Well seeing Im keeping my AT, she's going to get some attention. The old girl really needs a decent front end. I'd like more travel to match the longer custom ohlins shock and some better quality forks than the standard damper rod jobbies and also be adjustable. Ive got a front end of a 99 KTM Rallye, 50mm whitepower extremes. After doing some measuring the KTM steering stem is a lot bigger than the Honda and there are bearings to match them up. At the least it's going to require a new stem machined up and fitted to the clamps. The KTM clamps also have milled out areas where the bearings sit and the Honda clamps are flat, maybe I'll have to have some spacers made up to fit into the milled areas, also the steering stops are all in the wrong places. Qbviously its not going to be easy, ive thought maybe some custom clamps might be the go, ive been quoted $900 by Franks, yikes, anyone know anywhere else that makes clamps that might be cheaper ?? Another option is to fit some XR600 forks, they are cartridge forks and are adjustable, they are also the same diameter as the AT fork, 43mm so they would slip straight into the AT clamps and I'd only have to sort out spacers and brakes. Im not sure that longer forks in 43mm would be strong enough for the AT's weight, again any thoughts ?? Any thoughts or ideas would be appreciated greg
Greg, Why not sell the WP units and with the funds buy some XR600 forks? Seems as tho it would be less work and more of an easy fit. 43mm is a bit light on however. Good luck mate.
Not so sure if the XR forks are indeed better. The XR carries a lot less weight than the @ and I recently had a little encounter with a Pajero, necessitating the replacement of the tripple clamps. It was really just side tap on the front-end and no serious sttuff, and I was really really disappointed in how easy it bent. Makes we wonder about the rest of the suspension in terms of taking a beating. Just my 2c. I also found the RD04 have better front suspension than the RD07, but the Touratech kit made a world of difference to my @'c frontend. Have yet to bottom her after I've done the conversion.
Squily, late model XR forks are cartridge forks, they can be made to perform much nicer than the damper rod AT forks, they would just need to be sprung & valved to suit + they are adjustable also they are 280mm travel. I have a custom rear ohlins in my At and have 250mm rear travel so some longer forks would be good to match. I have stiffer springs and emulators in my forks but I still bottom them, I ride reasonably hard plus I weigh 140kg+. The thing Im concerned with the XR forks is if they will flex to much, One thing I thought of was to drop 10-20mm travel from the XR forks to give em more overlap, this would make them 260-270mm travel, still a good improvement on the 220mm of the AT. Or if I used XR600 clamps as well I could maybe fit an SRC fork brace for them.
Hey Greg, If you need to get some custom stuff made up, it might be worthwhile to fire of a Pm to Sean Campbell, (he's a Gosford advrider too) he can tell you who built the frame, suspension mounts, etc on his gs1150 - It has yz450 forks instead of the stock teriblelever setup. He said he had it done on the Northern beaches. View attachment 123642
Thanks RJF, bloody hell I love that GS of Seans !!!!. Just for interest, here's a thread of a guy who fitted XR600 forks to a Transalp http://www.transalp.org/phpbb2/viewtopic.php?t=52
It handles sweet as too, Totally diferent to a normal GS. Very easy to throw around at low speed. It even has a splash guard to keep water out of the electrics now - Someone test rode it through a few water crossings and it wouldn't start when Sean got back on. Bit of crc fixed it thankfully
Why not fit the most modern perhaps best forks made - CRF450R forks? (revalved and sprung of course) I confronted similiar issues to when I had them mounted on my XR600R - would I use the XR stem or use the machined down CRF stem. (I had purchased 06 model 450R new clamps and stem for $100US) Wise heads prevalied the and XR stem was binned and the CRF stem (which is MUCH thicker) was machined down to take the stock XR bearings. It only meant a spacer at the top was required for the top CRF triple.
Fair enough but for the dollars you are mentioning you could have a CRF front end. Extremes are getting on a bit aren't they? Didn't they have terrible inherent seal blowing capability? Not to say showa's dont do seals but ime on 2 bikes with 450R front ends only one seal in 5000km. (it's always the brake side seal of course!!)
Greg....maaaaate.....why wreck the AT by bolting up that inferior WP rubbish! Bolt up a nice set of XR forks! I'm sure you'll find some silly bastard to buy those crappy Extremes off you Now seriously, i'd get myself down to the local wrecker with the measurements in hand and see what front ends are close to yours. Also, as i think you mentioned, there are bearings that can be used to adapt this sort of stuff, you just need to consult the bearing interchange book at your friendly local bearing supplier.
I think he was also worried about the vintage of the XR forks. Perhaps a pair of XR650R forks - they are widely praised as excellent forks and they are bigger than the older XR forks (46mm v 43mm) http://cgi.ebay.com/ebaymotors/NEW-HONDA-XR650-XR-650-XR650R-650R-R-FORK-FORKS_W0QQcmdZViewItemQQcategoryZ35592QQihZ005QQitemZ150139103522QQrdZ1 That shipping quote is bogus - I had USPS express from California for my 450R forks for US$124. All up these forks will probbaly go for 3-400US so for perhaps 600-700aussie you would have them here. You'd still face the challenge of what triples to use but I would bet you could source an enire 650R front end off ebay and then simply play around with spacers and stems until it fitted your twin. At least then with a 650R front end you could use the same shop (Honda) when they are needed...
I reckon go with conventional forks too, simply because thats what the NXR 750 Rallye bikes used, and I reckon Greg should build an NXR copy View attachment 123985
haha RJF, good point, thats a AT750 marathon, basically a tarted up proddie AT. Here's an NXR750 prototype I wonder what size forks are on that bike
ive had the extemes in my garage for a couple of years, actually all the KTM guys prefer them to the 1st few years of USD forks. They are from 99 so are lightyears ahead of the AT forks and as I say if Im going to decide to get into some serious engineering I'll use them. The XR600 idea appeals as it's a lot easier. Several guys in the US have fitted them to Transalps and are very happy with the result