Britbike forum Forums British Motorcycle specific Brands Panther forum Seeking Panther Wisdom

My winter project this year is restoring a 1958 Panther M75. Really just starting to get going on it. One of the first things perplexing me is I think the bike may have an incorrect hub on the rear. All of the Panther M75's I've seen pictures of have a have a right angle speedo drive on the rear hub below the axle. The bike I'm restoring had no speedometer cable and I see no spot for a speedo drive on the rear hub. Also all the Panther 75 photos I've seen, the rear hub is all steel. My bike has an aluminum ribbed hub similar to the front hub, which leads me to believe my bike may have something other than a Panther hub on the rear. I know there were minor changes from year to year, just wondering if anybody could confirm whether this is a Panther hub on the rear of my bike.




Most Panther 75 photo's I've seen have the brake rod above the swing arm with the speedo drive below the axle. There appear to be no holes on my hub that could accommodate a speedo drive. Also, the number on the brake lever doesn't correspond to the number in the parts manual I have (although my parts manual is for older 65/75's than mine).




The following pics are screen grabs showing the rear hub, speedo drive, and brake arm the way I'm thinking my bike should be.






I guess worse case scenario I could try to use a front wheel speedo drive to have a functional speedo, but I tend to try to do fairly "correct" restorations when possible. Any input would be greatly appreciated.

BZ

Hi,

That looks like a correct 'Panther' hub and brake plate for a 58 bike to me. Panther started offering these alloy hubs as an option in 55.

Keith.

Thanks for the info. Do you happen to know what type of speedo drive Panther's w/ the alloy hub would have used?

BZ

looks a mess to me , whats going one with the rear brake rod ? its a bit late a panther for me but im surprised and amazed they did such a thing , if its correct its a model i shall avoid

Show a picture of the other side, maybe some models had the drive on the axle like other british bikes?

BZ

Yes, somebody has bent the brake rod like a pretzel. I'll be making a new one. Like many unrestored 50+ year old bike, I've been running into poor repairs, stripped threads, etc.....




Here's the foot pegs removed. You can see one has been pretty crudely repaired.










I still need to semi flatten the tube, but hopefully my repair looks a little better.

One of the battery clamp rods was missing and a piece of 1/4"-20 all thread had been jammed in the 1/4"-26 threads of the battery tray, so I made a couple of new ones.






The end of my rods aren't threaded yet. This is my first Brit bike restoration so I'm still needing to acquire a few things like Whitworth tap and dies, and some Whitworth heli-coil kits.

Hopefully in the next week or so, I'll get the Panther up on it's work table and start getting it disassembled and really get going on the resto.

BZ

The angle of the brake lever says that mess is a DPO induced mess and the shoes are very undersize. Instead of fitting new shoes they instead have been bending the rod to keep it in adjustment.

Hold fire on the whitworth taps and dies until you get in further, the nuts and bolts will have whitworth sized heads but the threads will be cycle, which is usually 26tpi with an option for 20tpi on the larger sizes. Cycle threads are deliberately 26tpi to ensure good clamping forces so nuts do not come loose.

As Downhere suggested it looks like there is a speedo drive on the opposite side, its currently got a cover on which will come off once the axle nut is undone.

Thanks Kommando and Downhere. It certainly looks like there would be room to accommodate a speedo drive on the right side of the hub.

The little bit of work I've done on the bike, I've run into BSC, BSF, and BSW threads. I was looking at the tap/die kit that British Tools sells for $315.00 that has an assortment of all 3 of those threads. I was also looking at the British made tap and die sets that www.tap-die.com sell. Either way it's quite a chunk of change, and that's not including the heli-coils I'll need. I'm going to have to look for another Brit bike to restore to justify all the outlay on tools I've spent.

BZ

Still trying to figure out if my Panther has the correct Panther hub on it. Pulled the rear wheel off to have a look at the inside of the hub.



Inside the drum has a gear for a speedo drive like other Panther's I've seen photos of.





Now I'm thinking it might be a Panther hub, but the brake plate has no spot for a speedo drive, so possibly an incorrect brake plate.

BZ

That rear brake plate looks very like the 6" C15/B40/B44 BSA rear brake, the sprocket looks very home made in how its attached, bolted on and the heads of the bolts looking very worn from rubbing. What is the brake diameter ?

Also,
Is it the pic or what?

Doesn't the drive gear in the hub look bad???

You've got a right old mixture there!

Kommando, you nailed it. Underneath the brake shoes, the brake plate was stamped "BSA 40-6025", and it is a 6" drum. Upon further inspection, I believe the hub is a Panther hub. The speedo gear is stamped "P34139/1 441 RH" which corresponds with the Panther parts manual I have. As Rickman mentioned, the teeth of the speedo gear are messed up. It looks like somebody squeezed it really hard with something probably trying to get it off and bent the teeth.

Does anybody happen to know if the "RH" stamping on the speedo gear would be referring to the threads of the gear or does it have to do with the rotation of the speedo drive? I can't see enough threads to tell if its LH or RH. I haven't had any luck getting the gear off. Soaked it in Kroil tonight and I'll give it another shot later.

Something else I was wondering. I'm coming up with 9/16" x 20tpi threads on the axel. The axel looks like the illustration in my parts manual. Is that a thread size that was used on Brit bikes?

BZ

Cycle Thread is not only 26TPI, 7/16th and above there is the option for 20TPI so its a cycle thread. You find the 20TPI on crank nuts and other high torque items like axle spindles. There are some UNEF 20TPI threads which I have used as cheaper options for helicoils and taps, the thread angle is the same with slight differences in the peak and trough, BSA and Triumph used this same ruse when they changed from cycle to UNF in the late 60's.

The RH is for fitting to the left side of the wheel whereas if it was for fitting to the right hand side of a hub it would be a left hand thread. Self tightening and all that. Some single nortons apparently have brake hubs left and right handed.