Designers, Manufacturers and Installers of the Finest Quality Traditional & Contemporary Architectural Joinery

Tel: 01969 623020

Design & Specification

All our products are manufactured on a bespoke basis, completely flexible to each individual job, therefore specification can vary greatly. We are only too willing to help design or advise on the different options available to best satisfy your requirements. Listed below are examples of some of our standard specifications we recommend, but please remember that being bespoke manufacturers we can usually meet any requests.


Biker Bespoke Joinery, Leyburn - Certified Timber

Certified timber is one of the most renewable and sustainable natural raw materials available on the planet. Timber window and door replacements that combine character and performance will almost certainly add value to your home, whilst helping to reduce energy costs and consumption.

All Biker Group’s windows and doors are manufactured using the highest quality softwood or hardwood timber sourced from sustainable resources. Our softwood timber is treated against fungal and insect attack.

Laminated or engineered timber is also used for stability.



European Oak
  • European Oak
  • Sapele
  • Red Grandis
  • Beech (internal use)
  • Iroko
  • Poplar (internal use)


European Redwood
  • European Redwood
  • Douglas Fir

Engineered Timber



Double and single glazing is available to most joinery items, depending on specification requirements.

Double glazed units exceed Part L Building Regulations requirements in thermal efficiency by incorporating argon filled cavities with warm edged spacer technology and low E inner panes.

The thermal insulation values or U-values of each joinery item are noted on the quotation. For added security, the double glazed units are installed with security glazing tape externally.

Biker Bespoke Joinery Window Specification

Single Glazing

Single glazing is widely used in listed or period properties. We offer 3 types of glass for single glazing:

  • Drawn (Horticultural)
  • Float
  • Cylinder Blown

Single or Double Glazing

Options on both single and double glazed units also include:

  • Toughened or laminated
  • Obscure and acoustic glass
  • Fire resistance
  • Coloured, stained or tinted glass
  • Leaded glass


We use a wide range of ironmongery manufacturers depending on the circumstances.

All are high quality in their respective price ranges.

Finishes include:

  • Brass
  • Antique Brass
  • Chrome
  • Satin Chrome
  • Bronze
  • Antique Black
  • Pewter
  • Wrought Iron

Wide range of Ironmongery

Secured by Design ironmongery is often used for extra protection.


All items are sanded by both machine and hand and then checked before the application of a primer coat of microporous paint or stain. Please note that items supplied with just a primer coat have limited protection and warranty.

We strongly advise having external joinery items decorated in a controlled environment in our spray booth. We can offer a warranty up to 8 years for factory finished items with a Teknos 3 coat microporous paint system up to 5 years for a stain finish (subject to correct care and maintenance). Some of our paint systems use 4 coats and most colours can be matched.

Professional Decorative Finishes

Specialist Oils and waxes are also used for a translucent finish to internal timber.


Glazing bars can vary in thickness depending on the application, but are generally made as slender as possible for traditional appearance and elegant sightlines.

Ovolo and lambs tongue mould are predominantly used internally and splayed bead externally to replicate the appearance of traditional putty glazing.

A range of different weatherseals are used depending on the applications

Trickle vents are incorporated when required.