Spare time KR1 project finally finished...

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Coose
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Re: Spare time KR1 project finally finished...

Post by Coose »

Coose wrote: Fri May 15, 2020 1:24 pm I have just worked out some interesting numbers.

I just weighed my KR-1. With about 3/4 tank of juice (16 litres when full), just over 2 litres of coolant and just under a litre of gearbox oil it weighs 136.3kg, with a 53.9%F/46.1%R weight bias.

A standard KR-1weighs 131kg dry, so add 15kg for the fluids and mine is 10kg lighter, probably due to the lack of road gear, the pipes and minimal subframe. I could probably lose a couple more kg off the bike if I made an ali fairing/clock bracket, took off the sidestand and bracket, and got rid of the kickstart gubbins (but that's useful).

Or, I could lose 3 stone... :lol:
The weight of yours looks to be similar to mine, although my weight distribution looks to be a tad more biased to the front - not dissimilar to me! :lol:
(The quoted post above is from my thread).

The weight distribution would be influenced by whomever is on the bike anyway, so I suppose it's inconsequential anyway. 8)
RickNC30
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Re: Spare time KR1 project finally finished...

Post by RickNC30 »

The weights that I have quoted for standard bikes are the official factory figures - the 131kg that you cited in your original post is the weight of a KR1S, not a KR1 which is lighter. I`m guessing the main reasons for the difference are the 5-spoke vs 3-spoke wheels and possibly that as the 1S frame doesn`t have the pressed-in stiffening ribs in the side rails, it may be made from heavier gauge metal...?

I weighed my bike with all tanks brim full and applied the factory figure of 23kg difference between that and the bone-dry weight so as to have a direct comparison.

The standard exhausts, lights, clocks and bodywork are all pretty hefty components so losing those and all the associated brackets and replacing them with the lightest parts that I could source at reasonable cost probably accounts for most of the saving - the only significantly heavier assembly would be the USD forks and radial brakes, which would also account for the change in weight distribution but for me that`s a win/win with vastly improved suspension & braking performance and also a more `modern`, slightly front-heavy chassis bias.
Coose
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Re: Spare time KR1 project finally finished...

Post by Coose »

Yes, sorry, you're right about the standard weight. It'd be interesting to see what a standard KR-1 ACTUALLY weighs compared to the factory quoted figures and whether Kawasaki were maybe stretching the truth. Other than the steel fairing bracket on mine there's very little further weight that I could lose off it, but plenty I could lose off me!

Mine has ZXR400 USD forks and so they may be a little heavier than KR forks, and most of the stock back-end is gone on mine, hence the forward weight bias.

Also, how accurate are our bathroom scales?

Your bike does look great though, well done! 8)
RickNC30
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Re: Spare time KR1 project finally finished...

Post by RickNC30 »

OK - here`s the first instalment of a brief description of the build - I`ll start by pasting the couple of posts that I put on here last year...

1)

A simple USD conversion for the KR1/1S is to use ZXR400`H` model yokes. These have the same stem dimensions as the KR1 and fit straight on using the standard ZXR bearings and seals - the steering stops are in the right position, the only modification required to fit later model fork legs is to bore the bottom yoke where the legs fit through from 50mm to 52mm - this is a half hours work for any competent machinist.

Once you have bored the bottom yoke you have a front end which will take either ZXR400L forks or, better still, the ones from a ZX636 B1H (2003/4) or C1H (2005/6) model which both use the excellent 4-pad Tokico radial brake calipers. The fork legs from the ZX636 are the correct length to match the KR`s chassis geometry.

The combination of components that I`m using in my build is C1H fork legs, calipers and discs with a B1H wheel (interchangeable with the later model) which is a 3-spoker and matches my RGV VJ22 rear pretty well. Handlebars and radial master cylinder are from a late model GSXR600 and I`ll be using the mudguard from a ZX-10R as it is smaller and less clunky looking than the ZX-6R unit. I have modified the forks to suit the lighter bike by changing the springs for stock RVF400 NC35 ones (which drop straight in) and the oil for 2.5W instead of 5W.

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2)

Continuing the build - we have wheels...!

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The front is actually from a Hornet, simply because I had it in my spares stash, I already make an adaptor kit for it to fit the ZXR forks and it uses the same discs as the NC30. Powdercoating is the gold that Subaru use on Impreza wheels, done by Aerocoat (who also did the gloss black frame), discs are Arashi waveys.

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Rear is a 17" RGV250 unit, fitted using an adaptor kit made to the spec that`s posted in the archive on here, Talon sprocket, wavey disc.

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Shock is a Nitron R2, suspension linkage uses BDKs jack up arms. It`s probably common knowledge on here but fitting the 1S swingarm to the KR1 frame requires more than just boring the pivot holes for the larger diameter bolt. Because the KR1 uses metal cap type grease seals and the 1S doesn`t, you have to shim the ends of the bearing inner sleeve to avoid `squeezing` the frame when you tighten the pivot bolt (0.5mm each end did mine) and then shim the swingarm itself to control the sidefloat (1mm each end in my case). Shim sizes are 20 x 28 and 28 x 40 respectively - you can buy them on ebay from a supplier called `Screws City`.

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The finish on the swingarm is vapour blasted and then clear anodised, which didn`t come out exactly as expected but I think I quite like it - it`s a kind of satin finish mid-grey, looks very like mag wheels do when they been stripped for recoating. Good BS potential, though - `nah mate, it`s the factory race kit magnesium swingarm...`

Now the new stuff -

Engine arrived back from BDK, thoroughly cleaned and reassembled with a rebuilt crank, lightly ported but not tuned KR1S barrels fitted with their F3 KIPS valves, lightened flywheel and large diameter carb rubbers, I added the Chinese built (surprisingly good quality) PWK34 carbs

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Back to the chassis, another session saw the rebuilt brake calipers (freshly repainted in matt black by Powerhouse), master cylinders and HEL hoses fitted, along with the GSX-R handlebars, modified FXCNC footrest kit plus various brackets, front mudguard and the bulk of the wiring and electrical components, including the Ignitech DCCDIP2 ignition system.

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To be continued...
RickNC30
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Re: Spare time KR1 project finally finished...

Post by RickNC30 »

Next episode...

Engine, exhausts and carbs fitted -

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JL pipes modified to fit Tyga mufflers, home made hangers -

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Details of carb fitting - BDK provided carb/reed block rubbers for the PWK34s but I needed something to plumb them into the airbox. Found these new replica Z750 (twin) rubbers on ebay and they looked promising so I bought a pair - they fit just fine but the sealing rib misses the airbox wall by quite a bit so I simply filled the gap with some split 4mm silicone hose.

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The 34mm carbs have bigger bores and therefore longer slide travel than stock 28s so custom Venhill cables were required as the stock inner cables were too short and holding the slides 5mm off the stops. Happily the stock KR1 twistgrip has enough travel to pull them all the way to fully open. Carbs came equipped with `K26` needles - that doesn`t cross reference to the Keihin catalogue but the mid range fuelling is near-perfect so I`m happy to leave them in there. I started out with 135 main jets on BDK`s recommendation but have since gone up to 140 as the top end showed up a bit weak on the first dyno run.
Last edited by RickNC30 on Fri Oct 02, 2020 9:57 am, edited 2 times in total.
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JanBros
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Re: Spare time KR1 project finally finished...

Post by JanBros »

nice stuff 8)

shame about the glossy frame though, I don't like glossy beams. but that's me ;-)
My ultimate goal is to die young as late as possible !
RickNC30
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Re: Spare time KR1 project finally finished...

Post by RickNC30 »

The frame was scruffy and needed refinishing anyway - the look of the bike is based on Toni Mang`s 1982 GP machines which had gloss black tubular frames so that`s the colour I went for.

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I think the finished bike works as a visual package...

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RickNC30
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Re: Spare time KR1 project finally finished...

Post by RickNC30 »

Cooling system -

Has anyone here ever failed to notice that there are two types of YFZ450 radiator, only one of which fits the KR1, and ordered the wrong one...? I know I have...

Once I`d bought the right one, I trimmed off a few unwanted bits and made up mounting brackets as per Bernie`s diagrams - I actually ended up with a slightly modified version to allow for the fact that I`ve used rubber, not rigid mounts -

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Plumbing was pretty simple - only the right hand radiator hose needs work as the original shape goes nowhere near the rad outlet -

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Samco provided the solution in the form of a straight alloy joiner and a 90 degree bend in `classic black` to match the rest of their hose set -

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- so having turned the original hose round 180 degrees on the pump outlet, cut to length and clamped the new bits, the finished arrangement looks like this -

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RickNC30
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Re: Spare time KR1 project finally finished...

Post by RickNC30 »

Miscellaneous bracketry - all home made from aluminium sheet using a drill, files and an improvised folding bar.

Headlamp and clocks - TZR125 / RD125LC type headlamp fitted to OEM fairing stay with simple 90 degree brackets - very easy to make, fitting them to the OEM stay just requires a 4mm thick washer in the hole plus a penny washer either side and a short M8 bolt. More on the clocks later...

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Another simple bracket holds the speedo sensor in alignment with two magnet-headed M6 bolts which are fitted through the bobbins on opposite sides of the left brake disc. ZX-10R mudguard has the same bolt spacing as the bigger, heavier original ZX-6R unit but the holes are 20mm higher so the straight brackets just raise the mounting points to get correct front tyre clearance.

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Number plate & indicator bracket is an anodised CNC universal part bought for £20 off ebay. Back end uses the stock inner mudguard section plus a shaped alloy plate bolted to the rear end of the subframe onto which the plate/indicator bracket is bolted -

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Coose
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Re: Spare time KR1 project finally finished...

Post by Coose »

That's a great write-up! 8)

Just one thing regarding the coolant hoses - Roose Motorsport will make silicone hoses but a little longer for you to cut to length to suit the YZF450 quad radiator. They're a decent price too!

When you say there are two different radiators, is that two different "quad" radiators as there only seemed to be one when I bought mine last year?
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Re: Spare time KR1 project finally finished...

Post by RickNC30 »

I have a trade account with Samco so they are generally my first choice supplier for radiator hoses. The set on my KR was actually a cancelled customer order that was left on the shelf at Samco - they offered them to me for less than trade price so that was a no brainer.

The modification to the right hand hose has more to do with adding the extra bend to match the angle & position of the radiator outlet than the actual length of the hose.

There are two different radiators for the YFZ450 quad - the 2004-2008 model has the right mounting brackets to fit on a KR-1/1S, the 2009-on model doesn`t...

Rick
Last edited by RickNC30 on Sat Oct 03, 2020 8:02 pm, edited 1 time in total.
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500bernie
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Re: Spare time KR1 project finally finished...

Post by 500bernie »

A brilliant read Rick,

Lots of useful information.
In relation to the 34mm carbs, I ground off about 5mm from the top of the car where the adjuster screws in, this allowed me to use the standard throttle cable that I already had.
The 35mm Quad Vent carbs that Martin sells, will accept the standard throttle cables without any modifications as the fixing is on the top of the throttle slide (as opposed to part way down the slide or standard ones and 34mm carbs).

I will be reading through this again when I have a bit more time.

Cheers
Bernie 8)
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RickNC30
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Re: Spare time KR1 project finally finished...

Post by RickNC30 »

Thanks, Bernie - that`s interesting to know .

I`m in the same sort of situation regarding the cables as with the radiator hoses - I also have a trade account with Venhill who are very happy to do specials and one-offs so to phone them up, ask for a set of KR1 cables with +5mm on the carb inners and have them on my doorstep in three days was the simplest solution...
Coose
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Re: Spare time KR1 project finally finished...

Post by Coose »

That's ideal for both the hoses and the cables. 8)

The Roose hose solution is good for those of us who are normal punters though, which is useful should anyone do a search on here (which I've done a lot of with my build). They're really helpful, but call rather than email as they're quite old-skool.

It's still an excellent write-up though. 8)
RickNC30
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Re: Spare time KR1 project finally finished...

Post by RickNC30 »

Yes, absolutely -

I wasn`t intending to be in any way dismissive of your suggestions, just explaining the how and why of my own build - the whole point of doing this is to share as many ideas and options as possible with other owners and enthusiasts.
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