Category Archives: Project: Honda CRF 300L

Project CRF300L: old tubes and dirt bike rims

Project 300L Index Page
See also: Tubeless conversions

After less than 20 miles I’ve already got myself a rear flat, luckily at home. At some point I was going to remove the stock IRCs, seal the rear rim for tubeless tyres and fit some proper tyres for the ride to Morocco. May as well do that job now. While I’m here, allow me to give my usual shout-out for Motion Pro Bead Breakers, an alternative to standing on or otherwise levering the tyre bead to achieve the same result.

I spun the wheel on my exciting new stand you just read about but couldn’t see any nails or similar. I did wonder if I pinched the tube a couple of weeks back, but if I did, it only gave out now.
Pulling the tube out I was shocked to see a huge gouged hole like a mouse had got in there. Maybe I did it just now removing the tyre, but can’t say it was a struggle. Who knows, but I also noticed how the folded rubber tube cracked like it was ancient. Then I clocked a date stamp from November 2014. Yikes, nearly 9 years old! Well I suppose I should be impressed that a: Michelin date-stamp their tubes (can’t say I’ve ever noticed this feature before) and, b: that this tube lasted nearly nine years without a repair (assuming it had any use in that time)! Obviously the tube isn’t worth repairing. Good thing I noticed now. I just picked up some old Mich tubes from 2017 and they are nowhere near that far gone (nor do they have that date stamp). Could it even be a fake Mich tube?

Cracked rubber; not a good look.
No MT stamp
No lip so unsuited to DIY tubeless sealing ;-(

When it comes to sealing the rear rim, I was also bummed to see the stock Excel J 18 2.5 rim has no safety lip, in which case I can forget about doing a TL conversion. That’s odd as, like I’ve mentioned over the years, I recall actually grinding the safety lip off a rear DID rim on my tubed XT600 way back in 1985 to make desert tube repairs easier. I assumed such safety rims had become defaults on all spoke/tube rim as they help a tyre stay on the rim when it loses pressure.

This means I’ll have to lace a new lipped MT rim onto the hub to get TL – a couple of weeks and a couple of hundred quid. And while I’m at it I may as well get professional CWC Airtight sealing (left; as on my Himalayan) instead of my labour intensive DIY efforts, as on the Africa Twin. Or I could just live with inner tubes. On a travel bike (as opposed to a weekend trail bike) not sure I can go back to all that potential aggro and added toolage.

I also noticed there’s no cush drive on the 300L. It makes me think this is a dirt bike rim from Honda’s MX bikes. A part number check would reveal all – maybe later or you can do it for me.
Cush drives add weight and expense and absorb a little power, but reduce drivetrain lash to the transmission including the chain.

The thing is, at 28hp and however few torques, a 300L hasn’t got enough grunt to strain the components that much, so I can live with no cush. Apparently my old XR650L was the same but I never even noticed. A mate who’s currently importing one has, and dug up various rubber-insert sprockets (left) to reduce the lash from the much torquier 650 thumper. And in fact the 250L I had years ago didn’t have cush.

So net result of today’s puncture:

  • it pays to verify you inner tube’s age (if you can) as well as old tyres (all have date indexes). Or just get new tubes.
  • If I want a tubeless rear I’m going to have to get a new wheel built up on an MT rim, in which case I may as well have a proper sealing job done like CWC Airtight™.
  • OMG there is no cush drive ;-0
  • Is it time to consider mousses? A light slow bike like a 300L is suited to them, but afaik they come rated at no more than 15psi which to me is on the low side for road riding, even at only 60mph.

Project CRF 300L: Acerbis tank, crash/pannier bars, USB

Project 300L Index Page

My Acerbis 14-litre tank finally arrived from Italy, not as fast as some crash bars from Guang Zhou in just 12 days. So high time for a day of spannering and probable gnashing of teeth. Rally Raid are also sending me their trail wheel wrench with a 24mm ring for the rear and 14mm hex for the front.
Rally Raid suggest that from new you may want a full-size socket and tool to undo the axle first time so the hex is another tool to buy – an afternoon wasted locally before I submitted to amazon ‘next day’. But the idea of a recessed hex fastener in the front axle is actually quite clever – I’m sure the AT had one too and car gearboxes have similar drain plugs so there’s no protruding bolt head getting rounded off by rocks.

The other day after swapping the front tyre back to OEM IRC, I wore myself out trying to refit that front wheel axle with the bike perched over on a log. A lip on the axle shaft makes shoving it over to reach the thread on the other fork leg confounding; at least first time.
I like to think an upright, stable bike sat on a bike lift will make life easier. Luckily there was one an hour up the road for just 99p. Years ago we’d have laughed at such decadence and just used a milk crate. But when’s the last time you saw one of those?

Acerbis 37 litre

Acerbis tank
Still in the old carb days, Acerbis plastic tanks had a reputation for not always fitting so well – as did much after market gear, tbh. And now in the efi era you have to swap a huge fuel pump assembly with associated hoses and wiring.
But it seems Acerbis have upped their game in the 20 years since I fitted a gigantic 37 litre whale to the back of my XR650L (left). With none in the UK, my black-only tank cost me £320 imported from Italy. The finish looked a lot better than I recall, and the complex shape suggests a nod to the precision potential of CAD. Here, J-Mo describes the Acerbis tank job in meticulous detail, including tips and possible traps. Time to follow her lead.

New tank adds 6 litres to the 7.8 stock without looking massive.
After years I [re]learned syphoning. Use a thin long hose; shove it all into the tank to flood the hose; then pinch the end and pull it out and down way below the tank to the container, then release the pinch. It will flow at more than a litre a minute. A good skill to know in the post-fuel tap era.
Once unbolted, to release the tank pull off a vent hose coming up from the emissions canister (it pipes up through the tank to the fuel cap so fuel will not pour out). Then unclip white electric plug and unclip thick fuel line (can be a bit stiff). All explained on J-Mo link.
Tankside protuberance may protect radiator on RHS a bit?
In black you’d hardly notice the difference. Nice job Acerbis!
I also fitted a Cool Cover. Will improve comfort and easy to add padding underneath, if needed.

A calibrated refill revealed the tank holds 13.85 litres which is a figure I’ve seen elsewhere. That will do me and at a dependable 85mpg or 30kpl = 415km or 260 miles range.

Protection

A slim bike like a 300L doesn’t need engine crash bars – a well spec’d bash plate like the Ad-Tek the seller fitted to mine does the job.
But CRF-Ls have a vulnerable rad (like Africa Twin 1000Ls, as I found shortly before D-Day). The 300’s rad sticks way out into the RHS breeze so when you fall it takes the impact via some plastic. I think they’re all like this these days but what a crumby design for a small trail bike! Adventure Spec make a radiator brace (left) which bolts a sturdy frame round the rad and looking again, it’s actually seems OK for £66 and 240g.

What I really wanted were currently unavailable Outback Motortek bars (above right) which protect the rad, not so much the lower engine which a good bashplate does. Looks like they may be back sooner than I thought, but in the meantime I bought some Chinese no-name crash bars (above left; 4.2kg). Tellingly there was no fitted image but they looked similar to the Outbacks, or maybe I just saw what I wanted to see. They’re well made but turns out they fit low and the bashplate would have to go. I may have a rethink, fit them and get a flat sump plate instead.

Wrong bars. Or are they? Bags would fit nice and low. May have a re-think and revise bashplate.

As it is, unlike an AT etc, a 150-kilo 300L has much less self-destructive mass when it tumbles, So I think 22mm ø tubes at 2mm thick as used by China bars and Outback Moto are a bit OTT. I bet 18mm would do fine, as on the Himalayan’s tank racks (left). But 22 is what we get – possibly because of a shortage of well-braced/spaced mounting points to securely support a thinner structure? That’s how it seems on the China bars. My weldy chum who made my Him’s rear ‘ear racks’ was insufficiently motivated to tackle a complex pipe-bending task for anywhere near direct-from-China, let alone Outback’s prices.

Another reason for wanting tank/rad bars is to carry luggage up front where you can see it and get to it from the seat. That way you dispense with a rear pannier rack so the weight penalty can balance out) and just use a tailpack. ‘Fishform‘ they call this in kayak hull design – ie: more width up front. This way the engine/radiator bars double up as pannier racks.
I tried this idea with the AT (above left), and when I got back noticed serial RTW-er Nick Sanders had done the same on his T7 RTW bike (above right). A side benefit with soft bags on tank-side racks is the bags absorb impacts before the rack, leaving the rads asleep in their beds. I do wonder if these low Chinese bars with a wide frame are to mount a pannier may work well after all.

Later I lined the bars up under the engine and it was clear for small panniers the mounting would be way too low and probably drag on corners. Back on ebay they do go.

USB power plug
I took the chance to fit a USB power plug. You can buy them on ebay pre-wired with a fitting matching a spare switched socket somewhere behind the headlamp. ‘Switched’ means it only powers up with the ignition on. Annoyingly mine turned out to be a USB adaptor fitted into in a cigarette lighter which means another layer of electrical connection to play up, but I suppose the USB plug can be easily inspected changed. No all work or for long I found in March.

First I had to remove my GP Kompozit screen which weighs just under a kilo, fyi. Next, undo a pair of allen-head rubber mounts either side of the headlamp assembly and remove the whole thing. The auxiliary socket is soon located among the black spaghetti and the over-long USB plug lead clicked in.

Annoyance. Or is it just getting the knack?

But to quote the late Haynes ‘assembly is not a reversal of dismantling’. Is it ever? The lower mounts wouldn’t line back up. I assumed the new wiring was in the way and pulled it through but still no luck. Rubber grommet spacer-washers get pulled off as you try and shove the headlamp onto the mounts. Then I enjoyed a bolt dropping down onto the mudguard top. I managed to flick it out and resumed alignment; it did seem like the mudguard top was fouling the cowling – as John Cooper Clarke might have said. I removed the mudguard (loosening might have been adequate) and loosened the top headlamp mounts: that did the trick. It all went together like it should.

Next: will the Garmin charge off the bike once the ignition is on or go into mass storage mode. It did the later when the USB gets in a muddle. Go to Garmin Menu > System and change from Serial to Spanner mode. The Garmin will switch on as normal and a sign that it’s working is a flashing charging battery icon, as below.

Honda CRF 300L: first impressions

Project 300L Index Page

Impressions after 120 miles

  • Light weight
  • Adequate power
  • Proper screen
  • Returned to stock gearing (now ticks over @ 4mph in 1st)
  • Rally Raid suspension
  • Tall bars and other functional accessories fitted by seller
  • Mpg
  • Thinned out seat
  • Swingarm chain alignment marks
  • Annoying white rpm warning light
  • Mitas trials tyres on the road
  • Pathetic tool kit
  • Tiny tank
  • Vulnerable radiators

After replacing the front sprocket with the stock 14T and leaving the oversized rear for later, I set off for a 100-mile ride to Dorset. Had I looked properly I’d have realised the rear was actually a massive 45T not 42, as the seller claimed. Stock is 40T so that explained why I seemed to be belting along at 70mph+ along the A3 and M27, but cars were still passing me stuck in the slow lane.

The 300L is so light it initially feels skittish; I wouldn’t fancy it in strong crosswinds. But the proper screen (and my Mosko jacket) helped hold back some heavy showers and the thinned-down seat (from Peak?) had just about 100 miles of padding left in it.
Talking of seat comfort and convenience, I reflexively removed the 1970s relic seat strap. Did Soichiro Honda impose some edict that they shall be fitted to trail bikes in perpetuity? The other thing I did was saw open the rear seat bracket so that removing the seat means just loosening the two frame/rack bolts either side, not removing them altogether with washers and spacers tumbling into the gravel.
Fyi my lowered seat height with the stock rear IRC tyre refitted is 34.5″ or 87.6cm which is nearly an inch lower than Honda’s specs at 880cm.

I’d never heard off the annoying white light in the console which starts flashing ever faster as you pass 7000rpm. The red line is another 3500rpm away, so what’s the point of it? To warn you to change gear or you’re going too fast? Whatever, it seems it can be adjusted up the rev scale and out of the way (left).

I’m not so keen on the ET 01 and 05 Mitas trials tyres either. The seller fitted them for the LET. I’m sure once aired down the grip is amazing in UK mud, but the soft, square knobs squidge about at fast road speeds.

With the gearing still lower than stock, I have to assume that the speedo was over-reading even more than normal, but on the open road it did feel like the L held up well against what I recall of my Himalayan, and is definitely much better at speed than my WR250 with similar power and weight. And, contrary to my impression of riding a near-new 300 Rally last year, there’s definitely a tad more poke than my old 250L. A few 300L owners have told me the bike loosens up substantially once past 1000 miles, which I did somewhere around Southampton.

Arriving with one bar on the fuel gauge, I filled up in Dorset with 5.7 litres at 110 miles on the odo. That means there was over 2 litres or 40+ miles in the tank which seems unlikely over that distance. An average of 90mpg was shown on the console but I think the gearing may have messed with the odo reading. We shall see.

A couple of days later I refitted the stock 40T rear sprocket and IRC rear tyre. With a thick Michelin tube, the 4.00×18 Mitas weighed 6.9kg, while the IRC and a cheap tube were only 6kg – not a huge difference. And amazingly, both tyres and tubes were heavier than the back wheel, now at 5.3kg with a 40T sprocket.
The near-new Regina chain fitted for the seller’s very low 13/45 gearing was now a link too long and I’d left my chain breaker in London (I knew this would happen…). The OEM chain supplied loose was missing the joining link, plus I’m not sure I want to bother with it, even as a burner. I soon learned that you can’t bash out chain pins with a hammer and punch like you can on a pushbike; some serious force is needed, or YouTube suggested grinding off the end of the pin then prising the plate off. I don’t have a grinder either and a hacksaw didn’t work but luckily the Gear Box Bike Shop in nearby Poole was open on coronation Sunday and zipped off a link for a fiver.

Underside alignment mark – WTJOF?

While readjusting the cleaned-up chain, I took a moment to lament the passing of footproof snail cam adjusters, I bet there’s a way of retro fitting them to fiddly lock-nut adjusters. And is it me, or is the swingarm alignment marker maddeningly on the wrong, underside of the axle? I can’t bend like I used to could so had to lie flat on the ground, which means getting all the way up again. One… two… three… Ooof!

I checked the spring rate on the Rally Raid Stage 1 shock. On top of the spring was marked a surprising and reassuringly firm 100nm which is what it feels like. No wonder the seller found the 300 a bit tippy and decided to sell. I’m tempted to splash out another 200 quid on an HPA (above right) which seems to be a special order from Rally Raid, but am told it may need a change of spring. We shall see.

The bike’s tool kit sits in a space-wasting plastic box. I’m sure someone could fabricate a more functional replacement or even a 2-litre fuel cell in its place. Once opened I’m even more disappointed than expected: a single fat 14/17 open spanner and a pair of allens, enough to remove the mirrors, seat and side panels. Rally Raid make a nifty combo wrench (left) which does both wheels for under 30 quid, but it’s not in stock. Once I have that alongside my trusty Motion Pro Trail Toolkit with an added 8mm socket and a couple of allens I’ll be good to go.

3-4 mph at tickover – nice

Now back on stock gearing and rear tyre, I set off across the Dorset heathland to verify the odo against a GPS, while assuming the speedo will indicate the usual mandated 8% over. Speedo accuracy isn’t so important to me, but on a travel bike you want to trust the bike’s odo which are somehow engineeringly unlinked to the exaggerated speedo reading and often manage to be nearly spot on. Result: over 10 GPS miles the 300’s odo indicated 10.15, so odo is 1.5% over. I can live with that.
Also, riding along at tickover in first, the speedo indicated 3-4mph which is about as slow as I can balance sat down, and just as it should be for low speed control for do-it-all trail biking. I really wonder why the seller lowered the gearing so much – he rode the Lands End Trial, not the SSDT. I remember my XT660Z did an annoying 8mph at tickover as do many bikes. Way too high for tricking along or not fragging the clutch on walking-pace climbs. As I mentioned in my quick ride on a 300 Rally last year, the 300s do seem to have ‘Goldilocks’ gearing: low 1st matched with an overdrive 6th.
Other good things I noted. Even though the seller was shorter than me, the Renthal bars he fitted are, for once, just right for me when standing. They don’t look that tall so I think this must be innate to the bike’s design. What a relief not to get bogged down in the usual risers and re-routed cables, even if I might have prefered brace-free FatBar.

Out of interest and with the luxury of a flat, garage floor for the first time in my biking life, I decided to do the bathroom scales trick and weigh the bike, one wheel at a time. Result: with an added rack, bashplate, screen, frame protectors, Rally Raid suspension, barks, tail tidy, and a full tank (‘kerb weight’), my 300L weighed in at 146kg. It feels like it too and if you deduct say, 4 kilos for the listed accessories (some of which – bars, shock tail tidy – save weight over stock), that matches up well with Honda’s 142kg kerb weight claim. Next jobs: get that weight up!

• Acerbis 14-litre tank
• Chinese radiator crash bars
• USB power take-off
• Cool Cover
• Refit front OEM tyre
ª Go somewhere good