WP4860's on my XChallenge-First impressions

[Losttheplot]

Took the bike out for it's first off-road ride today, since fitting the new front end, which is basically the Original WP forks from a KTM 690 enduro R.

The difference is very noticeable.

The ride is smoother and the front end seems to "track" much better, there isn't anywhere near as much flapping of the bars when hitting rocks or ruts, and the bike seems more compliant with going where you want it to as well.

Got the bike off the ground on a few occassions, and there wasn't the usual crunch from the bash plate hitting the ground, so i can only presume the forks are taking the bigger hits in a much better the fashion than the originals.

First impressions are that the fork swop was very much worth the effort and expense

 

[r1d3rg652gs]

Did you have to make modifications or machining to stock parts or did you swap stock parts with ktm partd to make the transplant straightforward?

 

[mikedefieslife]

Interestingly I never bottomed out the forks on the xCountry during my Morocco trip, it actually seemed too hard and kept hopping from rock to rock. Good to know the WP4860s work well.

 

[Losttheplot]

Did you have to make modifications or machining to stock parts or did you swap stock parts with ktm partd to make the transplant straightforward?

it is almost a striaght forward swap. I used KTM tripple clamps, and had a local engineering shop remove the stem and turn it down to take the stock BMW head bearings. The ktm stem is around 5mm shorter than the original BMW item, but i have over 12k miles on this now and no problems. Apparently the BMW stem can be fitted to the ktm tripple clamps, but will need to be fitted using chemical metal or thread lock or similar. This is the route Timpo took when he built his bike up.

The parts i used where:

KTM EXC tripple clamps
WP forks for a 690 Enduro R
Talon front wheel for 690 enduro R
EBC brake disc from a 950 super enduro/ 60 enduro R (the standard EXC brake disc is to small)
KTM Calliper bracket from a 950 super enduro- allows the original XChallenge calliper to be used on the WP forks.
KTM EXC front axle.
BMW head bearings.

All in it probably cost around £1k in parts to change, but it was worth every penny!

 

[Losttheplot]

Interestingly I never bottomed out the forks on the xCountry during my Morocco trip, it actually seemed too hard and kept hopping from rock to rock. Good to know the WP4860s work well.

It's not just the bottoming out that is the issue, the rebound has a reputation for failing, leaving the bike like a pogo stick to ride. When i did the swop i knew i had a long ride ahead of me, and really didn't want any issues with the front end.

 

[r1d3rg652gs]

it is almost a striaght forward swap. I used KTM tripple clamps, and had a local engineering shop remove the stem and turn it down to take the stock BMW head bearings. The ktm stem is around 5mm shorter than the original BMW item, but i have over 12k miles on this now and no problems. Apparently the BMW stem can be fitted to the ktm tripple clamps, but will need to be fitted using chemical metal or thread lock or similar. This is the route Timpo took when he built his bike up.

The parts i used where:

KTM EXC tripple clamps
WP forks for a 690 Enduro R
Talon front wheel for 690 enduro R
EBC brake disc from a 950 super enduro/ 60 enduro R (the standard EXC brake disc is to small)
KTM Calliper bracket from a 950 super enduro- allows the original XChallenge calliper to be used on the WP forks.
KTM EXC front axle.
BMW head bearings.

All in it probably cost around £1k in parts to change, but it was worth every penny!

When you say ktm triple clamps you mean the bottom clamps or the high ones under the steering?
Is the front wheel a must change?
Also do the front disc have to change? Will that affect the abs function?
I was thinking of getting the emig conversion kit, check here

 

[r1d3rg652gs]

double post...

 

[Losttheplot]

When you say ktm triple clamps you mean the bottom clamps or the high ones under the steering?
Is the front wheel a must change?
Also do the front disc have to change? Will that affect the abs function?
I was thinking of getting the emig conversion kit, check here

That emig racing kit looks the nuts , but over £1000 by the time you have both top and bottom yokes? If your looking to spend that kind of money you could stick with the standard KTM clamps and use a hotrod welding fairing instead. This would get around having to refit your headlight and dash assembly to the KTM yokes, and would also cure the issue or the standard XC headlight being crap.

As an alternative the blingy triple clamps maybe get in touch with Molly on the rallymoto forum, he seems to make his own up and maybe more cost effective and bespoke to your needs.

When i said triple clamps i ment both top and bottom yokes.

As far as the front wheel goes, i found my original rim was actually made of cheese! After 10k miles it was looking decidedly battered and out of shape, where as the Excel that i now have on the front is almost as straight as the day i put it on (14k miles ago), and this rim has been across Nevada (which was like a bloody building site with all the rocks strewn about).

If you change the hub to KTM you will also need to change the brake disc as the original won't fit. As far as the ABS goes, i'd bin it. It's just more to go wrong with the bike and just a liability off road.

If you wanted to stay with the original front wheel you would need to get the fork bottoms changed on your new fork legs, or some shims made up to fit in the fork clamps. The original axle clamps from the XC probably won't fit as the standard legs are 45mm as opposed to 48mm on the WP's. The standard fork bottoms also need further machining to take the rebound adjusters.

IIRC the standard XC front axle is a smaller diameter than the KTM item. Easier to change the front wheel and know everything will work as it should.

HTH

Nathan

 

[PeterNI]

Is there another issue of the spacing between the forks being less than the originals cutting down on the cut on the steering?
I sent my front forks out to HotRod Welding to be machined to allow 45mm Marzocchi Shivers to bit in original tubes. Machining allows adjustment at bottom of forks. Bas at Hyperpro then fitted the Shivers, new seals, progressive springs, oil etc for a lot less than £1000! The euro exchange rate was so good I changed the rear shock too and helped myself to an XRack, XTank and a protection parts whilst at Eric's.
Even travelling from Northern Ireland, across England to Hull ferry and back worked out cheaper than buying the parts in the UK plus I got a custom suspension fit, which is so plush

 

[PeterNI]

http://www.ukgser.com/forums/showth...ding-a-kind-of-ride-report?highlight=Hyperpro

 

[r1d3rg652gs]

That emig racing kit looks the nuts , but over £1000 by the time you have both top and bottom yokes? If your looking to spend that kind of money you could stick with the standard KTM clamps and use a hotrod welding fairing instead. This would get around having to refit your headlight and dash assembly to the KTM yokes, and would also cure the issue or the standard XC headlight being crap.

As an alternative the blingy triple clamps maybe get in touch with Molly on the rallymoto forum, he seems to make his own up and maybe more cost effective and bespoke to your needs.

When i said triple clamps i ment both top and bottom yokes.

As far as the front wheel goes, i found my original rim was actually made of cheese! After 10k miles it was looking decidedly battered and out of shape, where as the Excel that i now have on the front is almost as straight as the day i put it on (14k miles ago), and this rim has been across Nevada (which was like a bloody building site with all the rocks strewn about).

If you change the hub to KTM you will also need to change the brake disc as the original won't fit. As far as the ABS goes, i'd bin it. It's just more to go wrong with the bike and just a liability off road.

If you wanted to stay with the original front wheel you would need to get the fork bottoms changed on your new fork legs, or some shims made up to fit in the fork clamps. The original axle clamps from the XC probably won't fit as the standard legs are 45mm as opposed to 48mm on the WP's. The standard fork bottoms also need further machining to take the rebound adjusters.

IIRC the standard XC front axle is a smaller diameter than the KTM item. Easier to change the front wheel and know everything will work as it should.

HTH

Nathan

Thank you, Nathan. What I really want to do is get a pair of WP4860 forks (250mm travel) like the 690 EnduroR 2014 ones and fit them without having to cut or machine anything. I don't mind replacing stuff from the XCh since I'd prefer a straightforward fitment. As far as the fairing is concerned I prefer the lynx series of fairings for the XCh.

 

[Losttheplot]

Thank you, Nathan. What I really want to do is get a pair of WP4860 forks (250mm travel) like the 690 EnduroR 2014 ones and fit them without having to cut or machine anything. I don't mind replacing stuff from the XCh since I'd prefer a straightforward fitment. As far as the fairing is concerned I prefer the lynx series of fairings for the XCh.

That is the same reason i went for the WP's. ( i couldn't find the 50mm marzocchi's that i was after). I looked at the standard forks and decided i wanted something that used as many off the shelf components as possible, just in case i needed parts during the last big trip.

IIRC The Standard XC forks are 270mm, and the earlier enduro R forks are 275mm. The basic 690 enduro was 250mm of travel, but i can't comment on the later bikes.
Worth considering the effects on ride height, unless you plan to reduce the seat height a bit?

The EXC forks will also fit very well, though at 300mm travel you may need an inch poking through the top yoke to maintain ride height.

Those Lynx fairings look very smart.

 

[r1d3rg652gs]

I will lower the seat height. Order 10mm shorter shock (=32mm lower rear axle) and a lower seat as well and maybe a tad softer/lower spring from hyperpro. 250mm is fine by me. Thanks again.

 

[Dansin]

My Dakar has a YZ front end and yokes which doesn't incorporate a steering lock. I now also have a GPR V4 steering damper from a WR450 that I wanted to fit.

A bit of 3D design work and a contact with some 6082T6 and a CNC milling machine.

Cost of materials and machining was £120. The design cost was just my time.

 

[GB.]

Awesome

 

[kito]

Thats a nice bit of machining. Who did it ? All that would need doing is a bottom yoke and the wp48 would work with the bmw top yoke

 

[zimi]

WP 48 KTM EXC or LC4 better for X-Challenge

Hello Guys,

I check this post with interest. I need to swap my fork, because it's damaged. I found a complete KTM EXC fork (with triple clamp) from 2004 for 200 euro.

Would you take it?

Ready this thread I understood that they are longer than others, so I will have to let them out of the upper triple clamp to keep the same height.

Is there any other disadvantages using an EXC fork?

Is the brake caliber fixation points the same as on a LC4 Adventure?

Thanks for you help!!!

 

[Losttheplot]

Hello Guys,

I check this post with interest. I need to swap my fork, because it's damaged. I found a complete KTM EXC fork (with triple clamp) from 2004 for 200 euro.

Would you take it?

Ready this thread I understood that they are longer than others, so I will have to let them out of the upper triple clamp to keep the same height.

Is there any other disadvantages using an EXC fork?

Is the brake caliber fixation points the same as on a LC4 Adventure?

Thanks for you help!!!

The EXC forks should be fine- what sort of diameter are they? IIRC it was around this time that KTM went from 43mm forks to 48mm.

The 43mm forks should fit straight into the original BMW yokes with minimal machining, you may even be able to use the original BMW front wheel (though the original rim was made from cheese).

If you use the larger forks they will also be fine. You can either remove the stem and replace with the original BMW stem (this will need fixing in place with a suitable resin), or you can get a machine shop to turn the KTM stem down to fit the original BMW steering bearings.

It's no problem with the EXC forks being longer. IIRC it is only by approx 25mm, and if it bothers you, the legs can be raised in the clamps to accommodate this.

HTH.

Nathan

 

[magno]

The only problem with using KTM triples is that the space between them is less than the OE triples and as a consequence you lose a considerable amount of steering lock. This is not a problem for fast open trails but is an issue for more technical and slower sections. Many people have warned me off this conversion due to this.

The latest thinking is to use the OE forks with shiver internals as these are a less sticky fork than the 43mm WP's. The problem with the 43mm WP forks is that some work great and others don't. Very much dependent on how everything is clamped up. The Marzocchi's don't seem to suffer this problem.

I have some WP4357MXMA which I will have available very soon. Revalved and sprung for an XC. They have done about 20,000kms overland but are externally excellent condition. They will need a service but will bolt straight into the XC triples and I have the correct brake caliper bracket too.

 

[zadaleko]

so you saying that they're going to be available... hmo so Im First