starting a 650 vintage racer build... lil help?

tstruyk

Hey guys,

My Dad and I are considering venturing into the Vintage racing world and have chosen the XS for the platform. Basically he has 2 right now, one that he would like to possibly convert, and ultimately have me race. My Dad is a solid wrench and basically what we are looking for is some direction that will help save us time and money.

The goal of the project is to build a strong, reliable vintage racer that will allow me to be somewhat competitve with the rest of the guys out there in the class.

My intial priorites lie in suspension and brakes... what is the idea direction to go with these? Is there a setup that is gerenally looked to as the "way to go", I understand all to well that may depend on who you ask, but I've found in most classes of racing there is a standard setup that most folks would agree is "user friendly"

other thoughts in no particular order

tank (size, shape?)
rearsets
clipons
wheel size and tire selection and availability
bodywork to include front fairing and bellypan
exhaust routing and/or design for maximum clearance

I'm not super concerned with power output until we can make the thing turn and stop... Laughing

power is easy relatively speaking.

any assistance would be greatly appreciated! I know I'm gettin into ALOT of very general questions that will have a few hundred answers but I am VERY new to the machine, and my dad will be somewhat new to building a bike capable for racing... I have experience setting up a race bike, and he's been an XS owner for years. I hope together we can have a lil fun with this!

thanks again

tim

yamaman

I think your race regs over there are a bit softer than ours, we have limited chassis mods in Oz, though basicly no rules inside the engine, provided it's under 1300cc's!

I like the way your thinking, sounds like your on the way!
I think 18" wheels are a must, also rear-sets (as you'll soon be scraping the stock pegs). Make sure your head stem & swing-arm bushes/bearings are in top shape. I run Koni rear shocks with std front springs (34mm forks, not allowed 35's in my class). Depending on how you want to set up your front i.e. clip-on's or bars-forks dropped right through ect, you might want a steering damper, definatly a good fork brace!

I run a twin front disc-drum rear, cdi ignition (no battery), Mikuni VM34 carbs with k&n pods, open rev cone megas, clip ons, steering damper, tapered roller steering bearings, needle roller bearings in place of plastic swing arm bushes (bronze bushes are fine), 750cc kit, 18" wheels with dunlop TT100gp's.

Bodywork is up to you, full race set up or std seat and tank is fine too.

Good luck, keep posting, cheers

tstruyk

sounds like to get her off the ground I am looking at minimum:

Springs (are there emulator kits available?)
Rear shocks (any ball parks on geometry would be a WORLD of help)
Clipons
Rearsets
braided lines with possibly a MC upgrade and some decent pads
18" rims
fork brace
run through the bearings/bushes
With the low HP these put out is a damper that much of a requirement? I dont run one on my SV, wouldnt dream of racing my R6 without one... I'll do a fork brace for sure!

My sponsor can help fabricate a catch pan from one of the SV's we are running, and I bet he can cut down a mold off my R6 for an upper. Theyre good at fabricating that kinda stuff... not "high dollar custom" good, but useable, clean and inexpensive. Worst case I can bolt on some old school MX number plates and give her hell!!

I can deal with the seat and the tank for now, just looking to get up to spec first and then we'll fine tune with hopped up carbs and a 750cc kit...

if you dont mind me asking, whats a good HP number to shoot for? I know the SV that I race I cant really compete without close to 80 at the wheel... and my R6 with less than 110 I'm getting left in the dust... thoughts? I dont want a grenade I have to rebuild 8 times a year...

Also do you have anyone in particular that you source parts from? Are they custom fab'd or is there an aftermarket, market for them?

thanks again for the help! Once I get pointed in the right direction I can get it rolling, I'm really not this high maintanence!!!! Laughing

yamaman

Not sure what size Koni's I have............not high, not low.....stockish std

Low hp doesn't mean you can't get the head shakes!
You only need a steering damper if you are going to use clip ons and run your forks up through the triple trees a fair bit (which you probably will)
On your R6- you probably have raised the rear to get it to turn in better, aswell as a bit more weight over the front- on modern bikes you can't realy run the forks up through the trees, so they raise the rear.
On old style bikes, there is more scope for running the forks up, so it's better to do it that way! This also reduces your trail and your wheelbase, this sharpens up your steering
It's when you do this (depending on how much you change it all) that they can have a tendancy to get a bit loose. You might also consider fabing up new bump stops-to stop it slapping to far! Shocked

I run a cable tie on one fork staunchion all the time- lets me know how far the forks dive under the hardest braking. Then when I do a mod with the front end- after I'm done- I pull the front down with tie downs so I can see there will be no other clearance issues.........This is important!!!!! Exclamation

HP-whatever you can afford. Aside from the 750 kit, roundslide carbs, open zaust and ignition- my bike is basicly stock and I have a great time on it.
You want to be competive...........with what? I race against a SOHC CB 750-1036cc on methanol thats got over 100hp- he has to crash (and rarely does) for me to catch him!
So I could do everything possible to a XS with a million $ budget, and he'd still hose me!

Idealy I'd like a fresh bottom end, Mikes 750 barrels, dress up the heads a bit (lots of info on the net on how to go about that), maybe up the valves, a megacycle cam or similar, upgraded oil pump and filter system with a nice compact cooler. Hope Santa's reading this!

Parts from MikesXS and 650central- MMM at 650central races a XS and isn't afraid to share his knowledge-can be a valuable rescource.
If they havn't got it it's ebay or the fab shop!

Suspension mods-what does your rule book allow? I'm not allowed piggy backs or over 34mm forks.

Hope some of this helps, it's all just my opinion. Others might disagree, and would be great if they did, like to hear what some others think. Just need to enjoy it! Very Happy

Cheers

Tomterrific

You need to call 650central.com before3 you turn a wrench. Michael is a XS racer and race bike mechanic with many years experience. He owns Vintage Brake as well as 650central. Michael, along with another XS racer and tuner, have a full on race program available. This program is the collected secrets from the tuners of XS 650 when they were factory racers.

Michael will know the AHRMA rules for the class you want to run and tell you how to build an over kill bike.

Tom Graham

dwyatt

Good advice here. I'm doing the same type build myself and am about 3/4 of the way done. Look at the rules for the organization you plan to race with, that will dictate many of the modifications you can make. When you call 650Central, ask about the porting they are partnered with 650Performance.com on, you will want Craig's head work above all other engine modifications. He also has a killer performance manual that is a must have. Max HP for this engine will be about 70, so spend all the time you can making it handle and stop, both very doable.

I followed most of the advise you have already been given here, but went a different way on suspension. I'm running cartridge emulators, and air assist on the front, Fox Airshox canted a bit on the rear to raise her ass to improve weight distribution. Check my pictures in the Gallery. This is a great place to go for ideas, but I encourage you to think out of the box as well.

pumps

Some stuff here, click on the various link on the left including Minton Mods

www.650central.com/

NorwegianXS

Maybe some ideas here: www.realclassic.co.uk/...32800.html

tstruyk

thanks for the input gang... I have yet to dive into the rule book (most likely AHRMA) as the initial mods will be very basic.

springs
Clip ons
rearsets
braided lines
upgrade the MC and pads (the MC I'll check on first but I would think that would be allowed)
fab a catch pan

once I get sag right I'll start playing with trail, believe me when I tell you after trying to dial in the 06R6 the ENTIRE YEAR of 2006... i have a pretty good understanding of set up Evil or Very Mad

Man that bitch is picky!!! and Actually... it was a constant search for MORE trail on the 06. from softer spring rates to a shortened upper clevis... even running the tubes a few mm BELOW the trips... what a nightmare!

By competitive I just mean I dont want to show up with a knife to a gun fight. I know someone will always be willing to invest more money in a motor than me... my goal is to invest more skill Cool

well thats the goal anyway... kinda fun bein the underdog. If the average HP is 60-65 I dont wanna show up with 30... Laughing

thanks for the links and the sources, I hope to have this together enough to hit a few trackdays this year, and be ready to rock and roll for 2010! All depends on Dads availablilty to work on it and how much $$$ I invest in my 09 season...

Once I get it rollin I'll post up some progress pics.

all input is welcome!

thanks again guys

Timmay!

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