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[Richard230]

This is a pretty decent review by Jay Leno of the Empulse R.  Craig was there (naturally) and he mentioned that Brammo would be selling (I assume to the public) a high-performance race bike.  It sounded like it would be street-legal, as he mentioned that you could remove the lights and run it on the track.  He didn't say how much it would cost or if it would have a transmission.

http://www.jaylenosgarage.com/collections/electric/2012-brammo-empulse-r/index.shtml#item=280507

[flar]

That would be the Empulse TTX that they keep showing off in various social media feeds.  I don't think they've released specs for it yet, though...

[CliC]

Interesting - first I've heard of the polymer coupling between the rear hub axle and the wheel.

[Richard230]

Interesting - first I've heard of the polymer coupling between the rear hub axle and the wheel.

Just about every chain-driven motorcycle wheel that I have ever seen uses a rubber vane (an expensive one might be called a "polymer coupling") cushion inside the rear wheel, between the hub assembly and the chain sprocket assembly.  This shock- absorbing system has been used on motorcycle rear wheels for many years and it is likely that when Brammo bought the rear wheel from the manufacturer, it was an off-the-shelf item and came with the rubber cushion as part of the wheel.  It is obviously a good idea that has been used successfully to reduce shock loads on the chain, sprockets, gearbox and the rest of the drive-train.

[CliC]

Hmm. My old Zook didn't have one (maybe didn't need one with a 400 thumper motor) and my Harley was belt drive like the Zero.

[manlytom]

nice, yet very complex piece of engineering this Brammo. he says batteries certified and can be "shipped" in a Boing. Hopefully not the 787....

now, want to ride one nevertheless and see how it feels. yeah weird that rubber rear wheel stuff...

So has Jay ridden the new Zeros ?

[spelunker]

He rode a 2011 S I think.  You might be able to find it on YouTube or on his website. He had a lot of nice things to say about it, however, I'd be interested to see what he has to say about the 2013 after the comments he made about the transmission in the Brammo. .

[Richard230]

Interesting - first I've heard of the polymer coupling between the rear hub axle and the wheel.

I am reading a book titled The Triumph Story , written by David Minton.  Last night I came across the following statement on page 88 of this book regarding Triumph's 1953 redesign of their 500cc Speed Twin to make it the 650cc Thunderbird:  "In 1953, both Speed Twin and Thunderbird were equipped with ac alternators and as these were crankshaft mounted the transmission shock absorber had to be resited.  It was incorporated into the clutch body of all models as a rubber vane type and, like all of its type, was a crude device that not only coarsened performance but which also exacerbated chain wear".

[jazclrint]

Even the RR has a cush drive.  I thought it was odd on the single speed RR, but the power hit so hard and you would have to have race wheels custom made without it, that they just went ahead and used it.

[WindRider]

Jay says that Bramo developed the 6 speed transmission.... Actually, I think that they just got that off the shelf?

[BSDThw]

Do you know an off the shelf transmission with neutral between 2nd and 3rd?
Maybe a Trial bike.

But I heard it so often, so I believe it is custom-made.

[WindRider]

Do you know an off the shelf transmission with neutral between 2nd and 3rd?
Maybe a Trial bike.

But I heard it so often, so I believe it is custom-made.

Interesting.   I thought that if they custom made it for an electric motor it would have a lot fewer ratios.

And no, I have not heard of a tranny with a nuetral betwixt 2nd and 3rd.

[Richard230]

My understanding is that the transmission was developed by an Italian company and Brammo bought it from them.  I don't know which came first, the transmission or Brammo's interest in it.  I suspect that the gear train and clutch used in the transmission are off-the-shelf two-stroke units, but I am just guessing as that just makes sense, since designing gears and manufacturing them is something of an art and very expensive, especially when they will be used in a low-volume vehicle.  Looking at the transmission, it seems very compact and I am not sure how the clutch fits into the seemingly very small case.  Maybe the clutch is on the end of the motor case, but then I wonder how it is lubricated. I saw a computer diagram of the transmission's guts, but I couldn't figure out how it works.  I would sure like to see the transmission with its case open.