User talk:Mobile Chicane/My sandbox
Yamaha Past Masters Racing Club (YPMRC)link title
Very friendly and fast expanding motorcycle race series, the old dayglo painted 'Head Bangers' from the Pro-Am series' in the 80's live on. The class survived throughout the 1990's but numbers were dwindling and grid were often mixed with 400's or Powerbikes, until a major effort was made by primarily D Mowat in 2003 to revive it, which was hugely succesful, and the series now has capacity grids for most races. The class is open to Yamaha TZR250, Yamaha TDR250, RD250LC, RD350LC, RD350 YPVS to compete against each other in the BMCRC (British Motorcycle Racing Club).
Damon Hill started his early racing career on a RD250LC
YPMers regularly race in the UK circuits at Snetterton, Brands Hatch, Lydden Hill, Pembry, Cadwell Park, with the occassional meeting in France.
Once at the race circuit the YPMers often camp together and give mutual support in terms of parts and advice for tuning, and it's not unusual to borrow an engine from a competitor. A very family orientated club with a wide range of ages competing, past top finishers are now competing at National Level, while some are still racing after many decades of experience.
Paddock Hill - Brands Hatch, first corner, 2005
It's often the case the more nimble TZR will be better at shorter circuits like Lydden Hill, and the YPVS will perform better at 'power' circuits like Snetterton. The RD250LC will struggle against the TZR and YPVS and the RD350LC will still have a handling disadvantage.
In recent years the class has had 'sub-classes' where the TZRs had their own Tour and the RDs and YPVSs had theirs, so that each rider had a hope of gaining some points in one of the embedded series. In 2007 all racers race in the same series.
THE RULES
Eligible machines
Yamaha road-going 250 & 350 parallel twin two-strokes. Includes "LC", "YPVS", "TZR" and "TDR" models. Only models of the same spec as the officially imported model. Reverse cylinder or V-twin model TZRs are not acceptable. Models with larger rim sizes or brake diameters than the official models are also illegal. Model 2XW-1 swinging arm, shock and linkages are permitted as these were officially fitted to later model 2MAs imported to the UK.
LC Model is RD250LC & RD350LC
TZR Model is 2MA and 1KT parallel twin
YPVS model is RD350YPVS
A blanket limit of 62bhp at the rear wheel for all eligible models. RD/LC and YPVS – TZR guidance still apply regarding modifications and components that must remain standard - All RD250 and 350 LC and YPVS models bikes are dyno tested on spec throughout racing calendar using Dyno facilities provided by BMCRC race club – the reading on the BMCRC dyno is the class guide and no other supplied readings are used in the event of bike testing. The clerk of the course has the final decision should a bike not comply to the regulations
Parts that must remain standard
Frame and subframe (brackets for road-going equipment such as the rear brake light switch may be removed)
Swinging arm (lower run chainguard must be added)
Wheels (bearings may be changed for higher specification units)
Wheel spindles v
Master cylinder (hoses and discs may be changed). LC models may use calipers and master cylinders from any eligible model.
Petrol tank (internal filters and taps may be removed)
TZR250 Carburettors (although needles and jets may be changed).
Ignition system, although static timing may be changed.
Engine castings
Primary drive gears
Gearbox
Clutch (may be fitted with an extra plate or stronger springs)
The ignitor box must be the same as the official import model (no re- mapping or FIII kit boxes are permitted), as must the YPVS control unit if fitted. RD350LC forks and front wheels may be fitted to RD250LCs to accommodate twin front disks. This mod is not permitted for other models. Electrical components may be re-located and fitted with additional waterproofing.
Standard parts which must remain, but may be modified
Crankshaft
Rotor may be lightened v
Connecting rods. LC models may use rods from YPVS models.
Cylinder barrels and head
Forks
Fuel cap
Yokes
Rear shock absorber (provision may be made for re-gassing). LC models may use any suitable item from any source. We permit the fitting of alternate springs to the standard shock.
Parts which may be removed
Electrical system including battery and lights but excluding ignition (Charging system including regulator/rectifier may be removed)
Speedometer, speedometer drive and cable
Powervalve cables
Oil tank and pump
Chainguard
Mudguard
Sprocket cover (may be removed or modified)
Airbox (may be removed or modified)
Thermostat
Kickstart mechanism
Rear brake fluid reservoir
Equipment for road use (mirrors, horn, indicators, rear footpegs etc.)
Other modifications
Rebores to a maximum oversize of 2.75mm. No big bore modifications are permitted
No additional fairings or streamlining may be fitted which alters the original silhouette.
'Double Bubble' screens may be fitted.
Race plastic is permitted, including any generally available seat unit which does not need to conform to the original silhouette
Steering dampers permitted
All fasteners may be replaced with items of a higher specification than standard
Exhausts may be modified, or replaced with any aftermarket item on TZR250 Models
Use of non standard or modified exhaust pipes for use on RD250LC, RD350LC and RD350YPVS models to comply with 62bhp limit
All machines must comply with the appropriate noise regulations.
Handlebars may be modified, or replaced with aftermarket items. They may be remounted in any safe position.
Rear suspension tie-bars may be modified or substituted to modify the ride height.
Fitment of the Yamaha “Blue Spot” model front calliper is permitted.
Fitting of TZR250 wheels/forks and brakes to RD/LC models.
If adopted then the standing regs over callipers and master cylinders will apply and only a single TZR front disc may be used.
TZR rear wheel must be fitted to existing RD/LC swing arm
In addition to the section “Parts that must remain standard “ bullet 3, the optional use of a standard fitment 3.5” rear wheel for TZR machines is permitted.
Any parts that, in the future, become especially difficult or expensive to obtain, are subject to a vote of approval for change to a designated aftermarket or alternative part(s). The changes are decided by ballot under the rules of the constitution.
No redundant systems
Any systems designed to affect horsepower readings during dyno testing are strictly prohibited
Tyres
Only moulded pattern tyres may be used.
No wets, slicks or cut slicks are permitted.
Fuel
Any generally available pump fuel including 4 star, premixed if necessary with 2 stroke oil.
Octane boosters and other additives are not permitted.
4 star BS 4040 max.
Max RON - 98.5 Max Lead - 0.10 g/l
RESULTS
2003
1st Tony Rand
2nd Jon Puk
3rd Andy Ball
2004
1st Jon Puk
2nd Pete Fishwick
3rd Wayne Bullen
2005
1st Ricardo Ballerini
2nd David Hallett
3rd Darren Mowat
2006
1st Tyler Bacon
2nd Doug Howell
3rd Pat Herron
2007