Choosing a DIY electric kit

[D C]

I have come to the conclusion that advancing years (66) and an ongoing left knee problem indicate that I should enhance my cycling pleasure and help to preserve my joints by fitting an electric motor to one off my existing bikes.
I have a 21inch Schwinn Rocket 88 with full suspension, one of the last original Schwinns circa 1999 which is in excellent condition and my favourite mountain bike of all time, I also have a slightly older but good quality hard tail Raleigh with suspension forks which I use with spiked tyres for use in icy winter conditions.
My riding is pretty much all off road and I still wish to pedal as much as possible without assistance, I would just like a little help on the longer runs and steeper hills of which there are plenty round here in the Scottish Highlands.
Although I've been riding and maintaining Mountain Bikes for around 35 years I have no experience of electric bikes at all and I've spent several hours doing on line research. By reason of cost and possible suitability I am drawn to the Alien Ocean road legal kit at around £550 or the Cyclotricity eKit basic at £399.
I would very much like to convert the Schwinn but there are a few difficulties. Due to the nature of the rear suspension a conventional rear carrier can't be fitted though I do use a seat post attached carrier which at 12 inches long and 4.5 inches wide looks big enough to take a battery, nor is there room on the frame for a drinks bottle type.
This would indicate that the Cyclotricity basic kit with the 36v 7ah seat post battery may be best, the Schwinn bottom bracket doesn't have a square taper meaning a pedelec system wouldn’t fit anyway. I would perhaps prefer a larger battery but the main problem for me is that I want to retain my existing combined brake/gear shifters and the kit comes with replacement brake levers rather than in line brake sensors which are available as an option for the Alien Ocean Kit.
I am unsure if it would be possible or wise to use the system without the brakes cut out.
The Alien kit should fit the Raleigh, it can take a rear carrier so would have a better battery (10ah) and has a square taper bottom bracket and in line brake sensors but I would really prefer to keep this as a winter bike.
One other slight concern is that it's stated on a few sites (mainly American) that a front wheel motor shouldn't be fitted to alloy forks as they will eventually break, can this really be correct?
One more question on throttle switches, I'm unsure if a thumb operation or twist grip is best, or which would be the easier to operate for bumpy off road use.
Thank you for having the patience to read this rather long post and I would be very grateful for any observations, ideas or advice and would love to hear from anyone who has fitted either of these kits or any others.

Dave.

 

[Deleted member 4366]

You can still fit the pedal sensor because there's lots of simple ways to adapt it, but only fit one if the kit has a panel to adjust the PAS level. You need at least three levels on the panel.

You can fit any battery on a seat-post rack. You want the battery weight as far forward as it will go, and as low as the suspension clearance will allow. My bikes all have 20aH batteries, which weigh 5kg+, and the bikes quite manageable. You'd hardly notice a 10aH one.

You can buy those in-line brake sensors separately to use on any kit:
HWBS - Hidden Wire Brake Sensor 1pcs - BMSBATTERY

My experience of those pod-type batteries that fit behind the seat (know as Frog batteries) shows that they're not really suitable for off-road. The constant bumping causes the weight of the battery to bend the main bracket downwards. The nice plastic side covers break more or less straight away, and after you've had to pull the main bracket up a few times, it'll eventually crack and break. The other thing is that OEM bikes that have this type of battery have plastic spacers (half-clamps) that fit around the frame tube to prevent it from damage. Nearly all the kits I've seen don't supply those essential spacers, so check with the supplier if you still want that type of battery.

 

[D C]

You can still fit the pedal sensor because there's lots of simple ways to adapt it, but only fit one if the kit has a panel to adjust the PAS level. You need at least three levels on the panel.

You can fit any battery on a seat-post rack. You want the battery weight as far forward as it will go, and as low as the suspension clearance will allow. My bikes all have 20aH batteries, which weigh 5kg+, and the bikes quite manageable. You'd hardly notice a 10aH one.

You can buy those in-line brake sensors separately to use on any kit:
HWBS - Hidden Wire Brake Sensor 1pcs - BMSBATTERY

My experience of those pod-type batteries that fit behind the seat (know as Frog batteries) shows that they're not really suitable for off-road. The constant bumping causes the weight of the battery to bend the main bracket downwards. The nice plastic side covers break more or less straight away, and after you've had to pull the main bracket up a few times, it'll eventually crack and break. The other thing is that OEM bikes that have this type of battery have plastic spacers (half-clamps) that fit around the frame tube to prevent it from damage. Nearly all the kits I've seen don't supply those essential spacers, so check with the supplier if you still want that type of battery.

Thanks for the really helpful reply, just the sort of advice I'm looking for and backing up my own gut feeling about the "frog" battery.
Dave.

 

[103Alex1]

I'm unsure if a thumb operation or twist grip is best, or which would be the easier to operate for bumpy off road use.

Thumb. Twist grip prone to breaking on full throttle over bumps.

Disclaimer rolleyes

Opinions may vary. The use or otherwise of any information contained in this post is at the discretion of the reader and no liability whatsoever is accepted for its accuracy or for any disappointment, excitement, rage, burned dinners or inadvertent orgasms arising from the reading of same.

I would perhaps prefer a larger battery but the main problem for me is that I want to retain my existing combined brake/gear shifters and the kit comes with replacement brake levers rather than in line brake sensors which are available as an option for the Alien Ocean Kit.

Are your brakes mechanical rim brakes with combi-shifters then ?

 

[D C]

Thumb. Twist grip prone to breaking on full throttle over bumps.

Disclaimer rolleyes

Opinions may vary. The use or otherwise of any information contained in this post is at the discretion of the reader and no liability whatsoever is accepted for its accuracy or for any disappointment, excitement, rage, burned dinners or inadvertent orgasms arising from the reading of same.



Are your brakes mechanical rim brakes with combi-shifters then ?

Yes they are, thanks for the advice to go for thumb rather than twist, sounds right for me.
Dave.

 

[103Alex1]

. I've got one of those Hidden Wire Brake Sensors d8veh mentions above that wouldn't work with my hydraulic disc brakes, if you did decide to go down that route. It's spare / unused - available @ cost if you don't want to import a single part from China and it's the right solution for you. Was going to keep it for possible use on another conversion but that's looking unlikely in the foreseeable.

 

[D C]

. I've got one of those Hidden Wire Brake Sensors d8veh mentions above that wouldn't work with my hydraulic disc brakes, if you did decide to go down that route. It's spare / unused - available @ cost if you don't want to import a single part from China and it's the right solution for you. Was going to keep it for possible use on another conversion but that's looking unlikely in the foreseeable.

That's very kind of you, I will certainly need this part at some stage so would like to take up your offer.
I can do a cheque in advance or paypal.
Dave.

 

[hopper_rider]

If you convert a standard bike, do you need to change the whole braking system?

 

[D C]

If you convert a standard bike, do you need to change the whole braking system?

I hope not.
It seems a fairly simple conversion job if you have a suitable bike to start with, mine isn't that suitable as it has a suspension system system that pivots round the bottom bracket and zero clearance space to fit a sensor.
Has anyone got any thoughts on if it's legal to not have a brakes cut out or if it's OK to fit a motor to alloy front forks?
Dave.

 

[Deleted member 4366]

If you convert a standard bike, do you need to change the whole braking system?

It depends what braking system you already have. Can you be a bit more specific about what's on your mind.

 

[hopper_rider]

It depends what braking system you already have. Can you be a bit more specific about what's on your mind.

There are a few spare bikes that could be possible contenders. A Raleigh Michigan and a Terrano Freestyle. Full frames. 26in Wheel and 700C wheel.

Then several folders.
An Apollo 16 inch wheel, A Space Genie (Brompton clone sort of), an an old style Raleigh? shopper folder.

 

[D C]

I'm just about to take the plunge and order an eKit e-bike conversion kit direct from Cyclotricity with the option 36v 10ah rack battery, just a thumb throttle (no pedelec system) and see how I go with that.
I have to start somewhere and this kit seems to be a reasonably priced starting point for me to sample and learn about electrically aided cycling.
I hope to fit it to my Schwinn Rocket 88 which may be tricky with the rear rack, don't quite know how I'm going to solve that one yet but there's always a way. If it's to much of a problem then the kit will go on my Raleigh winter bike, minus spiked tyres of course.
Sadly the kit will take 3 weeks (I am assured) to be delivered to me as there's no stock at the moment.
The new Kudos range of Mountain Bikes would have tempted me but only available with 18 inch frames so being 6'1" tall and 33" inside leg I would look a bit silly on one.
Once I get the kit set up I'll report back here as to how I get on etc.
Thanks to all for the helpful advice so far.
Dave.

 

[Deleted member 4366]

If you convert a standard bike, do you need to change the whole braking system?

If you have cable brakes of any type, it's very straightforward to fit a kit. You don't have to change your braking system. Hydraulic brakes need a bit more DIY to fit sensors.

 

[Deleted member 4366]

This is the rack I use on my full-suspension bikes because the clamp is steel. Aluminium ones will crack and break after some time. I only paid about £6.99 for mine. I think they came from Australia, but found them on Ebay. They didn't have the Schinn name on them, which is why they were cheaper.
Schwinn Bicycle Seat Post Rack | eBay
here it is without the Schwinn name:
Cargo Rack for Mountain Bike Bicycle | eBay

 

[D C]

This is the rack I use on my full-suspension bikes because the clamp is steel. Aluminium ones will crack and break after some time. I only paid about £6.99 for mine. I think they came from Australia, but found them on Ebay. They didn't have the Schinn name on them, which is why they were cheaper.
Schwinn Bicycle Seat Post Rack | eBay
here it is without the Schwinn name:
Cargo Rack for Mountain Bike Bicycle | eBay

That's great information, I do have an existing seat post rack fixed on the bike but one of these may be a better option.
Thanks again for a useful link.
Dave.