Xr 650r
 

I'm building my '03 XR into a deep wilderness RTW'er.

I recently purchased the Acerbis Safari tank set-up(23Ltr front, 13Ltr underseat + seat). I bought this second hand.

I've heard a disturbing report that the underseat tank has a tendency to split! Has anyone else heard of this or have had experience?

Also, has anyone actually taken these to the limit of mileage? I've heard its 650 km's +, but I would like to know for sure.

yup, the seat tank splits. for extra adventure, the fuel can then ignite and, if you're as unlucky as Bertil, you only find out once the fire has taken hold of your luggage, jacket and burnt through the strap of your rucsac. still, he survived the adventure so all is well and I'd avoid them like the plague. you may also struggle to fit luggage and reach the ground. soft luggage increases the risk of cracking the under-seat tank where it touches the sub-frame

that said, you've bought it now ;-)

range depends on terrain, but I'd plan on 17-20kpl unless its either all sand (13-17kpl) or all tar (20-22kpl).

with 24 + 13 litres, you need to do 17.6kpl to hit 650km. ie that's not unreasonable, but I'd plan on doing some less demanding legs before you commit to needing it!! can you rig the reserve on the main tank to somewhere around 7 litres so that you know where your point of no return is? (ie 7litres in front and 13 behind to get you back home (if the rear hasn't split yet))

enjoy your trip - great bike, but I wouldn't rely on the sahara underseat!

Cheese & Crackers! Thanks Rich, you really didn't have to scare the Begeezus out of me like that did you? I mean, all I was really worried about was actually running out of fuel in the tank, not roasting my royalty as I'm riding!

Anyhow, perhaps it could serve as a water tank then? I don't like the idea of only having 23Ltrs of fuel onboard though. A few years ago, a mate of mine poured boiling water into the plastic tank of his WR 426. He then proceeded to pump the tank with compressed air. The resulting increase of capacity when it cooled was an extra 2Ltrs. That 2 litres may come in real handy some day. Has anyone tried this with a large capacity Acerbis(or similar) tank? If so, how did the final fitment go?

I have also just bought a Mikuni TM40 pumper carb for the 650. It is said to increase fuel efficiency(not to mention power). Does anyone have experience with the mileage from using this type of aftermarket carby?

water is good ... unless its all leaked out by the time you need it!
it really depends on your plan. if you're going to need, say, 500km range then you need 25-30 litres. I've found plenty of places where 500km range is useful, but you get to meet more locals if you have a shorter range!

personally, I'd prefer the IMS tank (and not fret about the diaphragm pump). mine started life at 26/27 litres, but stretched with the weight and sun's warmth so it took 29 litres :-) you can supplement this with fuel bladders of 8-10 litres.

or there's a 45 litre alloy tank from switzerland ... that should do for 1,000km!

Ok, your still putting the wind up me. All my water leaked away? Sheesh! What are you trying to say Rich? Only the biggest fool would utilize the underseat Acerbis tank?

As for the 45Ltr alloy tank, the thing that worries me is if you drop the bike...onto a sharp rock! Alloy is not as forgiving as plastic, I have personally had to walk a very long way due to a perferation in the bottom of my 'alloy' tank. At the same time I was coming down with chicken pox. I thought(I wished at the time) that I was a dead duck.

Also, a 45Ltr tank up front in one hit!? I think it might be comprimising the whole reason for using the XR-R in the first place - the ergonomics and handling(even though any long distance tank will affect the ergonomics, but 45 will be espescially drastic).

Hey Rich, you mentioned 8-10Ltr fuel bladders, can you elaborate on these, please?

IMO, the sahara underseat option is one thing for rallying and quite another for going out on a limb without support. we had alloy rear tanks on our XRRs - 11 litres for water (thinner on left for airbox hump) and 13 for fuel. there are pics at www.overland-solutions.com. the side skin was 3mm to protect against rocks and I tested the protection very hard one afternoon! the real issue for me was welding alloy boxes - I lost all the water from the left when the bottom seam unzipped :-( fortunately, we weren't in the bush at the time.

there's no simple way to give a good bike (eg XRR) 500km range plus water and kit for several days. but most people don't really want to anyway! if you DO want several days autonomy the handling and weight will be compromised, but not too badly. if I were to get another XRR, I'd take a close look at the 45l tank - my XRL was fine with a 43l tank. as you say, keeping all your fuel in one place sounds risky - but even if you distribute fuel, you still have to get it to the carb and that's one of the Achilles heels of the Adventure - the tap is vulnerable.

bladders ... there's a good thread http://www.horizonsunlimited.com/hub...e-gas-can-5231. I tested and used ortlieb bags with flush Nalgene lids so that they fold away to nothing. 8/9 litres storage for about £20-30.

O.k. That kind of sorts out the fuel situation, thanks Rich, your advice is appreciated.

Suspension. The front takes care of itself, what with Honda using a quality set up that is easy to shim to accept a little extra load. The rear, however is a different matter. The shock can handle aggressive race orientated riding, but for sustained overloading I think a heavy duty spring is needed. I'm over 100kg's and will probably have in excess of 80kg's of equipment. Does anyone know where to get a heavier spring? Does anyone have any suggestions on re-working the shock for monster sustained loads?

FWIW ... leave the front alone and consider replacing the rear shock. we replaced the rear spring with a specially wound one 20-25% stiffer, but I'm pretty sure you can't adjust rebound damping and that's how I came to dislocate my collarbone ... we were pussying about too slowly in deep sand and the shock was overheating ... compression damping was maxed, but I couldn't find any control for the rebound so I got fired over the bars as the bike flipped on its nose at 30kmh.

gear ... what are you carrying? with full rear tanks and all our gear, there was 10-18kg on the front (incl fuel bladder) and 60kg on the back (18kg was structure/tank + 22kg fuel & water + 20kg tent & gear)

Now my bike is the opposite. The rebound damping is easily adjustable and very good. But the compresion adjuster does little or nothing! My bike is an 04 Aussie model, I wonder if yours came with a different shock?

I've got the Acerbis tank. Mine has stretched to 26 litres all on it's own. I've also bought a couple of those Ortlieb bag thingies, but I'm yet to use them.

Rich, sorry don't want to sound a smart arse having just bought a 650, especially as you've done a hell of a lot on the XR650 and i've read your stuff with great interest.

Both my Aussie import (and my mates Euro spec bike) have rebound damping adjustment on the bottom left hand side of the shock, though its well hidden by the swinging arm. I only found out after finding mine was like a pogo stick the way it was set up when i bought it, as the previous owner had backed off the rebound damping.

I expect I´m wrong! sorry for the misinformation. I recall an adjuster at the bottom of the shock and I wound that up, but to little effect. I expect you´re both right that its rebound adjustment.
I´m thinking of getting another XRR so I´d appreciate ideas on later, better mods and shocks. I probably won´t ride it as hard as previous trips as my body could do without the pain and suffering of unplanned dismounts.
cheers
Rich