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Discussion Starter #21 (Edited)
The “Big” KTM/Husky rear wheels are much too wide at the hub - don’t fit. (Well not without insane mods!)
Potentially you could use your rim and spokes, laced to a new hub - maybe not worth it.

With axle size changes at different year models, wheel swaps can be “problematic”, especially, as I’ve mentioned, the cush drive rears (more difficult, but not impossible, to convert axle sizes. Ask me how I know!).
Maybe I'll just grab a new set of rims which can fit between both bikes and sell the oem 701 wheels.

Since it's taken me so long to get this to work, I may be able to swing getting some marchesini's. Anyone know off the top of their head if you can get the same marchesini sm base rims 17x3.5/17x5 and swap between a fs 450 and 701 by only changing the spacers/adapters?

If not the marchesini's, what about warp9's?
 

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Thinking about the rear wheel when converting the FC450 to FS450 and back.

First, wondering if anyone can confirm the FS450 has stock gearing of 14t front, 45t rear? have seen conflicting info that the FS runs a 13t front, which is same as the FC.

Second, it would be nice to avoid needing to change the chain on each conversion if possible. Looking at the rear axle and axle block, and I got the sense that you might be able to rotate both to reduce/expand the wheel base slightly. Anyone had any experience with this? might let me get away with running a ~49t rear using same chain (down from stock 52t for FC) when running in supermoto trim. Which seems like a fairly good compromise, assuming both the FC and FS do run the same size front sprocket.
The best quick change option, using the same chain, is to swap the front sprocket to one bigger, and run 3 (or 4? Can’t remember) smaller on the Sumo Wheel, then reverse the axle blocks. This requires minimal chain adjustment. Unfortunately this means the SM wheelbase is longer, while the MX wheelbase is shorter. Opposite of ideal. Such is the nature of comprise.

The close ratio 5 speed transmission really requires external gearing changes for Supermoto to suit tracks/usage.
(My race kit includes 3 front sprockets and about 7 rears. Of course I enjoy some level of OCD)
 

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Discussion Starter #23
This is where I'm at. Grabbed all of these from various sources. The forks in particular came from Euro for cheap <$900 USD. Other parts I grabbed used off ebay or via online oem part stores. Should be almost there if I can sort out the rear wheel issue.

Front wheel left side spacer x1 78909012000
Front wheel right side spacer x1 7800901200
Front wheel axle x1 78909081000
Front wheel axle screw x1 54809082000
Front fork x1 34158S0801
Top triple clamp x1 7890103411630
Lower triple clamp x1 2610103201630
Bar supports x2 59401039032
Bar support bolts x2 0032100356S
Bar clamps x2 77201038000
Bar clamp bolts x4 25080256
Hourmeter bolts x2 912040163
Hourmeter bracket x1 78112920044
Fork protection set x1 59001094100DB
Front brake line clamp screws x2 0017060206
Fork protector screws x6 59001092050
Front brake rotor spacer x1 58409161000
Front sprocket x1 79233029013
 

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Discussion Starter #24
This is where I'm at. Grabbed all of these from various sources. The forks in particular came from Euro for cheap <$900 USD. Other parts I grabbed used off ebay or via online oem part stores. Should be almost there if I can sort out the rear wheel issue.

Front wheel left side spacer x1 78909012000
Front wheel right side spacer x1 7800901200
Front wheel axle x1 78909081000
Front wheel axle screw x1 54809082000
Front fork x1 34158S0801
Top triple clamp x1 7890103411630
Lower triple clamp x1 2610103201630
Bar supports x2 59401039032
Bar support bolts x2 0032100356S
Bar clamps x2 77201038000
Bar clamp bolts x4 25080256
Hourmeter bolts x2 912040163
Hourmeter bracket x1 78112920044
Fork protection set x1 59001094100DB
Front brake line clamp screws x2 0017060206
Fork protector screws x6 59001092050
Front brake rotor spacer x1 58409161000
Front sprocket x1 79233029013
Triple clamp was the most difficult/expensive to source. Had to pull from Austria via an online seller here in the US. Took 2 months to get to my door.
 

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Discussion Starter #25
Maybe I'll just grab a new set of rims which can fit between both bikes and sell the oem 701 wheels.

Since it's taken me so long to get this to work, I may be able to swing getting some marchesini's. Anyone know off the top of their head if you can get the same marchesini sm base rims 17x3.5/17x5 and swap between a fs 450 and 701 by only changing the spacers/adapters?

If not the marchesini's, what about warp9's?
Have emailed motostrano and toxic to find out on the marchesini's. Will let people know what I find.
 

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Discussion Starter #26 (Edited)
Have emailed motostrano and toxic to find out on the marchesini's. Will let people know what I find.
Also emailed king-wheels to ask the same thing on a set of alpina's, which I'm sure can be sold with the same hubs and two sets of adapters/spacers, so I can switch the same rims between both bikes. So I'll go that direction worse case.
 

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Also emailed king-wheels to ask the same thing on a set of alpina's, which I'm sure can be sold with the same hubs and two sets of adapters/spacers, so I can switch the same rims between both bikes. So I'll go that direction worse case.
Let us know, but I think the width means different hubs between both.
 

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Discussion Starter #28 (Edited)
Let us know, but I think the width means different hubs between both.
Toxic got back to me quick. Apparently Marchesini don't sell the kompe's for the 701. Which is odd, because I swear I have seen people running them.

But it does sound like its possible to do what I'm looking for with Warp9 forged wheels. Either their switch or stiletto design.

I'll wait to hear on the alpina's before I pull the trigger, as I think I would prefer a set of those over the w9's.
 

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Discussion Starter #29
Let us know, but I think the width means different hubs between both.
You are right. The rear alpina for the fc450 is smaller and doesn't have a cush drive hub, unlike the 701sm rear alpina.

Still thinking through options. Guess an option may be to get a set of alpinas for the 701sm, as well as a separate rear alpina for the fc, and sell the oem 701 wheels.

Clearly a proper fc to fs conversion is much more difficult than I expected.
 

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Discussion Starter #30
So I finally got everything I need, and converted the FC 450 to a FS 450 last weekend.

Started playing around with suspension yesterday. Note that I'm using actual FS 450 forks and I swapped the shock spring to a 5.2kg/mm spring.

Checking my sag numbers with sport settings, and I'm at 20mm/70mm on the rear which isn't too far off Husqvarna's recommended 20mm/80mm. But not sure what to aim for on the front? Just checked and rider sag on the front is 15mm @ 156 psi, which seems low.
 

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Discussion Starter #32
So from what I have read. It sounds like 10mm/25mm (static/rider) seems about right on the front for a sm. But frustratingly, I'm getting about 15mm of stiction on the front forks, even after pulling the dust seals and greasing. They are brand new, so doubt this is abnormal. But far out, it does make setting the front up difficult.
 

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So from what I have read. It sounds like 10mm/25mm (static/rider) seems about right on the front for a sm. But frustratingly, I'm getting about 15mm of stiction on the front forks, even after pulling the dust seals and greasing. They are brand new, so doubt this is abnormal. But far out, it does make setting the front up difficult.
Double check the wheel alignmen/front axle tightening sequence.
Any misalignment ads to stiction.
I like to tighten the clamps with the forks compressed a bit.
 

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Discussion Starter #34
Double check the wheel alignmen/front axle tightening sequence.
Any misalignment ads to stiction.
I like to tighten the clamps with the forks compressed a bit.
Yeh, thought that may be an issue. So loosened lower triple clamp bolts, and non-brake side ping bolts. Jumped on the bike a bit and did it back up to spec. No difference.

It actually sounds like 15mm of stiction isn't actually that uncommon for a sm. From what I'm reading anyway... Way more than I have seen on my road race bikes.

So going to start using the racetech method to calc sag from here on. Hopefully get something close to 25mm on the front without backing off preload too far. At the moment I'm at 140 psi (compared to 154 psi std). So really don't want to drop any more.
 

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Discussion Starter #35
Took the time to do this properly today, using the racetech method. Got much different (but more consistent results).

At 140 psi, I'm getting:

fork stiction (under weight): 18mm
fork rider sag: 51mm
fork stiction (no weight): 13mm
fork static sag: 21mm

So 21mm/51mm on the front, which suggests preload is low.

But upping the preload to 150 psi gives me a lot more stiction. In fact, I'm getting about 22mm of stiction (under weight) when at that pressure, and it only drops the rider sag about 4mm (47mm).

If I ignore stiction, I imagine I will be able to get something like 17mm/40mm by continuing to up the preload. But doubt I'll be able to get the front to the 15mm/25mm target I keep seeing people aiming for without some ridiculously high preload.

So lesson is obvious I guess... The shock isn't too far off after replacing the spring... But when you are carrying extra weight, you probably need the think about fork internals too.
 

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I’d also run an O ring or cable tie, to see how much travel you are using. On the biggest hit.

Perhaps use that as another guide to air pressure, and low speed compression damping?

What ever feels best for you, on the tracks you ride.
 

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Discussion Starter #37
Finally got the bike out on track yesterday.

Didn't have a great time with it to be honest. 2-3 sec a lap slower than on the 701. That's running the same rubber as I normally do on the 701, on a day with great weather and a tight track where a FS 450 should be faster.

Two main problems were mid corner instability and closed to open throttle response.

First, mid-corner feel.. I just can't get it to lean without feeling like its going to wash out. And can't get the right feedback from the front wheel. The suspension feels way too stiff when going around the corner, but I wouldn't want to get much more front end dive on the heavy breaking zones. So not sure how to best address it. Note that I checked front fork travel at the end of the day. Was around ~150mm from memory. Will need to check my notes.

And two, the closed to open throttle response is waaay too harsh. Can't modulate coming into corners where I can't maintain some entry throttle. That, in combination with the pretty aggressive engine breaking, makes the bike tough to get along with. End up needing to push it really hard to even get a half respectable lap time. Note that I'm running a FMF pipe, and haven't messed around with mapping yet.

So for next time. I'm going to switch compression and preload settings to 'comfort' and see how that feels. And I'm also going to look into getting a vortex ECU with the right mapping for the bike. Hopefully they can also provide a low engine breaking map, and/or maps which are FS not FC specific.

Will put up a video of the bike later in the week.
 

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Still running the MX tripple?
Slipper clutch.
 

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Discussion Starter #39
FS triple and forks. But yes, no slipper. Really think the engine braking can be improved with proper mapping though...
 

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Quick question, why didn't you just get and FS instead of trying to converting and FX/FC? On a tight track the FS should be about 10 seconds quicker than a 701. Which track was this that you did your testing?
 
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