BMW G650XChallenge FRONT SUSPENSION

[plumber mike]

Originally Posted by Glowplug

I've had an Ohlins in the rear since last winter, and threw in some Hyperpro progressives in the front for the heck of it with 15w. I'm back to the stock springs but what has been really great is the addition of 5W oil! With 10 and 15 the forks seemed harsh and to "freeze" up, now the forks finally feel like they are working. Heavier springs might be good for riders heavier than me or loading their bikes up with gear and extra fuel...

5w--do it!

Just for a reference, what is your weight geared up? And maybe a dumb question, but isn't a progessive spring soft until it gets closer to full compression where you need stiffness?

[Glowplug]

Good questions Mike--I tip the scales around 200 pounds + gear. I think I have the rebound on full soft and the compression around 3/4 to full soft.

As for progressive springs, the answer is yes. I think the idea is that they will give you plushness over small bumps but still be able to handle the big ones. The spring rate on the Hyperpro is supposed to be firmer than stock. I can't say if they are better or worse. They are worse with 15w oil. Stock springs are bad with 15w in my experience as well.

[Cruz]

Originally Posted by tbarstow

They respring and revalve the forks. The OEM valves are crimped on (or so I'm told). TrailTricks has the set up to crimp the new valves in. I don't know which valves got put in, but its an incredible difference afterwards.

Trailtricks have replied to my e-mail with a quote of $500 plus postage.

[tee bee]

I,ve recently bought a pair of 45mm factory shivers off ebay for £290 they fit straight in the yolks. All i need to do now is strip them down change the wheel ,caliper mountings ,get the bm ones machined out for the rebound mechanism. Then apart from setting them up to my riding style the jobs done.
Wish me luck !!

[Dukehunt]

About to start the WP conversion to XC

KTM Front wheel (in transit)
EMIG racing conversion kit (in transit)
KTM Disk rotor
04 KTM WP forks, re-sprung with stiffer springs, new 5w oil and seals (need to test)
KTM Front Brake Caliper (hopefully the XC brake lines and master Cylinder will be adequate)

Go to go to the Moto GP at Phillip Island so I will start when I return later in October

Any know if any thing in particular to lookout for ?

[dirty boar]

Cruz is that $500 USD. heard that there is a suspension shop in Sydney OZ going to make some cartridge for the forks about $800 AUS.

dale

Originally Posted by Cruz

Trailtricks have replied to my e-mail with a quote of $500 plus postage.

[Cruz]

Yeah $500usd plus postage.

Here is his reply.

Yes ,we do it few times a year ,we cut the cartidge and put a new one after modified the valving and crimp it ,i got the crip tool last year and cartidges are avaible from marzochi italy
cost is around $500

[Dukehunt]

Originally Posted by Cruz

Yeah $500usd plus postage.

Here is his reply.

Yes ,we do it few times a year ,we cut the cartidge and put a new one after modified the valving and crimp it ,i got the crip tool last year and cartidges are avaible from marzochi italy
cost is around $500

Hey Cruz that is getting expensive to modify the existing forks
Swap to WP's isn't chap either, glad the Aussie dollar is doing well

My total so far is:
Forks $380
Front Wheel $290
Brake Caliper $80
EMIG Triple clamp and kit $680

So far $1430 and I haven't put it together yet

[Deco]

I am on the same track as Duckhunt.

I have a terrible head shake at around 65-70mph on asphalt. Dirt is fine. I have progressive spring in front and OEM air shock in rear.

My thinking is the EMIG stabalizer will help with the head shake and will allowing me to up garde to the 48mm WP forks, as funds become available, making for a much better front end. I am about half way through the install, so I have no report other than the install has been fairly easy to this point.

Any suggestions on replacing the rear shock? Ohlins, Hyper Pro, etc.

[Dukehunt]

Originally Posted by Deco

I am on the same track as Duckhunt.

I have a terrible head shake at around 65-70mph on asphalt. Dirt is fine. I have progressive spring in front and OEM air shock in rear.

My thinking is the EMIG stabalizer will help with the head shake and will allowing me to up garde to the 48mm WP forks, as funds become available, making for a much better front end. I am about half way through the install, so I have no report other than the install has been fairly easy to this point.

Any suggestions on replacing the rear shock? Ohlins, Hyper Pro, etc.

Hey Deco
Running an Ohlins rear, so far so good, to me it feels much better than the air shock as it behaves like a normal bike, but I am sure all will change when the front suspension is sorted and it will be back to the drawing board on all the settings.
One thing though, it is bloody tall with the Ohlins fitted, I am only 5'8" and it is a real stretch to touch the ground , I can only get one tip toe on the ground at a time and have to mount the bike from the right hand side as it makes it easier to get on.
I have the forks with only the top 2 lines showing above the top triple clamp as I agree that the front is nervous at speed and don't want to steepen the rake unnecessarily. I tried them further through but it was unstable.

[Rone]

Originally Posted by Dukehunt

Running an Ohlins rear, so far so good, to me it feels much better than the air shock as it behaves like a normal bike, but I am sure all will change when the front suspension is sorted and it will be back to the drawing board on all the settings.
One thing though, it is bloody tall with the Ohlins fitted, I am only 5'8" and it is a real stretch to touch the ground , I can only get one tip toe on the ground at a time and have to mount the bike from the right hand side as it makes it easier to get on.
I have the forks with only the top 2 lines showing above the top triple clamp as I agree that the front is nervous at speed and don't want to steepen the rake unnecessarily. I tried them further through but it was unstable.

I am 1m74cm. I have an Ohlins too. It is modified. There is a spacer (6mm) inside so the bike is +/- 2cm lower in the back.

[Max Kool]

Originally Posted by Deco

I am on the same track as Duckhunt.

I have a terrible head shake at around 65-70mph on asphalt. Dirt is fine. I have progressive spring in front and OEM air shock in rear.

Not sure if a steering stabilizer will help you. Most headshakes that I know of are "low speed" oscillations (low speed as in "quite slow left to right movement", 1 Hz or even lower, with a low amplitude). You need to tighten up the steering damper quite some to ease these. Steering stabilizers are mostly efficient in damping high speed shakes from ruts and rocks that would normally shake the bars out of your hands.

I know from first hand that the Xchallenge is quite susceptible to tire choice. On Michelin Enduro III and IV this bike behaves very bad at higher speeds on tarmac at any speed over 65 mph. On Michelin Baja this bike is much better.

Consider different tires first before you invest in a steering damper, otherwise you might end up with a bike that is stable, but will hardly go round tight corners imho, or otherwise is excellent in thed desert but still shakes its head.

(don't get me wrong, I'm not against steering dampers, I'm just doubting if it's the most efficient way to solve your particular problem)

[D K]

I'm doing the same mod..
One question for you: why not use the KTM triples?? That's what I did. Much cheaper.

D

Originally Posted by Dukehunt

Hey Cruz that is getting expensive to modify the existing forks
Swap to WP's isn't chap either, glad the Aussie dollar is doing well

My total so far is:
Forks $380
Front Wheel $290
Brake Caliper $80
EMIG Triple clamp and kit $680

So far $1430 and I haven't put it together yet

[Cruz]

Trying to find some to buy in the first place is the hardest bit here in Australia.

[Deco]

Originally Posted by Dukehunt

Hey Deco
Running an Ohlins rear, so far so good, to me it feels much better than the air shock as it behaves like a normal bike, but I am sure all will change when the front suspension is sorted and it will be back to the drawing board on all the settings.
One thing though, it is bloody tall with the Ohlins fitted, I am only 5'8" and it is a real stretch to touch the ground , I can only get one tip toe on the ground at a time and have to mount the bike from the right hand side as it makes it easier to get on.
I have the forks with only the top 2 lines showing above the top triple clamp as I agree that the front is nervous at speed and don't want to steepen the rake unnecessarily. I tried them further through but it was unstable.

Thanks for the comments. I am planning on either the Ohlins or HyperPro. I''m 6' so I have a slight advantag...:)

Let me know how the install goes and I'll do the same.