Topic: Got an idea for a very trick chainguard in kit form.

[754]

 So hre is the deal , i offset my wheel.
 My bike and a few others like late 750,s run a notch at the rear shock, because it's that close.
Which  makes it hard to make a nice chainguard, because that area  gets cut out, and a very thin chain guard loses support.
 The other thing , a lot of chainguards are flat   so to do one out of angle makes it hard to find suitable material  to have a nice rounded edge on the side.
 The next problem is the end looks way nicer rounded, but I will leave that to the person making the guard.

 The proposed solution;
I have some material stashed that I have not yet found a use for, except maybe chain guards.
 4 3/8 x 4 3/8 square tubing,  with 3/8 wall....the good part is a nice radius on the outside corners, the perfect look.
 So here is what I am thinking  I cut it long enough for a guard plus a few inches for extended arms.
 Then I make a cut one side of the angle, parallel to the outside so that there is about 1 /8  wide material from the inside corner.
 The other side will  be about 3.5 wide and a bit less on the other end, this will leave a lot of material for your mounting points, and allow a 1 piece guard....I hope.
 It will take a lot of sawing and milling and thinning to finish off the guard, but I think it will be worth the effort.
 I will add a pic of one I made out of angle , it will show how the curved end can be formed, and the shock cutaway... the main reason it's hard to make it from one piece.
 Will add some sketch/pic in next day .
Cleary not simple, not for everyone.

[754]

I did some quick measuring, it may be easier to do this from 6 inch aluminum channel , with one leg (side) cut off.
 Then round off the radius at the 90 degree corner.,

[seanbarney41]

Excited for pics, have been trying to wrap my head around a way to do something similar

[calj737]

You want to "thin" 3/8" material down to an appropriate thickness for a chain guard? Thats a LOT of work. I'd still expect it to be easier to get new sheet good, brake it, then cut it. Or cut it then brake it.

Remember what FunJimmy did with his? Look back at his thread for what/how he made a very inexpensive ally guard.

You could grab an entire sheet of stainless, cut out the number of guards by nesting them, then have those bent with a metal brake, polish them, then you'd have a permanently shiny, strong part.

[slikwilli420]

I bought a piece of rectangular tubing for just such a project. Its like 1.25 x 4 and 1/8" wall. I would be able to design a 2D drawing to cut with water jet, then cut off the mirrored pieces on the back side. This would leave the channel for the chain to run through and tabs on just the outside for mounting. You could get crazy with the design and only have minor finish work and some polishing for a killer chain guard.

[754]

You want to "thin" 3/8" material down to an appropriate thickness for a chain guard? Thats a LOT of work. I'd still expect it to be easier to get new sheet good, brake it, then cut it. Or cut it then brake it.

Remember what FunJimmy did with his? Look back at his thread for what/how he made a very inexpensive ally guard.

You could grab an entire sheet of stainless, cut out the number of guards by nesting them, then have those bent with a metal brake, polish them, then you'd have a permanently shiny, strong part.

Have you ever made a chain guard that was cut out around the shock ?  And then by the time you reinforce it , so it does not brake in a week . Then you look at all the reinforcement and think, make it out of thicker, mill away what you don't need, eliminate the fasteners and welding.
 I meant a chain guard not an oil guard... not for everyone..

[MauiK3]

754
Hey, no new projects until the rear rack project is going!
I know, I know, I do the same thing, I have a lifetime of home projects sitting before me.

[rosewood]

754,

look forward to seeing some pics.....I'm just started thinking about making one for my project bike. I'm going to try my hand at a laser cutting and laminating acrylic sheet to make a mould from then doing one in either carbon fibre or glass for a nice light weight version, should be able to sort the notch out for the shock this way aswell. I did a rear guard in a similar way and it came out quite well..

rosewood 

[calj737]

Have you ever made a chain guard that was cut out around the shock ?  And then by the time you reinforce it , so it does not brake in a week . Then you look at all the reinforcement and think, make it out of thicker, mill away what you don't need, eliminate the fasteners and welding.
 I meant a chain guard not an oil guard... not for everyone..

I have done exactly as I described to make shields/guards for bandsaws, lathes, and other equipment. A sheet that is "broken" has far superior strength than straight sheet. A chain guard need not be 1/4" or greater thick. In fact, the sheet metal guard on my 550 from TTR400 is probably made exactly as I described. Looks to be laser cut or water jet cut then passed thru a brake.

[754]

They are all good and strong till you make the bite size cutout..
 Not  firveverybody.. clearly. .

 It sort of like paint, tank  sidecovers could be one colors he'll even wrapped.  But nooooooom so e folks want more than "just doing the job.."

 I think it's healthy to discuss making stuff on a forum.. when I offered to help show how to build a  forkbrace with as little as a drill, hacksaw and file  and a tap... someone actually went and made one.

 Once I post a pic of my chain guard I used, it will become clearer ....or not..
 Looks like channel could be the way to go.
 As Buttera said it's easy, just get a chunk of aluminum, and just mill off everything that does not look like the part. 

[calj737]

They are all good and strong till you make the bite size cutout..

You making a chain guard or a foot rest? 

[754]

Cal, i think you just don't understand. L take any of your lightweight guards, put the cutout in in, and see what happens..

[calj737]

Cal, i think you just don't understand. L take any of your lightweight guards, put the cutout in in, and see what happens..

I do, Frank. We just disagree. Since I have one on my 550 made from thin sheet metal by Kevin Bidgood (TTR400), with cut-outs, I have a very good idea of how durable and strong it is. And, how much abuse do you intend to apply to a chain guard anyway? Mine is mounted by a 6mm button head screw at the front, and maybe another nearer the rear. I haven't looked at it in a long while, so I don't recall specifically.

I'd be happy to snap you a picture tomorrow in the daylight if the rain holds off so you can see what it I'm describing.

[seanbarney41]

what are you guys even argueing about?...make a nice, effective chainguard, if not, hush ya mouth...

[754]

Actually I know what custom chain guards look like, when I was in the retail parts business I sold them,
 But , and I will repeat this only one last time, on some 750,s with the chain line moved out on late models , some come factory with a good portion of the guard cutout. The smaller the guard, the less material left to hold the bouncing end of the chainguard.
 I don't expect everyone to get it, but it appears everybody else probably did.
 I will post a pic of mine that I modded, then it will be apparent, to most people..

[calj737]

Gee, I've never seen a 750 chain guard. What a treat that will be...

Do as you wish, Frank. Make what moves you. Its your time and you should enjoy it. Me, I'll stick with techniques and materials that make things stronger and lighter. That moves me-

[754]

So look at the pic above then consider swingarm up till 76 had no mount past the rear shock.

 So one day I guy named Frank  built a chainguard, start off with a piece  of angle seemed a good idea.
 And then there was a shock clearance problem , maybe because he used F shocks and they Use a CUTOUT chainguard. So Frank cut and checked and cut, and it fit finally. Early swingarm no rear mount.
 But then there was very little support  for the guard past the cutout... hmmm where have we heard that before ?
  And then....
 All the #$%*ing Kings Horses and all the #$%*ing Kings men , and even  FunJimmy, could not keep the back of the #$%*ing chainguard from Vibrating again.
 So Frank thought he was clever and he reinforced, and it worked, but the look of it #$%*ing licked, so he was not totally happy.

 Then Frank got the need to fix his motor as he wanted to go see an OldScrambled guy race at Bonneville. And the cries of use your 78 F motor you got there that is rebuilt became louder and louder.
 So Frank decided to use it , knowing full well the chain must  be spaced out further, And Frank thought, that can't be that hard moving out the rear sprocket, and keeping the same swingarm.
So he proceeded, and it was way #$%*ing complicateder than you can imagine. And he got through most of its but the but the #$%*ing chain was hitting the guard and it had to come out even further..  Fuuuucckk..
 And to top it all off, if you backed it up it flicked off the master link  clip, a few times.. so it became #$%*ing clear that the design had to change...
 And a lot of guys on the forum have experienced this lack of clearance for your normal guards and the need to cut a #$%*ing hole in the guard. Because they run long shaft motors.
 So this 754 fellow thought one piece may be the way to go, not easier not cheaper, and a lot of milling involved.. clearly not something everyone is willing to do . But it is a way to make it work.. and it can be light.
 With one major drawback...
 Not every one will #$%*ing understand the basic issue .
 So now I will add a pic of a guard with the #$%*ing hole in it so maybe most people will get it.

[scottly]

Frank, last time I looked, the NHRA rule book listed minimum thicknesses for steel and aluminum chain guards...

[754]

 Here is an example of a guy that could have just bought something lighter, easier..
But chose not to, because he had an idea he wanted to get out of his head and likes  playing on the milling machine and making something new and different..
 A buddy made up a few of these hubs.. front and rear..
 First he started with a 110 lb block of aluminum..!

[calj737]

So look at the pic above then consider swingarm up till 76 had no mount past the rear shock.

 So one day I guy named Frank  built a chainguard, start off with a piece  of angle seemed a good idea.
 And then there was a shock clearance problem , maybe because he used F shocks and they Use a CUTOUT chainguard. So Frank cut and checked and cut, and it fit finally. Early swingarm no rear mount.
 But then there was very little support  for the guard past the cutout... hmmm where have we heard that before ?
 ...
 So now I will add a pic of a guard with the #$%*ing hole in it so maybe most people will get it.

I didn't know Jed Clampett rode a 750, but now I know who his fabricator was. Good stuff.

[stou]

WOW!!! Those wheels look awesome!