Down under, an idiot and a 400F

Experts I have a question. I will be lifting the rear of my bike to get a more aggressive stance and ensure clearance with the tray under the rear frame with 14.5" shocks. Look I am going after is like GoingsMoto's 550 in the making.

Popped the front wheel on a steel reinforcement rod to see where an 18" rim would roughly sit. I want to lift the rear a bit more but when I dropped the shock the swingarm hit the exhaust mounting loop. Is this normal?

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Looking for options to create the clearance. Can cut the loop off but planned on using the original exhaust mount to attach my planned custom muffler. How about bending it out, should it actually clear the swingarm?

Here is the rear clearance. These are approx 13" I think so still looking for a bit of lift, looking at custom Hagons to get the results I am after:

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You could bend it but I guess it depends what you really need the loop for. If you wanted it just for an exhaust mount you could always cut it off and weld on two small mounts which you could then mount a alloy exhaust bracket too.

If you do bend it out the way, keep in mind that you may have clearance in the shed, but you need to allow just a little more for torsional flex in the rear end as the swingarm can go from left to right a teeny bit under cornering forces.
 
Happy to bend it Staffy and would give it a bit extra to take the flex in the swingarm into account.

Do you know if it's supposed to clear the swingarm?
 
Probably not. It looks like it's lower than the swingarm at the lowest intended swingarm angle so I think they didn't need to take it into account, but I don't know a lot about these bikes so take what I'm saying with a pinch of salt champ.
 
On my 400fs, I remember it hitting. But since I did custom exhausts, that hoop was always cut off anyway.
 
eyhonda said:
On my 400fs, I remember it hitting. But since I did custom exhausts, that hoop was always cut off anyway.
Click to expand...

What did you hang the muffler off instead then?
 
I don't have the bike anymore but here is a pic of it in one of the earlier builds.

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The exhaust is a hard to find Yoshimura type exhaust made by Kerker. It had a removeable baffle (I used a tab to remove it easier). If you zoom in, you can see the hanger (welded to the exhaust) was connected to the centerstand bracket on the frame. Of course, you can't use the centerstand in this scenario.

FYI, the NOS Koni shocks in this pic are from a 900f.
 
Thanks eyhonda, looks good that shorty muffler, little shorter than my plans so I may look at retaining the hoop and pulling it out a fraction.

I think I would like a little more lift in the rear of my bike too because of the tray and hoop. Anyone know what options I have? Taller shocks? Move the swingarm pivot points?
 
Easiest way is use longer shocks, but what you have there looks pretty close. Best way to check your clearance is to remove the spring off the shock, then mount it up and pull the swingarm / wheel up to mimic full shock travel. If it clears, then you're OK.

If you go with longer shocks, you 'd want to check your chain doesn't touch the top of the swingarm pivot (you're effectively lowering the chain line). If that happens, you can get around that to some degree by using larger sprockets front and rear (IE 1 tooth up on the front and 3 teeth up on the rear will get you a similar ratio to what you have now)
 
Got it. Do these bikes have chain sliders?

What length shocks can you get? Do they go up as tall as 15" or 16"? Are there severe handling consequences to going that tall on the rear?
 
Yes, it will wobble and you'll probably fall down.
It can be compensated for to a degree by fitting different offset yokes to increase trail but the steering angle will get steeper and make things unstable (think shopping cart wheels, they are designed for 3~4mph)
 
That's a whole other discussion! When I built my 400f awhile back, I went with a lower offset triple which has more trail. I then raked it to decrease it. Generally speaking, a 1 inch difference (1 inch down in front or 1 inch up in rear) will give about a 1 degree change in steering rake. For a detailed calculation, use this link:

http://www.rbracing-rsr.com/advchoppercalc.html

Experiment with the numbers and you can see the immediate change.
 
I don't think I will need to lift the rear that much. Did some mock ups today and a 1" lift is actually quite a lot.

I think the 900f shocks will be ideal.
 
So a big thanks to Ian for the fork lowers, very kind to send me some replacements from his stock pile and I thought I would waste no time in getting them cleaned up.

Turns out my air sander is brilliant for getting parts prepped for buffing. My technique still sucks arse so I have decided to not go for mirror shine but just clean and generally shiny.

Here are the lowers with an ever increasing pile of shiny bits:

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The air tool is not great for those nooks so I will need to get some more grits of paper to clean them up.
 
neevo said:
I don't think I will need to lift the rear that much. Did some mock ups today and a 1" lift is actually quite a lot.

I think the 900f shocks will be ideal.
Click to expand...

'and an inch is better than a mile in the right direction'
(I think Keith Richards?)
Doh, it was Bill Wyman, knw it was one of the Stones ("A New Fashion")
 
neevo said:
So a big thanks to Ian for the fork lowers, very kind to send me some replacements from his stock pile and I thought I would waste no time in getting them cleaned up
Click to expand...

Glad to help out. That stuff is looking good. You're getting the hang of this by the looks of it.

cheers
ian
 
bikeboy said:
Glad to help out. That stuff is looking good. You're getting the hang of this by the looks of it.
Click to expand...

Kind of ;)

The pics are always a bit misleading but I have decided to go for a shiny finish rather than mirror as I just can't seem to get them that finished.

The missus prefers shiny anyway and it should be easier to maintain.
 
Stripped the front wheel today so that I can send the hub out to have the fins taken off on a lathe. Contemplating doing the same on the rear too, anyone got some major concerns?

PJ was taking about the heat generated from the rear drum but it looks like there is still plenty of meat on there. If it is a dangerous thing I will just have the cross find removed.

Ready for some lathe action:

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Rear got some sanding action and should be ready for the buffing wheel when it comes back.

Just need to sell a kidney to get new spokes and rims.

Getting a WM2 & WM3 combo from Buchanans with Sun rims (because I want them anodized black and the selection is greater), can anyone comment on the quality?

Edit:

Also got some left over frame tube and was thinking of making a brace for my swingarm. Is this a bad idea?

Mainly for aesthetics but some added flex reduction can't be a bad thing can it?
 
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