Raising the tail

[joebloggs]

I've seen bikes with bespoke subframes, and shortened OE etc but I've yet to see one with the downward bend straightened out, sure you can lift the back with different length dog bones but it lifts the whole bike, straightening out that bend would raise it to virtually the same level as the top of the tank with 4-6 inches removed from the frame, OK maybe a slight exaggeration but it'd be far higher without fabricating a new frame.
OK so you will need to rotate and lower the tank bracket accordingly and if you want to retain the OE plastics you'd have a bit of trouble but I'm only planning to have a seat and tail so no problem for me.

So has it been done, and if not, is there something I'm missing?
 

[fj1289]

I assume you are going for the street fighter look?   Specifically the German influence?  Been a while since I've followed the trend closely. 

[joebloggs]

I assume you are going for the street fighter look?   Specifically the German influence?  Been a while since I've followed the trend closely. 

Far from it, I want to raise the rear so when the subframe is shortened the tail piece doesn't sit to low, for me it spoils the line of the bike. It wouldn't be as steep as the German style, but a fair bit taller for not a lot of effort 

[joebloggs]

I assume you are going for the street fighter look?   Specifically the German influence?  Been a while since I've followed the trend closely.  

My inspiration, but if you search for it online you'll find most pictures are taken looking up at the bike, the tails to low, I want to try one simple fix to raise it to where it should be, or at least closer.

[fj1289]

I see the lines you are going for. 

I'd probably fabricate a temporary prop to hold the tank at the correct position and  completely cut the tank mount off the subframe.  Then cut and weld the rails on the subframe to the position you want and then cut and weld the tank mount as required to the modified subframe.   

Then probably do some plastic welding on the side covers to get it all to come together and look "factory". 

Fred's work and now this have me wanting to build an FJ fighter!

[joebloggs]

I see the lines you are going for. 

I'd probably fabricate a temporary prop to hold the tank at the correct position and  completely cut the tank mount off the subframe.  Then cut and weld the rails on the subframe to the position you want and then cut and weld the tank mount as required to the modified subframe.   

Then probably do some plastic welding on the side covers to get it all to come together and look "factory". 

Fred's work and now this have me wanting to build an FJ fighter!

That line makes quite a bit of difference to the tail height, complicates the seat (hoping the stock seat pan will work with relief cuts, heat and plastic welding) I think I can get away without shortening it as much which I believe saves me from having the front of the subframe narrowed and gives a longer seat to shape (I'm hoping for something like GPZ1000RX rider seat)

Wasted most of today playing with the swingarm/shock, swapping relay arm etc only to get back to where I started. Doh



I have two and a half subframes to take to the welder, one to be modified, one to keep an eye on angles and the other to be harvested if required.

The main reason for straightening that bend is space around the carbs/filters. I've had to grind material out of the subframe to clear them, the further I raise, the more I need to remove. I had considered widening the top mounts and use Rose joints (Not sure your term for them) but this over complicates things and I'm not that worried about weakening the frame, solo only and I'm a light rider. 

Like the 1TX pic I posted I'm only having the tail piece, but no battery box, I've found away of hiding the fuel pump and all the wiring from the motor under the seat so it should be all fresh air between the rails, not everybody's cup of tea but it works for me.

[Pat Conlon]

You don't need the fuel pump, you can convert the carbs over to gravity flow with larger float needle seats.

[joebloggs]

You don't need the fuel pump, you can convert the carbs over to gravity flow with larger float needle seats.

I know but I like the idea of the pump kind of protecting the motor from hydrolock, I've drilled one of the tank mount bolts out to M8 and hung a bracket on it that holds both pump and adjustable voltage regulator. With the tank bracket as it is you can see neither, may be a different story after its modded.

[joebloggs]

You don't need the fuel pump, you can convert the carbs over to gravity flow with larger float needle seats.

[giantkiller]

Here's what I did with the turbo bike shortened the original seat. The seat pan has a section that almost looks like it was made to be cut out.  And 2 channels that can be overlapped and then I plastic welded them together. Then just shortened the tail frame.

[giantkiller]

Hope to get back to this project this winter.

[joebloggs]

Hope to get back to this project this winter.

The turbo should make it a little more lively.

I've seen pictures and description of your seat mod before, think I've rear every post on the subject, I'm more concerned about height rather than length, basically I want stock height, or higher, after shortening the frame, 5 inches will probably be enough.

Re the lower subframe rail, I'm not planning on using the mount at the rear of the frame, but the M8 originally for the footrest hanger and weld it to the subframe near where the battery box sits. Most of this will be visible to don't want a dodgy looking join on view (OK if you have sidepannels)

Preping the engine for paint today, again, what a ball ache, if I had to do it again I'd take it to a paint shop and pay someone to do the job.

[giantkiller]

Yep paint work is beyond me. I have a paint shop owner who likes my projects. So he gives me a deal. Going with midnight blue. Only slightly more blue than the stock color. I have a set of stock graphics in red.

Can't wait to see your progress.

[joebloggs]

The other day I thought to myself how well the Rearsets sit into relation to the shape of the swingarm, the arm seems to curve around them as if by design, well I fitted the exhaust to see how far out it was and...... well you couldn't script it.



It's not perfect tbh, the mid pipe follows that curve but the end can would hit the arm under compression.

[joebloggs]

Finally got a call from the welder asking me to pop in and help modify the subframe.


No other pictures of the frame being modified, he welded the subframe to the workbench, pumped a ton of heat in it and straightened out the bend below the rear fuel tank mount, the rest was a bit of a blur, he'd ask what I wanted, I explained and he turned my ideas into my new subframe.

TBH if I knew the labour cost before I would have gone to a custom frame builder, basically I was paying for someone to teach himself how to modify a motorcycle subframe, it wasn't cheap.



Take no notice of parts not being lined up, nothings bolted in place.



100mm shorter but still at a similar height to the stock tailpiece, straightening the top tubes out made a fair difference

Exhaust next