Race Bike Improvements

**bluninja** · 5th June 2003, 14:51

After seeing KK get so excited about racing and getting some go faster parts I thought I'd add this thread. Maybe some discusssion and info will flow.

My SV650 needs to be upgraded for racing. Apart from the normal psychological need to 'fix' the bike before upgrading the rider I do have some issues with ground clearance and suspension on the bike. Since shedding 40 kgs in the near future is not an option (unless I ride with no head, or only one leg) I need to beef up the springs.

Here's my shopping list.

1) Race Tech front springs at 1.0 kg/mm, Gold Valve emulator for cartridge forks, 20 wt oil. Approx cost $700

2) Ohlins rear shock $1400

3) Ignition Advancer (5 hp gain) $60

4) Race bodywork $900

4) M4 Exhaust $1400 (5 hp gain)

I intend doing items 1 and 3 fairly soon, and hope that the rear spring is beefy enough to cope for now. Cheap HP, plus better handling. Ohlins would be next, as it finishes the handling off and allows me to raise the rear for better handling and improved ground clearance. I would love to do the exhaust and a bit of rejetting, but, I can probably get more useable speed by streamlining the bike with a race fairing.

The questions I have is whether, having the suspension sorted, I should get tyre warmers, and then move to slicks after that. Or would I be better doing the bodywork, and then the exhaust/jetting first?

So if you don't have sponsors with bottomless wallets, and can only spend a bit at a time on a racebike...what are the best mods (after rider training, fitness, skill), and which ones give the best valu for money?

TTFN

**SPman** · 5th June 2003, 16:51

Tyre warmers and slicks sound VERY serious! - how pro do you want to go?

Personally, I would go jetting/exhaust, then bodywork.

**Dave** · 5th June 2003, 18:00

Once you get to the top 10% of the riders in your class then you will need to spend the money to get tyre warmers.All they allow you to do is go hard with confidence right from the green flag.
The thing that causes tyres to need replacing is heat cycles-IE> the number of times a tyre heats up and cools done,eventually wears cures the rubber,making it less grippy.Tyre warmers will mean that in a whole day,the tyres will only go through one cycle instead of 5 or 6.But were talking about the last 5% performance from the tyre here.Not going to be an issue at clubmans or trackdays.Slicks are great but unless your going to buy wets and extra rims,you'll be watching an awfull lot of racing from the pits.
At least road tyres(race compounds) will still cut it in the wet.

**wkid_one** · 5th June 2003, 20:35

Si - before you go RaceTech go see Suspension Tech in Ellerslie - local guy (support him) and better price!

Refer to my previous comments for KK - you only bother upgrading the bike when you are riding the socks off it. Why spend money on improving the bike - when you never realise the potential coz you are the limiting factor.

I would do the Handing (suspension) first. See someone to rate the shock and springs to your body weight. Have the geometry altered if you can - fix rebound, compression etc. That will be your biggest gains.

Look at other things like reducing unsprung gyroscopic weight - like rims and brake rotors as this will not only improve power to weight - but also handling immensely.

**bikerboy** · 5th June 2003, 22:53

Yeah, carbon fibre wheels !!!!!!!!!!!!

not my money, haha.

**wkid_one** · 6th June 2003, 10:31

Hmmm - one doesn't need to go that far - smaller rotors, lighter rims, playing with wheel base, geometry etc is usually the best first bet. Magnesium good (however will Simon's propensity on hairpins - life expectancy might be limited - LOL j/k).

It is funny how everyone looks to ultimate power to improve their riding - when in actual fact the $1000 you spend on that - would be better spent on either making the bike handle better so you can carry more overall speed or on personal tutorage so that you learn to ride quicker/safer/smarter....why bother spending money on straight line speed??? Races are won and lost on the corners generally - not straights. Think about this - someone can corner quicker than you - you then just spend the whole straight catching up with them only to see them pull away again in the corner!!! Not my idea of fun.

The other thing to consider is low stress power improvements and making the improvements in a systematic and planned fashion. Why bother putting a pipe on? It may give you 7hp - but where in the rev range does this come in? Is it useable given the natural useage of the bike and rev range? Do you get it at the trade off of lower HP in another part of the rev range? Does it affect fueling and give you mid corner stuttering? Does is reduce responsiveness? Does it mean you are then having to spend money on dyno time, jetting, air filters, pistons, etc etc.

Plan your power improvements as the engine is designed to work in a balanced fashion.....freeing the exhaust may have an adverse impact on the power due to restricted airflow.....there are trade offs with most things - and it can end up costing you a lot more than you think in the long run as 'fixing one problem' generates another one that needs remedying.

Just food for thought - why do you think all Major race teams spend so much time and money on telemetry of the bike/car - trying to optimise the setup of the bike/car

Setting the bike up also generally has the best 'bang for your buck' in terms of results/improvements.

**bluninja** · 6th June 2003, 12:05

About riding the socks off your bike. My suspension upgrades are needed as 'the bike is undersprung for my weight. I don't want to wait for the front to constantly chatter and slide under heavy braking cos the forks are bottomed out and then bounce up as soon as I release the brake to turn in with a wallowing bike. I spoke to Norm at Suspension Tech, and Peter at Hawera Motorcycles. Seems the only thing to do with the rear is replace the unit, or live with it. Seems silly to spend time and money with the bike out of action testing the spring to find the rate, and then finding a spring to fit with the right rate......which would then overpower the damping on an unrebuildable and unadjustable shock.

I have invested a lot of time investigating the power side. The M4 exhaust improves bottom end torque and overall power, without the need for rejetting. Yes I could get more power by doing the jetting, cams, and airflow. But I want to work to keep the standard airbox to be able to race in F3 in the nationals. I agree totally that it's something that needs to be aproached systematically, and it's not top of my list.

I guess the same has to be said for suspension. Front and rear suspension must balance...I can't just up the front springs. If I up the springs I may need to upgrade the damping to cope. If I change the bike geometry for quiker steering I may make it less stable, and if unable to dial out, would need a damper.

Upgrading a race bike is rather a holistic exercise. Power is nothing without control anybody?

TTFN

**wkid_one** · 6th June 2003, 12:09

Tell me about the suspension issues - VTR's are notoriously soft in the front - and wicked hard in the back. Wish I had done what I did a few weeks ago and gone for the suspension tech springs ages ago - what a difference

**750Y** · 9th June 2003, 12:58

hey wkid,
what sorta money did norm charge for the front springs.
I need some soon as my bike is suited to a 68kg rider and I am 96kg and I can't quite get it adjusted 'perfect'.
in the states the racetech are $89 US + shipping + GST i guess at this end.
I also have the goldvalves so they'll go in at the same time. then it's out to the back with a heavier spring.