ホンダトライアル履歴

Official Blog of the HONDA TRIALS HISTORY web page. More info ar www.onlytrial.com

Monday, 18 January 2010

1978 Honda TL 250 and HT250 David Fraser

This one located in Spain and still under restoration could be one of the few David Fraser HT250 survivors today.

THE DAVID FRASER TL250

Based on the TL 250, David Fraser, who built a several trials machines, made this nice Honda trials edition. The engine was increased to 312cc. and made also a special frame finished chrome plated.
The frame has a plastic (polypropylene) sump shield, mixing square section tubes to rounded sections tubes.

The bike was on sale in UK but I'm not sure about the batch. (most probably a few units)

Some time later, David Fraser Products announced details of a new and revolutionary bike:

THE DAVID FRASER HT250

The bike was designed using the XL250S (1978) twin exhaust motor.
This very competitive package mounted for first time on one trials bike history a unusual intermediate chain.

(later in 1985, JJCobas from Spain applyed same solution on his revolutionary bike)

This is the later JJ cobas double chain system. Picture by La Mola Restoration Trial Bikes from Barcelona for a Spanish collector.














Here you can appreciate the clever intermediate chain System, from J.F., Spain, still under restoration.


This second chain comes from gearbox sprocket to countershaft mounted on the swinging arm pivot. The large chain comes from this swinging arm pivot to the rear wheel.
The innovative system allows to maintain a constant chain tension without any tensioner help.

George Silk engineer from UK also make some studies talking about same chain concept.
See following Youtube interesting video.

This is s short clip looking at trials riding and features some very early hill climbing and Mick Andrews on his Ossa at the annual Scott trial in Yorkshire. It then goes into featuring George Silk who had a new concept for a trials gearbox and swinging arm
http://www.youtube.com/watch?v=PydVlLGxkx4

This rare bike was made in a really small series. Less than twenty were built.

More info about Fraser HT250 at: http://www.onlytrial.com/from_1974_35.html


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