Reduce unsprung weight

Light wheels are worth it.

Forty or fifty years ago, the lightest commonly available rims were "valanced" (shouldered) Borrani Records, then Akronts. Akronts were heavier but preferred by the dirt bike guys because they were stronger. Then the Japanese came in with their unvalanced, or shouldered, forged alloy rims that were stronger but MUCH heavier. The dirt guys loved them because they were strong AND they didn't hold dirt behind the shoulder. The roadracers, before the bikes' power levels went up into triple digits and especially before hanging off (side loads) took over, all preferred the Borrani Records. Light gauge painted spokes with alloy nipples were also common; plating weakens the metal, that's why they lightest wheels sported painted spokes.

I recently bought a Chinese knock off of a Borrani/Akront and it is both thicker in section and disappointingly heavy.

I recently learned that the only US distributor for Borrani is Buchanans in Asuza, CA; if I can't straighten my bent Borrani, then I plan to buy a rim from them, assuming that the re-pop Borranis that they now sell are as light as they were back when.

It's not just how light they are, but where the weight is located on the wheel too... at least for certain aspects of the physics. When considering the force applied to the bike frame and rider, where the weight is located on the wheel, doesn't matter. When you consider the energy needed to impart spin in the wheel, and the gyroscopic effects of the wheel, where the weight is located, matters very much...

Needless to say, physics isn't always in line with our intuition... if you watch the video I posted the link to, there's some non-intuitive stuff that is surprising.

Dances with Shrapnel said:

Good information Time Warp and thanks. 1.47 lbs is significant. Would it be fair to say there would be a similar or even greater weight savings between a steel and aluminum 2.15 or 2.50?

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I do not have a 19 inch Borrani handy but just weighed a 2.15 WM3 18" at 3.95 lbs. (1973 Moto Guzzi fitment)
The weight I had for the 1.85" 19" shouldered alloy was one of Don Penders rims.

Per https://www.accessnorton.com/NortonCommando/what-do-wheels-weigh.21895/page-6

Excell flanged WM3x19 alloy rim – 2.18 kg. (4 lbs. 12.9 oz.) per APRSV
Stock steel WM2x19 rim – 2.53 kg. (5 lbs. 5.2 oz.) per APRSV
Dunlop WM2x19 steel rim – 2552 g. (5 lbs. 10.0 oz.) per gortnipper
Jones WM2x19 steel rim – 2662 g. (5 lbs. 13.9 oz.) per gortnipper

Bare wheel with bearings
MKIII Commando 1.85x19 wheel – 12 lbs 7.2 oz.
Excel shouldered alloy WM3-19, 8/9 gauge SS spokes, disc hub, bearings, spacers - 11 lbs. 1.8 oz. – per gortnipper

gortnipper said:

Per https://www.accessnorton.com/NortonCommando/what-do-wheels-weigh.21895/page-6

Excell flanged WM3x19 alloy rim – 2.18 kg. (4 lbs. 12.9 oz.) per APRSV
<snip>

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I think we need to review the alloy rims in more detail before a conclusion on weight advantage can be drawn. For instance, how come the Weinmann rims are so light? Furthermore, if weight advantage is their merit, why are specific weights and details of their design so hard to come by?

-Knut

Weinmann primarily make lightweight bicycle rims, since the 30s. So, I would guess they focus on designs that favor reduced weight over ultimate strength.

Their rims were used on BMWs in the 50s and 60s I think (dont know till when). I have read that early Weinmann alloy rims had a shallow valence as opposed to the later ones, which leads me to believe the above is true.

ludwig said:

Edit :
Posting it here made me wonder if that is really so , so I checked a few old shocks , and the difference is small :
damper rod + piston can be nearly as heavy as the damper body with oil or gas , depending an material used , so the orientation of the damper body is less important than I intuitively tought .
." Meten is weten " , like they say in Dutch ..

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Yes, indeed: measuring is knowing.

As of curiosity, how much does one of your Marzocchi weight? As I stated higher, a Fournalès oleo-pneumatic unit is about 900g or 2lbs.

http://www.mawsolutions.com/html/maw_prices.html

Always good to know whether or not you can run with the big dogs. A quick look here will show that
most of us are likely to look elsewhere. Naturally, all the premier manufacturers are going to be
fairly close in price. You rarely get more than you pay for.
Oh well....

xbacksideslider said:

I recently learned that the only US distributor for Borrani is Buchanans in Asuza, CA; if I can't straighten my bent Borrani, then I plan to buy a rim from them, assuming that the re-pop Borranis that they now sell are as light as they were back when.

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I had been tempted to get a pair for my 1973 750GT but there seems to be some question of where they are really made.
Made in China perhaps with some input in Italy to say they are made there might be the case.
One report I read said they are not that great given the cost, who knows, but it put me off.
The Excel's are probably much higher quality but only go to a 2.15 width but even those are close to US$600 a pair. (iirc)

Time Warp said:

I had been tempted to get a pair for my 1973 750GT but there seems to be some question of where they are really made.
Made in China perhaps with some input in Italy to say they are made there might be the case.
One report I read said they are not that great given the cost, who knows, but it put me off.
The Excel's are probably much higher quality but only go to a 2.15 width but even those are close to US$600 a pair. (iirc)

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They are made in China and shipped back to Italy for distribution. The old wheel builder in AKL who did my Excels is not too impressed with the new Borani and dropped them. His feedback was the seam was poor, and overall too many of the rims were too far out of round.