View Full Version : The Rorty R11 Stiletto single-seater buggy

03-29-2007, 10:42 PM
Finally! Well, here it is, the new [url=http://www.rorty-design.com/content/R11_Stiletto_manual.htm:3ni384xs]R11 Stiletto[/url:3ni384xs] single-seater, short course style buggy. Although the R11 Stiletto shares some of the R16's parts, the chassis is unique, with the exception of the front bumper!*It was just too difficult to redesign the front bumper. http://www.minibuggy.net/modules/Forums/images/smiles/whistle.gif

The R11 specifications and dimensions are as follows:

Brakes – Front – Wilwood BDS callipers with 254mm [10"] diameter discs.
Rear – CNC twin piston calliper with 203.2mm [8"] diameter disc.

Chassis – Spaceframe constructed from 1.5" OD DOM steel tube.

Engine – Any 2, 3 or 4 cylinder, chain-drive, motorbike or snowmobile engine.

Steering – Aftermarket rack and pinion with 1.3 turns lock to lock.

Suspension – Front: Double, unequal length, tubular A-arms, with Fox shocks. Travel; 533mm [21"].
Rear: Double, unequal length, tubular A-arms, with Fox shocks. Travel; up to 508mm [20"].

Tyres – Front: BF Goodrich 30X9.50R15C All Terrain.
Rear: Goodyear Wrangler MT/R 31X10.50R15LT.

Wheels – Front: 15" x 7.5", .190" aluminium.
Rear: 15" x 8.5", .190" aluminium.

Ground clearance – 339mm [13.3"].

Overall height – 1628mm [64"].

Overall length – 3577mm [141"].

Overall width – 1981mm [78"].

Track – Nominal 1733mm [68"].

Weight – 465 kg [1025 lbs] (depending on engine size, wheels etc.).

Wheelbase – 2438mm [96"].

The R11 PDF Stiletto manual contains:

• 171 pages of clear instructions and supporting images.
• Fasteners list.
• Materials list.
• Parts list.
• Suppliers list.
• 109 CAD drawings.

For a short while I will be offering the usual AU$20 discount to existing customers, with a AU$25 discount for new customers purchasing both the R11 Stiletto and R16 Shotgun manuals.

03-30-2007, 01:10 AM
Rorty another top design.
Quick question you've got a R6 *R11 *R82S *and the R16 what happened to the R7 R8 and all the other inbetween numbers??

03-30-2007, 01:25 AM
Thanks for the kind words!

I've actually got from 1-19 (not counting commissions). Some are ancient, some are only 3D models, some are complete and ready to publish and some probably won't see daylight for a while.

One is actually a Class 1 desert car that was a project I was working on for a guy in the US, but he changed his mind and decided to race some sort of boat instead. He paid me, so I'm not in any rush to do anything with it.

03-30-2007, 11:16 AM
Hi Rorty

Congrats on the newest edition - Cool Stuff.

Is the weight of R11 1025 lbs [depending...] based on some assumed engine, tire, etc weights?

The R11 and R16 specifications indicate a weight difference of 55 lbs, did you use the same assumptions on both buggies for the engine, tire, etc weights?

I'm interested in the estimated weight of the R11 frame with suspension, steering, RPM box and drive axles. (no engine, seats, tires wheels).

And while your pencil is sharp and your calculator is warmed up…
What is the weight difference of the R11 and R16 in the condition listed above (if not 55 lbs)

Thanks for all the hard work.


03-30-2007, 12:09 PM
Nice work Rorty!

Very racy and I'm betting it will be a killer on and off the track.

03-30-2007, 03:32 PM
Thanks all for the kind words.

Frank, yes, the weights of both cars are based on an average 1000cc engine weight of 145.5 lbs (Fireblade 143 lbs, GSXR 1000 145.5 lbs, ZX10 148 lbs and R1 148 lbs). The Busa engine weighs just over 180 lbs.

As for the rest, I'll have to get back to you because all the other info is on my workstation. It's Saturday morning here and I haven't fired it up yet! Feel free to remind me if I forget.

03-30-2007, 03:39 PM
she is about 20" to long for stadium racing, 120 is the so called rule there...

04-02-2007, 03:28 PM
hi rorty,the stiletto looks great.i have a aprilia rsvr 1000 v twin engine ,was wondering what ratio fnr box would you use and what kind of performance to expect.giving the size and weight of the buggy

04-02-2007, 03:36 PM
blokhead, thanks for the kind words. You'd probably want an overall ratio of between 6:1 and 6.5:1, but the best bet would be to talk ratios with Dan when you're buying the FNR.

With an RSVR 1000, the performance would be mental!

04-02-2007, 03:44 PM
I'd say you can get away with the 4.6:1 setup with that engine. *The torque it produces should be insane. *If you run a taller tire - say closer to 31 or 33, you might think about a slightly higher ratio like the 6:1

With a shorter tire - say 26" tall, the 6:1 would make the thing extremely quick, but top end will probably be limited to about 110 - then again, if you've ever been in one of these smaller cars at 100, you'll realize that anything above about 85 starts getting pretty sketchy and above 95 - 100 is scary. *Cool, but scary!

Go with the 6:1 and smoke everybody off the line.

04-02-2007, 04:01 PM
What I was referring to was the overall ratio and not the FNR internal ratio, which upon reflection (I was thinking of the shorter tyres), with the specified 31" tall tyres, would be closer to 7:1. Check out what size engine sprockets are available for the Aprillia first and then have a chat with Dan.

I agree, 100 MPH is plenty for one of these cars and you'll seldom even make that....no matter what your buddies say!

04-02-2007, 06:19 PM
I think 7:1 is going to be too short - you won't have any use for 2nd or maybe even 3rd. (If it's a 6 speed).

If you can overdrive the input shaft it might let you use the 7:1, but just from what I've seen Jay use in the Coyotes, with a Busa power plant, the lower ratios offered by Dan will let the engine be more flexible and make the bike tranny be "wider" if you will. *It will allow you to use the first couple of gears.

Jay started out with a higher ratio box and finally ended up working down to the 4.6 (or 4.??) before the engine was usable. *Since I would believe the Aprilla to have equal if not more torque than the Busa, the lower ratio tranny will be better.

As you've pointed out, this is probably a good question to toss at Danno.

04-02-2007, 07:06 PM
Don't forget this is a track car and acceleration is the goal and not top speed. First gear would ideally be a "pits & trailer" gear. Second gear then becomes "first" and there's no danger of grabbing neutral on the way from actual first to actual second.

If the car isn't going to be used as a track car, then a lower ratio would be more suitable for wider ratios and general driving in the desert and dunes with higher overall speeds.

04-04-2007, 05:47 PM
As for the rest, I'll have to get back to you because all the other info is on my workstation. It's Saturday morning here and I haven't fired it up yet! Feel free to remind me if I forget.
Hi Rorty,
Have you had any time to ponder my questions on the R11 and R16 weights (thank you for the info you had right away)


04-04-2007, 08:25 PM
Thanks, I had forgotten. The R11 chassis including all brackets, A-arms, rack, nerf bars etc. is as close to 380 lbs as makes little difference. The four shocks I'm guessing weigh close to 75 lbs and you could add to that another 15 lbs for the major fasteners.