Ironhead Sportster drum brake/rear axle

[hammysdyna]

Hi I'm building an ironhead chop (with alot of help from my mates), it started life as a 75 ironhead and at some point somebody put it in a very ugly plunger frame. I got an original 70's weld on hardtail from the states and have now chopped the frame and welded on the hardtail. At the weekend when we were looking at the drum brake we realised that the brake plate was non standard and someone had fabricated it from brass plates and over the years it has worn and run out of true. The brake drum is original but now has got us wondering what the set up should be as we aren't sure what else has been fabricated to suit the plunger frame. Can anybody tell me what the axle diameter should be as looking at some other website some people say it should be 5/8" and some say 7/8". Also if anybody has any more tech info on a rear brake brake wheel for ironheads (explode diagrams, part no. etc) it would be greatly appreciated.

Cheers

Hammy

[johnnythunderpants]

Prob not the answer you're looking for but if the OG set up has been butchered, and being as it's going to be a non standard bike, you'ld do better getting a later hub with a bolt on sprocket and run a single caliper disc. Easy to figure and install on a hardtail frame as well. Hope this helps.

[the_french_owl]

Hi, hammysdyna

Neither 5/8" or 7/8", they're all metric, 19mm. The threaded part is smaller and it's an inch thread of some description. The axle went a bit bigger on the Evos, but what the fcuk do I know about Evos...

I might have a spare mid 70s back plate will have a look if you wish...

Patrick

[hammysdyna]

Many thanks Patrick. I think I have sourced a new brake plate from the states but really appreciate the offer. If it doesn't turn out to be any good I'll give you a shout. Thanks for the info, where did the metric bit come from? (same place as the front end I suppose?)

Cheerss

Hammy

[the_french_owl]

where did the metric bit come from?

No idea... It came with the K Model, front and rear wheel... The racers also used metric bearings in the cases, starting sometimes in the WR history... They might have seen the downfall of imperial bearing sizes coming...

Don't forget, most of the Wisconsin area was full of german emigrates, a lot of H-D engineers had german names or descent, Schiltz or Budwizer beers and all... I knew one a long time ago that had worked on the K project, Ernst Mitchl... He spoke english with a dreadfull german accent!!!

Patrick