locked rear wheel

hi all,
bit of a disaster today, i took my recent bobber build, out for another test run today, did about 12 miles and bike started to slow down, thought it was fuel starve , or engine fault,
slowed for a roundabout , and back wheel locked, and would not budge, smoke coming from rear hub, wheel paint blistered, and alloy flakes showing at hub to wheel gap.
had to be recovered home.
i have modified this rear end, by putting a radian 16" wheel on and converting to drum brake ,rather than the standard disc.
but i did about 50 miles on it before christmas, without any problems.
took wheel of f, and then brake plate, (which came off easilly)
it seems the brake plate has been rubbing on the lip on the wheel, eventually melting the alloy lip ,and jamming the wheel. brake shoes are fine.
dont know what happened here, i pushed the bike out of the garage ,before ride, without any binding ,and no nasty noises whilst riding, as far as i could hear,
Radians are not common at all, in uk. anyone any idea what could have caused this .
looks like i need a new wheel and brake plate !!
i
i will post pictures of damaged hub and plate in a mo,

 

it appears the lip that should be on the wheel hub (bottom 2 pictures) has melted and welded itself into the groove in the brake plate
what the "f" could cause this? anyone else had this happen?

 

Do you need to make a spacer to keep the brake plate clear of the wheel?

 

the center of the brake plate rides on the wheel bearing. it does make sense that he needed a spacer or had the incorrect brake plate

 

Ok makes sense.

 

hi, the wheel and brake plate came from the same breakers in Ireland, but i dont know if they came off the same bike, they were advertised as Radian, do any Radian models have different brake plates, theres no spacer ,between the brake plate and the bearing, as far as i can see on the drawings,

 

Don't see any spacer between the brake plate and bearing here.

https://www.partzilla.com/catalog/yamaha/motorcycle/1986/radian-yx600s/rear-wheel

 

The Radian has same brake plate as the 650 and 550 Maxim.
The XJ550R Seca has a different plate and pads, not sure if they’re the same diameter?

 

thats because the seca 550 has a wider break shoe

 

you should not need a spacer if the parts are correct.
also if all the spacers on the axle are correct .
it sounds like the center of the wheel bearing moved in allowing the plate to hit the drum on the wheel.
if it was not properly spaced on the chain side it could cause this when you tightened the axle.
check out the other side and see if there is any damage on the chain side
there may be slight differences between stock wheel widths and the wheel you swapped in or in the axle spacers.

in the end if nothing is damaged on the axle and its spacers a thin shim washer in the brake drum may be all you need. if the wheel is not damaged to badly
a machine shop could turn down the rim of the drum where contact is being made.

you could use a parts catalog or something like partzilla to see if all the axle parts are the same between doner bike and your bike

can you ID current bike and doner bike?

this link shows collar and bikes it crosses with part 18
Yamaha 90387-172J8-00 - COLLAR | Partzilla.com

 

clutch hub part 15
Yamaha 1JK-25366-00-00 - CLUTCH, HUB | Partzilla.com