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3305
Joined
5/25/2014
Location
San Diego, CA
US
FWYT
2/24/2021 8:14am
2/24/2021 8:14am
Edited Date/Time
6/7/2021 7:44am
I've been wanting to do this for a while and the plan was to get bike to do a full rebuild with and include the Showas in the mix. That is looking like it won't be in the budget for quite a while so I've decided to do the swap
on to my trusty 2004 KTM-200.
I had picked up a set of the Showas a while back in remarkably good condition. Actually, I have two sets because the first set was just OK. Even picked up an aftermarket top clamp of some sort. Both sets are from a 1998 RM250. I am going with the Suzuki clamps for the gullwing design that is needed for these forks.
First order of biz is to check the fit into the head tube. Remarkably, they both use the same steering head bearings. Holy crap!! One less hurdle!! Or do many bikes use the same size steering head bearing? I don't know, but I am relieved.
The stem in the Suzuki clamp, however, is just a little too short. I mean just a little, maybe 5-10mm. The collar that threads onto the stem at the top, under the top clamp, only can thread on about one turn.
I really don't want to get into a custom stem. Cross referencing a longer stem possibly? But looking at the Suzuki bottom clamp, the boss is raised at least 8mm. I think what I am going to do is press out the stem and take down that boss to essentially move the clamp up in the frame and give me the length I need. I am not an engineer but that does not seem like an area where removing that material will cause a structural issue. (Please tell me I'm right. hahhaa)
on to my trusty 2004 KTM-200.
I had picked up a set of the Showas a while back in remarkably good condition. Actually, I have two sets because the first set was just OK. Even picked up an aftermarket top clamp of some sort. Both sets are from a 1998 RM250. I am going with the Suzuki clamps for the gullwing design that is needed for these forks.
First order of biz is to check the fit into the head tube. Remarkably, they both use the same steering head bearings. Holy crap!! One less hurdle!! Or do many bikes use the same size steering head bearing? I don't know, but I am relieved.
The stem in the Suzuki clamp, however, is just a little too short. I mean just a little, maybe 5-10mm. The collar that threads onto the stem at the top, under the top clamp, only can thread on about one turn.
I really don't want to get into a custom stem. Cross referencing a longer stem possibly? But looking at the Suzuki bottom clamp, the boss is raised at least 8mm. I think what I am going to do is press out the stem and take down that boss to essentially move the clamp up in the frame and give me the length I need. I am not an engineer but that does not seem like an area where removing that material will cause a structural issue. (Please tell me I'm right. hahhaa)
The other thing I've found this that some after market bearing kits sit a little higher than OE. Usually it has to do with the seal. Yamaha, for example, have a seal flange that allows the bearing to rest on the clamp. Many of the aftermarket kits have seals with a full faced flange that the seal rests on and makes the bearing sit a few mm higher.
That one almost looks like it has a washer under the bearing.
Hope that helps.
The Shop
Next is steering stops. I'm going to keep it simple and carve up some aluminum and just bolt them in place using the existing KTM steering stop lug. Should be plenty strong. (still have to shape and finish them.)
but it should be plenty strong. Side note- I picked up a crummy little Harbor Freight bandsaw a while
back dirt cheap but the older gentleman who owned it before me had taken the time to set it up
and it cuts just dead nuts straight. Sometimes you get lucky.
Can't wait to hear what you think of the conversion.
Edit- After looking at these photos, I realized that the portion where the damper bolts on should be trimmed to more of a "V" shape. I'll do that before moving on.
I'm not going to mess with the valving yet as I have to ride it first
to see what's up.
Also going to go with the springs that are in it for now, as well.
5mm wire, 42.75mm OD and 23 active coils.
According to this calculator http://www.racingsuspensionproducts.com/spring%20rate.htm
the springs come in at .50kg/mm which seems way high. Oh well. I'll just ride it first
and see how it feels.
Stiffness Preference: Standard Stiffness
Age: 45 years and Older
Height: Standard Rider Height
Gas Tank: Standard Gas Tank
Lowering: Not Lowered
Rider Weight: 180
FRONT FORK SPRINGS
Recommended Front Spring Rate: 0.40 kg/mm (Use closest available)
Stock Front Spring Rate: 0.42 kg/mm (stock)
Pit Row
Yes, we're going with a little Ti hardware.
Now I just have to get a day to go ride!
Initial first thought is that I definitely like them more than WP's that were on the bike. No harsh slap down and soaks up those braking bumps better. I will hopefully be able to get to ride some more next weekend. Keep in mind I am just a 50+ B rider. Not some Pro who hauls ass. But so far I dig them!
Went racing last weekend. I dig 'em. More supple on the choppy stuff and squares.
The rider needs work for sure, though!
I still need to trim the steering stops a little more as lock-to-lock could be better.
Overall I am very happy with how this whole project worked out!!
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