Tyre pressures with pillion?

[Fallout]

The manual specifies to run the Tiger rear at 42PSI. I actually run it at about 40psi because I prefer the softer feel (or at least, it feels fine at 40!). However, recently taking a pillion has started shredding my brand new Battlax. So I think I need to get the pressure up to help counter this problem!

The question is, how much? I can't find any mention of pillion/weight PSIs in the manual, nor on the Tiger forum, nor does anyone seem to have any decent advice there. I'm thinking if the book says 42PSI and I've been running 40, then maybe 45 is a decent enough step up without being overkill. Any ideas on how to work this out or what would be a sensible pressure to try?

[Luckypants]

I had a similar problem with the VFR last year and made this thread http://forums.sv650.org/showthread.php?t=182686 which garnered useful advice from the collective about increasing re-bound damping to control the extra 'bounce' in the spring due to the extra pre-load for pillion/luggage weight.

I also had Michelin check the tyre. The upshot was after Michelin looked at it was that the tyre was overheating leading to accelerated and uneven wear. Partly this was due to an unsuitable tyre for pillion use but also under inflation for the load. I was running at 42 psi, but as a result of Michelin's advice and my own research I increased this to 44psi for pillion (45psi with luggage as well) work. Honda say 42 psi for both solo and riding with pillion. Basically my research told me that a tyre needs to increase pressure by 10% when hot in normal road use, so I experimented a little on my favourite twisty 11 miles and found that at 42psi the pressure increased by 15% indicating that the tyre was getting too hot, upping this to 44psi the pressure increased by 10% indicating the correct temperature. Even though the gauge said 48psi when hot at both 42psi and 44psi cold pressure, obviously at 42psi the tyre gets hotter in order to raise the pressure by 6psi.

HTH

[Fallout]

Thanks buddy. I don't know what I'm realistically going to do about rebound and other shock tweakage, as that thread is suggesting. I suppose I could play with it over time, but I suspect it'll be hard to judge it's effect on tyre wear, and like you I'm not really going to be able to tell if the rebound is right. I've spent my riding career on ****ty old bikes with spring leaf suspension from western stage coaches. The Tiger is as advanced as I've ridden, so wouldn't know any better!

At the least the PSI suggestions you've given me are definitely worth a try. 44/45 sounds like I was expecting, having chatted to someone else as well, that's what they thought. I'll give that a bash for the next 500-1000 miles and see how the wear changes. Fingers crossed it'll be enough to nip this wear issue in the bud.

[Luckypants]

I think you do right to just change pressures to start with. Get your gauge out and set the cold pressure after the bike has been outside 30 minutes or so if kept in a garage, you need the tyres to be at the ambient air temperature. Then go out and do a 'normal' ride for you with pillion of at least 10 miles and then check your tyre pressure as soon as you get off. It should rise by 10%. Experiment with cold temps until you get it right.

When you're happy with tyre pressures, if the tyre still doesn't clean up after 1000 miles then look at tweaking the suspension.

Run the rear at 65psi and the front at 50psi, that should sort the issue one way or the other.

[Biker Biggles]

Originally Posted by specialone

Run the rear at 65psi and the front at 50psi, that should sort the issue one way or the other.

Thats agood way to discover the "hardness factor" of bits of roadside furniture and whether your CE rated clothing actually works.

[Bibio]

as said add a few PSI but also start by winding your preload up as you might be running out of travel, this will increase tyre wear due to squashing the tyre when the shock bottoms out or is reaching the lower end of it's limit.

as for setting up your suspension, i wrote a basic guide on here somewhere.

[johnnyrod]

As said by Luckypants above, tyre shredding is really more down to the suspension not being too kind on it than the pressure per se. It will have a tough job with a pillion on a powerful bike though!

[Luckypants]

Originally Posted by Bibio

as said add a few PSI but also start by winding your preload up as you might be running out of travel,

I had assumed that Fallout had already set pre-load to compensate for a pillion, he seems clued up.

[Fallout]

Oh, I'm clued up! Whether I can be arsed or not is another matter entirely. It's wound up pretty high already but I might as well max it out and see how that feels. It's definitely not running out of travel as I would expect a knock or jolt or something, but there's quite a lot of travel on the Tiger and it's been pretty smooth for the most part.