Interesting, never considered having bearings made, I assumed those need higher tolerances than a steering stem and crossed them off the potential options list as cost prohibitive. The KTM uses a pair of 50.25 x 29 x 15 units, the R6 calls for a 55 x 31 x 18 on the bottom, 55 x 30 x 17 up top. A 50.25 x 31 x 15 doesn't seem like it'd give much roller area, or am I overthinking it?
If stems are same length changing bearing is option. The one I make for sv is 47x30x15. We use it to mount gsxr forks on 1st gen sv, R6 forks on fz07...and few more applications.
You've got me curious now, I'll drop the forks out of the KTM again so I can get some fresh stem measurements in comparison to the R6 setup this evening.
Going with custom bearings, the overall length difference between the bearing areas of the stems are different enough that a spacer would need to be incorporated in, below the bottom bearing. The other bit needed would be opening up the bore of the KTM upper dust cup to clear the R6 stem, and it should otherwise be plug and play at that point. If machining the R6 stem to take KTM bearings, the spacer issue still needs to be addressed, and as I suspected the lower set of threads on the R6 stem foul the ID of the KTM bearings. Either option I'd love to have the R6 stem bored out, it's a heavy pig.
do you just make a spacer for a commercially available bearing? If not as that possible, like a bushing? Just curious.
That is option but not much harder to just make new stem or machine one if that is what it needs. Bearing I make for sv needs to be smaller OD to fit frame. There are also rollers you can buy in pieces but finding metric combo to work can be impossible.
Ok, clamps should be sorted, one they're home I have to start assembling a roller so I can figure out how drastic the mods to the shock need to be. Before I go shopping for new bits, anyone got any of the following? 3rd gen R6 clipons KTM 250/300 SX tank, that'll fit on my 2016 250 XC Lightweight R6 front wheel
To add to the needs: R6 front wheel spacers... I must have given two spare sets with my 03 when I sold it instead of keeping one for myself, bah. First clamp test didn't quite fit as expected, which was a good thing. It showed that A) I miss-estimated that the lower bearing would sit flush on the R6 clamp, ignoring the ridge underneath it, and B) my lower race in the frame wasn't actually fully seated. The joys of prototyping... it was close enough to prove the concept though, R6 clamps can be adapted.
Cheap, and cheap. I'll go to proper race worthy ones with replaceable bars once the bike is in trackable form, but I needed SOMETHING on it in the mean time to make moving it around easier and to start looking at any potential clearance issues, etc, get a feel for ergonomics, mock up duty.
Will we see this monster this season at NHMS? I’d love to see it in person as well as perform on track.
Maybe? I'm funding limited which means slow build rate. I'm currently waiting on front wheel spacers before I can send the roller to Kates for an initial stab at suspension setup, I then need to figure out bodywork, rearsets, source good clipons, source a good master for one caliper, etc. The rearsets in particular are going to be the big pain, I can either order a custom set out of Spain from Beon, or have some welding done to allow the use of say, R6 units. Bodywork is going to be minimal, really just worried about a tail/seat with the right erogs, hopefully without having to heavily modify the subframe. Once that's done, It's going to get tested on Thursday test and tune / Friday Penguin days before I grid up. Won't be till next year at the earliest that I spend the BIG chunk of change to pump it up with the BRC500 power plant assuming it proves out as a 250 first.
I've talked with him a bit to get an idea of the overall feasibility of the project, I haven't chased custom parts too hard yet again, budget limited so tackling items one at a time. Did he get settled in at his new shop yet?
What are the odds I could find a KTM frame to match a 2016 KTM 250XC without spending half as much as a whole used bike?
To follow up on the frame question, I put the bike back together with some TLC as the NETRA woods weapon it was when I got it, and did a woods day on it. This was the toughest singletrack I've attempted to date and the bike made it seem almost easy. Like, giggle inducing fun as opposed to my normal white knuckle how many crashes will this loop be woods time. I'm now really hesitant to chop it up, it's too fun. So I need to find another frame or basket case bike to be the basis for this project. In the meantime I've got an improved front clamp set sorted, and picked up a 500XC-W in sumo trim for no good reason.
