Motorcycle Classics 961 SE magazine article

Motorcycle Classics 961 SE Article

The January/February 2016 issue of the Motorcycle Classics magazine that is just being delivered to subscribers and newsstands, has a nicely done article by Editor Richard Backus on my 2015 961 SE. You might want to pick up a copy and give it a read. I gave Richard access to my bike for a photo shoot and a hundred miles of riding it by himself, while he was here in Utah attending the Bonneville Vintage GP AHRMA races in September. I think he did a great job describing the bike's performance, it's evolution, and my long personal saga regarding the acquisition of it. It's a 5-page article beginning on page 58. The story is also available without the photos through the Motorcycle Classics website. I'd be interested in reading any comments from Access Norton readers. The issue has a black Brough Superior on the cover, and contains some great stories on other classic bikes.

Bob Jones (Precisionbob)

Great article.
I just read it online.
It has your personal story, and the trials and tribulations of Norton 961 acquisition. :lol:
I think Richard Backus' test evaluations were fair.
Well done.

Enjoyed the article, read it at

http://www.motorcycleclassics.com/class ... fzhur.aspx

bluto said:

Enjoyed the article, read it at

http://www.motorcycleclassics.com/class ... fzhur.aspx

Click to expand...

Thanks for posting the link, Bluto. Loved the article - PBs experience as told by Mr. Backus is very encouraging.

Great to read and to be able to relate. Everyone else has to just keep wondering. Thanks for posting.

My story is identical to that of Bob Jones, except my original number was 32. After 4 years my bike arrived, but I immediately realized that it was running extremely poorly - decreased power, very slow throttle response with spluttering, surging throughout the mid rev range, and seemed to be running hot. My original diagnosis of running lean turned out to be correct. I was assured that the "new" map for the aftermarket pipes had been uploaded to the ECU. So I took it to be dyno-tuned, and what an amazing difference! You can see from the power curves below (if I've managed to upload the image correctly), that pre tuning peak hp was a pathetic 23, and torque 39 lb/ft. Post tuning was 68 hp and 56 torque at the rear wheel. We overlaid a Power Commander V (polarity on the Norton is reversed) and excluded the O2 sensors. Additionally, during tuning at about 4,000 revs, there was complete loss of power to the fuel injectors and all kinds of lights were flashing (reported on other posts). This turned out to be caused by a loose ground wire to the engine casing behind the right piston, and a slightly loose one attached to the frame under the seat. Hope this is of help to some of you who may have experienced similar problems.

I think I've worked out how to load the dyno-map attached to my original response, below.

Hello Candyman , Good Work . This will give you 135MPH @ 8000 RPM with stock gearing , enjoy it !

Hi Candyman

Your analysis of the bike before the Power Commander was fitted is no where even close to the stock motorcycle performance, I think you must of had an issue with the bike and in the process of fitting the Power Commander you have either masked the problem or cured it.

Feel free to drop me a P.M if you have any further questions


To All

I need to point out once again that any unauthorised calibration work such as power commander fitments or incorrect calibration / exhaust combinations, as with any manufactures new vehicle, will void all engine related warranty claims.

Just for peace of mind I have taken a bike from our production line and given it a quick dyno run to ensure that we haven't got any issues. Please see the image below.

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Couple of things to bear in mind however.
1 - All dynos around the world will vary in the number given out based on all sorts of factors, even a simple software selection of which correction factors you select (note that we have used DIN, with Smoothing Factor 4 on a Dynojet 250i). However, I wouldn't expect this to vary more than 5 or 6 hp on a 961 commando at peak from dyno to dyno.
2 - The best way to use dyno charts is as back to back comparisons on the same dyno, i.e. Just because your bike pulls 55hp in one shop and then 65hp in a second shop it doesn't mean your bike gained 10hp because of what the second shop did, it just simply means that on one dyno it pulled 55hp and the other 65hp.
3 - I didn't have the probe connected to measure the bikes RPM, which (due to the way the Dyno software works) means the graph does't show a torque curve. (If your feeling board or up for a challenge and know a few measurements and ratios you could calculate the torque curve by knowing that I did the dyno pull in 4th gear )

The point I'm trying to get across however is that this is a standard motorcycle with standard exhausts, pulling at the wheel 74HP (on our dyno). We've done this with many different commando 961's and always get the same results of peak wheel hp of 72 - 76.

Hello Simon , Great information . Would you expect the peak HP to be higher on a 961 that has had the Motad shorties and re-map service done ? Is there any chance you can give us the dyno graph for a bike that has had this performed ? That way we can compare them . Keep the information coming ! Thanks , Tony .

Great info. Thanks for sharing Simon.

TonyA said:

Hello Simon , Great information . Would you expect the peak HP to be higher on a 961 that has had the Motad shorties and re-map service done ? Is there any chance you can give us the dyno graph for a bike that has had this performed ? That way we can compare them . Keep the information coming ! Thanks , Tony .

Click to expand...

Hi Tony,

For sure with the "Motad shorties" (long and short for off road use only) you release some horses, but more so in the mid range than the peak power area, but don't forget with the "Motad shorties" you have the benefits of looks, the slight weight saving and most importantly the sound ! (you get the sound with the long version as well).

We see about a 10 % bhp gain in the mid range with either the long or short off road silencers fitted.

Hello Simon , Does Norton or can Norton produce a Factory Racing kit someday ? This Kit should be sold as no warranty or after warranty OFF ROAD USE ONLY printed on the box... And can you raise the rev limit just a pinch as well ? Please ... Tony

Hello Simon , Here is my dyno graph , using CF SAE , Smoothing 5 and also a Dynojet but no model number. A 3rd gear pull , Just under 68HP .

I wonder if DIN vs SAE account for the lower numbers ? Clearly smoothing = 5 gives less ripple.

TonyA said:

I wonder if DIN vs SAE account for the lower numbers ? Clearly smoothing = 5 gives less ripple.

Click to expand...

I have been doing some reading about Dynos and wanted to share what I read. It said that DIN will read slightly higher than SAE , also less smoothing ( 4 instead of 5 ) will give a higher reading and the gear that is used for the pull. So , using 4th gear would have given higher numbers than a 3rd gear pull . The article said these differences could add up to 10 % . In that case 67.2 X 1.10 = 73.92 HP Tony

TonyA said:

Hello Simon , Here is my dyno graph , using CF SAE , Smoothing 5 and also a Dynojet but no model number. A 3rd gear pull , Just under 68HP .

Click to expand...

Hi Tony,

That looks bang on to me, overlays more or less exactly what I've got here.

TonyA said:

TonyA said:

I wonder if DIN vs SAE account for the lower numbers ? Clearly smoothing = 5 gives less ripple.

Click to expand...

I have been doing some reading about Dynos and wanted to share what I read. It said that DIN will read slightly higher than SAE , also less smoothing ( 4 instead of 5 ) will give a higher reading and the gear that is used for the pull. So , using 4th gear would have given higher numbers than a 3rd gear pull . The article said these differences could add up to 10 % . In that case 67.2 X 1.10 = 73.92 HP Tony

Click to expand...

Agreed, although the gear used should't make a difference to power output. The gear selection is aimed at using the ratio in the box that is closest to 1:1. Ball park average is its 1 gear down from top (top gear is often an 'over drive' gear) , next time you're on the bike put it in 4th, twist the throttle and watch the mph needle rise at approx the same rate as the engine rpm needle.

Bike engines convert fuel into a rotational force aka Torque. Power is simply the rate at which it can produce the Torque.

Power (KW) = Torque (Nm) x Angular Speed (Rads/s).

Gears decrease angular speed (revolutions per time) in order to increase torque output. Gearboxes cannot increase power output, merely transform it.

i.e. engine Speed of 4000 rpm but only 16 Nm Torque could be converted into wheel speed of 152 rpm but with 410 Nm of Torque

It looks like the peak torque is right around 6500 rpm and figures to about 48 ft. Lbs. Does that sound correct?

Glen

No , 5200 and 66