8 replies to this topic

[scooby doo]

Please help !!! I have recently purchased new backplates and mini fins on my mini , but when fitted they rub together on the outside diameter. the old drums had 4 sawn down washers spacing the drums off slightly. Is this normal practice or am i doing something wrong . please help....

[KernowCooper]

No its not normal practive to have cut down washers fitted, and other have reported here before some contact with the backplates, its either the backplates are a copy part and a bit on the generous diamension, or the drums. Either could be relieved slightly to enable fitment without washers which is not good engineering as the drum / wheel is not on a flat face

[tiger99]

Don't try to sort this out yourself, as you will lose all your legal rights if you modify anything. The supplier is entirely liable, as the goods are not of merchantable quality and fit for purpose, so you should really take them back and demand a full refund. If people don't do that, the supply of amateurishly designed parts that don't fit will continue, and get worse. None of us likes going back to a supplier and having an argument, but on occasions it has to be done. If you don't get satisfaction, let them know that your next port of call will be Trading Standards. That threat usually brings results.

 

And yes, as KernowCooper says, it is very bad engineering practice, and quite likely unsafe, to be using washers in that way. You don't know what it is doing to the stress distribution between hub face and drum, and more seriously, to the wheel studs. A single circular shim with a big central hole and 4 smaller holes for the studs, made of good quality material of uniform thickness, such as gauge plate, would be acceptable, but washers,never.

[scooby doo]

ok thanks for that. i think part of the problem is that the handbrake cable protector bracket is sandwiched between the  backplate and axle casting using only two of the three backplate bolts which makes the backplate sit slightly out of square. this causes the drum to rub in one area in particular.??

[scooby doo]

I think turning up a purpose made spacer sounds the best option as i have a large lathe at work. probably use ally tooling plate Many thanks again for your help and advice

[bikewiz]

ok thanks for that. i think part of the problem is that the handbrake cable protector bracket is sandwiched between the  backplate and axle casting using only two of the three backplate bolts which makes the backplate sit slightly out of square. this causes the drum to rub in one area in particular.??

The handbrake cable protector should be bolted to the back of the axle casting, as you call it, not sandwiched between it has a small spacer on one bolt to make it sit square. That may be causing your clearance issue.

[dklawson]

 

ok thanks for that. i think part of the problem is that the handbrake cable protector bracket is sandwiched between the  backplate and axle casting using only two of the three backplate bolts which makes the backplate sit slightly out of square. this causes the drum to rub in one area in particular.??

The handbrake cable protector should be bolted to the back of the axle casting, as you call it, not sandwiched between it has a small spacer on one bolt to make it sit square. That may be causing your clearance issue.

 

 

+1 on George's observations.  

 

I would call that handbrake part a cable anchor and it goes on the inboard side of the radius arm flange, not between the arm and the backplate.  Putting it on the wrong side will move the backplate towards the drum by the thickness of the cable anchor... which I am guessing is about the same thickness as the washers mentioned earlier.

[cradley-heathen]

i know its not whats going on here, but i have had drums catching on the backplates with genuine iron drums too, i find the backplates are easily knocked out of shape if the arms have been removed or mistreated in anyway.

 

but i agree with others comments, those handbrake brackets are fitted in the wrong place!

[scooby doo]

Many thanks to all. I have now repositioned the handbrake bracket on the outside and all is fine. The backplate is true and square and the drums no longer need spacing out with washers. HAPPY DAYS !!!!. that will teach me to assume the previous owner knew what they were doing.Even the original backplates were on upside down .....Once again many thanks