Hi Richard!
Congratulations on your new toy! I like mine as well, and need to install it on the Nomad as I did on Sherpa. The press of other matters has delayed things.
Yes, to install the PAT, you must remove the Star-Fangled Nut (SFN) and replace it with Tout Terrain's removable substitute. It is not required, but also a Very Good Idea if you use only The Plug2. If you don't, the sharp sides of the SFN "petals" can wear through the insulation on The Plug2 lead, causing a short. The replacement TT SFN is aluminum, so will require installation with anti-seize to prevent future problems and galling against the inside of the steel steerer. To make clear...while you
can install The Plug2 alone with the original SFN in place, you
must remove the SFN to fit the PAT or it won't fit in the steerer.
Please don't drive the SFN downward into the steerer, which is butted at the lower end and then blocked by the mudguard mount. It will cause you all sorts of grief trying to proceed from there if you do. Far better to remove the SFN.
Removing the SFN is easy if you follow my instructions here:
http://www.thorncycles.co.uk/forums/index.php?topic=3800.0As for what to "do" with the PAT...that's easy as well. When you first receive it, the power lead is doubled back on itself and held with a twisty-tie. Leave it that way, pulling out only the wire you need to make a connections at each end. The rest of the doubled lead will serve to gently wedge the PAT in the steerer, preventing disconnection and also preventing moisture from being trapped. Rual is absolutely correct in his caution to avoid foam, and you don't want corrosion to occur inside the steerer. If need be, you can use a fingernail-sized square of closed-cell foam on one side if the doubled wire doesn't do the trick. The closed-cell foam (part of an old camping mat) won't absorb moisture. If you do this, be
sure to leave enough room for water to pass by and drain out. I'd avoid it is at all possible.
[By the way, a spoke holder hidden
inside the seat
post will prevent the problems Rual had. I show the one I made here:
http://www.thorncycles.co.uk/forums/index.php?topic=3896.msg18563#msg18563 Fitting a nitrile o-ring at the seatpost/seat tube intersection also does wonders to keep moisture out.]
I can offer a couple cautions most people seem to overlook when installing the TTTP2 with or without PAT:
1) When installing the top cap, be *sure* there is enough room between the snap-in electrical lead at the bottom of the Plug and whatever you use as a SFN
before you tighten the bolt. TT's removable SFN replacement is at a fixed height...and there may not be sufficient room to clear the lead
once the cap bolt is tightened. This occasionally leads (sorry) to broken connectors and the effective demise of the TTTP2. I "dry fit" mine very carefully, then usually add a 3mm spacer below The Plug (remember, The Plug also serves as the top cap for the spacer/bearing stack).
2) When routing the wires, be sure to allow for future headset replacement/fork removal. It may seem a dim-distant possibility now, but someday you'll need to replace the sealed bearing cartridges on your Thorn-fitted FSA headset. Remember, too, Thorn thoughtfully brazes a threaded plate at the bottom of the steerer for directly mounting mudguards. It leaves a small gap on each side for the wires to pass through. The Plug and PAT must be fitted into the steerer from
above...the leads exit from
below. To remove the fork, the connections have to come apart. I use Dean's mini-connectors at the ends to allow future service. They provide a very firm fit, are gold-plated, and are available at any hobby shop catering to the R/C car/airplane/helicopter/boat enthusiast. Details, part numbers, and links are here:
http://www.thorncycles.co.uk/forums/index.php?topic=3896.msg17113#msg17113 Similar mini-/micro-connectors are available from other firms and vendors.
3) Though others have disagreed (due to the insulating effect on low-current connections), I have had stellar luck using silicone dielectric grease on the electrical connections to prevent moisture and corrosion problems. It isn't required, but works well for my needs.
4) If you test-fit the lot together, you'll probably find yourself needing to remove the connector from The Plug's top cap. Per Tout Terrain's tech notes, the connector really does pull directly outward and away using reasonable force and a couple strong fingernails on the connector,
not the leads. There is no latch to undo; a direct pull on the connector removes it.
5) If things ever go really sour, it is possible to replace the connector and use telephone wire to replace the leads and I have helped several people do this with success. It is an involved procedure I won't take space to give the details here, but it is possible so keep that in mind if needed.
Best of luck, Richard. The installation requires some thought but is not as complicated as it first seems. I laid mine out on the floor the first time, then used what I saw to ponder and develop the routing. If you run into a rough patch, give a shout!
All the best,
Dan. (... who thinks you're going to like your new toy)
