fucks yeah DIY hardtail
I like where this is going.
this bike rules so hard
I like that it’s been shortened but that looks like an 18 and a 21 or 23… I’m going 16R/18F with fatter tires front and rear. That bike is fucking awesome tho.
---------- Post added at 11:09 PM ---------- Previous post was at 11:06 PM ----------
Started making the jig today. Obviously still need to make the rear portion that will locate the dropouts, but I’m getting there…
Lanesplitter <3
Is that at work?!? They just let you take up a jig table for XX days?
I can haz co-op?
It’s not attached to the table. It’s a sturdy structure with leveling adjusters, will probably have to re-level it at the beginning of each work session…
Ah, well if you sharpie around the feet and put it back where you picked it up from you probably won’t have to re-level it.
Rad.
Drew rough frame geo in CAD. Looks like a derake is going to get ugly with tire/triple interference with suspension travel… Might have to go with stock rake… still looks alright… and even in that case might need to clearance the lower tree for the tire…
Stock:
-5 Rake: probably too aggressive for the frame clearance as well… but I don’t think much, if any, de rake is going to happen with those triples while maintaining a level ride height.
I think it looks better with the stock rake than the -5 anyways…de-raking is probably going to marginally raise the front ride height on top of it, so you’d probably need MORE clearance chopped out of the triple clamp to go that route. The only other option is chop the neck off and move it UP while keeping the stock rake… as in cut the welds away and put the spot where the gusset is shown in your drawings up where the top tube is and re-weld, then blend another peice of pipe at an angle from the old location down to the spine…make sense? if not throw your inventor file up and I’ll play with it to show you what I mean…
I know what you mean, but the whole neck assy is cast, can’t move it around much… pretty much only change the angle. (don’t want to rebuild that whole part because it has the vin on it) The ride height in both pics is the same which is why the tire is so much closer to the tree in the second pic. If I can clearance the lower tree enough maybe I can do like -2 or 3 rake…
ohhh gotcha. the neck itself is a cast piece welded to the frame? damn. what if you knocked the plate out of there, cut the top tube halfway between the neck and the front down-tube and then flip the neck upside down and sleeve that top tube back together and then gusset the top side?
crude MSpaint:
[ATTACH=CONFIG]22706[/ATTACH]
EDIT: actually visualizing that and seeing the angle the neck is welded to the top tube, that may actually both lower AND de-rake it…
It’s more complex than that:
If I derake it at all it will be by removing the downtubes from the casting and shortening them and bending the toptube right where it goes into the casting which actually raises the bike a tiny bit, too.
---------- Post added at 05:50 PM ---------- Previous post was at 05:15 PM ----------
The top model is stock. the second model is 25 degrees
Forks are off a GSXR-1000. 720mm (28.3) from axle to cap. Can be shortened 3" max, but the issue is tree/tire clearance, not fork length or travel.
The trees will be custom made.
stock fork spacing spacing is 6.125" between the tubes
new fork spacing 4.5"
new tire section width is 4.25"
I can clearance the tree for the tire a bit for sure. The tree in the model is 2" thick… I can probably hog an inch out of that… no front brake really decreases the moment load on the tree.
So check it out. Tinkered with it a bit and may have a solution. The images shown are with the fork internally lowered about the maximum amount.
Fork at 25 and even ride height (4.5")
Fork after 2" of travel (about the range of the gsxr shortened fork:
Obviously this is no good. Tons of clearance issues. Also not the fork poking out of the top of the triple tree. YUCK.
HOWEVER, if I raise the fork and push it down into the tree flush (total of 1.25") , i wind up with a slight angle to my frame (1.3 degrees). but the result isn’t too detectable by eye.
25 degrees of rake, 1.3 degree frame angle:
And after 2" of travel:
I could make this work for sure. Again, need to have the forks and wheels on the bike before I can really do much beyond conceptualizing…
What is the proper process for changing rake angles?
---------- Post added at 06:14 PM ---------- Previous post was at 06:13 PM ----------
Also, point out what you cut and shortened… I’m looking at it and not seeing the difference
Two ways. Look at this pic:
Option 1, cut a pie from the neck gusset and bend the neck down. Doing this with a cast neck seems like a bad idea… Doesn’t raise bike though, which is good…
Option 2, grind the weld off of the downtubes and horizontal gusset tube, shorten them, bend the neck down where the tup tube meets neck casting and reweld. raises bike nearly an inch which is bad because it doesn’t help with the tire/tree interference.
In the second 2 models I changed the angle of the whole frame up 1.3 degrees. (this would be the same as lengthening the forks). The stem becomes 1.25" higher off the ground.
that cast neck is really fucking stupid, damn! I’d probably stick with stock rake just because of that…but that’s me…
Thanks for the explanation. How do you make 50 mm forks fit on a compatible triple tree? And also fit that neck? Seems like a ton of work… And then what about brakes and wheels and hubs and axles… Yikes.