Triumph Bonneville 750 Nostalgia Drag Bike Excalibur

Meremere Motorcycle Drags 2015

2015-01-20T18:02:00.000-08:00

The annual Meremere motorcycle drags was held on a swelteringly hot day in January at New Zealands' Meremere dragway. About 150 bikes turned out for the fun day event, mostly street motor cycles.

Image by Matt Wooding

Image by Popeye Pics

Traction proved to be a problem with bike only managing 11.4 as best E.T. Initially clutch slip was

an issue probably from sitting unused for some months. Gradually it came back to us and then it was a case of trying to tune it to the slippery surface. Followers will recall Excalibur runs a lockup clutch with adjustment available for spring pressure plus centrifugal pressure.

Classic Club run to The Shed ~ Museum

2014-06-05T01:43:00.001-07:00

Excalibur was the center of attention when the Waikato Classic Motorcycle club came visiting. Pictures were published in their June newsletter. About ten bikes turned up on the day. The visitors were treated to morning tea. There was lots of motorcycle memorabilia on display and the talk was lively. Click link below for Newsletter PDF.
Waikato Classic Club Newsletter

Team Excalibur celebrates Competition Bike victory in the shed museum.

2014-05-18T16:10:00.000-07:00

Jamie with the trophy display.

A 100 year old veteran V-twin JAP presides over the event

Wing commander V-twin Enfield and Lieutenant Colonel Ariel Square Four were also in attendance.

Excalibur sits on the table where it was made.

The 4 season trophy haul amounts to 21. Excalibur has claimed Comp Bike championship twice, the NZDRA or IHRA Nationals twice plus the most coveted of all, Mr. Dragracer trophy.

The season concludes with prizegiving

2014-05-11T03:16:00.000-07:00

Prizegiving on 10May2014 at Pukekohe Hotrod clubrooms.

Jamie with a few words for the crowd.

Excalibur features again on the clubrooms wall as a permanent part of history.

Excalibur on display at NZ's only "motorcycle only" swapmeet.

2014-03-29T20:12:00.000-07:00

30March2014 was the annual Waikato Classic club swap meet. It's the largest "motorcycle only" swap in the country. The invitation to display Excalibur gave an opportunity to talk drag racing with fellow motorcycling enthusiasts..
The bike, fresh from the seasons' combat was on show from 7am till noon.

Display board with photographs.

Excalibur souvenir flyer with website addresses was available as a free giveaway.

NZ Nationals 2014

2014-03-17T01:19:00.001-07:00

The 2014 NZ Nationals was planned as a two day event. A cyclone caused wet conditions on Saturday so the day was abandoned. Sunday was forecast for improving weather and race organizers were determined to proceed if at all possible.
There was a poor turnout from competitors and spectators due to the conditions. However it was the final round and Team Excalibur did have a mathematical chance of championship victory. It wasn't to be as Jamie red lighted in the semi finals.
Best time of the day was 11.02 coupled with the second best speed on record of 118.2mph

Comp-bike series championship win for Excalibur

2014-03-03T14:18:00.001-08:00

The Triumph won by 270 points from the nearest rival to claim the championship victory.

The bike finished the series a mere 20 points behind "Most successful dragracer of the season" winner.

The airshifter trialed before Comp4 was abandoned due to problems getting it to work reliably.
A misfire in the semi finals saw Excalibur beaten to the line by .03 of a second.

"Petrolhead" Magazine fantastic picture of Excalibur wheelie!!

2014-02-16T22:26:00.000-08:00

Here Jamie was trying the technique of trailing his feet however it resulted in a surprise wheelie. It seems that moving some of his weight back was enough to aviate the front wheel.

Excalibur snatches win at Comp3 twilight meeting

2014-02-15T15:27:00.000-08:00

Excalibur snatches the win at Comp3 1/8mile "Night of Thunder", Fram Autolite dragway, Meremere NZ!! The bazaar sequence of events that enabled Excalibur to seize the championship lead began when championship leader (Greg Pratt) failed to turn up. Excalibur started the twilight meeting struggling with air shifter gear change issues, however luck went our way in each of the elimination runs. Also we were top qualifier. Before the final pairing against Ian Hilder's "Rice Rocket", the Prostock bike suffering ECU problems eventually failing to make the start. This forfeited the winner's trophy to the Triumph with Jamie only needing to appear, which he did with a convincing 6.87 @ 97.6mph for the 1/8mile.

Pic taken at earlier Meremere motorcycle drags 2014

Jamie staging at twilight

The engine was fitted with the thinnest head gasket I made from an old copper toilet cistern!! It's about .015" thinner so the compression will be approaching 10:1. The pistons required relieving at the squish band for a 1mm clearance. Also the inlet valve-clearance-to-piston was tweaked.

A rare new-old-stock pair of +.020 10.5:1 compression pistons was purchased. The downside is that they are 1mm (.040") smaller than current so engine capacity would decrease but the extra power from added compression would more than make up for it. Another issue is finding a barrel set at std (or +.020 in good condition). Naturally I'd be cutting the fins off. Ideal would be a fin-damaged std barrel that could be freshened up to size.

The air shifter proved to be quite a battle with a variety of ECU settings trialed. Kill time was progressively widened, more/less leverage, lubricated clevises, larger air line, etc, all to no avail. Finally the drive chain was tightened up tighter than any normal rigid road bike would be. The advise received was to make it tighter than would seem reasonable. This appears to be the solution at the time of writing.

Lowering the footpegs showed decided advantages. It allows staging of the bike in the absolute vertical position unlike previous "lean to the left" posture nicknamed "tripod". A minor issue is the clutch drag which becomes an issue in the higher rev range. With toes on the ground and heels on the pegs, it doesn't allow much holding of the bike from rolling forward. Hence lower staging revs are used. Lowering the pegs still further is being planned.

Planned upgrade before Comp4 at 2March is "oil-in-frame". The upper right frame tube will be utilized as the oil tank with strainer, filler cap, return line, breather and sight-level-glass fittings.
Ironically, an original ('71-onwards) Triumph 650/750 uses oil-in-frame so it's a kind of 'retro fit' in a manner of speaking.

Can Excalibur win the Compbike championship, leading the points with one round to go? Check back shortly for official points tally and at 2March for championship result..

Please see Excalibur Facebook page: https://www.facebook.com/ExcaliburTriumph

Meremere motorcycle drags 2014

2014-01-20T18:32:00.000-08:00

Meremere motorcycle drags presented Team Excalibur the opportunity to experiment with settings and a new air shifter in a way not otherwise possible at a Competition meeting.

A great surprise and thrill was the official T-shirt for the days' event featuring Excalibur with Jamie pulling a wheelie in a previous comp meet.

New T shirt design released at the weekend.

Jamie riding at the previous Comp meet against a Vrod Destroyer.

Pit box for the Meremere motorcycle meeting. Other bike is Orbs' weapon, a GM V6

Best time on the day was 11.008 making this the 2nd best on record for the vintage '73 Triumph Bonneville powered lightweight dragbike.

Excalibur on top at comp2

2014-01-11T21:04:00.000-08:00

Team Excalibur emerged on top at Competition 2, claiming scalps on its' way up the elimination ladder. A best time of 11.009 was recorded which is the second quickest on record for the Triumph. In the final pairing the opponent red-lighted, gifting the victory to the T140. Just as well for us as Jamie missed a gear, managing only 11.4 for the run. In the heat of competition, mistakes are common. This time it "went our way"...

A retro tail piece was made from polystyrene and carbon fiber by rider, Jamie.

A pair of 4wire LS2 coils were fitted and configured in the Microsquirt ECU. A jumper on the MS board was reset to move the software from direct coil control to 5V trigger signal as LS2 have inbuilt igniters. Very fast charge time means a 4ms dwell is required.

Season 4, Comp1 then Spring Nationals

2013-11-23T23:59:00.002-08:00

Excalibur run at near record pace at the Spring Nationals posting 11.01 ET on the first pass of day one. The weather was very hot for November and wind direction changeable. A number of adjustments were tried but times couldn't eclipse the early marker. Competition saw Excalibur climb to the semi finals against Greg Pratts' Vrod Destroyer. Jamie lost the run with 11.19 ET red light and finished the day third.
Changes made before/during the meetings were:
Gear ratio raised to 4.60:1 from 4.63:1
Ignition dwell settings 5ms, 6ms and 8ms.
Compression was raised by a small amount.
New inlet valve guides.
Steel head steady trialed.

The teams' new T-shirt design which is also available to supporters

2013-05-28T06:49:00.001-07:00

A couple of pics out of the photo collection.

Excalibur riders' eye view.

Excalibur wins 2012- 2013 National championship

2013-04-25T20:14:00.000-07:00

Excalibur wins the IHRA Comp Bike National series championship.

The final round concluded on April 28 after twice being rained off at New Zealands' Meremere dragstrip. The weather was fine with a light headwind.

In the final pairing, Jamie powered the 750 Bonneville drag bike to a respectable 11.08 @ 115mph. In addition, a new class record of 10.98 and 118.9mph was claimed for the record book.

The ambient air temperature was notably cooler than the previous meeting so it was decided to apply aluminum tape to the cooling fins of the cylinder head. The thought is that the T140 engines' compression ratio is a bit too low to generate enough effective heat thereby reducing horsepower.
A clue to the phenomena is that an 02 sensor shows the mixture richening with higher revs. Also the bike has recorded record times for each subsequent March, the hottest temperature meetings.

Next weekend is the end-of-year prize giving at Pukekohe hotrod clubrooms. A week later will be the annual Excalibur celebration at the place where the Bonnie dragbike was made.

NZ Nationals action! Excalibur sets new marker.

2013-03-16T21:57:00.000-07:00

IHRA's NZ Nationals at Meremere was a 3 day affair.

Day one gave each competitor a single qualifying run between 4pm -6.30pm. Jamie re-acquianted himself with the T140 and the initial run showed all was well.

Day two was hot with a light northerly breeze from the tropics. There was a question over the weather, as a storm was forecast to hit the following day. It was decided to bring forward the eliminations and hopefully conclude the competition early on day three.
A new personal best (PB) time and mph was recorded during the days' qualifying. The new record marker is 10.98 ET @ 119mph. This will be the new Index for the PCB class from next season.

Day three was set to run the semis and the finals with 4 bikes remaining in the competition.
2 Hyabusas, a Vrod plus Excalibur T140. Sadly persistent rain prevented any racing and the meeting was called off at 1pm. A "rain date" is believed to be 21st April at the time of writing.

Each of the runs at the meeting was faster than National index. Our goal of a 10 second run has finally been achieved.

The coolest thing is that Excalibur has a chance to win the Comp bike meeting plus be the winner of the championship! It has come down to one of the Hyabusas or Excalibur. Check back soon to see if the vintage '73 T140 can beat the Hyabusa for Comp bike honors.

John's 650 chop at our pitbox during qualifying.

Settings for meet:
Shift light 6100rpm
Rev limiter 7000rpm
Mph@ 6000: 104.5
Mph@ 6500: 113
Drive ratio: 4.63:1
Ign timing: 38'

Comp4, series final round, Feb 2013

2013-03-04T02:18:00.000-08:00

Team Excalibur entered the final round with a mathematical chance of a championship win.
Rain delayed the start with one round of qualifying to sort the bike. We had the Microsquirt box fitted which was controlling ignition, shift light and rev limit.
The semi finals pairing against Greg Pratts' mighty Vrod Destroyer was lost due to a red light. The run gave Excalibur its' best all time ET: 11.079 @ 115.8mph.

Excalibur was placed 3rd for the day. As of writing it appears that we are 3rd in the championship.

Comp3 night drags

2013-02-10T16:46:00.000-08:00

Jamie takes 3rd, most importantly he eliminates early championship title contender Greg Pratt riding the mighty Vrod Destroyer in the first pairing. It will come down to the last round Comp4 and any of 3 riders can take the title.

Pic by Maria Panova

Youtube footage at twilight of Excalibur vs Vrod Destroyer. Hold onto your hat!!

The clutch lockup has us puzzling over the settings. Either the clutch will be inconsistent as part of its' character or the rider needs to relearn it. Also a .015" thinner headgasket was used for more compression. A best time for the 1/8mile on the night 7.1 @ 93mph.

Wheelies!!

2013-01-25T22:22:00.002-08:00

These are a few pics that came from Comp2. Adjustments to the clutch lock up will solve the wheelie issue though it did prove a crowd pleaser!!

Comp2 Jan '13, runner up

2013-01-13T17:19:00.001-08:00

Excalibur in readiness for action at Comp2, Meremere, Jan 13 2013. A 18 x 4" drag slick has been fitted and guard/seat moved to allow the extra clearance for the bigger tire.

A lock up clutch was adapted from a Yamaha Banshee. The hope here is that the 2-stage locking of this clutch will enable more consistent launches without excessive wheelie.

The result from Comp2 was a satisfying runner up spot with a trophy and certificate..

Specifications as at Jan 2013

2013-01-03T15:30:00.000-08:00

Excalibur, Triumph Bonneville '73 nostalgia dragbike specs. @Jan 2013

Frame: Chromoly 1" dia x .050" wall thickness, tig welded.
Forks: Modified FXR150, 33mm stanchions, shortened
Front wheel: KDX200 hub & disc with spoked 18" WM2 alloy rim
Rear wheel: WR250 hub & disc with spoked 18" WM3 alloy rim
Bodywork: Rear guard & seat is carbon fibre, bullet-nose is alloy
Brake calipers: Nissin motocross, single acting
Bore & stroke: 77.5mm x 82mm (773cc), lightened T140 barrels
Carbs: Amal mk2, 30mm, 650 mains
Fuel: Methanol, 600ml tank capacity
Oils: Motor; castrol R (400ml), Gearbox; ATF (500ml)
Oil pump: Stock 650/750
Valve gear: Stock valves & springs with lightened rockers
Pistons: Stock T140 Hepolite balanced
Compression ratio: 9.7:1
Exhaust: 1.5 inch O.D., 37.5 inch long
Crank: Stock T140
Conrods: Stock T140, balanced
Crankcases: Stock 1973, RH gearshift, matched pair.
Primary drive: Chain, duplex 29/58
Clutch: Hyde, dry, 7 bonded plates
Gearbox: Stock 5 speed, lightened selectors
Cams: Inlet; Stock T140, Exhaust; stock T120, stock T140 camwheels
Ignition: Boyer Bransden electronic mk3
Battery: 16v Lithium Polymer, 1000 mAh
Gearing: 4.32:1 overall
Weight: 95kg (209 lb)dry, 96kg (211 lb)wet
H.P. Approx 72hp, according to ET vs weight online calculators
Best 1/4mile E.T. 11.1 March 2012 NZ Nats
Best 1/4mile speed: 117mph Nov 2012 Comp1
Engine builder, design concept, technical detail: Pete Morrison
Rider from this season: Jamie Flavell
Frame and exhaust fabrication: Jamie Flavell
Pitcrew: Pete, Orb, Peter.
Sponsor: H.D. Cycles, Hamilton, N.Z.

Mid season update

2013-01-02T16:27:00.000-08:00

I have 10days before the comp2 meeting. I need the tire, lock-up and the ECU working by then.

The tire should be straight forward although the rim on the bike is a WM3 (2.15") while M&H claim a WM5 (3") is correct but a WM4 (2.5") would do. They say no to the suggestion of WM3. The 2 bikes I know that run this slick have them on WM3 so as a last resort I'd go with WM3 as well.

The lock-up appears to be easy too with some careful milling of the 3 holes to accommodate the Triumph stud pattern. Should the adaption turn to custard on the day I can remove it on the spot.

The ECU presents the greatest challenge by far. The software has a massive array of settings and variables. The upside is that if all goes well, we can enjoy a shift light, rev limiter, ign advance control. Also later on, air shifter, launch control and fuel injection. The learning curve is steep and I see lots of people struggle with electronics of this nature.

Spring Nationals, Jamie in action

2012-12-05T21:39:00.001-08:00

Jamie launching Excalibur during the Spring Nationals Nov 2012. Picture is from http://www.kiwidragracing.com
A M&H drag slick 18' x 4" is on the way from the U.S. The search has begun for a suitable rim. A lock up clutch is also on it's way and the hope is to adapt it to the stock Triumph clutch.

Spring Nationals win, comp bike bracket

2012-11-25T02:43:00.000-08:00

Jamie won the Nationals at Meremere aboard Excalibur with an awesome run of consistency that paid off.

Jamie

The Vrods qualified fastest but skilfull riding by Excaliburs' new rider, claimed the win. A most pleasing result gave winnings of a $300 purse which will be put toward a new drag slick tyre.

On the day, Excaliburs' times were approx 1/4 second slower than index but luck went our way in the semis with a win by a slim margin. The finals saw Greg Pratts top qualifying Vrod Destroyer redlighting.

Team Excalibur pitcrew member Orb with the bike in pitlane at Fram

Season 3, Comp 1, new speed record

2012-11-13T23:39:00.000-08:00

For those interested in the fortunes of the dragbike Excalibur I can report that the bike has exceeded the MPH record currently set last year. A new MPH figure was recorded of 116.98mph, eclipsing the existing record by almost 2mph.

To outline a bit more detail, my son who had never riden a Bonneville before, proceeded to do 11second runs consistently thoughout the 2day meeting at FramAutolite dragway. At the close of competition and after a dozen runs, Jamie had a best ET of 11.30 and had beaten my mph maximum. He finished 3rd in the competition. Jamie currently weighs in at 65kg (143lb) which is 5kg lighter than me at the time of my best ET.

Changes for season start Novemeber 2012:
Crankshaft: a 750 crank was fitted. Full weight. B/E-030.
Gearbox: updated high gear layshaft and shim endfloat. Shimmed camplate.
Exhaust: as before. (New smaller diameter under construction).
Cams: as before, T140/T120
Carbs: as before, 30mm
Compression: as before
Gearing: 42T rear sprocket. Overall 4.2:1
Valve spring pressure: 70
Other planned changes were delayed.

Jamies' 11.3 run

Team Excalibur Nats win celebration, the scene of the crime!

2012-05-21T15:24:00.000-07:00

The team plus supporters turned up on Saturday 19th to celebrate the Nationals win. The event was held in the workshop where Excalibur was made, referred to as "the scene of the crime". It was a cool day in May but plenty of beers plus nibbles were laid on.
A great night was had by all with plenty of talk about direction for the bike over the next season.

Next on the agenda is to strip down the engine and inspect. The crankcases haven't been apart since the bikes was first assembled 2 seasons ago. A 750 crank with the full flywheel is to replace the current 650 shaft. Another possibility is to fit the engine to a roadbike for testing and tweaking. This would be especially invaluable for adaption to the Microsquirt fuel injection. Pics of the engine internals will be added to this blog shortly. Thanks.