Posts by tag: 500cc Gran Prix

Moto Guzzi October 3, 2017 posted by

Flawed Masterpiece: 1955 Moto Guzzi 8C “Otto Cilindri” for Sale

Fans of modern machinery may not understand how Moto Guzzi, with their clunky driveshafts and pushrod v-twins, is allowed even a grudging membership to the sportbike club. Of course, a look back a bit further shows Guzzi was very successful in a variety of racing classes throughout the 40s and 50s. But they wanted to play in the premiere 500cc Grand Prix class with Gilera and MV Agusta, both of whom used inline fours as the basis for their race winning machines. Guzzi knew that, in order to compete without years of development, they needed to try something new that would increase power without increasing weight, and they did it with the "Otto Cilindri." Long and low, with a period "dustbin" fairing that made it look like a wheeled torpedo, the bike was as terrifying for riders as it was for the opposition.

The brand new 500cc Grand Prix machine was powered by a brand new V8 engine... Let's just stop there and let that sink in for a moment. A motorcycle. Powered by a 499cc V8. That's not a euphemism or a catchy name. That's "V8." As in "has eight cylinders." It also had four gear-driven overhead cams, eight Dell'Orto carburetors, liquid cooling, oil stored in the frame, and weighed in at 326 pounds with the full fairing in place. If this thing had actually finished a few more races, it'd be in the pantheon of all-time greats. Unfortunately, that's why this bike is a glorious footnote, instead of an unforgettable masterpiece.

The main issue was that the 78hp produced by the ferocious engine was too much for the tire and suspension technology of the time. The bike was capable of very nearly 180mph, but period testing and races were plagued by crashes, with riders eventually refusing to pilot it until it stopped trying to actively kill them. Which is saying something, since basically the entire sport of motorcycle racing was trying to kill riders during this period. Handling was likely compromised by the engine being set too far back in the frame. This was common practice at the time, ostensibly to increase traction at the rear, but put too little weight on the front for stability and handling. Mechanical failures didn't help: the bikes overheated and broke cranks with alarming regularity.

The Otto Cilindri was terrifyingly fast, even considering the mechanical and handling problems: it actually finished fourth and fifth at the 1957 Isle of Man TT, with the fourth-place bike running on 7 cylinders. Considering the ambition of the project, the reliability and handling challenges are no surprise and it is likely that, with time, the bike would have realized its full potential. Unfortunately, Moto Guzzi pulled out of Grand Prix racing in 1957, so this project will always be more of an interesting "what if."

From the original eBay listing: 1955 Moto Guzzi 8C for Sale

Moto Guzzi 8C "Continuation"

Model year 1955

Rare opportunity to acquire one of only 7 "continuation" built in 2001 by Todaro/Frigerio from original Moto Guzzi Factory drawings.
This is the last built, fitted with ORIGINAL crankshaft, pistons and timing gear.

Fully working.

 

Parade race and collect.

Bike is currently located in Italy, 33080 Roveredo in Piano, but i can get them delivered all around World at cost, no problem.

Hat tip to Odd-Bike, where I originally saw this bike posted. Just a handful of the V8 race bikes were ever built, and only two of those remain. But in the early 2000 a small run of seven "continuation" models were built to the original's exact specifications, including the magnesium engine cases and brake drums, although the continuation bikes will likely benefit from improvements in metallurgy. Note that the seller claims this is "fully working" which means that, not only is this a historical artifact, it's also an actual, rideable motorcycle. I'd bet this is one of the rarest, most exotic and historic machines we've ever featured on this site, although it's a bit older than our usual focus. Just how incredible this engine was in concept and execution is beyond the scope of this post or my limited engineering knowledge, but if you've never heard of this thing, it's worth checking out additional sources.

-tad

Flawed Masterpiece: 1955 Moto Guzzi 8C “Otto Cilindri” for Sale
Suzuki December 28, 2015 posted by

As Seen on CSBFS: 1982 Suzuki RGB500 Mk7 XR40!

1982 Suzuki RGB500 for sale

This gorgeous Suzuki RGB500 is for sale in California and Tad wrote it up on our sister site, Classic SportBikes For Sale. Here is an excerpt:

Ridden by such luminaries as Barry Sheene and Randy Mamola, the two-stroke Suzuki RGB500 was eventually developed into the dominant machine you see here, but it went through a significant evolution following its introduction in 1974. As you’d expect, the bike always had power to spare, but high speed handling was suspect at first.

By the time the 1982 bike rolled around, Suzuki had moved to a “square” 54mm x 54mm engine for a grand total of 495cc. It was far more reliable than previous iterations and featured the same stepped cylinders seen on the RG500 Gamma road bike that had the rear pair of cylinders raised up slightly higher than the front pair. With a dry weight of 292lbs and 120hp, the bike could reach speeds of up to 170mph, which is pretty terrifying considering the tire technology of the time.

dc

1982 Suzuki RGB500 for sale on eBay

s-l1600 (2)

from the seller's listing:

1982 RGB500mk7 XR40

This is not a street bike folks, this is the real deal, A real factory Suzuki GP road race bike... This bike has the stepped square 4 motor with magnesium crankcases, magnesium carburetors, and dry clutch... The Chassis is loaded with magnesium, Titanium and Aluminum, stuff you would expect to find on a factory race bike... First year of "Full Floater" monoshock suspension... Chassis number 42 motor number 49... Bike is in unrestored, excellent condition, just as it rolled off the race track in 1982... This bike from part of the team Heron Suzuki stable, bike has been museum store in Japan since last raced... these bikes are tad more rare than a TZ750 and much more powerful... It is the perfect bike to dominate vintage racing and is eligible for the "classic TT" in Phillips island This is a rare opportunity to own a real factory GP bike, don't let it slip by, you'll be sorry if you do...

s-l1600 (1)

Suzuki January 8, 2014 posted by

Smoke Squared! 1983 Suzuki RGB500 in Oklahoma

1983 Suzuki RGB500 for sale

A quick browse of the archives serves as a great reminder that this isn't an "ordinary Suzuki RG500", it's a full on factory racebike, the RGB500. This example has a rather thin description but like many bikes on eBay it could be listed to see what interest may be out there and further investigation will be required. For instance the ad states that it may have raced in the Isle of Man TT but can't yet prove that. Nonetheless, these opportunities don't come up that often.

dc

1983 Suzuki RGB500 for sale on eBay

from the seller:

This very rare motorcycle was purchased by us here in the US, we were told it was raced at Isle Of Man, but we are unsure of the team it was raced for. Great vintage shape as you can tell from the pictures. This motorcycle has been on display for many years and has not been ridden/started during that time. This is the same kind of motorcycle that piloted Barry Sheen to many GP wins!

Smoke Squared! 1983 Suzuki RGB500 in Oklahoma