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1966 T120C TT Restoration - Pipes & Tribulations - November Update

The past couple of months has been a little frustrating in trying to obtain exhausts that correctly and a suitable headlight (and busy, hence belated update!) My first choice of exhaust would have been the cross-over ones that exit to the left rear, like the ones on Steve McQueen's 1963 Bonneville TT desert racer. I sourced some from JRC Engineering in the US - but these didn't fit, believed to be for pre-unit models. They also weren't really like the Steve McQueen ones I wanted - as fitted to his 1963 Bonneville desert sled. I decided in the end to go for the 1966 TR6C slash cut open pipes, exiting the left - these look and sound great. Originating from the same period, they would be age-appropriate, and I've seen photos of them fitted to a 1967 T120TT which was used for desert racing, so they make it just a little different than standard with a nod towards the bike's Mojave origins (they're also a great deal quieter than the big bore TT pipes!)

Original faulty exhausts - slash facing downward on lower pipe

LF Harris produce these slash cut pipes and they're of very high quality - and easily available in the UK at a reasonable price. However, the first ones which arrived were faulty. The LH lower pipe was "slashed" - top to bottom, rather than sideways (see above). Back they went to Supreme. Another set was sent out. When fitted, these were a slight improvement, but still not quite right - the LH pipe was cut at noticeably less of an angle than the RH one - they just didn't look right to me. Supreme then got in contact with LF Harris who agreed to collect the faulty ones at their expense and send out another set - if these weren't right, then they would make up a new set. Thankfully, it was third time lucky and they look great - in fact I prefer them to the Bud Ekins style ones. Great service from both Supreme and LF Harris in sorting out the issue quickly.

Build work continued, with Terry sorting out the electrics. A new alternator and stator had been fitted, together with a Boyer Power Box and Pazon electronic ignition. Standard coils had been hidden away behind the switch panel using a custom made bracket - I don't like seeing standard coils under the tank of a TT, it just doesn't look right. However, I'm now aware that ET coils similar in size to the original (though not in colour) are available from Vintage Triumph Parts in the US - they're, at best, reasonably similar in appearance but I don't know what they are like performance-wise. I might mount the originals as dummies under the tank (or maybe I won't bother!)

Second pair - slightly better but lower pipe still not right. Mk I TT - TR6C headlight with QD bracket, scrambles bars, big trials tyres, Morad alloys. Big bore breather loosely fitted.

I already had a 1966 Triumph NOS rear light and deliberated for some time over whether to fit a small 1966 TR6C headlight or a Bates one. I decided on using a QD headlight bracket which I already had, and eventually bought a good quality newchrome TR6C headlight, allegedly Lucas, from Paul Goff. The lens - fitted with a low wattage, high output H4 bulb, needed some minor modification to fit - as is often the case these days with pattern parts - albeit minor.

The next question was where to site the horn - I didn't want it visible under the tank, like a roadbike. Terry managed to find a small horn and installed it neatly inside the headlight. An LF Harris dipswitch/horn from Supreme and an NOS light switch was sourced off one of Terry's contacts (not cheap at £75, but that's what you have to pay for genuine items these days, and it's cheaper in the long run than buying some inferior pattern item made in India or China which won't fit properly and will in all likelihood not last).

Wheels with alloy Morad rims laced with stainless spokes to refurbished hubs had been built and fitted with an Ensign 3.50 x 19 Trials Universal front and a Pirelli MT43 4.00 x 18 trials tyre rear. These were fitted and engine work completed. The front tyre looked absolutely huge! I'd expected something similar to a (now unavailable) Dunlop Trials Universal but this had much more of a shoulder and was bigger all round - though it's not dissimilar to the big front tyres fitted to true desert sleds in the '60s and '70s which were often as wide as 4.00 inches. Terry just managed to fit it, with little clearance. The Pirelli MT43 rear wasn't quite as big in comparison, but again, bigger than a Dunlop Trials Universal. When I saw the bike in the flesh though I thought it looked good.

My original plan had been to have a slimline '66 tank painted in Alaskan White with Pacific Blue racing stripes - a '66 TR6C paint scheme in reverse. Once the Alaskan White had been applied, I changed my mind and decided to use the repainted tank in original colours which came with the bike. This had been painted by some guy in California who had made a very good job of it. Once it was fitted I knew I'd made the right decision - the Alaskan White/Grenadier Red colour scheme really is stunning. Triumph produced so many striking paint designs that it's difficult to choose a favourite, but this is definitely a contender. John then set about painting the other tank in the 1966 TR6C colour scheme, Pacific Blue with White racing stipes. This will be put away for the next (1966 Trophy Special) project.

I decided I wanted some of the finned alloy rocker caps fitted like the ones supplied by JoMo and TriCor and seen on many US competition and street bikes, so a set was ordered from the UK. When they arrived they were chrome with just 2 fins (US ones had 4 and were polished alloy). Back they went.

UK "finned" rocker covers. No thanks!

Terry fitted an alloy rear mudguard which had come with the bike to the rear, but I decided to use a stainless one instead for strength, given my intention to fit a taillight. The alloy one will be retained to return the bike to standard spec if required. I then spent a week deliberating on whether to fit a different taillight and bob the mudguard as on a desert sled. Eventually I decided to just stick with the standard one with the '66 taillight. I was slowly coming to recognise that sometimes you just can't beat original Triumph styling!

Next issue was shocks. I had already decided I wanted open shocks in place of the shrouded standard ones. These were commonly fitted to desert racers and I like the look of them, over the originals which just look a little too old-fashioned to me. I liked the idea of black springs. First off was a set of £300 Ikons from Norman Hyde. These duly arrived - good quality shocks, I already have a pair I fitted to my Hinckley Scrambler which I use for daily transport. However, there was no way on earth these would clear the chainguard and the brake rod - routed inside the LH shock on the '66 T120, leaving very little clearance. Back they went and a refund was quickly received.

Next came a pair of 320mm Hagons - which were a match for the 12.9" originals, apparently. Apart from 320mm = approx. 12.5". Nearly 1/2" shorter which is quite a lot, so back they went. Then I spent quite a bit of time on the phone and emailing Bike Revival about the US Progressive Shocks they supply for T120s. After a fair bit of correspondence and provision of measurements it became clear that these would also not clear brake rod and chainguard and were intended for later OIF T120s.

Back on the phone to Hagon again and more measuring. Eventually decided their 330mm (13" - 1/8" longer than standard) should fit.They arrived and fitted - just, though the brake rod will rub (slightly closer than with standard shocks, but rubbing here is common). Now I'm having second thoughts about whether I should have fitted chrome springs instead (to be decided)!

Mk II Stainless rear 'guard, '66 rear light, correct slash cut pipes, Hagons. Breather routed via oil tank and under rear mudguard.

Terry now had the bike running. Original carbs had been resleeved - initially the slides were sticking and needed a little polishing, then Terry wasn't happy with the LH one. After a bit of tweaking, Terry now has it running smoothly.

The timed breather had been removed during the engine rebuild and converted to a later type obe, with three 1/16" holes drilled throught the inner drive side crankcase and the drive side oil seal removed to allow it to breathe more efficiently through the primary chaincase. Terry had machined a crankcase drain plug - which fits into the primary chaincase filler plug - to fit a big bore Thruxton-style breather. This is a common mod (described in detail in "Triumph Tuning" by Stan Shenton) a vast improvement over the timed breather, and standard fitting on all 650s and 750s from 1970 on. Terry had performed this mod many times. I insisted on following Stan Shenton's guidance to the letter and trim the scavenge pipe by 5/8" - Terry wasn't keen on the idea but went along with it (now I'm thinking maybe it wasn't such a good call...)

There was some question of how best to route the pipe. The big bore clear pipe was obtrusive and unattractive. Terry tried several options, settling for using smaller bore black oil pipe routed back into the oiltank and exiting at the rear mudguard. It was neat and effective, in all appearances little different than standard but more eficient - and avoids the usual dripping you get with the timed breather.

Crankcase drain plug converted to breather plug (in primary chaincase filler), fabricated by Terry using the ferrule through which the clutch cable attaches to the gearbox cover.

The bike was coming along nicely but I wasn't happy with it. Terry had already said he didn't like the headlight bracket, and other people had commented on it. I thought it looked good though. Then I looked at them again. Terry had a point - it didn't look go with the bike really (I'm very susceptible to subliminal suggestion!). A set of standard headlight ears were duly ordered from Supreme.

I looked at the bike in person and at photographs of it. Terry had sent me a link to a 1968 TR6C he'd seen advertised for sale on the web with the slash cut exhausts - not far off standard but a little. Suddenly, in a moment of clarity, I realised what the problem was! The bike in the photos looked good - not great - but the overall image of it was eye catching, with clean "Triumph" lines. Mine was starting to look a mess. The bars looked out of place, headlamp brackets cheap and I hated the stupid trials tyres. I wasn't sure if I liked the alloy rims either - they'd seemed a good idea at the time, similar to ones I'd seen on old TT steeplechase bikes and desert racers. In real life it was striking - but in reality, using it on the road with those tyres was never going to be a great experience.

I phoned Terry and told him I'd decided to fit Dunlop K70s and possibly obtain hubs to build a set of standard wheels for the future, though we'd see how the rims looked with the K70s. Bars were to be replaced with standard ones. I also already have a two-tone seat cover, and have decided I might fit that as the bike appears to have had one fitted originally in photos. I was reluctant to do so before as it has no "Triumph" on the rear and common consensus is that in '66 it should. However, having recently seen a photo shot in 1966 of an almost new looking T120R in Washington State with a two-tone seat cover and no logo (see under "Specs - 1966 TT Special" tab), it's occurred to me that the early batches of '66 Bonnies, like mine and the one in the photo, would not have the logo (which was likely introduced in December 1965).

MK III - original bars, standard headlight ears fitted. Like the look of those slash cuts.

Within about 10 minutes Terry sent me photos of the bike with the original bars fitted (I think

he was quite happy to return it to a more standard spec!) It looks a lot better, as I see it.

Note US polished alloy finned rocker covers. Tempted to fit a finned rocker oil feed too - I've got an original US Webco one but it needs a good clean up.

Chrome springs on Hagons - the black ones just didn't stand out enough... Seat off to have original base painted and two-tone, logo-less cover fitted. I know the Competition bikes were supposed to have all black seats but in reality a lot of '66 TTs in particular left the factory with the 2-tone seat - including this one I believe - and the previous owner informs me it had no logo (I believe the pre-December 1965 T120Rs and Cs had these logo-less seat covers, as explained under the Specs - 1966 TT tab). The 2-tone cover goes well with the '66 colours. Waiting on the clocks, which are being refurbished (3 months now? And waiting...)

Front Dunlop K70 fitted - big at 3.50 (standard TT Special size) but positively svelte compared to the Ensign Trials Universal. Note kinked lower stay, to clear '69 TLS brake. The outer edge has been polished to a semi-matte finish, which is how they would have left the factory. Also note clearance between mudguard and tyre - the original kidney-shaped brackets fitted to the TT lift the mudguard higher off the tyre than the standard T120R ones. Might be better for the TT track or desert, but this is more pleasing on the eye.

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