TRAIL ZONE

ASK DR PHIL:

COOLING AIR-FLOW AROUND WR450F CASES

Hi Dr Phil: Mudguards in front of engine cooling radiators, oil cooling radiators, crankcases and now that inconvenient little gap between the frame tubes (Radiate Me page 73 of TRAIL ZONE issue #29). Call me a classic bike fan if you wish (ex-Triumph Thunderbird and Greeves Scottish), but put the mudguard around where the mud and stones comes from and not where it goes. Put it back around the tyre. Just like on the new Tenere. Second point, what is this mud you keep mentioning? Victorian two-wheel trail riders need to be very adventurous to find any. Keep up the good work. I might even add a motor onto my Specialized Epic dual suspension mountain bike one day when I am too weak to push the pedals.

-- Dave Chadderton, via www.trailzone.com.au

Thanks for your email, Dave -- I'm pleased to see you too are a Greeves fan-club member, I’ve got a ‘72 or ‘74 model MX 250 Griffin! You make a good point about stopping mud at the front wheel with a mud guard, unfortunately with today’s 320mm front fork travel the rear trailing edge of the front mudguard would be skating along the trail at only half front fork travel if we implemented your suggestion! Not like the old days, eh!? Actually Yamaha Australia's Queensland office has done plenty of evaluation on this matter, what with their extremely hot summer temps, and they (and I for that matter) have proven that a roaring hot set of dirt bike thumper crankcases cools SUBSTANTIALY BETTER surrounded by air and not caked solid-to-the-frame-rails with dried mud, and their clutches last longer too due to cooler oil temps.
-- Dr Phil, www.trailzone.com.au (Want to comment? Then email askdrphil@trailzone.com.au)