Serious MT500 Surgery

[Mr Kay]

Those of you acquainted with my mighty green sex rocket will know that it is a fair way from standard, particularly with the long CCM swinging arm, KTM front wheel and Brembo brake.

Well, 2011 has taught me a great deal about what I want from my MT500 and how it needs to be changed to become the, ahem, ultimate MT500.
Top of the list (as it always has been) is reliability. The fanciest bike in the world doesn't mean Jack when it suffers catastrophic failure halfway up a Spanish mountain.
Next we have ease of maintenance. I'm not naive enough to expect my old nail to actually be totally reliable so the next best thing is to make it easy to fix when it does break down. I've been working on this aim for a while now, I machined captive spacers for the front wheel for instance. This means that when refitting the wheel, you don't need to juggle it along with a loose spacer and speedo drive.
I've decided not to pursue outright power as the low compression military spec 500 motor should be more reliable than the 604s (though I'm not ruling this out for the future). What I do want though, is faultless fueling and a perfect spread of accessible midrange from straight off idle.
There's more, but I'll keep you in suspense for that!

The first part of this project is to fit the Keihin FCR carb that some of you may recall on the Carbo-Boingo. Unfortunately it doesn't fit in a standard 500 frame.




So with a bit of this:


a bit of this:


and a bit of this:


We get this:


For the grizzly details, as ever, check out http://www.throbbingmissile.com
I will be aiming to keep both the blog and this post updated with my progress and hopefully have the bike completed in time for Stafford 2012.

[bth2bth2]

id be interested in seeing your design for the captive wheel spacers.

brian

[Mr Kay]

id be interested in seeing your design for the captive wheel spacers.

brian

Nothing fancy to it Brian. The KTM bearings are something silly like 25mm ID so I turned top hats that sleeved them down to the MT's 15mm spindle and were wide enough to fit neatly between the forks. The speedo picks up off a magnet on the disc.

[bth2bth2]

i see...i missed the fact you were using ktm wheels.

cheers
brian

[Minter]

I'm impressed Alex! Be intrested to know how the FCR performs with the rotax.. I can't fault them on their Austrian cousins!

Maybe we should start an 'ultimate MT' thread or an ultimate MT stand at stafford!

[TDIPower]

I was quite impressed by the Talon wheels/spacers i had for the husky SM wheels. the spacer in the centre of the hub actualy comes through the bearing each side (means its easier to drift the bearings out) the spacer fits over this and has a lip so the seal holds it in place. OK the husky had no Cush drive but im sure with a bit of thought it would be possible to change the bearings and seals to accomodate such a design on the MT.

[Mr Kay]

Another productive evening in the workshop, I've cut all the replacement gussets and started tacking them in place.

Maybe we should start an 'ultimate MT' thread or an ultimate MT stand at stafford!

I like the idea of a Stafford stand. Anyone else fancy building a bike worthy of this illustrious company?

[Barrie]

I hold the title for ultimate bargain MT for 2011?

[Mr Kay]

As well as refitting my wife's beauty salon, eating too much food and drinking too much drink, I've managed to get in some good work in the workshop.

Gussets at the frame join are pretty much complete:



Good chassis design dictates that the ends of the gussets holding the rear shock mounts are not welded. This means water can get in and rot the frame from the inside out:



I've made new gussets that incorporate two shock mounting positions and will have a filler cap through which Waxoil can be sprayed once the frame has been painted.


The next bit I'm working on is the new airbox and exhaust.

More details in the Cesspit!

[ellrider]

I hope you do as good a job on the wife in the Salon.