Grin Brompton Kit

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Chopcat   1 mW

1 mW
Posts: 16
Joined: Apr 29 2019 1:51am

Grin Brompton Kit

Post by Chopcat » Jun 21 2019 12:43pm

After looking at all of the options available here in the UK and stumbling across this forum, it was clear that the Grin solution was the one for me. Primarily because they are so open about what goes into their products and provide all the test information. If you look at other kits available they don't even tell you what battery specifications they supply. And all apart from the 250w restriction that we have.

So after a lot of arguing with the customs people here and paying a fair wack for importing the parts (roll on open trading between both sides of the pond) - it all went together very easily. I went for a Sempu torqe sensor and one area I tackled was where the folding wheel rubs on the cable coming from the sensor. In hind sight I might have been able to drill the hole further round on the bottom bracket but the 3D printed cover does the trick to stop the tyre contacting the wire.

I went for the LiGo packs as I love the idea of knowing exactly what is going on with the batteries and got a saitiator to charge them. Which is a great bit of kit.

Overall I love the ability to program the bits easily with a mac and the riding experience is superb. I get around 25mph max but going sensibly around London I get 40 miles on an 80% charge. I tried keeping the existing brakes and adding a tripwire but the folding and unfolding sometimes meant it got stuck on ebrake and an inopportune moment. So I swapped to a set of ebrake levers and that solved that.

I have yet to sew up a bag for the batteries, other than that it's all that I could wish for in a folder. In fact the kit was so good I ordered another to convert my Specialized tricross. But that's another story....
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beast775   100 kW

100 kW
Posts: 1215
Joined: Jul 05 2007 11:55am
Location: victoria british columbia

Re: Grin Brompton Kit

Post by beast775 » Jun 24 2019 3:26pm

Excellent build . I've used the smaller crystalyte hub and it worked great on a 1960s Raleigh folder..I'm interested in the ligo batts , seems I will end up with them in the future.
2 FINGER SALUTE TO buying gasoline for 14 years now.
I spent all my money on bicycles women and beer the rest i just wasted.

Oli.Hall   10 mW

10 mW
Posts: 25
Joined: Oct 03 2019 5:27am
Location: London, UK

Re: Grin Brompton Kit

Post by Oli.Hall » Oct 03 2019 5:35am


I am interested in buying exactly the same setup for my London commute too!
I found your post because I am also interested in how to solve the ebrake issue. Could I ask which levers you used in the end please?
Have you found any other issues or minor inconveniences that I should plan for with the kit or in usage?
I was hoping to be able to build a torque sensor controlled system with the SAW20 motor but without having to use the CA computer because it is so damn big! Do you find the display is useful when you are riding?

I would also like to know how much I am likely to be charged in import duty/vat and I was just about to email to ask them if they know how much the duty rate is. Would you mind sharing how much you got charged for import duty/tax please? Send me a PM if you like.

Kind regards,

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