Frames... Road versus off road

[Pete Walton]

As some of you are probably aware I am in the process of converting a 25DD into an off roader. Having a good look at the frame today I am of the opinion that there seems to be not a great deal of strength between the beam/top tube section and the rear sub frame, ie a couple of bolt's at the top and the engine plates at the bottom. I wondered if the battery/tool box (which has been discarded) was designed to stiffen this section up much in the way the tiger cub used the petrol tank to stiffen the swan neck...
I could easily fabricate some tube with brackets to bolt in place of the batt/tool box, but am I being over cautious ? Are the engine plates and two bolt's sufficient to stop any twisting/stress ? Has anyone any thought's on this or done a similar conversion ????

Thank's Pete

[John Wakefield]

Pete
The toolbox is a stressed member of the frame & in effect ties in the top tube/rear sub frame with engine plates. On the trials version there is a bolt in tube. You would be well advised to do something similar on your frame, particularly if you are going to use it off road.

[dave higgins]

Hi pete, i bought a hawkstone once that had this section modified, the two bolt mounting brackets were removed & the main frame was brazed to the rear section with the support of two side gussets.
But i would imagine, that the origanal design would suffice, i think most frames are designed to flex to a certain degree. dave.

[greeves246]

Garys brew ! Lol

INTERSTING SUBJECT ! ONE SCRAMBLE AT THE BONANZA I SAW A DCX FRAME IN THE SCRAMBLES LINE UP !!!!!!

[Pete Walton]

Thank's for the feedback guy's... Whilst I agree with Dave that frames are designed to flex a little, as mine was designed with the addition of a batt/tool box to tie the section's together, which I've discarded, I'm going to go along with John and fabricate a simple tube section to replace it... Better safe than sorry.....
Pete

[greeves246]

Hello peter

Pete ! The off road bikes had a little lug 1/8 gauge 1" wide and 1" long from the top tube and a semicircle of steel 1/8 gauge from the top of the swinging arm spacer between the engine plates and a tie bar flattend with a mudgard lug on the back of it bolted between i see them often at jumbles on there own might be one at bonanza !.

Gary