1930-1931 Front Brake Plate

[Paul_B]

Hi folks,

In short, I'm looking for a front brake plate (4080-30) for an Ariel front wheel (4000-30) - OR - if all else fails information on possibly modifying a 1933 front brake plate (4080-33) so the brake shoes (4100-26) fit into the hub (i.e., are there any drawings/etc available for the two brake plates?)


The long winded version:

I have an Ariel front wheel (model 4000-30), marked as year 1930-32 (with the 90 degree spoke flange).

For this I bought a brake plate (4000-30), marked year 1933-37, (this was the only one available from Draganfly so thought I'd try).
I also bought a brake cam (4115-30) which fits nicely in the brake plate.
I also bought some brake shoes (4100-26), year 1926-31, from Draganfly (these are shop bought shoes & modified by drags before sold).

When I put the brake shoes, cam and plate together they are exactly the same diameter as the wheel hub (i.e., they don't fit into the hub) - the brake shoes interfere with the hub when the brake cam is in the "off" position and don't sink into the hub

I can't seem to find any information on what the 1930-31 brake plate is like, and how this differs from the 1933 model I have.

I guess the only way to decrease the brake shoe diameter would be to either reduce the diameter of the brake plate pivot (and grind the brake shoe at the points that contact this) or decrease the width of the brake cam. As either of these routes would mean I can't return the items I thought I'd ask for any advice on here first (either about 1930/1933 brake plate drawings/dimensions or if anyone had a spare 1930 brake plate).

Thanks if you made it this far down the page

[Roger Gwynn]

The 4080-33 has the torque arm position altered by 5.5 degrees but is otherwise the same as the 4080-30, the shoes and other parts should all fit. 4080-30 is the same as 4080-29 but with a dust rim added. As the plates are sold without the dust rim the 4080-30 should supersede to the 4080-29 with a note about the lack of dust rim. I will ask them to fix that.
I suspect that the linings may be a little oversize and could be easily filed down but check first that the semi-circular end fits neatly onto the fulcrum, if not, a little fettling here should fix that. If not happy doing either of those complain to Drags by asking nicely what to do. They will fix the problem and/or swop the later plate for the earlier one, you could return the shoes at the same time and ask them to make sure they fit the brake drum.
As always if there is a problem the first point of call should be the supplier, they are morally and legally obliged to fix it and Draganfly have always done so, even before it wasn't a legal requirement.

[Paul_B]

Thanks for the detailed reply Roger.

Drags have been very helpful each time I've contacted them to discuss it. I think with the quoted workshop costs & lead time I'm not losing anything by having a bash at it myself first anyway (famous last words).

On a related note, as the wheel hub inner surface (which will be in contact with the brake shoe when the brakes are applied) is just painted sheet metal at present, are there any established practices or tips about adding anything (rough painted surface, liner, etc) to increase the braking friction (or to protect the hub surface) or alternatively to reduce heating during repeated braking - if that's an issue.

I couldn't find anything useful in the standard parts list or workshop manuals I have.

[Roger Gwynn]

I think that a smooth flat surface is best, any roughness may increase friction but is likely to wear the lining away rapidly and may cause grabbing. The back brakes are not bad as the leverage ratio is better than the front and the foot can apply more pressure but best to get everything in good condition or as good as can be achieved. If the inside of the drum is painted that ought to be removed. The ancients were very concerned with 'side slip' so tended to favour the rear brake, we know better now of course. Side slip was skidding of the front wheel on the often greasy roads, cobbles, wooden blocks, tram lines and something that horses left on the road. We only have potholes and too many car drivers.

[Paul_B]

Well, when you put it like that it certainly makes me appreciate potholes.
Although I have yet to go over any serious ones with girder forks and a rigid rear end