Dropping The Front - How Low Can You Go.

[Dieselman7.3]

Interesting for sure

[Millietant]

Hmmmmm, an almost, but not quite. Cover the front end and the back single sided, three spoke set up looks tasty, but that Paris/Dakar sized tank and the scaffold pole forks need slimming. Pretty radical though. The sons of anarchy crowd will love it.

Not sure it would be good to ride, to say it would steer like a truck might be an insult to trucks - and I'd worry about the (jarring/fatigue with scaffold pole forks that long with no damping of the impact forces) loading the front end puts on the headstock....hoping the welds and tubing are suitable.

BUT, as motorcycle art.... I love it !!

[2big]

 

This thread got me thinking it was about time for me to manufacture some new dog bones.

Having to work last night, I seized the opportunity.

These dog bones are 115mm centre to centre.

Square ends.

Wow great result Gavin, excuse me for jumping in....could be just what I'm looking for...so replacing the existing 125mm dog bone with 115mm one raises the seat height by how much? 30mm on a 3XW

May I ask - what stock material did you use?
was that in conjunction with the stock shock?
Cheers Jan

[Millietant]

Hey Jan,

I think I read that Gavin has a YSS shock on his bike, but even with your standard shock this should maybe give nearly inch extra height at the rear and might give you a little bit of needed extra legroom (add that to some Buell footpegs, if they fit and you could have a fair bit of extra legroom  )

I know some people have made dog bones out of 1" x 1/4" flat mild steel - but not sure if that would be good enough though. I'm sure Gavin will advise.

[fj1289]

I'll just share this and slowly back out of the room......

1st - NEVER seen a build make an FJ motor look small!

2nd - I've seen motocrossers with a lower rear rise height!

3rd - the silver clutch cover almost makes it look like a separate gear box just like a hardley

4th - so close to something really cool - instead landed on really goofy - so much missed potential

[fj-f3a]

This thread got me thinking it was about time for me to manufacture some new dog bones.

Having to work last night, I seized the opportunity.

These dog bones are 115mm centre to centre.

Square ends.

Wow great result Gavin, excuse me for jumping in....could be just what I'm looking for...so replacing the existing 125mm dog bone with 115mm one raises the seat height by how much? 30mm on a 3XW

May I ask - what stock material did you use?
was that in conjunction with the stock shock?
Cheers Jan

Jan

My "Stock Shock was Shot." (She sells sea shells, The sixth sick sheik, etc)

The YSS shock was recommended, affordable and easily getable.

The material is 316 stainless steel cut from a 150 X 150 angle iron and is nearly 7mm thick.

My intention is to manufacture as set from 4340 Steel Bar.
4340 is not available in flat bar, so I will have to machine a 40mm round bar.
I would then like to have them properly heat treated and ground to final thickness.

I feel Mild Steel flat bar would be OK in the short term.
Make sure it is at least 1/4" (6.35mm) thick and 32mm wide. DO NOT SKIMP on the Width.
Placing one over the other and tack welding each end is a tried and tested method for maintaining alignment.
Use a vertical milling machine or a pedestal drill in good condition for drilling the holes, NOT a HAND DRILL.
Try to be as accurate as possible in keeping the holes centered on the flat bar.
Use a 12mm drill bit. If pilot drilling remember, not too big. The pilot should only be as large or slightly smaller than the WEB of the 12mm drill bit. Remember to debur.

When rounding the ends, use as Hack Saw and File so as not to generate excessive heat.
Again, be accurate with the end rounding to keep as much "meat" as possible around the holes, a full 9mm (3/8")
You do not need to round both ends, but .......

If using Mils Steel or Stainless, please, do your Pre-Flight Checks before riding.
Remember to lift the rear wheel occasionally to check for Stretching around the holes.

We really should not use stainless for Structural Parts (well, maybe 17 4 PH is OK) as, from what I have been taught, it fatigues and cracks.

This is a fantastic mod. It reduced the "Bike on centre stand" rear wheel ground clearance from about 55mm to around 18mm.
The bike looks sexier, turns in better, is a darn side easier to lift onto the centre stand and it's possible to remove the rear axle without removing the muffler.

That's a Win, Win, Win, Win situation.

Gavin

PS

I forgot to add, after doing this mod, be careful when placing the bike on the side stand the first few times.
It is different!

[Little Pink Steve]

This thread got me thinking it was about time for me to manufacture some new dog bones.

Having to work last night, I seized the opportunity.

These dog bones are 115mm centre to centre.

Square ends.

Hayabusa bones might be your answer
Wow great result Gavin, excuse me for jumping in....could be just what I'm looking for...so replacing the existing 125mm dog bone with 115mm one raises the seat height by how much? 30mm on a 3XW

May I ask - what stock material did you use?
was that in conjunction with the stock shock?
Cheers Jan

Jan

My "Stock Shock was Shot." (She sells sea shells, The sixth sick sheik, etc)

The YSS shock was recommended, affordable and easily getable.

The material is 316 stainless steel cut from a 150 X 150 angle iron and is nearly 7mm thick.

My intention is to manufacture as set from 4340 Steel Bar.
4340 is not available in flat bar, so I will have to machine a 40mm round bar.
I would then like to have them properly heat treated and ground to final thickness.

I feel Mild Steel flat bar would be OK in the short term.
Make sure it is at least 1/4" (6.35mm) thick and 32mm wide. DO NOT SKIMP on the Width.
Placing one over the other and tack welding each end is a tried and tested method for maintaining alignment.
Use a vertical milling machine or a pedestal drill in good condition for drilling the holes, NOT a HAND DRILL.
Try to be as accurate as possible in keeping the holes centered on the flat bar.
Use a 12mm drill bit. If pilot drilling remember, not too big. The pilot should only be as large or slightly smaller than the WEB of the 12mm drill bit. Remember to debur.

When rounding the ends, use as Hack Saw and File so as not to generate excessive heat.
Again, be accurate with the end rounding to keep as much "meat" as possible around the holes, a full 9mm (3/8")
You do not need to round both ends, but .......

If using Mils Steel or Stainless, please, do your Pre-Flight Checks before riding.
Remember to lift the rear wheel occasionally to check for Stretching around the holes.

We really should not use stainless for Structural Parts (well, maybe 17 4 PH is OK) as, from what I have been taught, it fatigues and cracks.

This is a fantastic mod. It reduced the "Bike on centre stand" rear wheel ground clearance from about 55mm to around 18mm.
The bike looks sexier, turns in better, is a darn side easier to lift onto the centre stand and it's possible to remove the rear axle without removing the muffler.

That's a Win, Win, Win, Win situation.

Gavin

PS

I forgot to add, after doing this mod, be careful when placing the bike on the side stand the first few times.
It is different!

[2big]

Thanks Gavin; great advice in fact a massive thanks to all you guys - honestly dont know how I'd sort this without your help.....

So inspection today suggests I've only got 28.5mm clearance under the new GSXR wheel when it's on the centre stand I'm looking to raise the ride height by 30mm, will that work on the stand?

I'm also concerned that when I take out the pivot pins and bushes the shock's gonna give me a whack. Is it under tension when at rest. What's the process for taking it all out? Should probably fit some grease nipples whilst I'm 'down there'.

Good shout on the hayabusa ones - 115mm length between centres

Existing is 125mm between centres, 155mm overall, 12mm clearance hole and, 6mm + material thickness, 18mm wide in the bone, 30mm wide at the knuckle ends

As always grateful for your help and advice
Cheers Jan

[Motofun]

If the rear wheel is suspended and hanging free there is no compressive load on the shock.  When you pull it the swingarm will drop to the ground.  Measure the delta and use a shim, slightly thinner, and when you're done the rear will be higher and the rear tire will be ever so slightly off the ground when on the center stand.  The bike will lean more when on the side stand so you may want to address that.  I fabbed up some hockey pucks for that purpose.  I ground the bottom of the side stand foot flat, drilled and tapped the foot in three places, then cut the puck to shape and counter sunk the mating holes.

[Millietant]

Really simple method Jan, put a piece of wood in front of the back tyre and a piece behind the tyre. Push them both against the tyre to support it in it's position and when you take the bolts out, the wheel/swinging arm won't drop.

Or, if your wheel is out, just wedge something under the rear-most bit of the swinging arm, the end of forks  (garden kneeler stool, toolbox, bits of wood etc) to stop it dropping when you remove the bolts.

[2big]

If the rear wheel is suspended and hanging free there is no compressive load on the shock.  When you pull it the swingarm will drop to the ground.  Measure the delta and use a shim, slightly thinner, and when you're done the rear will be higher and the rear tire will be ever so slightly off the ground when on the center stand.  The bike will lean more when on th side stand so you may want to address that.  I fabbed up some hockey pucks for that purpose.  I ground the bottom of the side stand foot flat, drilled and tapped the foot in three places, then cut the puck to shape and counter sunk the mating holes.

So the rear wheel has to be clear of the ground for the centre stand to work properly and that defines the max height of the raise? You're suggesting I use the washer spacer to ensure clearance and undo the old dog bones and use that drop height as a measurement to custom make some new ones? Good idea for the puck - have something similar on my ktm....

[Sparky84]

Really simple method Jan, put a piece of wood in front of the back tyre and a piece behind the tyre. Push them both against the tyre to support it in it's position and when you take the bolts out, the wheel/swinging arm won't drop.

Or, if your wheel is out, just wedge something under the rear-most bit of the swinging arm, the end of forks  (garden kneeler stool, toolbox, bits of wood etc) to stop it dropping when you remove the bolts.

I just use a strap over the top and through the wheel to hold it up, same as I do to hold weight of wheel when I need to reinstall wheel or take it off.
They are knot just a tie Down strap, they can tie things Up too  

(Much better than rope in the bedroom or wherever)

[Pat Conlon]

....You're suggesting I use the washer spacer to ensure clearance and undo the old dog bones and use that drop height as a measurement to custom make some new ones?

A washer is cutting it too close. You might get a new back tire that is slightly larger, then you're stuck. You can't roll your back tire for chain lubing or adjustments.

I suggest a 1/2" piece of plywood under the back tire.

[2big]

Excellent advice - simple plan, worked a treat...
Hayabusa dog bones, 115mm between centres only £9 on eBay!
Probably worth fitting some grease nipples whilst I'm down there...
Many thanks guys; I'm off to the shops
Cheers Jan

[andyoutandabout]

Ignore my earlier comment; this thread has morphed into something wonderful. Think I see some Hayabusa dog bones in my future. Especially if they are like $9. If I don't use them I can always throw them at the wall for that price.