Tag Archives: CWC Airtight

Africa Twin: Sealing the Rear Wheel for Tubeless

AFRICA TWIN  INDEX PAGE
I’ve been rewriting loads about conversing spoked rims to tubeless.
There are several updated pages from here on what, why and how.

If ever a bike wanted tubeless wheels it’s the AT (and T7 for that matter). These bikes run 21-inch fronts and were initially pitched at a low price to get them moving. Choppers aside, cast wheels are unknown in 21-inch, while OE spoked tubeless wheels (as on many European 21-inch advs) are expensive. The new 2020 1100 AT Adventure Sport finally has a tubeless 18/21 set up.

MT or WM?

at-wheels.jpgI’ve investigated various proprietary methods and, after 12 years and a lot more theoretical and second-hand knowledge, decided to give DIY sealing another go – but carefully this time and only on the back wheel (above, top) where it’s fairly easy to do. Like nearly all 21s, the AT’s front rim lacks the ‘MT’ safety lip or ridge which is important if planning to run tubeless tyres. Without it, a TL tyre seals less well on a regular WM rim (above, bottom) and may leak. And in the event of a flat, it will slip into the rim just like a tubed tyre with the usual undesirable results.
The only way around that it to get the rare, lipped, 2.15 x 21-inch Giant rim from CWC for £111. Add anodising, spokes, wheel building, their Airtight™ vulcanised sealing band (similar to DIY mastic) plus post and that’ll be nearly 400 quid. I could seal it myself and save £120, but 21-inch wells are narrow and curved and so are less suited to taping. So while CWC make my wheel, I may as well cough up for the Airtight and be done with it.
The high cost of a new wheel build is why DIY is so attractive, providing your rim is MT with the requisite safety lips. Most rear wheels, tubed or tubeless, have been like this for decades (they will be stamped ‘MT’ on the side, as opposed to ‘WM’). And the AT’s rear well is also nice and flat and 55mm wide which makes it easier to seal well.

Things you will need

  1. The wheel resting on a spindle
  2. Solvent (Brake cleaner, Toluene, MEK, Acetone, etc)
  3. Microfibre rag (lint-free) and Q-tips
  4. Runny adhesive – from Superglue to Seal-All
  5. Thicker sealant – like Goop or Bostik 1782
  6. Sealant tape such as 3M 4411N (not the 2mm thick 4412N). From £18 on ebay
  7. Or some etching primer and mastic sealant like Puraflex about £6 for 300mm
  8. A tubeless valve

Rim sealing procedure

Clean rim thoroughly with solvent using a rag, toothbrush and Q-tips
Apply a runny glue around the nipple and into the threaded centre. I used Bostik; thinner would have been better. Expect microbubbles. Leave to dry for a day.
A day later overseal with thicker sealant. I used clear Goop. Let it dry for a day.
Wrap the undried glue in the non-sticky side of masking tape to stop the lower Goop blobs sagging out under gravity. Or spend days turning the wheel and doing four nipples at a time.
Tape up the rim with 50mm 3M 4411N.
Because I used thick glue and maybe too much, the lumps stuck up quite a lot so made it hard for the non-elastic tape to fully contact the rim floor. I pressed down between the spoke nipples as best I could and did the odd prick here and there. Then I removed the backing film while allowing for some overlap.
As good as I could get the tape. But I’m confident the glue alone has sealed the rim.
I decided to cover the 3M with some regular plastic tape to protect it during tyre mounting.

Or…

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… spray on some etching primer, let it dry then apply a coat or two of Puraflex mastic. Don’t go too thick or you’ll lose the well’s depth and ‘slack’ needed for easy tyre fitting.

If you’ll be in a wet environment, consider also sealing the spoke nipples from the outside.

The mastic sealant method is probably better. The tape adhesive might lift if it gets very hot; a black tyre and rim sat in the hot sun. But then, pressure building up in a hot tyre will tend to push the tape down.

Mounting and inflating the tyre

Mounting is easy as there’s no tube to worry about. Soapy beads help reduce the effort needed and tubeless tyres are actually quite flexible – or that’s how the Michelin felt. I know from cars and the Tenere years ago that home mounting tubeless tyres can be tricky. It took me most of the day to get the TKCs on to the Tenere, and that was with a pokey 2.5cfm 4×4 compressor. Because there is no inner tube pushing the tyre on to the rim, you need both edges of the loose tyre to at least make a partial seal with the rim and allow pressure to build up. When that happens, the seal improves, leakage stops and you’re on your way. Using a small car compressor and with the valve core removed to allow faster filling, nothing happened for a bit and then pressure slowly built up as input outpaced leakage. At around 35-40psi there were a couple of loud bangs as the last segment of bead slipped over the safety rim and into place.

I am fairly confident my gluing alone has made a good seal. The tape is probably redundant. Overnight there was no drastic pressure drop. If there is in the next week and I can’t fix it, I’ll swap back to the tubed wheel and will anyway take a spare tube. This time I’m not using Slime sealant, though I’m told it doesn’t affect the 3M tape’s adhesion.
I’ll be monitoring it with TPMS but a few days in it was about 8 psi down and the same again when I picked the bike up in Spain in March. So it seems to depressurised down the mid 20s psi. I seem to recall this was normal in the early days and so gave the back a shot of Slime in Spain. No more leakage.

Tubeless: professional spoke rim sealing

Tubeless Conversion Index Page

Updated Summer 2020

These two methods are the only professional spoked wheel options I know of available in the UK. In the US Woody’s Wheel Works have been sealing rims for years, but even they admit it’s a tricky business. All will probably insist your supplied rim has a safety bead.

BARTubeless polymer band

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A new idea I tried in late 2015 on my CB500X was permanent rim sealing by BARTubeless in Italy (left), as suggested by Rally Raid. I was one of the first in the UK to try this. They come with a 4-year guarantee. A polymer is applied and sets hard in the well of the wheel, which has been heated by steam. It gets done in Italy.
The tyre was a Golden Tyre GT 201 tubeless on the back and a similar K60 on the front. More here and here. One thing with Bart and similar thick linings is that they take up a bit of well depth in the rim which reduces the slack needed for easy tyre fitting or removing. I recall RR said the rear GT tyre was hard to fit.

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I thought I had no air loss but tbh I don’t think I checked much, and over a couple of months there was quite a lot of leakage. Could have been the tyre bead, the valve, even the alloy rim might be porous. At an MoT weeks later they noticed the pressures were well down, but the stiff TL tyres disguised this, as they so often do.
Note in the picture top left the label says not to drop below 1.6bar (21psi) because the rims used by RR then did not have safety lips. They probably offer safety-bead rims now; certainly on the Africa Twin Bart rims they now sell. In the UK, wheel specialists Central Wheel Services near Birmingham will BARTubeless two wheels for you for £300.
Balance the cost of either of these proprietary rim sealings with the many hours but modest cost and possible satisfaction of doing it yourself.

CWC Airtight System: Vulcanised band

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Central Wheel Components in the UK do a version of the BARTubeless spoke sealing. They call it Airtight. and again, as far as I know, I was among the first to try it on my Himalayan ride to Western Sahara. It costs £120 a wheel but it’s done in the UK (by ATS, a UK tyre outlet owned by Michelin).

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A hooped band whose size matches the wheel rim is fitted to the rim and heated to vulcanise in two stages over two days. Alternatively, on narrow front wheels liquid rubber is applied in three stages and cures in air but takes four days.  The reason I use this is because the rim section is narrow. If I was to convert your rear wheel.
There’s not much more detail on this brief page. Because the band version is vulcanised – a form of chemically (sulphur) assisted rubber ‘heat welding’ – rather than just glued like tapes or sealants, you’d hope the seal will be more secure and permanent, certainly more than tape which can come away when it gets hot.

I had this system on the rear wheel of my Himalayan on an Excel rim with the safety lip and fitted with a Michelin Anakee Wild 130/80-17 M/C 65R TL plus a splash of Slime.
In Morocco I’d guess it lost a pound or two psi a week judging by the readings off my TPMS – though with elevation and temperature changes it was hard to evaluate accurately. This was with Slime plus a small nail in the back which I chose not to remove.

I think I prefer Airtight over the BARTubeless as the rubber may be lighter, would flex with the wheel and it takes less long.

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Alpina sealed spoke nipples

The Italian Alpina system individually seals each spoke nipple with a rubber o-ring, and is sold for many road bikes and so must be considered road legal.
The benefits of this system is that spoke tension can be adjusted while maintaining the tubeless seal. But how often do you do that on a decent rim? The permanently sealed bonding systems above may not work so well doing this, but as we know we’re usually talking very small turns of the nipple to adjust tension, and should a leak develop it can be re-sealed. Also, there are 36 potential leak points. It seems a way over-complicated way of doing it compared to a single band like Airtight or BARTubeless inside the well.

Kineo wheels

Beautifully forged after-market Italian Kineo tubeless rims, popular with custom builders. They’re the only ones I know of and for a Transalp will be at least €1000 each. You’re welcome.

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Back to Tubeless Conversion Index Page

Enfield Himalayan: desert ready

Himalayan Index Page
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While I was busy dodging the winter under the shady mangroves of the Coromandel peninsula, Simon-with-a-workshop quietly worked on my Himalayan, like a gnome chipping away in a pink rock-salt mine. The long list included:

Bolt-ons

Move the Oxford heated grips control module to an accessible position and rewire it to the ignition, not the battery, as the original owner had done.

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Fitting ancillary leads off the battery for my heated jacket and Cycle Pump/battery optimiser.

Fitting a switch to kill all lights. Handy for battery saving as well as leaving the highway unnoticed for stealthy wild camping.

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Refitting the cheap LED headlamp which came with the bike. It’s the same one I put on my XScrambleR. Never rode that bike in the full dark but although it saves watts (or is it amps?), I suspect the LED lamp looks better than it shines.

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To monitor engine temperature a Trail Tech engine temperature sensor is more useful, accurate and quicker responding than relying on the stock ambient air temp sensor. At a cold start it will show ambient anyway, same as the stock in the dash, but once running, reading off the spark plug, the TTech soon shoots up. Even with the oil cooler and the ‘under piston oil sprays’ we read about, the low-tuned, air-cooled motor’s reading reaches a staggering 240°C at 65mph on the motorway, dropping to around 175°C in town. The spark plug is of course just about at the hottest point of an engine so basically it’s quite normal. ‘They all do that – sir‘.
Under the seat the Himalayan’s ambient air temperature sensor got relocated anyway to a position less affected by the motor’s downwind heat flow so it gives a truer ambient reading once on the move. It’s a common mod.

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Garmin Montana cradle fitted to left mirror stalk with RAM mounts and hardwired to the ignition. I thought they’d not fit for want of cable slack, but I was wrong and the adjustable Rox Risers have raised the stock bars a healthy 50mm. It required releasing a clip off the braided ABS brake line under the tank somewhere, and the barely needed cold start cable was also on the limit. With the raised seat it’s now easy to stand up and to not stoop once I’m up there. Halleluia.

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barkbt06
recycle

My ancient Barkbuster Storms are now on their 7th outing since fitting to my XT660Z back in 2008. I should win some sort of recycling award. Simon had to make some simple mounts as for some reason, the curvy BTC 06 adaptors (right) which were recommended didn’t fit. Could be that a decade on, newer Barks have changed shape.
The Barks require the slightly adjustable stock screen to be set fully forward, but riding back I can’t say the turbulence was any better or worse than in the original position. I think that at the speeds the REH can achieve, it’s all a bit academic. And as it is I’m sat on a motorbike out in the open air. There will be turbulence.

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Like so many bikes I’ve owned lately, I assumed the stock shock would be a budget keep-the-fender-off-the-wheel job, so I pre-emptively ordered the Thai-made YSS which took a few weeks. Some reports claim the stocker is too harsh, others say too soft, others just right. On the road it didn’t feel too bad – perhaps the usual mix of over-sprung and under-damped. It weighs over 4.8kg and half appears to be coil-bound, but in fact there’s a couple of mm gap in the coils (left) which adds some progressiveness.
It would have been good to evaluate it properly, but the shiny red YSS is sat there like a cream cake on  cushion. Getting it fitted, I asked my LBS to check the linkage grease. Who knows if they did. I may also rivet on a flap to stop it getting plastered with crud spun off the back wheel.
The YSS is about a third lighter at 3.3kg, costs £290, is length adjustable by 10mm, has 35-click rebound damping and will work with an HPA which probably costs half as much as the shock. Out of the box rebound came at 20/35 clicks and with 12 threads exposed below the spring preload collar. Looks like a good place to start. On the short ride back from the LBS I did detect a little more compliance with small irregularities. Otherwise it felt the same. With most suspension upgrades, I’ve found you can’t tell much difference until road surfaces deteriorate or the speeds increase.

YSS fitting advice: The preload collar at the top of the YSS is now quite hard to access – removing the airbox lid on the LHS may help, as will a shorter, right-sized hex key, as opposed to the rod supplied. There is a tiny hex screw on the collar which locks it to the threads (hex key supplied). Either risk leaving it loose (collar may unwind), or make sure when fitting the shock that it’s in a position where you can get to and loosen it from the LHS – about ‘7 or 8 o’clock’ if 12 = forward. You will then probably need to wind or unwind the collar a full 360° to get the screw back in a lockable position.

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A tenner’s worth of Chinese fork preloaders were also fitted on the front but are currently set at zero. The stock spacer inside the top of the fork needed to be shortened.

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The steering head bearings got regreased. Along with swing-arm linkages, it’s a common precautionary requirement, and not just on inexpensive Indian bikes. My BMW XCountry’s head races were shot at just 6k.

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My initial seat foam bodge proved to be poor, mostly because the foam I used had the springiness of Philadelphia cheese. A fellow Himaliste recommended some pre-cut stick-on foam seat pads on ebay (left; £15 each). At 20mm I bought two and rode home with them shoved under the Aero lambswool pad.

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With the yellow backing still on, it all slithered around a bit and after only 120 miles the butt was sore, but I can definitely see the potential in raising the seat height. And I do wonder if the old lambswool pad makes things worse.
Cool Covers sent me one of their durable aerated mesh seat covers to try. Like wool, the idea is that air circulation reduces heat and improves comfort, but with bike saddles, one man’s fur-lined throne is another man’s agony. Luckily, the Cool Cover just stretched over the two racing pads now glued to each other and the stock seat. The back edge of the top pad was crudely trimmed to level it off. In the picture below the seat looks like it’s sloping forward – not good – but it’s actually the taut cover over an air gap. The foam below is more level than it looks.

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Let’s hope it makes a difference but bike saddles are usually more miss than hit. Seat foam apart, the combination of seating position, bars, footrests and the presence of a screen all have an influence, but it’s also down to tank range – in other words how long you sit riding uninterrupted. My CRF250L should have been the usual agony, but because I could only do 120 miles before reaching for the fuel can, the 5 minutes it took to do that rejuvenated the cheeks. One of the worst saddles ever was the BMW F650GS, probably because it easily did 200 miles between fill ups. One of the best was my GS500R Overlander. I never worked out why.

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Wheels and Tubeless Tyres

wmwheelrimsNote: being a maddeningly illogical Imperial British standard, the ‘WM’ wheel rim width designation you commonly see (in the UK at least) doesn’t correlate with actual rim width in inches. But it is close – see table right. They say ‘MT’ is a modern, fully logical (but little seen) equivalent, where the MTxx number refers to the actual rim width in actual inches.
As confusingly, rim width in inches does not correlate with notional tyre width where, 
for example, a 120 section width (120mm; 4.7”) is converted to inches. But it is close-ish.
Stock REH rims are WM1 (MT1.85) on the front and WM3 (MT2.15 – need to check) on the back with a 120/90 17 tyre.

himtublieTo enable easy puncture repairs I wanted reliable tubeless wheels which meant sealing the spoked rims. Along the way I was happy to ditch the steel rims in the hope of saving unsprung weight which I keep going on about. A mate had given me some ageing 18 and 21 Tubliss. The back was a bit too old to risk; a BNIB front got fitted and Slimed with the new Michelin (left).
On the back, for the sake of simplicity I wanted an Excel 18-er with a new Tubliss (Tubliss don’t do 17 size). Then I was told max width for an 18-er Tubliss is 2.15” rim, like the stock, I think. The Anakee Wilds were recommended for a 2.5-inch rim. We’re talking a notional discrepancy of a third-of-an-inch here, but let’s try to do it by the book for once. Shame as an 18-er would have saved a couple of kilos in tyre and rim and greatly opened out the range of off-road tyres. But another problem is tubeless tyres (which do differ significantly from tube type) are rare in 18-inch size. Seventeen TL tyres are much more common.

CWCAirtight

It wasn’t on their website but CWC’s brochure mentions an Airtight™ vulcanised spoke-sealing band (left). It’s similar to the Italian BARTubeless polymer sealing I had on the Rally Raid CB500X of a couple of years back (and which CWC also offer).
I’m always keen to try something new for my Ongoing Tubeless Saga, but not so fast, chum! CWC can only Airtight a 3-inch (WM5) or wider rim. Next problem: there were no 18-inch Excel rims in that width, so it was back to a 17-inch rim in WM5 to fit an Anakee Wild. Confused? So was I but we got there in the end.

MichelinAnakeeWild

Tyres were always planned to be Michelin Anakee Wilds, one of the few do-it-all travel bike tyres I’ve not yet tried. On hearing about my plans Michelin kindly supplied them for free, along with a couple of back-up tubes which I hope I won’t need. Rear is a 130/80-17 M/C 65R TL. The front gets the larger 90/90-21 M/C 54R TL to balance the lift on the back. And it all comes with lashings of Slime.
Simon did some weighing before Sliming (add about 250g per wheel):

Stock front wheel with Pirelli MT60 90/90 + tube 13kg
Front wheel with 90/90 Anakee Wild + Tubliss 14kg
(Stock steel front rim 3.77kgsource)

Stock rear wheel with MT60 120/90 17 + tube 15kg
Airtight  Excel + Anakee Wild 130/80 17 TL 14kg

Stock steel rear WM3 rim 2.15 x 17 3.84kg (source)
Excel WM5 17 rim + Airtight band 3.5kg (acc. to CWC)

Michelin Anakee Wild 130/80 17  7.5kgPirelli MT60 120/90 17 + tube 6kg

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So, a kilo gained on the front due to Tubliss and heavier Wild tyre; a kilo lost on the back despite the wider Excel being barely lighter than the steel stocker. I wonder if there’s an error somewhere, considering the new Michelin is 1.5kg heavier than the stock MT60 and tube.
The whole ‘alloy is light’ thing can be a bit of a myth until you get to the exotic stuff. Look at MTB frames or an old, two-ton Range Rover or handlebars (right). But, although it’s been decades since I’ve had wheel problems, I’m pretty sure the CWC-built Excel will be stronger than the steel stocker.

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At 7.5kg, the TL Anakee on the back is hefty. I rationalise that the added mass is down to the tougher tubeless carcass. If it’s anything like the punctured Anakee or Tourance I rode on last November, it’ll be stiff enough to cautiously ride airless while staying on the rim until I reach a village tyre menders (right). Here are some more dims regarding 18 or 17-inch Anakee Wild tyres:

Anakee Wild 120/80-18 M/C 62S TT Max sectional width 131mm, max diameter 663mm, weight 5kg,
Recommended rim width 2.75”

Anakee Wild 130/80-17 M/C 65R TL
Max sectional width 142mm, max diameter 654mm, weight 7.5kg (verified by SV), Recommended rim width 3.0”

Both will easily fit the width of the Himalayan’s swing arm, but at the front (back) of the swing arm, clearance gets down to less than an inch with the taller 18. A bit of chain wear and you’re good to go. On the front the mudguard now looks fairly close to the new Wild, so for mud clearance I’ll lift it a bit as mentioned below.
Riding back 120 miles, the fresh Anakees rode a lot more securely than some also-new K60s I’ve ridden with other bikes. No weirdness in bends and no vibration or noise (a common complaint) that I could tell.

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Michelin have just brought out a new TPMS and sent me one to try out. It will be particularly welcome for keeping tabs on my untried tubeless set up. The unit is USB rechargeable and sits magnetically in a stuck-on dish. So it’s easy to remove or nick, and might fall out on rough ground without an extra method of adhesion.
The read-out (psi or bar) flips every few seconds between front (as shown below) and rear. It’s interesting to note how pressure climbs by up to 20% as the tyre warms up.

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Fabrications and load carrying

Apart from some custom Bark mounts, all the Him needed made was a sand foot plate welded on the end of the sidestand.

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And Simon managed to hand bend and bolt on a pair of very nice unbraced C-racks (as I’ve decided to call them). I’d originally bought the RE pannier rack from India for only £77 (right), but while cheap, the thing weighed over 5kg. You don’t need all that metal unless you’re running alloy cabinets.
Inset in the circle below, Simon pointed out a weak spot where the lower C-rack bolts to the pillion mount which is welded rather bolted to the subframe. But the unbraced rack has some give, plus the soft bags will also absorb impacts, so hopefully it will take quite a crash to break the mount. It actually wouldn’t be hard to brace from the upper curve of the C-rack to a point on the stock tail rack, just above the indicator.

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ROVAFLEX

I forget that I’m an unsung Kriega Ambassador; they’ve just sent me a set of their new OS22 throwovers (below) to try out. I was a big fan of the OS32 on my WR250R a couple of years back. The OS22s feel very rugged and weight in at 2.5kg each. This time, to save weight I’ll fit them as throwovers without the platform, and use the tabs on the back to secure it to the C-rack with brilliant q/d RovaFlex cable ties (right).

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They’re the same size but 40mm slimmer than the 32s which looks quite a lot, but the slack will be taken up on the front by the 6-litre Lomo Crash Bags (left). Hopefully I can get away without my 30-L Ortlieb Travel Zip which can make getting on an off a chore. I have a 10L Kriega Drypack (right) knocking about if I need more capacity.No six-megaton bashplate you say? On the tracks I ride these days they’re more useful at keeping flying gravel from damaging the engine paint. When it gets that gnarly, I’m down to walking pace, ready to deploy outriggers. The new tyres and firmer shock have raised the clearance a bit so the tinny, stock bashplate (below) will do fine for the moment.

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Lifting the front mudguard is a good idea now that the fatter 90/90 Anakee Wild is closer to the plastic. One time on the Tenere in Morocco I rode onto recently rained on clay which jammed the front wheel solid. A right faff to clear with Moroccan farm workers milling around saying ‘Oi, you’re front wheel’s jammed, mate!’.

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On the Him it’s easily done with slightly longer fork brace bolts (below) and some M6 spacers raising around 10mm, before the mudguard hits the downtube on full compression. It’s worth remembering these spacers (search ebay: ’15mm ø aluminum bushes M6 hole’; right) want to keep a broad contact between the brace and fork mounts as there’s some leverage stress here.

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So there it is. Just about all done in one fell swoop, as they say in Simon’s neighbourhood. Riding back to London, initially the Him felt a bit odd as modified bikes always do. The jacked up shock and new Michelins have given the bike an altered stance, but despite the sliding seat pads I soon settled back in to it.
It’s not fast, but somehow that’s not frustrating and I’ve yet to put my finger on exactly why. Am I still in the honeymoon period of enjoying the novelty and kidding myself it’s better than it is, as so many owners claim with their bikes? Or with the Himalayan, have Royal Enfield stumbled on some magical combination of looks, gearing, power delivery and value for money which, for the moment ay least, still makes this bike such an enjoyable ride?
It’s getting trucked to southern Spain shortly – a liaison stage to Morocco which I’ve done enough times already. We’ll see how I feel once the shine has worn off after a month on the trails and backroads of southern Morocco.

Himalayan Index Page
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Converting spoke wheels to tubeless

TUBELESS INDEX PAGE MOVED

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