Supertwin Race Bike
- This topic has 3 replies, 2 voices, and was last updated 3 weeks, 1 day ago by
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Posts
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Hello all,
I’ve popped by a few times to read the technical forums and I thought I might stop by and say hi and show off my race bike I’ve been building for the supertwin category in Aus. Still currently a WIP but most of the way done, I’ve spent a lot of time riding the bike and getting some well needed practice in.
Had several issues in the early days with the brakes and suspension but Im pretty happy to say I’ve mostly sorted that all out on the front end now. Next on the agenda is to figure out the rear suspension and geometry. Ive had issues with the rear end squating and dragging the belly pan on the ground, jacking up the rear preload solved the immediate issue but had to really overdo it due to the soft spring and ended up getting a lot of skating about under braking. I’ve considered throwing in a YSS shock, although if anyone knows of an alternate drop in replacement Im all ears.
Current plan is to start racing next year, should be ready in time, with just numbers, crash guards and lock wiring required to get it fully race prepped. For now, enjoy some photos from the last couple of track days. In case anyone is wondering, the fairings are modified 2005 gsxr 600 race fairings, windscreen is from slipscreens UK
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Welcome to the forum , and that’s a beauty for the track 🙂 – We hope you win any races you do!
Try YSS itself or Suzuki Bandit 1200 ( I am not sure if it is Mk1 or Mk2 , be sure to measure it as the Hyosung is typically 315mm shock , so that it doesn’t rub on the swing arm itself (notice how close the spring is to the actual metal of the swingarm area, very tight fit.)
Front Forks = You can get HAGON RACING springs made in the UK for the Hyosung 650 (I am not sure if they still do them but it is worth double checking!)
If not, you can fit other 51mm forks through the yokes (Eg. using a Kawasaki fork , might mean you use a Kawasaki wheel , I don’t know if the races require you to have a speed KMH/MPH sensor or not , like Hyosung does but it would be the final hurdle) . Just some ideas!
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Thanks for the advice and ideas!
Good shout on the kawi forks, hadn’t realised they were 51mm. I’ll be checking that one out for sure, as the BPF showas would be a very nice upgrade. I dont have requirements for a speed sensor, I just use it for my gear indicator so I’ll have to work out another way to keep that one working. I’d pulled the current forks apart a couple of times previously and I suspect a previous owner had already put heavier springs in them, measured them up as a 1.0kg/mm linear spring but couldnt find a supplier who made them in the right length (35.5 x 355) and Im pretty sure thats not standard? So maybe they came from Hagon, couldnt see any hyosung fork springs listed on the website but I’ll probably shoot them an email to see if they have anything that just isnt listed.
I did noticed the rear shock was very close to the swing arm, I had made an attempt previously with an R6 shock I had lying around to see if it would fit and it was a no go too. Seems the larger diameter spring just wouldnt fit in the gap. Had a look over some bandit 1200 shock dimensions on the YSS website and it seems like the 96-00 shock would possibly drop in, but is a touch shorter at 300-310mm. The 01+ is longer, but has the same spring diameter as the r6 so not super confident it would fit. Decided to bite the bullet and take the safer option of the YSS hyosung shock upgrade.
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I am not sure which Kawasaki as such , but Honda and Aprilia should have 51mm shocks also,  which those bike brands, we could possible have broad options of fork spring upgrades in their 51mm tubes.   I have personally not ever had to order a single Hyosung fork spring, Kayaba just sells complete forks only  (Kayaba Japan who still make shocks for Suzuki and Hyosung , KYB for short)  , go for the SHOWA forks if you find them or OHLINS !
If push comes to shove , anchor a magentic bolt sensing pickup next to the fork leg which counts the wheel speed , and have a small mini cockpit that tells your kmh/mph speeds if you have to have one.
Gear position = This is off 250cc , but it gives ideas if you want to know what gear you’re in
[Tutorial] Gear position sensor fault – Neutral switch GV 250 Aquila EFI 2010
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- This topic has 3 replies, 2 voices, and was last updated 3 weeks, 1 day ago by .
-
Posts
-
-
Hello all,
I’ve popped by a few times to read the technical forums and I thought I might stop by and say hi and show off my race bike I’ve been building for the supertwin category in Aus. Still currently a WIP but most of the way done, I’ve spent a lot of time riding the bike and getting some well needed practice in.
Had several issues in the early days with the brakes and suspension but Im pretty happy to say I’ve mostly sorted that all out on the front end now. Next on the agenda is to figure out the rear suspension and geometry. Ive had issues with the rear end squating and dragging the belly pan on the ground, jacking up the rear preload solved the immediate issue but had to really overdo it due to the soft spring and ended up getting a lot of skating about under braking. I’ve considered throwing in a YSS shock, although if anyone knows of an alternate drop in replacement Im all ears.
Current plan is to start racing next year, should be ready in time, with just numbers, crash guards and lock wiring required to get it fully race prepped. For now, enjoy some photos from the last couple of track days. In case anyone is wondering, the fairings are modified 2005 gsxr 600 race fairings, windscreen is from slipscreens UK
-
Welcome to the forum , and that’s a beauty for the track 🙂 – We hope you win any races you do!
Try YSS itself or Suzuki Bandit 1200 ( I am not sure if it is Mk1 or Mk2 , be sure to measure it as the Hyosung is typically 315mm shock , so that it doesn’t rub on the swing arm itself (notice how close the spring is to the actual metal of the swingarm area, very tight fit.)
Front Forks = You can get HAGON RACING springs made in the UK for the Hyosung 650 (I am not sure if they still do them but it is worth double checking!)
If not, you can fit other 51mm forks through the yokes (Eg. using a Kawasaki fork , might mean you use a Kawasaki wheel , I don’t know if the races require you to have a speed KMH/MPH sensor or not , like Hyosung does but it would be the final hurdle) . Just some ideas!
-
Thanks for the advice and ideas!
Good shout on the kawi forks, hadn’t realised they were 51mm. I’ll be checking that one out for sure, as the BPF showas would be a very nice upgrade. I dont have requirements for a speed sensor, I just use it for my gear indicator so I’ll have to work out another way to keep that one working. I’d pulled the current forks apart a couple of times previously and I suspect a previous owner had already put heavier springs in them, measured them up as a 1.0kg/mm linear spring but couldnt find a supplier who made them in the right length (35.5 x 355) and Im pretty sure thats not standard? So maybe they came from Hagon, couldnt see any hyosung fork springs listed on the website but I’ll probably shoot them an email to see if they have anything that just isnt listed.
I did noticed the rear shock was very close to the swing arm, I had made an attempt previously with an R6 shock I had lying around to see if it would fit and it was a no go too. Seems the larger diameter spring just wouldnt fit in the gap. Had a look over some bandit 1200 shock dimensions on the YSS website and it seems like the 96-00 shock would possibly drop in, but is a touch shorter at 300-310mm. The 01+ is longer, but has the same spring diameter as the r6 so not super confident it would fit. Decided to bite the bullet and take the safer option of the YSS hyosung shock upgrade.
-
-
I am not sure which Kawasaki as such , but Honda and Aprilia should have 51mm shocks also,  which those bike brands, we could possible have broad options of fork spring upgrades in their 51mm tubes.   I have personally not ever had to order a single Hyosung fork spring, Kayaba just sells complete forks only  (Kayaba Japan who still make shocks for Suzuki and Hyosung , KYB for short)  , go for the SHOWA forks if you find them or OHLINS !
If push comes to shove , anchor a magentic bolt sensing pickup next to the fork leg which counts the wheel speed , and have a small mini cockpit that tells your kmh/mph speeds if you have to have one.
Gear position = This is off 250cc , but it gives ideas if you want to know what gear you’re in
[Tutorial] Gear position sensor fault – Neutral switch GV 250 Aquila EFI 2010
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- You cannot reply to this topic.