I have been doing a little research. It appears I can go with fork axle reducer bushing to fit a 17mm axle in the popular fork swaps. The choice is a YZ or a KTM 4850 forks. The YZ has been done using tbe yz wheel. To use our stock wheel will require axle bushing our a custom axle from flattrackaccessories.com. The brake caliper will require a new hanger but Aquitic's bracket should work. I can go with the WP 4850 forks. The lower triple will need to be machined to 48mm. An axle bushing or new axle will be needed. The brake caliper bracket is from a KTM 990 or a 940. This swap has been used for the 650gs. I have found valving suggestions for the 650gs swap. It should be close for our bikes. Now the big question, which way should I go? Which fork is better, the YZ or the KTM?
Think you have a typo there with the lower yoke needing to be machined to 60mm not 48mm, if you look around you will find there are 17mm axle holders for the WP and some of the CCM 640's used them, the CCM WP's are already shortened to 890mm length as well, there is a bit of info in recent pages of the YZ fork thread at Advrider and Gravelseeker there has a set of 4860's from a CCM he wants to sell
I talk to flattrackaccessories.com today. They can make a 17mm axle for the yz forks. He needs the measurements to make an axle and spacers. He told me it would run 140.00 for axle and spacers.
I received a yz front axle. But the sucker is tubing. I am going to have the local machine shop turn it down to 15mm. I think I will go ahead and have an axle made. The2mm difference moght make the stock axle too thin. Flattrackaccessories.com told me 140.00 for the axle and spacers. I am going to see what the local guy will charge me, it might be cheaper.
Yes 17mm. I scrapped keeping the stock wheel and went with the YZ wheel. I have everything I need. I have a yz brake line in case our stock line is too short. I am keeping our stock front master cylinder. From my research, our master is 13mm while the Yamaha master is 11mm. It appears some of the Yamaha guys switch to the larger master. I will see how it works.
I didnt think the yamaha hose would bolt up to the brembo master - good if it does. I got a jap master from a KLR650 which bolted up fine. what do the 13mm and 11mm measurements refer to?
The piston diameter in the master cylinder. The brakes both use a 10mm banjo bolts. The brimbo is 10mm by 1.25 thread, the Yamaha is a 10mm by 1.00 thread pitch. Just use the appropriate thread pitch banjo bolt.
Just got my Terra back from the engineering outfit that fabricated a new axle so Im now running the original wheel and that huge Brembo chunk of rotor with the KYB fork.Brake caliper adapter is by Aquatic additional spacers need to be fabricated to centralise the Terra wheel Does it stop better ?? Oh yeah !! One off engineering like this is pretty expensive - but its cheaper than not bring able to stop. I did witness a new rider T boning a car last week which kinda made my mind up. So there you go Ive come full circle on the brake issue, Ill post some photos when I get the new braided line and the routing tidied up To do this conversion to this level in Australia will cost you at least $1500
Job Done You can see the little blue Rattel Engineering caliper bracket and thats all you'd notice.The axle is steel using the YZ nut as it is part of the fork fastening system. Im still using the 12ml piston KLR master and the rubber line. It gives a really nice progressive feel to the lever and will do stoppies. I see there is a floating disc available on ebay now
