Truth or BS? Rear Wheel Swap

[texoot]

I fitted a set of Suzuki sv650 wheels to my Skorpion,with a single disc of a sv 1000.
Frontwheel weighs 9,6kg and rear 13,5kg.Tyres are 120 and 160 wide.
Weights are complete with disc,chainwheelcarrier,chainwheel and tyres.

[texoot]

Bike is not finished yet.

[basser23]

tex,
That is sweet! Who's header is that? Custom?
Nice swingarm and shock mount,subframe...
details on wheel mounting please...

[texoot]

The header is stock,but I made a new y-piece and the rest of the header is going where the shock was sitting.
Swingarm is stock but modified for the shock,also made a mount on the frame.
Subframe,oiltank and airbox I made myself.

About the wheels:I put the frontaxle in a lathe and made it from 20 to 17mm.The disc is exactly in the right place,no spacers needed!
Rearwheelaxle was 20mm from the sv,and I made room in the swingarm and the chainadjusters for the bigger axle.For the rearcaliper I made a new mount of 10mm alu.The chainwheelcarrier has also been in the lathe to adjust for the chain alignment.The bearing is brought further to the inside.
I took the bike for it's first ride today and all is working well,even the rear suspension.It feels very soft,but it corners quite neutral.Bike feels very light with the new wheels and without the fairing and all the other heavy stuff.

[morbidelli17]

Beautiful work!

That is exactly the approach we're going with for the rear wheel, except that by using sleeve/spacers on the stock axle, we're able to make the rear spacers captive.

Is a single front disc enough stopping power? The SV1000 has a 310 disc.

Thanks - M

[mforza]

I'm in the proces of swaping for cbr600 f2 wheel. ill post some pictures when its done.

[texoot]

Beautiful work!

That is exactly the approach we're going with for the rear wheel, except that by using sleeve/spacers on the stock axle, we're able to make the rear spacers captive.

Is a single front disc enough stopping power? The SV1000 has a 310 disc.

Thanks - M

What do you mean with the word captive?
I did use the 20mm axle because it is hollow,and thus lighter than the stock axle.

You're right about the 310mm disc,it is in fact 2mm smaller at the caliper,but it's no problem.Maybe the brakepads will in time hang a bit over the disc,but then I'll grind some of the pads away.
Braking is very good,altough the frontfork is a bit weak and causes a lot of diving.Stock Muz and Szr have also single disc,and the bridge between the legs help against torsion.

[morbidelli17]

Captive = they stay in place when the rear wheel is removed. SV spacers are not captive, so when you're rushing to install the rear wheel and meet second call at the racetrack, the spacers fall out and roll away under something, thus causing you to combine obscene words into new and colorful combinations. Will remember that about the axle. May have to revisit that issue down the road a bit.

More as it develops ...

[morbidelli17]

I'm in the proces of swaping for cbr600 f2 wheel. ill post some pictures when its done.

Front, rear or both?

[morbidelli17]

Getting closer. All that's left on the wheel swap is the rear brake caliper. That front end is complete overkill for this application. I love it.

Lots of little details. New handlebars are going on. Footpegs (new ones, maybe) relocated. Will post up details of swap as I get them from my tuner.

It's been half a year since I've ridden this bike, and I cannot wait - especially because I am told that Dunlop is coming out with a 160 DOT race tire that will fit this perfectly.

[basser23]

Sha---weet!
keep us updated as I know you will
Chip

[texoot]

Looking good so far,is this subframe custommade?Do you keep the stock oiltank,these plastic one's are prone to leak do they?
Do you need a steering damper on your Muz?They have quite a lazy steeringangle and are thus very stable straight forward is my opinion.Or did you raise the back that much?

[morbidelli17]

Thanks, Chip!

The origin of the subframe is unknown - it was on the bike when I bought it. It's funny, but my tuner says the plastic is less likely to leak than an aluminum tank! Ah well, what I have is working, and I'll leave it for the moment.

The SV forks are shorter than the stock MZ forks, and most of the guys who race these things on the West Coast had at least an inch of stock fork tube sticking up through the triple. So the SV fork is almost exactly the length that I had the MZ forks set at. Even with that much fork tube sticking up, steering was indeed quite lazy, with conservative geometry, and I didn't run a steering stabilizer. So we've basically got that same geometry. But we had the steering damper on hand, and just figured better safe than sorry. In the pic below, you can just barely make out the right fork tube sticking up through the triple clamp.

Right now, I don't know the shock length, but I can tell you that the unloaded swingarm angle from horizontal is 11.5 degrees.

Once this part of the project is complete, if I can prevent myself from immediately putting on a full TZ250/Ducati848 fairing, one of the things I want to experiment with was inspired by you, Tex. Twin Works Factory over here makes a little adapter allowing you to put some early GSX-R brake calipers on a stock SV650 front end. I might try going with one of those calipers and a nice master cylinder, and see if I have enough braking power to allow me to eliminate one of the rotors and calipers on the front end. It would definitely be nice to lose that kind of weight.

[basser23]

What do your dogbones measure? I use shorter ones(125mm i think) on mine with the forks about 25mm up in the clamp.you may have similar...I know my short as. legs have me on my toes.

[morbidelli17]

I haven't measured them yet. The seat seems tall, but the rear of the bike doesn't do anything scary, so I'm not going to mess with dogbones until I get the wheels done. I know that Bill J. recommends the 125mm dogbones, and I hope to test some out during the summer testing schedule.

The goal now is to take the bike to Vegas for testing to make sure the forks, the rear wheel conversion and all the little bits (turns out my tuner/friend says he can get the Woodcraft-CFM rearsets for a second gen SV onto the bike) work. Then I'm going to race the first three rounds of CVMA. When that series goes into its summer break, then we'll mess with the motor, exhaust, carb, a bit, and hopefully some dogbones and front brake configuration testing.

I will give MAD props to my friend who is doing the lion's share of the work - I just keep hurling ideas at him, and we talk, and when we think something is a good idea, he can make it work. It is very nice to be treated like the most important customer in the shop. If anyone needs suspension work done on any motorcycle, I cannot recommend enough Ed Sorbo at Lindemann Engineering in California.