TT analysis: Spot the difference

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Quattro Bournemouth Kawasaki man James Hillier is one of the exciting next generation of TT riders. He has a TT win under his belt and has joined the elite 131mph average club, just missing out on a senior podium spot this year.

Our very own Senior MCN road tester is only in his second year, and is on sharp learning curve as he takes on the 37 ¾ mile track.

With both on Kawasaki ZX-6Rs in the Supersport class, what’s the exact difference between the two? We used sophisticated GPS-equipped datalogging to find out.

James is starting the Supersport race in first position; I’m back in 57th. James is on a full factory Bournemouth Kawasaki Supersport bike, a missile, with 140bhp screaming horses in a lightweight chassis, suspended by K-Tech suspension front and rear.

It’s a purpose built factory TT Supersport race bike, running Metzler rubber. I’m on a kindly loaned Chris Walker race school bike, with a standard engine and a relatively standard set up.

I have the same K-Tech suspension as James and the same Metzler rubber, but despite the full Scorpion race pipe and power commander I’m down on power – though 127bhp at the rear wheel according to the RJS dyno is very healthy.

So what is going to be the difference between a full factory TT rider and winner and an MCN road tester who should really know better? For the first time we’ve data logged each bike so we can see the actual difference in true MPH.

My conclusion? I’m staggered how big the difference is. Yes I was on a standard-ish bike, up against one of the fastest TT riders in the world, but I was trying my best and riding as hard as I could around the world’s most dangerous track.

It’s amazing what the top riders are capable of. James sets off as the number 1 rider and as we set of in ten second intervals I have to wait nearly ten minutes before it’s my turn.

James is already going through the Ginger Hall to Ramsey section before I leave the line! But I still give it 100% off the line and scare myself down Bray Hill despite, knowing even if I’m going to finish last, I’m going to do it with a bullet.

Bray Hill Speed
James Hillier: 157.2mph
Adam Child: 140.1mph
Out of the slowest corner on the track, Governors Bridge, James doesn’t shut the throttle down Bray Hill or over Ago’s leap. In fact he has the throttle open all the way to Quarterbridge! At the bottom of Bray Hill James he hits 157.2mph then shortly after Ago’s leap he’s doing 166.4mph.

I on the other hand am a little hesitant, as most would be on one of the scariest sections of the TT course. At the bottom of Bray Hill I hit 140.1mph, rolling the throttle slightly then rolling it back on at the bottom. I just pip 143mph before jumping on the brakes for Quaterbridge.

If I’m thinking 140mph is impressive, James’ carrying of so much speed by keeping the throttle constant, with zero hesitation, is mind-blowing. By Quaterbridge James is 20mph faster than me already.

Crosby Section speed
James Hillier: 172.3mph
Adam Child: 159mph
James hits Ballagarey corner (Ballascary as it’s known, the place Guy Martin had his infamous fireball crash) quicker than me, which gives him a faster speed on the run up to Crosby, which is downhill. He hits the fast left hander at Crosby at just over 170mph. Holly crap that’s fast into a blind left hander, surrounded by walls and houses (it’s where David Jefferies lost his life). Next he hits the jump shortly after and continues to accelerate up to 175.1mph. 175 on a 600...

I love this section of track despite the dangers and I try not to lift the throttle, but I still pop up from behind the screen to scrub off speed and hit the left hander at Crosby at just below 160mph. Despite being over 10 down on James, it’s far from slow and scares me every time.

Up to Ballacraine after Gorse Lea
James Hillier: 163.1 mph (speed on apex at Ballacraine 55.1mph)
Adam Child: 150.9mph (speed on the apex at Ballacraine 47.8mph)
The Gorse Lea section is very fast, and determines the speed down the short ish straight before Ballacraine, or traffic lights right during normal traffic days. James is nearly 15mph quicker through this section, hits the brakes later and carries more corner speed through the 90 degree right hander.

Again I love this section fast and flowing, it’s fast and scary and considering I’m up against a TT winner I don’t think my speeds are that bad. I know I can go through the right hander at Ballacraine quicker, but it’s blind and there is only a wall for run off. 

Highest speed recorded through Glen Helen
James Hillier: 137.7mph
Adam Child: 127.4mph
James isn’t just fast through this section but considerably smoother. He also touches 135mph plus in three different areas, where I’m much more ragged, on and off the throttle. Again this is where James’s skill and experience shows.

To get from the start finish to Glen Helen it’s taken James on the Bournemouth Kawasaki 4m 28.749sec and he’s averaged an incredible 129.822 mph. It’s taken me slightly longer at 5m 1.654sec, averaging 115.781 mph. I’m riding as hard as I can, but already I’m already half a minute behind the future Lightweight TT winner.

Cronk-Y-Voddy top speed
James Hillier: 166.9mph
Adam Child: 160.6mph
After the tight and twisty Glen Helen section it’s nice to get a bit of breather down the long straight. It’s all about horsepower and getting tucked in, making yourself as small as possible. I’m pleased to be only 6.9mph down on James at this point – not bad at all for a standard-engined bike.

Kirk Michael top speeds
James Hillier: 157.6mph
Adam Child: 133.4mph
James is a staggering 24mph quicker through Kirk Michael than me, and I’m still trying to digest that. You really get a sense of speed as you brush the houses and pavements through the small village.

My ZX-6R always felt a little nervous through this section and the K-Tech steering damper was working overtime. I short shift into 6th gear to try and calm everything down where James blasts through just short of 160mph. James’ skill and bravery really shows in this section.

Ballaugh jump
James Hillier: 44.1mph
Adam Child: 51mph
Yes! finally a section where I’m quicker than a TT winner! These are the comparable slowest speeds over the famous jump. Hillier slows down to 44.1mph where I only drop to 51mph. Yet from Ballacraine to Ballaugh James has averaged an amazing 138.311mph, taking only 3m 17.815sec.

I on the other hand have averaged 122.954 mph – respectable but enough to have taken me an extra 25 seconds to cover the ground. By the time we’ve jumped Ballaugh I’m already a minute behind, try as I might.

Sulby top speed
James Hillier 173.7mph
Adam Child 163.6mph
Top speed on my standard Chris Walker race school bike isn’t bad, only 10mph down on James on his factory Kawasaki. We were running standard chain and sprockets too, which makes the speed rather impressive for a standard bike out of the box.

We may only be 10mph down in a straight line but James gets on the power earlier and brakes later, and as a result in this section I lose masses of time.

Mountain Mile top speed
James Hillier: 171.3mph
Adam Child: 158.4mph
The mountain mile is all about horsepower. Uphill all the way, it’s just a case of keeping the throttle pinned to the stop. The entry onto the mile is important and so is the braking at the end for the Mountain Box, at both of which James is considerably better at than me.

The main difference in speed here is down to power and weight. James has more of the former and less of the latter, which means my standard motor will only pull 158.4mph uphill, throttle to the stop.

Slightly further up the mountain at the Bungalow we can check the times again and James is pulling even further away. To get from the start/finish to the Bungalow has taken James 14m 41.359sec. I’m nearly two minutes behind now at 16m 30.815sec.

Up to and through Creg-ny-Baa
James Hillier: 158.3mph > 55.6mph, 54 degrees of lean (apex) > 172.5 mph up to Brandish
Adam Child: 144.4mph > 45.4mph, 47 degrees of lean (apex) > 158 mph up to Brandish
This is one of the TT’s most famous sections, one most TT fans will be familiar with, which is why we’ve looked at it so closely. James passes Kate’s Cottage at 115mph, with 40 degree of lean and then accelerates up to 158.3mph!

I on the other hand pass the apex at Kate’s at 103mph with 37.8 degree of lean. I just about squeeze 144.4mph out of the bike before jumping on the brakes for the famous pub.

James brakes later and carries more corner speed – 10mpg more at the apex and carrying a staggering 54 degrees of lean – and don’t forget this is on the road on road Metzeler rubber! I’m neither as brave or as skilled, slowing down to 45.4mph and carrying 47 degrees of lean.

Meanwhile James again gets on the power sooner and reaches 172.5mph before Brandish where my eyes are on stalks as I hit 158mph.

First we’ve shown the staggering difference between a top flight professional TT rider, and a brain-out MCN road tester. I don’t mind admitting I got my arse kicked by the professionals; I was trying my hardest and my best lap of just short of 112mph average has left me over the moon.

Secondly we’ve shown how good Kawasaki’s standard ZX-6R is. The engine was standard, so was the gearing and we didn’t even change the oil. We just filled up the fuel and thrashed it repeatedly. We had extra power with the full race Scorpion pipe and power commander and K-Tech suspension kept everything under control.

But even so, for a near-standard bike to lap at decent lap time with only a few chassis modifications proves how amazingly good standard supersport bikes have become. And how the human element will always make the difference in motorcycle road racing.  

Thanks to:
Chris Walker race school and Chris himself.
Bournemouth Kawasaki, the whole team.
Frank Wrathall
Hel Performance
Scorpion exhausts
Metzler tyres
James Hillier and family
Jackson Racing
RJS performance centre
K-Tech suspension

Read the latest stories causing a buzz this week in News…

Adam Child

By Adam Child

Former MCN Road Tester with 15 years road testing experience on all kinds of bikes