Before everyone jumps on me for not using the search, well, I have. I've been doing a lot of it here and via Google and still have questions, that's why I posted here, in the track & racing tech forum.
Here goes...
I just picked up an '01 GS500 for super cheap. Since all my other bikes are track only I thought this GS might make an inexpensive, low maintenance and fun street ride for day trips (very aggressive back roads) and I might take it out for a session or two at track days just to mess with some of the new guys (I'm an advanced rider on my 600 but would ride this in intermediate group because of the lower top speed).
There's lots of talk on suspension setup and tire selection, but it's really hard to filter out the responses because you really don't know who's doing the writing and if they really know wtf they're talking about. I'm looking for responses from people who've actually done it, and are advanced *sport* or trackday riders, not commuters or highway cruisers.
1. suspension:
I'm 200lbs with gear on. Will a set of Sonic springs and R6 rear shock (both set to my weight) be sufficient? Should I be looking at .90 or .95 spring rate? What weight and height fork oil? I've read about guys running braces and emulators up front, but I'm not sure I want to go that far (and the expense since this was such a cheap bike).
2. tires:
I've got an endless supply of 120/70/17 race takeoffs to use for the front. They'll work, right? What about the rear? I'm seeing some people say don't go bigger than 140/70/17, but choices are limited... and others say 150/60 or 150/70. Can I get away with a 150/60?
Thanks,
-Banning
I'm not a tracker so I will leave that alone...
... But if you PM RichDesmond on here mate .... He IS Sonic Springs! ... Literally ... So there's your go to guy for the front end!
Doesn't take a genius to tell you your probably gunna need .90s our maybe even .85. there is a spring calculator on the website if you don't trust me. Good luck!
Thanks guys.
Burning1 is your guy. He will be on soon to answer your post
I may not be burning1, but I have some feedback.
Extreme street riding with sportbikes, I ran .96 sonic springs, 15w oil at I believe 5.25 inch from top
Quote from: J banning on February 08, 2013, 02:39:08 PM
.........................................I've got an endless supply of 120/70/17 race takeoffs to use for the front. They'll work, right? What about the rear? I'm seeing some people say don'pantablot go bigger than 140/70/17, but choices are limited... and others say 150/60 or 150/70. Can I get away with a 150/60?
Thanks,
-Banning
Although it's a bit dated now for what it's worth here is what's posted on gstwins.com at Racers Corner:
Race rubber is readily available for the GS 500, probably because it uses the same tires as Aprillia cup bikes. On a racing GS, the front tire size is the same as stock (110-70-17). For the rear, most racers I know use a 150-60-17 (stock is 130-70-17). The fitment guide will tell you the rim is too narrow for this tire. It is, but this does not result in bead failure, even under extreme racing conditions. It does modify the profile enough so that it impossible to get all the way to the edge of the tire. If you can't live with that, you can have your wheel widened to 4 inches by Kosman Specialties (http://www.kosman.net) for about $375, but then you won't be legal in Supersport class. I once tried the other racing tire choice (Metzler 140-80-17) and hated it. It is taller tire than stock and a non-radial. The bike steered like a cow, flopped unpredictably into corners and felt very top heavy. When I switched to the 150 radials, I almost drove off the inside of the track because it turned so easily. Race rubber is available from Dunlop (D-207GP and D-208GP), Michelin (Pilot), Metzler (Rennsport), and Pirelli (Dragon Supercorsa) in sizes 110-70-17 and 150-60-17. The Supercorsa and Rennsport are the exact same tire with different tread patterns. This makes sense since Pirelli and Metzler are the same company. Most people at BIR have historically run Michelins or Metzlers, depending on which manufacturers were offering contingency money. The way contingency works is you use their tires, fill in the form during race registration, put their decals on your bike, and finish well in the race (usually fifth or higher), and you get certificates useable for your next tire purchase. I have ridden the Michelin Pilots and Metzler ME Z3's back to back, and could not feel any real difference. I believe any big name race rubber will perform adequately, so go where the money is or just pick one randomly and see how you like it. I do remember a while back Pablo ran the Pilot Powers with a 150/60 rear on the track and had a handling problem after they were well worn. A feeling the bike was falling out from under him in corners. On the other hand many are running the 150/60 size on the Ninja 500 and GS500 bikes. I'm running a 150/60 rear right now but don't run at a racers pace or even close to it. I like it's handling.
Hi Banning,
Credentials: I raced a season on the GS, had about 30 trackdays under my belt, and ran the GS in the advanced group against superbikes. A few of my videos are posted up if you'd like to confirm.
I weigh about the same as you. The R6 shock should be perfect for your needs. I ran that and a late model Katana 750 shock. I can't say enough good things about the R6 shock, Kat shock was a little stiff, so I only recommend it to very heavy riders.
If you're considering this bike for track only use, you might want to consider a full front end swap. Emulators will work wonders, but there are limits to what they can accomplish, especially on a rough track. Another rider posted up about a CBR swap that appeared to be pretty straightforward, involving bearings. It's in his trackbike build thread.
You do not of course have to go for the full front end swap, and it causes problems if you want to keep the bike streetable. I would advise emulators for track use - they only cost $150 or so, and make a big difference. Dave Moss of catalyst reactions custom modifies the emulators, so it's worth talking to him. The result is a thing of beauty.
I've seen people shoe-horn a 150mm radial rear tire on to the GS500 rim. Personally, I advise against it. There are a few 140mm options that will offer a better profile. I personally ran a Bridgestone BT003RS rear with a Michelin Power One V front, and was quite happy with the results. Another great option is a Pirelli Diablo Rosso II rear (140/70/17) with your choice of Pirelli front. I'd advise you to look at a full DOT front tire.
One other option to consider would be a Katana Rim swap, which opens up a few options in 150mm and 160mm size. The benefit in doing so is that you could find rain tires, and slicks in those sizes. I have not personally done the swap, so you'd be on your own to find out the details. I am personally in the process of performing an RGV swingarm swap, and I cannot recommend anyone else attempt it based on the trouble I've gone through.
Im the guy burning1 is talking about.
My track bike is running a 08cbr600rr complete front end. I had to swap the steering stem bearings and add a couple spacers but its on there and torqued to spec without issue. Keep in mind, I still haven't hit the track yet, my first day here in Norcal is going to be the end of march.
Depending on how handy you are, you shouldn't have an issue mounting gauges to the upper triple. I am just running a tach, no speedo, ignition, or any idiot lights.
The only thing I don't like about this front end is parts are somewhat harder to find "cheap". the 07-08 front ends are pretty specific not sharing much with any of the earlier models. They do however share the same wheel as any 07+ cbr600 but they are spendy. Ive been trying to spy an extra front wheel but havent found any deals yet. I found my whole complete front end for 400 bones locally.
For a street bike, ease of install, springs and emulators may be your ticket. With so many suspension gurus that can set you up to run A group paces, sometimes I wonder if I should have just gone that route.
Good luck!
Thanks a lot for the replies guys. After reading the responses, I think I'll go with a 140 Pirelli rear, front springs and the emulators. I wanna keep this bike cheap and fun so as tempting as it is, I really don't want to go to the trouble (and expense) of a front-end swap. My GSX-R will continue to be my main track bike. This GS is just for street an a session here or there to mess with some of the new guys who think it'll be slow :)
I'll post up how things are going once I get stuff ordered, on the bike and some miles on it.
Thanks again.
Good call! The GS500 is a very fun track bike, even without throwing a lot of cash at it.
Quote from: J banning on February 08, 2013, 02:39:08 PM
Before everyone jumps on me for not using the search, well, I have. I've been doing a lot of it here and via Google and still have questions, that's why I posted here, in the track & racing tech forum.
Here goes...
I just picked up an '01 GS500 for super cheap. Since all my other bikes are track only I thought this GS might make an inexpensive, low maintenance and fun street ride for day trips (very aggressive back roads) and I might take it out for a session or two at track days just to mess with some of the new guys (I'm an advanced rider on my 600 but would ride this in intermediate group because of the lower top speed).
There's lots of talk on suspension setup and tire selection, but it's really hard to filter out the responses because you really don't know who's doing the writing and if they really know wtf they're talking about. I'm looking for responses from people who've actually done it, and are advanced *sport* or trackday riders, not commuters or highway cruisers.
1. suspension:
I'm 200lbs with gear on. Will a set of Sonic springs and R6 rear shock (both set to my weight) be sufficient? Should I be looking at .90 or .95 spring rate? What weight and height fork oil? I've read about guys running braces and emulators up front, but I'm not sure I want to go that far (and the expense since this was such a cheap bike).
2. tires:
I've got an endless supply of 120/70/17 race takeoffs to use for the front. They'll work, right? What about the rear? I'm seeing some people say don't go bigger than 140/70/17, but choices are limited... and others say 150/60 or 150/70. Can I get away with a 150/60?
Thanks,
-Banning
I am a 250 pound rider I run 1.0 in the front with a rear fully dialed to my weight and it is an awesome track bike! Went to jeenings all stock before and was still running high minute thirties. Now its low minute thirties after suspension upgrade. The tire I run are also called Dunlop unbeatable's (I think it was dunlop I would have to ask my tire guy to be honest) Also herd the sport demons I think they are called are pretty good. I run a 150 (unbeatable) on the rear with stock rim and rear brake arm just fine its tight but works fine.
spcassell,
Radial or bias ply 150mm rear?