KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Show us that box of bits in your shed!
russell
Smoker
Posts: 94
Joined: Sun Dec 02, 2012 4:44 pm
Location: isle of man
Contact:

KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by russell »

SAM_1478 - Copy.JPG
Hi
We hope to run our std KR1S in the Classic TT F2 race in August 2015 and looking for parts and advice along the way. Not sure if I am in the right forum index but we will see.
For now we are keeping bike std because we are looking for reliability, keep within the F2 rules/spec and above all cost as we are spending most on F1 ZX750R project.
What we have is a 1992 C3 KR1S with 12,000 miles with race bodywork and stripped of road bike stuff.
We paraded this at Donington in July but it ran a big end with Jame Ellison on board (embarrassing)
Since then with help from forum members we had Jim at Grampian Motors rebuild crank and supply new pistons,rings and small ends.
It ran fine after rebuild so now we need to do some more work to get it fit for purpose.
We have junked a lot of the road bike gear and we are getting Firefox Racing to build up a YSS shock and The Professor is tweaking the front forks.
I now have a number of questions that hopefully someone can help with ---

Firefox said their shock will have a ride height 10mm over std, is that ok/good?

Is it OK to fit a steering damper to the lug on side of frame? I think I read that it is weak?

Wanting to get rid of key and ign switch, can I fit a separate on / off sw connected to red multiplug under tank? see pics below hopefully.

Does anyone know what kind of fuel consumption we would get running flat out? We would like to race non stop for 3 laps (113 miles) to take advantage of other competitors refueling. We have enlarged petrol tanks before but need to know by how much.
Ronnie
You do not have the required permissions to view the files attached to this post.
Luders
Avgas Sniffer
Posts: 3926
Joined: Fri Jun 18, 2010 11:29 am
Location: Oxfordshire

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by Luders »

10mm will improve ground clearance and improve handling. The KR squats quite low on the rear end in standard trim.

You can't mount a steering damper there, but it will have to be ridiculously long. I think I have a steering damper bracket you can borrow/copy.

Yep, simple hotwire.

I'm not sure on fuel consumption, as you will spend a lot of the lap flat out. Based on 111 notmal race miles, I would expect to get through about 23 litres of fuel on a tuned race bike.

Anyone else have any advances on 23?
russell
Smoker
Posts: 94
Joined: Sun Dec 02, 2012 4:44 pm
Location: isle of man
Contact:

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by russell »

Cheers Ben thanks for that, I would have pm ed you for advice but I thought this might be more open ?
So suspension looks ok ?
So if I aimed for 24 litres I should be ok on std carbs etc. That would equate to 8 litres per 37 miles ?
Regarding damper lug if I can find damper suitable is it strong enough to use ?
What im after now is ---

Big 24 lt fuel tank or std one I can modify
Suzuki V22 hollow Swinging arm spindle
Spare engine or ( cheap complete bike)
Ronnie
User avatar
JanBros
Avgas Sniffer
Posts: 3306
Joined: Wed Jul 26, 2006 11:50 pm
Location: the land of Francorchamps

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by JanBros »

If I remember correct, I used at least about 10 l per hour when I did endurance races back in the days.

off course you can fit a steering damper on it, thats why it's there. but proper set up suspension normaaly doesn't need one, but off course/sadly I have no experience with the TT so it may be wise to fit one as it's not an ordinairy race track.
My ultimate goal is to die young as late as possible !
Luders
Avgas Sniffer
Posts: 3926
Joined: Fri Jun 18, 2010 11:29 am
Location: Oxfordshire

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by Luders »

TT course would be a nightmare without a steering damper Jan. Poor Ronnie would have tank slap central without one :D

A large portion of the TT course will be flat out for a 250 and it's punishing on the engine.

I'll measure a standard length shock when I get chance and see how long it would be adding 10mm to it. My Techno-flex is adjustable, but it's set 295mm. I do run 17" wheels though.

I have an old tank you can have to try and expand. I know there were people on here with more TT experience on the KR than me and my fuel consumption estimates are based on my race bike around Cadwell, so I'm not exactly comparing apples for apples.

Have a look on the forum for a member that has done the TT, I think it was back in 2010.

I'll get in touch next week about shipping this stuff to you, I think I have your business card still from when you sent me the gear linkage.
russell
Smoker
Posts: 94
Joined: Sun Dec 02, 2012 4:44 pm
Location: isle of man
Contact:

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by russell »

Yes a steering damper is a must for TT course not that I will be riding it those days are long gone.
Thats good about lug, I thought I read that it was a weak point?
I used to figure on 19 mpg riding TZ350s around here using 6 gal tank for 3 laps = 113miles. It may be a stretch to bring std tank to 24 litres but its worth a try as it saves around a minute on refueling. Down side is first lap with all that weight.
Will look at old mail regarding TT and many thanks for replies
Ronnie
User avatar
500bernie
Avgas Sniffer
Posts: 3396
Joined: Mon Aug 02, 2010 10:22 am
Location: Teesside

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by 500bernie »

Hi Ronnie,

You will be unable to do more than two laps on a standard tank.

Cheers,
Bernie :)
Firecracker Red and Grey C3 300
User avatar
JanBros
Avgas Sniffer
Posts: 3306
Joined: Wed Jul 26, 2006 11:50 pm
Location: the land of Francorchamps

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by JanBros »

standard shock length is 275mm
My ultimate goal is to die young as late as possible !
Luders
Avgas Sniffer
Posts: 3926
Joined: Fri Jun 18, 2010 11:29 am
Location: Oxfordshire

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by Luders »

Thanks Jan, so a shock at 285 would be ideal Ronnie.
mellorp
Heavy Smoker
Posts: 420
Joined: Fri Sep 19, 2014 6:44 pm
Location: South Manchester

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by mellorp »

On the TT circuit you will get about 20mpg. On a 250 you are flat out for a very long time, 1st 7 miles shut off a Quarter bridge, Braddon Bridge Union Mills roll it at Appledean and Greeba Bridge...

It is wasted effort to get a tank big enough to do 3 laps. With all that weight 1st time round your laps times will be slow and it will be like riding a different bike to the last lap. You also need a rest after 2 laps even if it's just a minute and a quick drink. You only need a bit of a head wind and your fuel consumption calculation will go out of the window. Give yourself some contingency. How long will it take to push in from Governors bridge compared to how much time you lose filling it to the brim and carrying the extra weight. It's all about minimising risk of failure. When your guy fills up just get a big rag to cup the filler nozzle when the tank is full to stop any spillage.

Suspension I would go to a suspension specialist. Maxton are the way to go (unless it's too late). You can gain more on a 250 by having the suspension to hold full throttle, more than having an extra 20bhp and a bad handling bike. Without a steering damper the bike will be uncontrollable. Think tank slapping and being thrown out of your seat whilst looking at brick walls at 130mph. I know I'd be camped in the Maxton carpark with a bag of cash until it was ready. I can't emphasise how important a proper suspension set up is.

Next get your wheels perfectly lined up, make sure the brakes don't bind not even by a small amount. Chain tension is important as it will need to be spot on otherwise you will snap it (too tight) or it will fall off (too slack). The right lubrication is also important.

Any 250 will struggle up the hill out of the Gooseneck until you get to the Mountain mile. Don't worry if you have to hold 3rd gear as it might not pull 4th (with the tall gearing you need)

For Sulby Straight you may need to touch the choke just to richen it up a bit as it is WOT for a very long time, it's also the place to relax, if you can, ready for the charge into Ramsey

You need to run in a new chain, crank and pistons and tyres towards the end of practice week

Go on a diet and hit the gym

HTH

BTW that's me at Quarter Bridge on the Rotax 250 (256 inline disc valve twin) #64 back in 1981 :-)

Image
Last edited by mellorp on Sun Dec 14, 2014 11:04 am, edited 2 times in total.
Luders
Avgas Sniffer
Posts: 3926
Joined: Fri Jun 18, 2010 11:29 am
Location: Oxfordshire

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by Luders »

That's helpful advice
russell
Smoker
Posts: 94
Joined: Sun Dec 02, 2012 4:44 pm
Location: isle of man
Contact:

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by russell »

Thanks for input Mellorp all that is good advice, I also raced here till 1979 and used a 8 gallon tank on a Suzuki RG500in 78.
I am just looking into trade off time saved/ handling weight. Anyway does anyone know anybody who raced these things around here? Looking for setup info if anyone can help
Ronnie
Professor
Heavy Smoker
Posts: 158
Joined: Mon Nov 20, 2006 9:23 pm
Location: Cornwall

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by Professor »

You can hold the throttle open and use the kill switch to lube the engine or the choke when shutting off. Although if you have std choke it should be easy on the KR, I would think using the choke might only work with bikes running on premix?

Glen English raced a KR at TT

The travel of the shock is roughly half of the rear wheel movement
Last edited by Professor on Sun Jan 04, 2015 11:57 pm, edited 1 time in total.
Hardcore you know the score
russell
Smoker
Posts: 94
Joined: Sun Dec 02, 2012 4:44 pm
Location: isle of man
Contact:

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by russell »

Questions --
Any idea of fuel consumption of std motor running oil pump and on 28mm carbs running flat out will acheive.
I need 1 tooth higher and 2 teeth lower alloy rear sprockets, where can I get em
Using std wheels what make, type and size should I be looking at for road racing
cheers
Ronnie
mellorp
Heavy Smoker
Posts: 420
Joined: Fri Sep 19, 2014 6:44 pm
Location: South Manchester

Re: KR1S / CLASSIC TT 2015 QUESTIONS AND ANSWERS

Post by mellorp »

I'd guess at between 20mpg to 25mpg
Do you need to retain std wheels for the classic. If not get a 17" RGV rear wheel conversion. I'd use Dunlop Q2's if its a bit cold/damp or Sportsmart2 if it's a bit warmer
Front sprocket should be a std spline (I think reynolds have the same sprocket for RGv's 3XV's etc) . The rear give these guys a call http://www.sprocketsunlimited.com/Sprockets.html

HTH
Post Reply