KR-1S.co.uk Forum

Hey guys, I introduce my pride and joy, a racing 1991 KR1S, I like to call it a KR1GP because its just so unique , it has participated in AA GP Championship from 1991-2000, around 75 horsepower, 12500rpm, 107 kg dry weight, front Marvic ultralight 17" magnesium wheel (h***a RS 250), rear ultralight 17" wheel (Yamaha TZ250WGP), front Bridgestone Battlax slick 125/70/17, rear 160/60/17 Pirelli Diablo Superbike Pro, Bitubo Racing suspension, stock forks (track adjusted - I'm looking for better USD ones too), GP Custom made exhausts, racing cylinders and pistons (new), lighter crankshaft, stock adjusted carbs (250 GP class was limited 28 carbs back then), custom made quick-shifter, Domino racing grips, h***a Cbr 900 brake pump, Nissin racing calipers (TZ250WGP), Aprilia RS 125 front fairing, rear custom made. Alot of what is made in the engine I don't know how to say in English but okay, it's full racing GP bike and was competing with world class machines in that class back then.
It's in process of resurrection - currently I'm only lacking a front spindle (not completely just the part that comes onto the spindle itself), and to connect the chain, also I need to paint the fairings and get a clear visor somewhere although I don't know where. And I'm searching for a 1R gearbox aswell. Basically it just needs everything to be put together
Will be done until March for sure - then it's going on the track

Sorry for my bad English.

Some pics:

1992


Now




Was in this condition 3 months ago
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Some other pics of the process:




Basically this is the last pic I found of the whole bike (now the rear wheel is green , and it has a temporary nc30 front wheel)


More pics and stuff coming up as I progress..
Also I have a fairing only with a speed (good condition), good front discs, etc. I'll put up pics of it later.

Also a video of it running last month: http://www.youtube.com/watch?v=Tgx5hUE8v1I

Cheers!

Loris

Hi Loris,

Welcome to the forum.

I believe Mark Jordan still has a 1R CR gearbox for sale.

viewtopic.php?t=8775&start=0

I'm just in the process of building a new race bike, so that might be worth a look for you to see what I'm doing and fitting.

Luders wrote:Hi Loris,

Welcome to the forum.

I believe Mark Jordan still has a 1R CR gearbox for sale.

I'm just in the process of building a new race bike, so that might be worth a look for you to see what I'm doing and fitting.

Thanks mate I'll check it out, I'm eager to see what other people are doing with their KR's.

I edited that last post when you were replying and I've added a link to Mark's retirement sale thread.

Here's my build thread.

viewtopic.php?t=9060&start=0

It's still in infancy stages at the moment, but you might get some ideas and the forks might interest you too.

.
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FORUM:
Hi Loris, glad you can join with us here

YOUTUBE:
videos sound pretty mean and healthy
although in later tacho video - revs drop bit slowly indication idle mixture/air leak/cable adjustment

PARTS:
viewtopic.php?t=4858&start=215
are you are after KR-1 or -1S Front spindle axle part??
youve got 1S forks? they are different parts

KR-1 front axle... has basic nut (left hand side in photo) external hex's


KR-1S front axle... has shoulder nut (right side in photo) INTERNAL hex - sockets

Oh I've just realised it, I need the one which goes into the fork, the 1S one, damn it sorry for the whole fuss :/

I noticed in that quick shifter video you have a standard flywheel. You can lighten those a bit or depending on how far you want to go, fit a race flywheel and convert it to total loss with dual pickup and Zeeltronic.

You mention your crank has been lightened, what was involed in the lightening on that?

I always thought there wasn't much you could do to the KR-1 cranks.

It has lightened rods, making it a little lighter but not so much. Anyway I'm thinking of making an airbox of some sort. But I've heard it's hard to get it right.

It's a long read, but extremely useful information...

http://www.rgv250.co.uk/forums/index.ph ... msearch__1

Condition as of last week

[/img]

Welcome aboard
Am i right in thinking/seeing that those are original KR1S pipes that have been modified to exit on one side?
What class did this machine race in,im guessing a national 250 championship as GP 250's dont have a carb size limit at any level of competition.
Cheers
Dave

It was competing at the Alpe Adria Championship in the 250 GP class.. Somehow I don't know why it didn't had bigger carbs, I assumed it was limited.. I'll ask my dad why it haven't had bigger ones

Yeah the exhaust has been custom made (the cans and the pipes), and its considered the most valuable thing on the bike (alongside the wheels).. It was the 7th generation of exhaust made by my dad's friend who was an expert in this field.. They finally got it right with the 7th one - the bike is revving to 12,5k (not 13) but it has way more low-end power. It gave around 5+ horsepower and the difference was so huge that one time my dad lent this exhaust to his friend who also owned a KR1S, and he gave the exhaust back after 2 days saying he's afraid of the bike how much power it has.

Thats impressive
In the UK supersport 400 class back in the 90's the rules called for the stock carbs to be used (28's),but a 250 GP bike would use 38's as minimum maybe even 42mm plus in some cases.
wow thats some revs to be pulling,most dont/wont go more than 11,500 with max power around 11 at most due to the stock ignition.
Thats accurate revs though,not what the stock one always is.

Yeah basically it has stock carbs because they couldn't get a hold of a better ones back then. (at a reasonable price)