Taking a GS1000 to the track, advice needed

[Rijko]

hi all,

i want to take a 1978 GS1000 to the track.
This is the basis for what i want to use.



I am calling upon The Force that is GSR to help me get this bike up to par, to aid this novice achieve a lot of fun.
The goal is to get a bike that will be fun to hone my driving skills at reasonable cost.
Solutions cheap enough to not end the hobby if i drop the bike.

Engine is standard, and i have several sets of carbs like VM28SS, 29mm smoothbores, early GSX750 flatslides.
Have Norris GS750 mild cams i understand will work on a GS1000.

Ordered a M-Unit v2.
Have a Dyna S, and a Dyna 2000 with 2.2. Ohm coils on the way.

Ordered a Compu-Fire but willing to drop starter motor, rotor/stator and RR
if that makes sense to go total-loss ignition.

Have an aluminum GS1100 rear fork and new Koni's as well as Marzocchi AG Strada shocks.

Have standard GS1000 spoked wheels, too.

Looking for good tyres for the track. TT100 ? Avon ?

Have read Smithy use 4 cm added length to front fork.
Have the MikesXS cartridge emulators and got the dimensions for converters from Dan (thanks Dan !)

Will use the twin-pot brakes from Dan's upgrade if that is a good option.
Chuck recommended nice 23mm offset discs ( http://www.ebay.nl/itm/252773128244 ) Thank you Chuck !

Help me out setting this bike up for the track ?

Thank you !
Rijk

 

[Carter Turk]

Curious what your intention is on the track?
To race or do trackdays?
Does this bike get use on the street or will it, after going to the track?
Are the cams in the bike now?
Have you ever been on the track?
Have all the carbs been tried on the motor?

Lots of questions, but I think all the above matters as to how the bike is set up.

 

[storm 64]

If the track is mud I'd recommend knobies... ☺

 

[Tom R]

I've tracked my gs1100 several times, it's mostly stock... Hagon rear shocks, sonic fork springs, recent brake master cylinder rebuild and stainless lines, Shinko tour master tires... it does fine. Just have all the maintenance up to date and running smooth and have fun.

 

[GregT]

If you've not raced or done a trackday before, leave it as stock as possible to start with.
Modify it as you think you need to - and only when you've identified a need for change.

IMO unless you're really short, the footrests are too high. With the very flat seat, you're going to need to use your legs to help locate yourself.
I'd drop them about 50mm. Ground clearance won't suffer as the alternator cover will touch down first...

Don't take the electric start off - they're a heavy pig to push start....

 

[RichDesmond]

Unless you're addressing a reliability issue, leave the motor alone. As a newbie track rider the last thing you need is more power.
Spend your money on suspension and tires.

 

[thebrandonbeezy]

Unless you're addressing a reliability issue, leave the motor alone. As a newbie track rider the last thing you need is more power.
Spend your money on suspension and tires.

The above can be said for the street as well, for riders of any level.

 

[Rijko]

Curious what your intention is on the track?
To race or do trackdays?
Does this bike get use on the street or will it, after going to the track?
Are the cams in the bike now?
Have you ever been on the track?
Have all the carbs been tried on the motor?

Lots of questions, but I think all the above matters as to how the bike is set up.

Just trackdays, and i want to use the bike on the road too even if it takes some
work to add some parts back on the bike.
I have lots of wheels, so if it makes sense i will dedicate a set of wheels to that.

Standard cams in the engine atm.

I have never been on the track, not looking for maximum power because i think
i can get myself in enough trouble with 90-100 hp
If i find i really need more power i have an engine with 130 hp but being a novice
on the track i think it's not wise to start with that much power.

Only a set of VM26SS carbs have been on the bike.
I have several 4-1 exhausts i can use.

 

[Rijko]

If you've not raced or done a trackday before, leave it as stock as possible to start with.
Modify it as you think you need to - and only when you've identified a need for change.

IMO unless you're really short, the footrests are too high. With the very flat seat, you're going to need to use your legs to help locate yourself.
I'd drop them about 50mm. Ground clearance won't suffer as the alternator cover will touch down first...

Don't take the electric start off - they're a heavy pig to push start....

good thinking, i'm tall and these footrests are not comfortable.
I have other seats, too so no problem to mount one of those to gain some extra room.

I like the electric start, a few kilos won't make much of a difference especially
for an inexperienced rider. Only reason i was thinking to take off the genny was for ground clearance.

 

[Rijko]

Unless you're addressing a reliability issue, leave the motor alone. As a newbie track rider the last thing you need is more power.
Spend your money on suspension and tires.

Good advice, thank you.

I hear a lot of good things on this forum about the Sonic's.
What would you recommend for the front, the 1.1 kg Sonic springs ?

I'm 185-190 lbs, if i use the spring rate calculator with extra weight
for gear, racing use, it advices 1.2 kg springs.
Don't see those listed on the site anymore.

Tracks are smooth in my area.

I have MikesXS cartridge emulators, should i use them with those springs ?

I have new but 25 year old Koni's for the back, hope that combines well.
Or is this old technology, and should i go for YSS or something like that ?
Ohlins are a bit expensive for me.

Looking for advice on tires too, i hear the Shinko's have lots of grip.
Would they be your choice too ?

 

[Tom R]

Shinkos wouldn't be my first choice, but they were already on the bike... and traction wasn't an issue with them.
I also track and race a cl175 in the AHRMA series, you'd be amazed at how much fun even 18 hp could be.

 

[hampshirehog]

Don't forget your brakes either. Slowing down better will improve your times more than going faster better.

 

[RichDesmond]

Good advice, thank you.

I hear a lot of good things on this forum about the Sonic's.
What would you recommend for the front, the 1.1 kg Sonic springs ?

I'm 185-190 lbs, if i use the spring rate calculator with extra weight
for gear, racing use, it advices 1.2 kg springs.
Don't see those listed on the site anymore.

Tracks are smooth in my area.

I have MikesXS cartridge emulators, should i use them with those springs ?

I have new but 25 year old Koni's for the back, hope that combines well.
Or is this old technology, and should i go for YSS or something like that ?
Ohlins are a bit expensive for me.

Looking for advice on tires too, i hear the Shinko's have lots of grip.
Would they be your choice too ?

The 1.2kg/mm springs would be way too much. The 1.1s should be good for you. Definitely use the emulators.
I don't have any experience with Konis, they may be ok, but won't be anything like a set of good, modern shocks. Should be decent to start with, but I highly recommend saving up for a set of Ohlins.
Chassis geometry is crucial also, I don't have much advice there having never taken an old GS to the track.

 

[Carter Turk]

I went with .5" longer (13.5") Works Performance Street Tracker shocks a long time ago.
First time on the track was in 2000, then took a 11 year hiatus for whatever reason.
At that time, I had the stock Katana shocks that caused the rotor cover to grind on high load left handers.
It can also be said that my body position wasn't ideal, causing more lean than neccessary to make the corner.
Coaches suggested getting at least a butt cheek off the seat, to lower the center of gravity.
I still probably could afford to hang off more, especially in right handers.
I tend to feel more comfortable going left eventhough the ground clearance is less on that side.
1980 leading axle forks had more adjustment than the 83's with the axle on the end and no preload or dampening adjustment.
Totally antiquated, but still works fairly well. I use 20W fork oil with Progressive Springs, pvc spacer, but no emulators yet.
The forks are lowered 3mm to quicken steering, however might be moot with a 61" + wheelbase, though I think with the longer shocks it makes a slight difference in handling.
I been running mis matched tires for years and really like the profile/grip of Dunlops 591SP front tire.
Nobody else here seems to use this tire due to the short life span.
It has a Harley moniker on the sidewall, but the compound is great on the track.
Pirelli Sport Demon in the rear works great.
I'm tempted to try Continental, but haven't yet.
I guess if VM26 carbs aren't set up for the 4-1 pipe, maybe try the stockers, but if ground clearance is an issue after the first day on track a pipe might be a good idea.
I don't think 4-1 pipes with oil plug and filter access will be any better ground clearance wise, they scrape at the collector.
Gotta use the RR style pipe that goes directly under the engine. The pipe could save 30 lbs of weight which is significant and put less weight on the suspension.

 

[Rijko]

The 1.2kg/mm springs would be way too much. The 1.1s should be good for you. Definitely use the emulators.
I don't have any experience with Konis, they may be ok, but won't be anything like a set of good, modern shocks. Should be decent to start with, but I highly recommend saving up for a set of Ohlins.
Chassis geometry is crucial also, I don't have much advice there having never taken an old GS to the track.

Thanks for your advice Rich !
I just ordered the 1.1 kg/mm springs.

 

[GregT]

In the initial stages of our 1000's development, a rear rim from an 1100E went in - 18in and a bit wider. Better choice of rubber.
The twinpot brake upgrade is a well documented upgrade - and will be necessary. Use drilled or slotted rotors.
We've finished up with Gazi shocks, these seem to be a southern hemisphere thing, made in Thailand as a pretty good Ohlins copy. About 2/3 the price of Ohlins...
They're around 40mm longer than OE.
We use progressive springs in a stock fork and it handles very well indeed.
It's possible to keep the electric starter but ditch the alternator rotor. I've posted a pic of the cut cover previously.

 

[Rijko]

In the initial stages of our 1000's development, a rear rim from an 1100E went in - 18in and a bit wider. Better choice of rubber.

glad you mentioned that, think my buddy has them.
What width tires did you use and what rear fork ?
Using 520 chain/sprockets ?

The twinpot brake upgrade is a well documented upgrade - and will be necessary. Use drilled or slotted rotors.

Will do, i bought a set of '89 ZX10 calipers yesterday
Talked to Chuck, i like the way he mounted them... "could be stock" look.
He used 23 mm offset, 296mm ss discs from a 98/99 CB600F Hornet.
I just ordered these new ones : http://www.ebay.nl/itm/252773128244

We've finished up with Gazi shocks, these seem to be a southern hemisphere thing, made in Thailand as a pretty good Ohlins copy. About 2/3 the price of Ohlins... They're around 40mm longer than OE.

I have a reseller that sells the Gazi shocks, will talk to him.
Did the extra height cause issues with the chain, did you use a bigger front sprocket ?

It's possible to keep the electric starter but ditch the alternator rotor. I've posted a pic of the cut cover previously.

Can't find that pic, but i take it you did the Yoshimura slashcut, leaving the crank intact ?

 

[GregT]

glad you mentioned that, think my buddy has them.
What width tires did you use and what rear fork ?
Using 520 chain/sprockets ?

We initially used BT45 rear and a 19in BT39 front, can't remember sizes sorry. The 39 is a soft compound and as long as you want to use a 19 front, it's better than Avons IMO. Went straight to 520, yes as we were eventually going to wider 17in wheels. Using 16 - 18T front sprockets depending on circuit with usually a 42 rear. Swapped in an alloy 1100 arm early on.
The BT's were good enough to beat bikes running on slicks. Good rider too though, LOL.



Will do, i bought a set of '89 ZX10 calipers yesterday
Talked to Chuck, i like the way he mounted them... "could be stock" look.
He used 23 mm offset, 296mm ss discs from a 98/99 CB600F Hornet.
I just ordered these new ones : http://www.ebay.nl/itm/252773128244



I have a reseller that sells the Gazi shocks, will talk to him.
Did the extra height cause issues with the chain, did you use a bigger front sprocket ?

As above, no probs. We use the softest available gazi springs. Bought through Australia, they'd only sold one other set of that spring in over 100 sales....The aussies must be fat buggers, LOL



Can't find that pic, but i take it you did the Yoshimura slashcut, leaving the crank intact ?

View attachment 51726

Crank intact, rotor boss cut back about 15mm. Shorter retaining bolt. Capscrews retaining the starter clutch tack welded.

 

[Rijko]

thanks Greg !

have a alloy 1100 arm, will use it. Trust the 18" rear, and 40mm extra height lift the front
enough, on a standard GS1000S with 18" rear wheel using BT45's i have to be careful not to scrape the genny cover on tight corners.
Will make the genny cover as you pictured.

Will keep the rest of the engine stock, go for VM28SS with K&N pods and have that setup tuned by Dynojet guru Ruud Fredriks.

Looking forward to trying the front with Sonic 1.1 springs and MikesXS cartridge emulators, my buddy is fabricating the converters from Dan's drawings.

Will mount BT39/45 tires and 520 with 16/42 sprockets.

I'm sure that will be a lot of fun on the track, the limiting factor will be me

I received the M-Unit today, looking forward to hooking it up.

 

[GregT]

With those carbs and a 4 : 1 pipe, it's worth dialling the stock cams in to 107 lobe center inlet and 109 exhaust.Very good midrange and top end with those figures.
If you search Utube for "GS1000 racing" there's an old vid on line of our GS in it's early form. Yours should approximate what you see. Wheelies optional....