ADVrider

Go Back   ADVrider > Bikes > Some Assembly Required
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 06-05-2013, 10:36 AM   #31
kellymac530 OP
motorcycle addict
 
kellymac530's Avatar
 
Joined: Feb 2010
Location: so. cal.
Oddometer: 1,052
Quote:
Originally Posted by DRjoe View Post
Well going by that theory then if you disconnected the tellerlever wishbone thingy your bike will not fall down because your shock is taking all the loads.
Of course it would move some. That telelever is a hindge. Remove the mount bolt through the block and it can swing forward and rearward which would let it move some. But it would not drop all the way down. The majority of the weight would still sit on the shock and the steering head.

Larryboy,
As far as remembering a teeter-totter, yes I do. I think I am older than you even . I will be 50 this year.
As I see the large A-arm bolt, yes it does need to be large but not for compression of the suspension. I agree, there is a % of weight that is transferred to the A-arm since the shock is mounted in back of the ball joint so there is a teeter totter effect as you state. But the distance between the A-arm pivot and the shock mount is much more than the the distance from the ball joint to the A-arm. So the % would be 20-30% on the A-arm pivot and 60-70% on the shock mount/steering head.

Then when the suspension fully compressed, as in bottoming out, which I did many times on the RT, the force is DOWN on the A-rm pivot bolt and the impact still hits full force on the upper shock mount, I even see it as MULTIPLIED on the upper shock mount since the fork ball joint is in front of the shock giving it more of the leverage you speak of in a seesaw.

I see the need for the large A-arm pivot bolt being primarily for braking and side loading. When you hit the brakes or run into a hard edged bump, like a deep pot hole or a parking bumper, the forks try to push rearward. The the impact is into the A-arm pivot. Then also when the bike is leaned into a turn and the tire is side loaded, there is a hidge effect again since the top of BMW forks are not solid mounted in the upper TC and there is no lower TC. That load sideways is taken by the ball joint and transferred to the A-arm pivot bolt. I have added a much longer steering neck tube, a lower TC, tons of thick plateing and gussetting, a support brace from that same A-arm pivot bolt to the lower portion of the head support and up to the rear of the steering head.

I know of a couple of people who have used that Bert Durssma frame and it is MORE than strong enough. it is engineered, tried, tested, and strong. That frame mounts at the A-arm pivot and the rear stay mounts, I have a 3rd mount point about 5-6" farther forward of those points where the stock steering head mounts...

I honestly see it as AS strong or stronger than those Durssma frames.

I am going to give it a try and if it is flexy or sketchy at all I promise I will fess up and post that.. If it is that way, then I am going to pop on that Durssma frame later.

If it si so weak that it shatters, win win win. 1} You would be proved correct. 2} I would likely fly over the front and break my neck and the titanium plates and screws would sever my spinal cord and I am dead...no more pain and suffering. 3} I am well insured and my wife and daughter would not have to work or deal with my idiot ass anymore....everybody wins.

I have had it on the wheels and jumped up and down on the bike and so far it feels solid with no give or flexing. I will keep you posted.

All of the challenges of my engineering or the lack there of are at least making me stay very conscious of it and are a positive thing, so keep that up. I appreciate the ideas. Extra eyes are always a good thing.

How about the pipe?
the seat?
any other stuff?
__________________
it is easier to ask for forgiveness than permission
kellymac530 is offline   Reply With Quote
Old 06-05-2013, 10:48 AM   #32
larryboy
Paint it black.
 
larryboy's Avatar
 
Joined: Jan 2005
Location: Über Alles,Ca
Oddometer: 13,659
Like I said before, your design, Fabrice's, that Burs frame...they're probably all safe, I don't like any of them and won't ride any of them.

At a minimum I would add the yellow bar I drew in...that's just me. It's not a win if the bike snaps in half and you get hurt, that's why we're here talking about it...I don't want you to get hurt.


Pipe, I prefer the cat down low and no muffler. I had a Buell, really liked the pipe underneath. It makes matching hard bags look so much better.
larryboy is offline   Reply With Quote
Old 06-18-2013, 05:47 PM   #33
kellymac530 OP
motorcycle addict
 
kellymac530's Avatar
 
Joined: Feb 2010
Location: so. cal.
Oddometer: 1,052
Forks

One of the biggest concerns people had when this build started was the lack of heavy springs available for the KYB forks to compensate for the extra weight of the Beast.

I have not ridden it yet, but so far the .50 springs I put in and the 5/8" spacers seem on the soft side, but quite doable and seem reasonably balanced with the rear shock just when standing on the pegs and bouncing....that said, I realize it is something I may have to address after some testing. So with that in mind I have been reading alot on the air forks on the new Crf450R and KX450F. I am really curious about just adding some nitrogen pressure to the existing forks to add some "air" spring rate to what I already have.

Here is a simple diagram of what they used to use and what they have now:

http://www.motorcycledaily.com/2012/...new-air-forks/

There have been tons of bikes that have used and air over coil spring suspension in the past. I have had a few bikes in the past with that set up. I understand that there are other problems that arise like stiction on the seals, or blowing out seals, and the usual fluctuation of pressure with heat build up causing the raising and lowering of spring rate, but, it could be a viable option for at least some air assist...what do you guys think?

Also, I have made alot of progress in a few areas. I finished the rear subframe and fender support. I mounted the tail light. I got a different front fender to match the rear...both the old KTM pumpkin orange not the typical newer KTM deeper orange.

I am still stuck on the clutch lever!!!! A real pisser. The BMW uses a 10mm cable end and most other bikes use an 8mm end...thought I solved it by customizing an 8mm cable end to fit the cable...nope, standard dirt bike levers use a different pivot distance between the pivot bolt and the cable end so the Moose lever and perch do not pull the cable far enough to dissengage the clutch totally...pissed again. So now I decide to just use the BMW perch...nope, the clamp is a single pinch bolt style and not a cap type clamp and my bars are knurled and the perch would not slide over the knurling....gently slid a screw driver blade in to spread the clamp...SNAP, broke it off. Tons of grinding, cutting, fitting and I made a special clamp out of the Moose perch clamp and the BMW perch...it works....doooohhh, too wide to use after market dual sport switch controls and will not allow the use of the OE BMW switches now because of my clamp mods....I now think my head will explode....more cutting and fabbing and I can make my Baja Designs style controls work with the modded BMW perch, but barely and I am slightly worried on the strength in a dump....any ideas on perches and levers that have the longer throw and possibly the 10mm cable end but clamp on the bars like a dirt bike????????
__________________
it is easier to ask for forgiveness than permission
kellymac530 is offline   Reply With Quote
Old 06-28-2013, 10:18 AM   #34
gots_a_sol
Gnarly Adventurer
 
gots_a_sol's Avatar
 
Joined: Aug 2009
Location: Charles Town, WV
Oddometer: 388
Cannon Racecraft could probably make you up some custom springs. I had them make up a set of 50's for my mini-moto as the highest rate off the shelf was 38.
__________________
11 Husky TXC250
09 Husky WR165 - VCHSS #79L
gots_a_sol is offline   Reply With Quote
Old 07-01-2013, 12:33 PM   #35
kellymac530 OP
motorcycle addict
 
kellymac530's Avatar
 
Joined: Feb 2010
Location: so. cal.
Oddometer: 1,052
Got my seat rebuilt, leather sides and rear seat with suede front. I got all of my wiring sorted out and hooked up...PHEW what a nightmare.

Tank all welded then sealed up. Fuel pump installed and hold down mount built.

Replumbed the oil cooler. What a PITA. Metric oil hose is just not available here in the US and neither are any fittings. I did finally find flexible 3/8" copper tubing is a good snug fit in the OE BMW oil line {12mm I believe}. So I picked up some and a few elbows and street 90*'s {male one side/female the other} and soldered up some hardline with rubber hose as the couplings. Works great, sheds heat, looks wierd {oh well} and is holding great because I used a air hammer with a point chisel on it to give the ends of the street elbows and hose end connections to flare them slightly so the hose and clamps can grab on better.

I fired her up and rode her around the block. The frame is VERY stiff. I have no concernes with my frame work at this point, I will continue to watch for stresses and fractures or bends, but it felt very solid. I may have gotten the fork rake a bit steep because the steering feels SUPER light. Like dirt bike light or more. I will have to see if there is any head shake or twitchyness as I increase my test ride speeds. It may require a steering stabilizer/dampner, but it felt fine at moderate speeds.

The brakes....yeah that was a known issue that I have not yet addressed and WOW does it need to be. I might as well have just dragged my feet.

Suspension: Surprisingly good. It feels well balanced, does not dive excessively under what limited braking there is and it does not feel harsh mushy. I have not propperly tested much, but it is a good starting point anyway. One wierd issue I have never had before, maybe you folks can help figure it out. Under braking or any compression of the forks there is a wierd moan or wheezy sound on rebound. Any idea on what the heck that could be?
It is possible it is in the brake somewhere, but it sounds like the forks. I can make it do it sitting still, holding the brake and compressiong the forks, but I have been alone here for a few days so I can not get down and listen while someone else compresses the forks...maybe my buddy will come by on wednesday and help me out.

Of course to fire it up I sorted out my wiring. Got everything connected and realized the wiring harness is way too long coming out of the big old fairing. I had to cut all of the wiring and shorten each one. I soldered each connection carefully, and used the good thick clear heat shrink tubing on every connection. Then oddly my dash panel stopped working. When I turned on the key, my low fuel light and neutral light would not light up until after I started the motor....rut row.

Cut open all of the wrapping I had done and tested all of the plug connectors, good. Tested all of my new connections..good. Then started looking closer....dooohhh.!!! There is a green wire with 2 brown stripes and a brown wire with 2 green stripes....barely discernable to the naked eye and you guessed it, I had swapped them backwards. Reconnected them the other way and dash lights are back...

Final issue so far is I still have the knobby tire trhat came on my YZ frontb wheel. It is a dirt only tire, it is old and very dry with a few splits and missing side knobs chunked off. It is a sand tire so very spread out knobbies and it just does not stick when turning tighter on the street....gotta go immediately. TKC80 coming asap.

I also made a small adjustment in my steering stops. The Yamaha triples and the Honda neck were different spacing and it did not have enough angle. I just ground a small notch in the neck and gained quite a few degrees more turning angle.

So far so good though and nothing too unexpected. So far I am really stoked on the progress. 4 months or so from tear down to first ride and all while I am in recovery and only able to work a couple hours a day...I feel good about it.
__________________
it is easier to ask for forgiveness than permission
kellymac530 is offline   Reply With Quote
Old 07-02-2013, 08:58 AM   #36
larryboy
Paint it black.
 
larryboy's Avatar
 
Joined: Jan 2005
Location: Über Alles,Ca
Oddometer: 13,659
Quote:
Originally Posted by kellymac530 View Post
I may have gotten the fork rake a bit steep because the steering feels SUPER light.


What's the rake and trail?


I just ordered new springs for mine, .76 front and 18.9 rear, time to hit some sweet jumps.
larryboy is offline   Reply With Quote
Old 07-02-2013, 09:23 AM   #37
kellymac530 OP
motorcycle addict
 
kellymac530's Avatar
 
Joined: Feb 2010
Location: so. cal.
Oddometer: 1,052
I set it up to be about the same as a KTM 525 exc which is 27* and the stock YZ 450 forks is set at 26.6* I believe so that was my goal, set it between 26 and 27* which would put trail at the stock YZ point, about 4-1/2"...
But with the heavier weight and a bit more sag that the stock YZ runs it is at about 25* rake and 4-3/4" trail.
how bad is it?
__________________
it is easier to ask for forgiveness than permission
kellymac530 is offline   Reply With Quote
Old 07-02-2013, 09:40 AM   #38
larryboy
Paint it black.
 
larryboy's Avatar
 
Joined: Jan 2005
Location: Über Alles,Ca
Oddometer: 13,659
Quote:
Originally Posted by kellymac530 View Post
it is at about 25* rake and 4-3/4" trail.
how bad is it?

That's what I shoot for on my custom builds...perfect, you're probably just feeling how easy the 21" tire knifes around compared to the 65 pound 19" that was on there.

larryboy is offline   Reply With Quote
Old 07-02-2013, 06:12 PM   #39
kellymac530 OP
motorcycle addict
 
kellymac530's Avatar
 
Joined: Feb 2010
Location: so. cal.
Oddometer: 1,052
phew, that is good news.
Mine never had a 19" wheel. Mine had a 17" cast wheel. My starting bike was not a GS like yours it was an RT.
I am hoping, and now more confident that the knifing under is the really bad front tire. But there is a TKC80 sitting in the garage. It will be on tomorrow morning and we shall see.

I swapped out the front brake master cylinder to the stock RT one...I doubt that will fix much, but worth a try. It is much larger bore and it was made for 8 pistons and ABS...so it barely moves to compress the 2 piston caliper now...

Has anyone been able to mount a 4 piston caliper on a 21" wheel? I read somewhere it had been done but can't find it now. The 320mm rotor takes the caliper pretty far out on the spokes so it might work. Next up is the big rotor and caliper bracket.
__________________
it is easier to ask for forgiveness than permission
kellymac530 is offline   Reply With Quote
Old 07-03-2013, 06:42 PM   #40
kellymac530 OP
motorcycle addict
 
kellymac530's Avatar
 
Joined: Feb 2010
Location: so. cal.
Oddometer: 1,052
Put a couple more miles on it today.... each ride I have been adjusting the little things a bit. Keeps getting better.
I pulled the brake line out from under the fork leg, YZ ran the brake line down the fork and looped it under the axle. Alot of people swap them out to a shorter brake line like the Honda CR uses and the newer YZs run. I left mine stock length, but routed it straight up and inside the fork leg so that I could get more slack at the top. I used the slack to run the line infront of my new headlight. The longer line worked because I am using the BMW MC for now and the banjo is on the bottom so I angled it forward.

I have finished all of my wiring, and some temp front turn signals. I put on a TKC80 front tire but I had to use a HD front tube for now....I am interested in a tubless rim...but I know those are still a dream. Then I thought of a Tubliss system, but I am not sold on them and I worry that it will not seal well on the inner lip of the TKC80, it has a angled row of ribs all the way around the inside of the bead area and that is where the Tubliss seals...

The tire made ALL the difference in the steering. The sketchy steering was the rock hard old tire with missing knobs. It would kind of skip when turning and I was worried it was too steep and knifing under, but now with the tire it handles smoothly, turns great and is no longer sketchy. I played for a while just doing figure 8s in my street at slightly increasing speeds and it felt great. Balanced and even in both directions. Tracks straight. I am actually really proud that my home engineering and jigging seems to be dead on.

I still need to make the cap for the fairing front, Desierto style but homemade. I need to finsih straightening the dent in the tank and spray it black which I already have the paint for. I plan on having a grahic set made for the tank, but that is later and only if they can match my plastics color...rare orange these days.

Anyone have any better ideas on the brakes?
I am ordering a 320mm rotor kit, but I do not think that is gonna be quite enough. The 20mm MC is TOO much. The 11mm YZ is too small {I think} and the caliper is just not enough. I am thinking a 14 or 16mm supermoto radial style MC and that 2 piston Braking caliper that JTH runs but I REALLY would like a 4 piston caliper....
__________________
it is easier to ask for forgiveness than permission
kellymac530 is offline   Reply With Quote
Old 07-03-2013, 11:02 PM   #41
Nixels
Face fears - live life
 
Nixels's Avatar
 
Joined: Sep 2006
Location: West Oakland, CA
Oddometer: 7,566
Sounds like you're making good progress!

Got any pix for us folks that are visualization challenged?
__________________
Coffee first, then all your other mundane bullshit. Benjava

SmugMug coupon: cwbkgu7KGL2D2/save $5
Nixels is online now   Reply With Quote
Old 07-04-2013, 08:39 AM   #42
larryboy
Paint it black.
 
larryboy's Avatar
 
Joined: Jan 2005
Location: Über Alles,Ca
Oddometer: 13,659
Quote:
Originally Posted by kellymac530 View Post
Anyone have any better ideas on the brakes?
I am ordering a 320mm rotor kit, but I do not think that is gonna be quite enough. The 20mm MC is TOO much. The 11mm YZ is too small {I think} and the caliper is just not enough. I am thinking a 14 or 16mm supermoto radial style MC and that 2 piston Braking caliper that JTH runs but I REALLY would like a 4 piston caliper....

I'm using the stock XR650R master with a 320mm rotor, seems fine for how I ride it...I wouldn't try to out brake a gixxer into a turn, but it stops just fine for normal riding.
larryboy is offline   Reply With Quote
Old 07-04-2013, 09:17 AM   #43
kellymac530 OP
motorcycle addict
 
kellymac530's Avatar
 
Joined: Feb 2010
Location: so. cal.
Oddometer: 1,052
What caliper LB?
Do you know what size piston the MC is?

I will be posting some pics soon.
__________________
it is easier to ask for forgiveness than permission
kellymac530 is offline   Reply With Quote
Old 07-04-2013, 10:22 AM   #44
larryboy
Paint it black.
 
larryboy's Avatar
 
Joined: Jan 2005
Location: Über Alles,Ca
Oddometer: 13,659
Quote:
Originally Posted by kellymac530 View Post
What caliper LB?
Do you know what size piston the MC is?

I will be posting some pics soon.

Stock XR650R caliper on a bracket to fit the 320 rotor, don't know the MC piston size. Probably on the 'net somewhere.
larryboy is offline   Reply With Quote
Old 07-04-2013, 05:33 PM   #45
kellymac530 OP
motorcycle addict
 
kellymac530's Avatar
 
Joined: Feb 2010
Location: so. cal.
Oddometer: 1,052
Just got back from its first voyage farther than around my neighborhood. Put 40 miles on it today and rode all over Murietta Ca. It ran flawless. Better than expected.
I got it up to 90 mph twice and it was a bit twitchy if you pull left and right on the bars over 40mph, but over all stable. It turns left and right very smoothly and transitions well. Obviously the handling is not as quick when flicking R/L as the 17" front tire was, but it was really controlled and solid. I notice it is very smooth even on the TKC80 front tire and the Kenda Big block rear tire. Between the longer travel and more plush suspension it feels even smother to me than it did in RT trim.

The muffler is perfection. Too loud for most of the BMW crowd, but perfectly comfortable for me, a MX racing, 3rd generation Harley family guy. When on the throttle it is crisp and a bit raspy with pretty loud volume, but not painful at all, but when at cruising speed I could not even hear it...NO droning at all....perfect.

I had 2 of my riding buddies ride it and both got on it pretty hard, I could hear them through their neighborhoods and they both loved it. Both thought it was a bit tall, but they both have shorter legs. For me the height is fine. I am 6' 0" with a 31" inseam and I can touch both feet very comfortably on the ground. One dead flatfoot and the other on the ground mid foot forward. If I really scoot forward and roll my hips forward I can actually touch flat foot on both. I am used to KTMs with heavier springs for track riding so single footing is my norm.

The brakes are substantially better with the 20mm RT MC...rideable, but barely. I ride with big gaps and a VERY heads up attention right now and at very moderate speeds so as to not need to panic stop. {yes I know I just posted a 90 mph pass...but that in a very special spot I have with NO houses, no cross streets, a full fence along the road and a concrete culvert parralelling the other side...no cross traffic, virtually no animal issues...and no panic brake issues. }
__________________
it is easier to ask for forgiveness than permission
kellymac530 is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 10:00 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014