920 lightweight

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Ohhh - I'm a lumberjack and I'm okay
I sleep all night and I work all day!

...do you really wear women's clothing and press wild flowers?
 
I have notice recently that a number of riding boots have the "gear change pad" sewed to the boot upper are on both feet.
Our old machines must be having some effect on the market after all!
 
worntorn said:
Last I looked on the Triumph site there was a 36 page thread entitled " Which boots do you wear when riding your Classic Triumph"

Glen
Click to expand...
What has the world come to!!!
Black is the only colour for motorcycle boots
And motorcycle seats
Anything else is is window dressing !!!
 
Hi Glen,

I salute you to your achievement! Is there a thread where you presented the build?
I'd be interested in a weight breakdown. 150 lbs is an incredible weight saving! I guess the major contributing factors are rear wheel and the front end?

As for performance, I believe the alloy barrel will allow less expansion (less piston clearance while on the run) and a lower head temperature, improving the mechanical and thermal efficiency of the engine.
The dynamically balanced crankshaft may also contribute to more torque by reducing deformation work.

-Knut
 
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robs ss said:
I have notice recently that a number of riding boots have the "gear change pad" sewed to the boot upper are on both feet.
Our old machines must be having some effect on the market after all!
Click to expand...
My Norton branded Clark boots have that pad.

Not brown.

920 lightweight
 
mdt-son said:
Hi Glen,

I salute you to your achievement! Is there a thread where you presented the build?
I'd be interested in a weight breakdown. 150 lbs is an incredible weight saving! I guess the major contributing factors are rear wheel and the front end?

As for performance, I believe the alloy barrel will allow less expansion (less piston clearance while on the run) and a lower head temperature, improving the mechanical and thermal efficiency of the engine.
The dynamically balanced crankshaft may also contribute to more torque by reducing deformation work.

-Knut
Click to expand...
This is the build thread Knut.
I didn't start a proper build thread in the rebuild section, my mistake.
The bike is about 150 lbs lighter than the MK3 or 120 lbs lighter than a kickstart only Commando, so the weight reduction is about 120lbs.
The lightweight front end and wheels gave the largest reductions. Tubeless tires also helped.
The alloy cradle, ISOs and fuel tank knocked off about 20 lbs. The rest is in smaller savings, such as hollow bolts, lightweight seat etc. There is no centre stand, just a lightweight sidestand. Single very light instrument with a GPS speedo and electronic tach , no drive cables or drives. 5 ounce horn that is surprisingly loud. Lightened primary cover. Alloy belt drive with Barnett al.plates. Some titanium bolts ( thanks Ken & CJ)
All of those standard items really add up.
 
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worntorn said:
The lightweight front end and wheels gave the largest reductions. Tubeless tires also helped.
The alloy cradle, ISOs and fuel tank knocked off about 20 lbs. The rest is in smaller savings, such as hollow bolts, lightweight seat etc.
Click to expand...

Thanks, Glen. Did you fabricate a front engine mounting made of aluminum as well?
Which brand and model supplied the wheels and forks?
Did you widen the S/A for the fat tire?
I guess the barrel saved 1.5-2 kg as well!

Some time ago I weighed some triple trees. Comparing aluminum billet yokes to N-V steel yokes didn't reveal a large weight loss, but forged factory parts may provide a significant weight saving.

Did you recalculate the steering geometry (rake and trail) ? The 850 frame and triple tree are a bit tricky. I guess your front wheel is 18" ?

-Knut
 
Yes the front mount is Al. as well.
The Al. barrel is 8.5 lbs and
stock cast iron is 23 lb.
The front forks are from a 2015 GSXR 600. They are Showa Big Piston with anti-dive.
Wheels are new replacement front wheels for a 2005 GSXR 600.
The front Geometry is nearly identical to the Vincent Special I built a few years ago.
Wheels are 17"
No change to the width of the swing arm as the 120/90/17 fits. I modified the swing arm for the 22 mm hollow axle.

Glen
 
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Glen,
Are there any downsides to the alloy cylinders?
Thanks,
Mike
 
gortnipper said:
Crazy. It makes me wat to hunt down some STR cases and STS alloy barrels...
Click to expand...
I didn't think the stock barrel was this heavy.
For comparison, the linerless TGA barrel I am preparing for my 780cc shortstroke weighs in at 4.55 kg or 10.03 lb.
The thicker casting end enclosed through-bolts make it less vulnerable to thermal and mechanical deformation, I hope.

- Knut
 
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YING said:
Glen,
Are there any downsides to the alloy cylinders?
Thanks,
Mike
Click to expand...
On paper they appear superior in that the engine will cool better.
In reality there is a concern that the liners may go out of round over time. There have been a couple of reports of this with long term usage of the Maney alloy barrels. One owner of a Commando with Maney 850 alloy setup switched his engine back to cast iron after a few thousand miles. There have also been 920 cast iron setups that have been put back to stock after similar problems. So on that basis aluminium doesn't look great nor does the 920 oversize. I have both in one bike!

The other worry is the cam followers running in an aluminium tunnel rather than cast iron.

On the plus side, Roger at RGM says his 81mm kit will holdup well.
Ludwig has put quite a few miles on his 850 Al. barrel, so time will have to tell. I'm looking at the 920 alloy barrel as an experiment, just like the rest of the bike.

Glen
 
That 920 must be a fun ride after taking 120lbs off it. Good thing you have some countryside close by where you can actually turn the wick up.

Did you find the wider tires on smaller rims slowed the steering a little compared to your skinny tire 19-inch wheeled bikes? Or did it all just work for you right off the bat?

I'm asking cuz I switched out a 19 inch front with a skinny tire for an 18 inch with a wider tire and immediately noticed a change in the effort require to drop into a turn with 18's on both ends. Could also have something to do with the rotating mass of a heavier larger 4LS brake wanting to stand the bike up. The rim difference is only 1/2 inch height, so in my case it is probably the big brake. Either that or reverse placebo effect, or my steering damper is turned up too high making the entire bike feel funny.

Below is for the part of the thread that was not on point. I like those leather boots gort. Very classy.

I need to get new boots myself, but in the meantime, I wear black Teknic boots for longer rides. Shift pads on both boots. The boots are left over from when I had the quick stuff with the monkey humping a football seating and high rear sets. I wear hiking boots for short test rides.

I like the man bun style boots. Probably go well with lilac flavored ice cream at a diversity gathering. I tried growing a sculpted beard. Got to around 6 inches, but my wife suggested I should move into the garage. The garage isn't big enough, so I decided to cut it back.
 
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