Brammo’s Wismann Responds To Carrera’s Take On Brammo Electrical And Mechanical Design


Skadamo published an article on Friday, January 22, about a blog post by DERBI project manager Carles Carrera, detailing the DERBI GPR EV. Most noteworthy was the following paragraph from Carrera:

Current production electric motorcycles as Quantya, Brammo, Vectrix or Zero, motorcycles that I love for being pioneers, have in my opnion two recurrent problems.

  1. They have a poorly developed mechanical platform, I mean all of them have been developed my electric experts without insight on motorcycle development, so they are heavy, or awful or difficult to ride or even worse, not fun to ride.
  2. On the other side, all the electric components are not developed as a whole, and although all of these companies are ran by experts on batteries, controllers and so on, I think they have lots of problems with all the components talking each other: the controller must talk to the batteries and the motor to tell them what to do and how to do it. And that’s not easy. In fact, generally the controller and the batteries don’t talk to each other at all.

Soon after this post, a user by the name of www.efmotion.com (we can safely assume it’s Mr. Carrera, right?) posted on the elmoto.net EV forum and provided a link to his blog.  He asked forum members to “pay a visit” to his blog and let people know what they thought.

Which they did.

The post caught the attention of user BrammoBrian, better known as Brammo Lead Designer Brian Wismann.  Here’s his response to Mr. Carrera’s post:

BrammoBrian

Lots of opinion here as well as some very broad statements that I would contend against, of course. Here are some points to ponder:

1. Communications – The Enertia features 3 separate CANbus networks on the bike (to isolate system critical vs. non-critical data) and every electronic component has a communication connection to the rest of the bike. We have a sophisticated Vehicle Control Unit that receives communications from all of these devices (batteries, motor, motor controller, charger, dash, handlebar controls) and makes system level decisions. We also log nearly 100% of this data in real time to an on-board memory card to allow quick and easy diagnostics of any fault.

2. The component suppliers you’ve mentioned have been working with Brammo for quite awhile – Perm Motors and Sevcon (who was just here this week helping with some integration issues on their side) have been working with us for 4 years and 1 year respectively.

3. The Enertia and Enertia TTR platform were developed from the ground up to be an electric motorcycle, this Derbi is a conversion. Converting a vehicle’s powertrain WILL lead to packaging compromises, whether you’d like to admit it or not. The Enertia was developed by a team of mechanical engineers, electrical engineers, and software engineers.

4. Cost – I would also contend that Brammo’s platform was developed from the ground up specifically to be fun to ride AND affordable… what is the cost of the Derbi prototype? I know the cost of the components, and I’d guess a retail version of that bike will run upwards of $20k and this prototype well over $50k if not more.

5. I do agree with you that it’s “not easy”. Welcome to the big time… jump in, the water’s warm. We placed 3rd overall in the TTXGP last year. Where did you place?

I’ll only assume that the statements you’ve made were made in ignorance or lost in translation. In my opinion, it is professional courtesy to stick to discussing what you are fully knowledgable about – in your case the prototype you’ve built, in my case I talk about the Enertia. Welcome to the forum.

We look forward to Mr. C’s equally measured response to Mr. B’s reply.

Harry Mallin is the moderator of the TTXGP Technical Rules Wiki, blogs at Brammofan(Brammo-related) and eMotoRules (TTXGP-related) and you can follow him on Twitter at@brammofan and @emotorules.

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  1. Written by Detroit Scooter
    on January 25, 2010 at 12:03 pm
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