Conversion Kit Advice for Commute Bike

[talkingwalnut]

Hi all,

I'm looking to add an electric motor to my MTB for my daily work commute (~9-10km, 54m elevation gain). We can get a lot of wind here so the commute can be a pain. I'm looking for something that'll help in the wind but not replace the cycling component completely.

I was going to get a rear-hub motor kitfrom ev-power but I realised I'll need to buy a new gear hub, install and rejig my gear setup. That's a bit more than I'm looking to do at the moment so I'm now leaning towards a front-hub motor kit. The general consensus is that they're not recommended for bikes with front-suspension but I'm thinking the lower powered kit might compensate for this (350W vs 500W). Is this a reasonable assumption to make? The bike won't be doing any off-roading, etc.

My other option seems to be a middrive kit, but they're more expensive. I'm in Ireland so ordering from US, etc. is liable to get me stung by Customs. I don't mind paying VAT but it does reduce the cost-benefits of ordering from some suppliers. The kit from EV-Power is working out at about €700 total (inc. delivery and VAT) and I'd like to keep to this budget. I don't mind paying a bit extra for a kit instead of buying separately if it means I don't have to spend time hunting things down.

So I guess the following questions are what I'm looking for some advice on:
1. Is this front-hub kit safe for my bike?
2. Is it suitable for my needs?
3. Is there a middrive kit alternative you'd recommend instead?


I can't upload a photo of my own bike at the moment, but here's a link to what looks like the stock version. I've changed the tyres on my own but everything else looks the same.

 

[d8veh]

You can get the BBS01 kits from Woosh Bikes and Eclipse in the UK.

You can put a hub-motor in the front wheel, but you need to know what you're doing, and it depends what forks you have.

 

[jesusjesus]

look like those ev-power Hubs are direct drive (heavy, no freewheel thus drag)

you probably would like a smaller geared type, if you are only looking to boost your pedaling.
IMHO, only go with DD motors if you need to run alot more power or use the motor most of the time.

don't know much about suspension bikes, but something small and light like a qute/bafang with a decent 48v battery and 350w(maybe 500w) controller might be sufficient.
if not you still have the 48v volt battery if you late want more oompf.

bmsbattery.com e.g

 

[Drunkskunk]

Hi all,

So I guess the following questions are what I'm looking for some advice on:
1. Is this front-hub kit safe for my bike?
2. Is it suitable for my needs?
3. Is there a middrive kit alternative you'd recommend instead?

Welcome to the forum.

That fork should be a Suntour XCM, and will have a cast aluminum lower section. It would be unsuitable for use with a front motor.

1) No. Unless you're considering very low power (150-200watts), then it's generally a very bad idea to put a hub motor on an aluminum suspension fork. Failure of a front fork at speed would be potentially fatal.
2) No.
3) Yes. The BBS02 would be a great mid drive alternative. However, setting up a mid drive would be more complicated than installing a rear motor. If you find rear gear adjustment daunting, a mid drive probably isn't something you'll want to tackle, as it would involve the same amount of gear adjustment to the front derailleur, along with replacement of the cranks and bearings.

If you plan to pedal, you'll need either a mid drive, or a geared hub. Geared hubs have an internal freewheel that disengages the motor when not in use. The motor you linked doesn't explain whether it's a direct drive, or an internally geared hub.

 

[talkingwalnut]

Thanks for the advice guys. I've dropped the supplier an email to see if they can tell me if it's a geared motor or a direct drive. If it's direct drive I'll probably look elsewhere.

I moved away from the rear-drive as I'll need to get a new gear-hub and adjust the derailleur (to go from an 8 speed to a 7) thus adding time and money to the conversion. It's not so much the time needed to do the conversion I'm worried about but the time I need to spend researching what I need and how to do it (a lot of reviews of the freewheel gear hubs aren't good). If I grab this gear hub can I use it with my existing derailleur (front and back) and shifter? What happens with the extra gear on the shifter? Is it just a matter of adjusting the rear derailleur to work with the new gear hub?

Would the middrive still use a derailleur? Have they more than one gear cog?

Sorry about the rather basic questions but I haven't done this level of work on a bike in a lot of years. It's easy to get lost in a maze of terminology

 

[wesnewell]

A DD hub motor is the most reliable you can buy. No gears to break. No clutch to replace. It will provide reliable service for many years and miles. I've got over 4 years and over 15K miles on mine now and it's never been touched. AFAIC, it's the only smart choice for a commuter. And because of its simple design it's also cheaper than geared type. Can take much more power than the other types should you want to increase power. The only disadvantage is if you lose power it will be a little harder to pedal than non DD systems. The likelihood of this happening is so close to 0 you might as well not even consider it. There's a reason you don't see many geared or mid drive kits for sale compared to direct drive kits. Think about it. I'd never buy a geared hub, and the only reason I'd ever get a mid drive is if I had mountains to climb.

 

[talkingwalnut]

...

Thanks wesnewell. This is the kind of use case I envision. Nothing more strenuous than a hill. So the DD hub is just a no-no for the front wheel because of the weight? Back towards the rear-wheel motor I lean

Can anyone with more biking experience than me comment on the freewheel gear hub situation? Would it just be a derailleur realignment job if I got the Shimano hub? Or is that dependant on the shifter, etc. I currently have?

 

[wesnewell]

Freewheels come in up to 9 speeds. You can use whatever you want as long as the chain you have now will work with it.Once you have the motor, you probably won't ever change gears. I leave mine in high gear ll the time. I can count the times on one hand I'v changed gears in the last 5000 miles. I think the chains the same on clusters up to 8 speed, but I'm not sure. I've never bought a bike with more than a 7 speed freewheel.

 

[jesusjesus]

The main reason the DD are selling better is price, most noob dont want to pay thousands of $.

The point is, dont haul around deadweigth. If you can get the results you want from a 3 kg gear motor why haul around a 6 kg dd? (that has drag)
better torque - essential for a commuter in cities, with alot of stops.

These DD kits are a joke running 500w and below, and i actually have one of these running at approx. 750w and that is bare minimum imo. I got it because i like the lower noise they make.

A that rear DD kit will do fine, there are good arguments for both mid drive and gearhubs – the most important part of ebiking is the battery, so make sure to do your homework there

 

[talkingwalnut]

Freewheels come in up to 9 speeds. You can use whatever you want as long as the chain you have now will work with it.Once you have the motor, you probably won't ever change gears. I leave mine in high gear ll the time. I can count the times on one hand I'v changed gears in the last 5000 miles. I think the chains the same on clusters up to 8 speed, but I'm not sure. I've never bought a bike with more than a 7 speed freewheel.

The main reason I'm looking at the 7 speed is it seems to be the best regarded (price and quality). I guess I could get a single gear hub (and new chain I guess). I only change gear for hills anyway so I don't think I'll miss them. I'd rather keep things simple.

Is there anything I'm not thinking of with this?

 

[wesnewell]

I know nothing about trade in Ireland, or their ebike laws, but usually the best bang for the buck is a 48V 1000W kit. Here's some of the UK kits.
http://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_nkw=48v%201000w%20rear&rt=nc&LH_PrefLoc=1&_trksid=p2045573.m1684
Not that a 500W kit isn't enough. There's just not much cost difference. And 500W is plenty for most people. My first kit was a 48V 500W DD rear hub motor. I could get ~40kph with it and I'm 270lbs. Needed pedal help up steep hills though with my weight. I quickly bought a 48V 1000W kit within 2 weeks. I still use it daily almost 5 years and 15,000 miles later.

 

[talkingwalnut]

I know nothing about trade in Ireland, or their ebike laws, but usually the best bang for the buck is a 48V 1000W kit. Here's some of the UK kits.
http://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_nkw=48v%201000w%20rear&rt=nc&LH_PrefLoc=1&_trksid=p2045573.m1684
Not that a 500W kit isn't enough. There's just not much cost difference. And 500W is plenty for most people. My first kit was a 48V 500W DD rear hub motor. I could get ~40kph with it and I'm 270lbs. Needed pedal help up steep hills though with my weight. I quickly bought a 48V 1000W kit within 2 weeks. I still use it daily almost 5 years and 15,000 miles later.

Thanks for the advice. I'm hoping not to replace the pedalling completely though. I still want to get my exercise, just make things a bit easier in high winds. Great to know that they have such durability though.

I'll probably order the rear-hub kit today, with the 7 speed shimano gear hub. The single speed cogs are a lot more expensive. Price-wise it seems to be about the same to order from ev-power. They've replied to all my emails too so I think they've earned my money

 

[d8veh]

If your bike is an 8 speed, you can still use a 7-speed gearset. On my present bike, I have a 7-speed freewheel and it has 9-speed changer and derailleur. It works OK. I just have to do one or more extra clicks on some of the middle gears. I use all the gears when I ride.

You will need a DNP freewheel with 11T top gear otherwise you won't be able to keep up with the motor when pedalling. You can also get 8-speed DNP freewheels that are a bit wider. They require a slightly larger off-set (dish) in the rim.

Whatever rear motor wheel you get, you'll probably need to dish it a bit to get your rim central, except some of the UK supplied kits, like the Oxydrive, come pre-dished. While I mention it, the Oxydrive rear kits have cassette motors, so no problem with gears. You can fit a cassette with as many gears as you want.

I just had a look on their website. This kit has a reduced price of £450. It has the new Bafang SWX02C cassette motor and a decent battery.
http://www.oxydrive.co.uk/electric-bike-kit/oxydrive-cst-11ah.html

 

[LockH]

"We can get a lot of wind here so the commute can be a pain."

Wind? AKA "free energy"? Currently investigating pleasures of recumbent riding, but maybe see also fairings? Also have bits of cloth to fabricate a small sail. EG:

 

[jesusjesus]

Ireland is a EU-member, so the same 250w pedelec rules (max 25kph)

 

[talkingwalnut]

If your bike is an 8 speed, you can still use a 7-speed gearset. On my present bike, I have a 7-speed freewheel and it has 9-speed changer and derailleur. It works OK. I just have to do one or more extra clicks on some of the middle gears. I use all the gears when I ride.

You will need a DNP freewheel with 11T top gear otherwise you won't be able to keep up with the motor when pedalling. You can also get 8-speed DNP freewheels that are a bit wider. They require a slightly larger off-set (dish) in the rim.

Would 14T be any good? Finding it hard to source a 11T hub nearby.

Whatever rear motor wheel you get, you'll probably need to dish it a bit to get your rim central, except some of the UK supplied kits, like the Oxydrive, come pre-dished. While I mention it, the Oxydrive rear kits have cassette motors, so no problem with gears. You can fit a cassette with as many gears as you want.

I just had a look on their website. This kit has a reduced price of £450. It has the new Bafang SWX02C cassette motor and a decent battery.
http://www.oxydrive.co.uk/electric-bike-kit/oxydrive-cst-11ah.html

I've already ordered from ev-power unfortunately. Plus oxydrive don't seem to offer Ireland as a shipping destination.

 

[wesnewell]

14t is the standard high gear for most freewheels. You should be able to pedal to about 25-30kph with it depending on how fast you can pedal. It will work fine for going up steep hills to assist the motor or going into a stiff wind.

 

[talkingwalnut]

14t is the standard high gear for most freewheels. You should be able to pedal to about 25-30kph with it depending on how fast you can pedal. It will work fine for going up steep hills to assist the motor or going into a stiff wind.

I managed to track down someone with an 11t for sale. Hopefully that's me all setup now

 

[talkingwalnut]

"We can get a lot of wind here so the commute can be a pain."

Wind? AKA "free energy"? Currently investigating pleasures of recumbent riding, but maybe see also fairings? Also have bits of cloth to fabricate a small sail. EG:

That's a nice idea but we all know that if it's windy and you're cycling, it's always in your face. No matter which direction you're going