Brompton conversion

[jamesporritt]

I have a 15AH 36V battery and would like a conversion kit for my Brompton. Must be powerful for steep hills and attain 15mph on flat road. I'm unfit and weigh 87KG. Can anyone advise which motor and controller I would need and from which shop? Budget is £0 to £250.

 

[matthewslack]

Search Brompton, find threads, some recent, all highly detailed!

 

[StuartsProjects]

Have you already worked out where and how the battery you have is going to fit ?

 

[jamesporritt]

No. A box secured to this on the seatpost or handlebar post? Or to two?

1pair Folding bicycle carrier block adapter for brompton seatpost adapter water bottle compatible31.8/33.9/34.9mm - AliExpress 18

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

 

[StuartsProjects]

Do you need to fold the Brompton for storage etc ?

 

[jamesporritt]

Replace bolts with winged ones for fast detachment?

Handlebar bag alternative?

 

[StuartsProjects]

Woosh do Brompton conversion kits, circa £500 with battery. UK supplier.

TopBikeKit do Brompton conversion kits, without battery, but at £320 are outside of your budget. On Aliexpress.

 

[saneagle]

Must be powerful for steep hills and attain 15mph on flat road.

Any hub-motor will do that because the 16" wheels multiply the torque, but you won't climb at high speed. Any motor that does around 328 rpm will get you to 15mph.

 

[jamesporritt]

Woosh do Brompton conversion kits, circa £500 with battery. UK supplier.

TopBikeKit do Brompton conversion kits, without battery, but at £320 are outside of your budget. On Aliexpress.

1.6kg TBK-74AD 36V250W 48V250W Front Motor with 16inch 349 Wheel Rim for Brompton/Cranston/Dohon/3Sixty/Aceoffix Bike [TBK-74AD 36V/48V 250W Kit 16inch] - $140.14 : Zen Cart!, The Art of E-commerce

Zen Cart! 1.6kg TBK-74AD 36V250W 48V250W Front Motor with 16inch 349 Wheel Rim for Brompton/Cranston/Dohon/3Sixty/Aceoffix Bike [TBK-74AD 36V/48V 250W Kit 16inch] - ★★★★★ Applicable to: Motor kit can fit Brompton,Cranston,Dohon,Pikes,Aceoffix,Kosda,Mint,3Sixty,Ruhm,Hcc Folding Bike or other...

www.topbikekit.com

I see they are asking $235.14 on their site plus $25 shipping estimator. £204.

Is their motor labelled 250W?

Do they charge VAT or anything extra when bought from their own website? Customs?

 

[jamesporritt]

Any hub-motor will do that because the 16" wheels multiply the torque, but you won't climb at high speed. Any motor that does around 328 rpm will get you to 15mph.

Climbing high speed would be nice. Slow is ok if it doesn't grind to a halt.

 

[StuartsProjects]

I see they are asking $235.14 on their site plus $25 shipping estimator. £204.

Plus VAT I think.

Is their motor labelled 250W?

Who knows, they may have been in the past, but this is a far East supplier so who can know what they are doing now.

Customs?

Maybe, maybe not.

 

[Peter.Bridge]

Me and loads of people here have bought stuff from topbikekit over the years. I wouldn't hesitate to recommend them. I have that motor in a dahon clone in a 20" wheel and it is marked 250w. I would just email them and ask any questions.

Never had to pay any extra in customs charges

 

[saneagle]

Climbing high speed would be nice. Slow is ok if it doesn't grind to a halt.

I used a tiny Q85 hub-motor running at only 14A and 36v. It could pull my 100kg up a 14% hill without pedaling, but at 4 mph. The motor was quite happy at that speed for a short distance.

 

[Peter.Bridge]

Me and loads of people here have bought stuff from topbikekit over the years. I wouldn't hesitate to recommend them. I have that motor in a dahon clone in a 20" wheel and it is marked 250w. I would just email them and ask any questions.

Never had to pay any extra in customs charges

ETA So the kit including motor wheel, KT display , controller and pas (not including battery)is $235 + $70 shipping (china post) $300 = £240.

Theoretically there is a custom charge but I don't think it is much and I've never heard anyone having to pay it

 

[StuartsProjects]

Me and loads of people here have bought stuff from topbikekit over the years. I wouldn't hesitate to recommend them.

Overall they might be an OK supplier.

But the Motor wheels they were supplying, specifically listed as for the Brompton, were not using standard Brompton rims, so some Brompton tyres would blow out. Might not be an issue for some I guess.

They seemed completely not interested when this was pointed out to them.

 

[jamesporritt]

Thanks everyone who replied. My son stole my Brompton at Xmas and I am looking for a bigger bike with suspension. He's fitter stronger and embarassingly taller with no need for a conversion.