Sam Burman — a motorcycle racer who designs and manufactures parts for her motorcycles — says the Monster Energy Motostar British Championship is perfect for her, as it is the only prototype racing class in Britain and allows her to make changes to the motorcycle while staying within the class rules.
Thanks to WNT (UK) Ltd
(www.wnt.com) increasing its support and becoming title sponsor of her team, she is able to make full use of the company’s technology centre in Sheffield, where she has access to a number of XYZ machine tools — and WNT tooling.
The additional funding and support from WNT (UK) means Sam has also been able to buy the latest Honda Moto3 motorcycle — a 250cc four-stroke single-cylinder bike designed for the ‘world stage’. That said, Sam’s bike will be one of just a few that will make the grid in the British Championship; it should also provide an advantage over her old 125cc two-stroke machine (this class of bike still competes in the championship).
One of the first areas that Sam has changed is the rear brake system. In the Motostar class, the power output and the weight of the machines are much less than with the larger-capacity bikes, so the back brake is not required to stabilise the bike. However, the machine must still have a fully functioning rear brake set-up, so Sam has replaced the original system with a newly developed Tech Evo V4 caliper with a vented rotor disc, plus a Tech Evo master cylinder and lever from Hope Technology — the Barnoldswick-based designer and manufacturer of mountain-bike components.
Sam has been able to reduce the weight of the rear-brake assembly, improve the looks of the bike — and have a rear brake that will stop the bike when needed. “These brakes are designed for mountain bikes, not racing motorcycles, but as I had previously used a Hope caliper on my 125cc bike, I knew I could make it work on the Moto3 bike,” says Sam. To make the Hope equipment compatible with the swinging arm of her new bike, Sam had to design, program and machine a new disc carrier, wheel spacers, caliper bracket and mounting block. With some help from XYZ’s Mike Corbett and WNT’s internal technical sales engineer Billy Poore, Sam made full use of the latest WNT W-HPC solid-carbide milling cutters to fully machine the parts from aluminium billets.
The W-HPC cutters feature a 55deg helix and twin flutes for maximum swarf evacuation at cutting speeds up to 700m/min. The range of W-HPC cutters includes standard- and long-series versions with diameters from 2.7 to 25mm.
“The swinging arm on the Moto3 bike did cause some issues with regard to mounting the caliper. There was nowhere to mount a sliding bracket to accommodate the varying chain lengths required for different final-drive gear ratios; this bracket is required to keep the caliper centred over the rear wheel’s axle. We overcame this by designing a two-part bracket; the small top section fits snugly into a recess on the under-side of the swinging arm, providing a mount for the larger lower-caliper mount.
“Having the support of WNT (UK) and access to the XYZ CNC machine tools is a massive boost for me, as the team can continue to develop and manufacture parts as the season progresses. Working shifts as a machinist at the TATA steelworks in Scunthorpe allows me to use my free time to get across to Sheffield and work with the guys to program new parts, then quickly machine them using the latest cutting tools and machining techniques. With this support, I am confident that when we get to Brands Hatch for the start of the season in April, we will be in a much stronger position than last year.”
The first Monster Energy Motostar British Championship race of the 2013 season takes place at Brands Hatch on the weekend of 5-7 April.