Jackyll the Tandem Part 2: Stripdown

Continuing from Part 1 where I introduced the new 1974 Jack Taylor Super Tourist tandem, we spent a weekend giving it a mini overhaul, cleaning, adjusting and lubricating all the main moving parts.  The bike looked mostly original, but there didn't seem to be anything blatantly wrong.  However there was only one way to find out, and it was definitely a good idea to at least know the state of everything before we did too many miles and wore out parts prematurely.


The first thing I checked was the headset, after doing some research on Jack Taylor tandems I found out that they came with an obsolete oversized French tandem headset, usually made by Stronglight. They have not been made for a long time so it is near impossible to find replacements.  There is the option of substituting a standard 1-1/8" headset as it is close enough in size that it will fit, apart from the top nut which is French threaded, however understandably original is best.

Thank god!  The crown race which is usually the first bearing surface to wear in a headset was baby bum smooth with absolutely no pitting.  The headset is unusual in that it takes 5mm ball bearings which is a bit larger than the typical 5/32" (3.97mm).  The headset was slightly loose when we picked it up so I was a tad worried, but once the balls were replaced, races cleaned and it was adjusted and tightened up it was perfectly smooth with absolutely no binding.  Fantastic!

Bottom Brackets & Cranksets

The stoker bottom bracket was somewhat smooth already and the front felt a bit dry.  The lockrings were on quite tightly and my lockring tool was useless against them, so I needed to enlist the help of my anvil to brace against to remove them using a hammer and a chisel.   After that the bottom bracket cups came out easily, luckily the fixed cups (which are usually difficult to remove because they have two very thin wrench flats typically) came off easily.

As I suspected the Captain's bottom bracket was a bit dry, however the axle was in great condition as were the balls, so this was just cleaned, lubricated and closed back up.  The stoker's bottom bracket was quite well lubricated however there was one slight pit in the axle, I cleaned this up, lubricated and closed it back up as well.  Funnily enough it still spun very smoothly even with the pit in the axle.  The cranksets were fine, except one of the teeth on the timing chainring (that's the chainrings on that synchronise the captain and stoker's cranks on the non-drive side) was chipped off.  Not a big deal.  The cranksets were polished up and the chains were replaced with new, it took three sets of chains to get enough length, the timing chain is a little bit longer than the standard 116 links that you normally get.

I had to purchase a special Spécialités T.A. crank extractor as the classic cyclotouriste cranks use a 23mm extractor thread which only they use.  It was also for peace of mind that I removed the cranks from their axles to inspect the square taper surface and to make sure they were installed with enough torque.  I've accidentally ruined a set of cranks before because I rode them slightly loose which deformed the square taper on the crank, once this happens the cranks are junk because the damage is irreversible.


The front hub was a different story, the whole time I had ridden it there was this constant clicking noise from the front, I suspected the front hub was mucked up inside.  This was no ordinary hub, it is a Maxi-Car hub which are considered some of the finest hubs ever made.  Add to this that I later discovered that they are an odd 110mm spacing, a French tandem specific spacing intended to increase strength due to a wider flange spacing which permits a stronger spoke bracing angle.

I removed the dust covers and washers and found this... not good news and it would explain the rumble and why the axle was not spinning all that freely when turned by hand.  It appears that water got into the bearings themselves and made a right mess of everything as it was completely caked up in a mix of rust and dried out grease.

The cups in the hub shell were quite pitted as well which also was no surprise.

Admittedly I needed to drop it off at the local bike shop to get the axle out as it was rusted in quite heavily.  Once out you could see the extent of the damage... The Maxi-Car hubs used a type of cartridge bearing called a Magneto bearing, this particular hub used the E10 size.  The interesting thing about these bearings is that they are designed to take a side load as well unlike typical cartridge bearings you find in bicycle hubs which only take the up and down load.  

These hubs are unique, not only because of the unusual bearings they use but as well because of how the stepped washers and dust covers go together to create a labyrinth seal.  Sadly the seals didn't work too well otherwise I wouldn't have had to deal with all this rust.  Funnily enough you can still easily get these Magneto bearings which also come with cups, however the worn cups in the hub are extremely difficult to remove and it's generally not done.  For now I've filled it up with grease and adjusted it, it still has a rumble but I will try an old school trick of grinding down the cups with the old bearings and grinding paste at a later date.

The rear hub is completely unbranded which was unusual, when we got it it had a T.D.C freewheel already attached which had dreadful shifting due to the non-profiled teeth and it had an odd quirk where it would catch on something when pedalling backwards, also it made some odd noises when freewheeling which I suspect was the spoke protector plate rubbing against something.  Freewheels are never easy to remove particularly when they are old and crusty, the freewheel is threaded onto the body of the hub so that the lower the gearing and the heavier the load, the tighter the freewheel is turned on the hub when it is ridden up hills.  Thus a tandem's freewheel is usually the most difficult to remove.  I gave the wheel to the local bike shop to remove the freewheel as I didn't have the tool, nor did I have a big vice and bench to remove it using the destructive method.   I was told it came off with just a lot of leverage and the threading was standard English thread.  Now onto the drum brake...

I noticed when we picked the bike up that the drum did not work at all, it felt like there were no linings on the shoes as the brake lever would bottom out.  I was completely correct, the previous owners must have ridden it until there was no more lining whatsoever.  The backing plate cleaned up ok, and the braking mechanism was fine however.  The shoes have been sent off to be relined by a motorcycle specialist.  Hopefully it should work adequately when it's been relined, the drum diameter is about 90mm so not too dissimilar to the Sturmey Archer drum I have on my commuter.

Finally I pulled out the bearings and had a look.  The cones were pitted as were the balls however the cups were in good condition, I also noticed the bearing cover on the drum side had a soft insulating washer, probably to stop the grease from being burnt when the drum was very hot on descents.  Luckily the balls were standard 1/4" bearing balls and I was able to substitute some Shimano cones to replace the old ones.  The axle was a little bit bent but not too badly, not a surprise as on solo bikes the axles on freewheel hubs are usually bent too with only half the weight on them.  

I also fitted a new 7 speed freewheel which required respacing the axle and dishing the wheel slightly to match.  The new freewheel is an IRD Classica 13-32 7 Speed unit, these are offered in a lot more ratios than the Shimano 7 speed freewheels which are more intended for cheaper supermarket bikes.  The sprockets all have profiled teeth with shifting ramps which improved gear changes dramatically, particularly with friction levers, you just push the lever and it goes right into gear with no complaints and a lot less trimming than before.  Now with a near new drivetrain and with lubricated and adjusted moving parts I'm a lot more confident doing some miles on this bike now I know I won't be riding it completely into the ground.  Stay tuned for many more updates!


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