users can get up to with a 13Ah battery and the controller set to max 15A of current. This range will however be highly unlikely to achieve in the city conditions where you have a number of stops for junctions and traffic lights. I think majority of members would be able to tell you what realistic figure you could get from the 13Ah pack that's has a real value of 13Ah. My understanding is that you wish to use it for work and more in the city so please be aware that the 50 miles may not be as quite achievable by you.

I honestly prefer to put everything straight and upfront even if i don't make a sale but to make a user fully aware then have an unhappy customer at later date.

Hope this helped a little bit. if you have any questions please feel free to post here or contact directly.

All the best

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Esteemed Pedelecer
Mar 26, 2010
If you are willing to spend around the price of the oxy kit you could get the Woosh big bear as a complete e-bike ready to ride BPM motor and 15 ah battery with the advantage of a fully fitted out bike no need for a mechanic, your old bike is available as a spare if you have any problems and with your weight I doubt you will need any more power.
Maybe look at the the step through to make you job easier (there is a cross bar as well) with all the jumping on off.
If you are pedalling a reasonable amount I would think you will see a range greater than advertised but it is a very individual thing, I used to get 80 km out of 36v 10 amp battery in hilly terrain but I like pedalling (different bike).
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Esteemed Pedelecer
Sep 22, 2012
Any of the recommended motors will do what you seek.

You can believe Trex, so when he says the larger diameter motors such as Ezee and BPM are harder wearing that is something to take on board.

So it's either one of those, or the bigger diameter Oxydrive.

The harder part of your equation is battery life.

You are looking to do 30 miles in the city, but with lots of stop/starts.

At 64kg you weigh next to nothing which will help reduce your power consumption, but the stop/starts will increase it.

As Andrew from Oxygen says, the 50 mile quotes are based on fairly easy going with only a few stops and starts.

I reckon a 13ah will do your more difficult 30miles, especially if you do a bit of battery management by turning the motor wick down.

But the only way to be certain will be to try it.


Esteemed Pedelecer
May 16, 2014
From your post I don't think you have ridden any e bikes, and if it was me I would go and do that first. You can get an idea of what the different kinds of motors can do and which works best for the job you want it to do.

As to the claims made for milage. All the manufacturers and dealers are dissembling there. It's like the claims made for petrol consumption. In an ideal world with ideal conditions and flat ground - with the power turned right down - maybe.

You should get the biggest battery you can get for sure.


Esteemed Pedelecer
May 15, 2011
your choice is prettry limited. You'd need 15AH battery for the busy days. The cheapest option is as Geebee said, buy a woosh Big Bear.
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Oct 31, 2014
Thank you all for your replies...I think I may be more confused though lol

So much choice and only one decision!

I get that calculating a distance accurately is not really possible as there are so many factors that can affect it so I'll take them as an educated guess.

No I haven't been on an electric bike yet. I'm going to jump on a train to Onbike today. This should give me a much better idea and help me decide.

The Big Bear does look like a good option and a comfortable ride but for now I think a kit is the best option (this may change throughout the day!). The Woosh BPM kit also comes with a 15Ah battery.

My bike needs a full service before a kit is installed and with the cost of this service and replacing parts that I know need changing I would be spending pretty much the same price including the kit as I would if I bought the Big Bear but with less hassle.

I'll post back later, hopefully a few test rides and answers.


Esteemed Pedelecer
Aug 7, 2014
West Sx RH
My woosh 15a 09 bottle battery easily does 30 miles with about 40% to spare, I use on assist 7.


Oct 31, 2014
The trip to OnBike was a success and well worth it, I got to test ride 4 different bikes. I tried 2 mountain bikes (and very nice ones too) with crank drives and 2 step through's, 1 with a rear motor and the other with a front motor. The step through's although comfortable, the position feels strange and scooter-like but would make getting on and off easier (maybe another time). The mountain bikes felt solid and with really good power on the climb (want one!).

For now, my first step into Pedelecs is going to be the Woosh hub kit. The price difference and larger battery for what I need it for seems to make the most sense. I do like the Oxydrive kits, they look like they have a better build and the integrated controller on the battery holders are much slicker, I feel that it should go on something better than my beaten up Subway :)

One thing I'm still not sure about is to go for front or rear hub motors...I couldn't really feel a difference on the two bikes I tried.

What do you think?


Oct 11, 2014
Maldon CM8
I have the woosh BPM front hub and love it- easy to fit, perfect for a 180mm disc, soft but strong start from stop within 1/2 crank rotation. Only problems:
1) controller box is a very tight squeeze on the 20A controller
2) controller set on max assist- Woosh are sourcing new parts on a slow boat from China which aren't available for a couple of weeks, so worth checking with them first.