fitting new Falcon alloy rear shocks

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I have been looking at replacement shock absorbers lately and have come to the conclusion, given the era of CNC there are a lot of nothing to write home about products with hand machined and assembled price tags.
Still kicking myself for passing up top of the range Wilber's twin shocks with high and low speed adjustable damping for a then asking price (used but excellent) of $700 (US$490)
Even a pair of Ikons are in the $600 range but am sceptical of the alloy body version long term.

I've got about 50,000 miles on a pair on basic Ikons with absolutely no issues. In fact, I don't even think about the rear end at all so, they must be doing well.
 
It is unlikely that your springs were too soft, much more likely that there was not enough damping. With more damping the shocks pump down lower, so the spring is compressed more. Mostly when the front of the bike feels bad, it is the rear wheel jumping which causes it, you just feel it to be at the front. If you up the spring rate, you just end up riding a pogo stick. If you have soft springs at the rear, you get more suspension travel which can help the bike to steer better coming out of corners under power, instead of tending to run wide.
Many years ago, I was racing my Triton and it felt so bad in the front, I was afraid to ride it fast. A friend was watching and saw the rear end jumping as I went down the straight. Because I was actually on the bike, I could not see it happening. We took the Konis off and upped the damping a bit, and fixed the problem. The bike became much better. Something such as that can destroy your confidence. I have never had any real problems with the front end of any bike I have raced, except for yoke offset and I have never used any special set-up. The rear is critical.

Al you may have a point about the damping, I’d not thought about that but it does sound logical / possible.

And whilst I agree that it is very often the case that ‘front end issues are caused by the rear’ it wasn’t the case this time. The front wheel was visibly bouncing up and down. It only happened around Gerard’s which is a LONG sweeper (technically it’s taken as two bends). So in this case, I know I had issues at both ends, and each end was possibly also effecting the other!

It occurred to me that as I only do few track days these days, I could waste the next 3-4 seasons on incremental trial and error problem solving... or I could bite the bullet and do it right (Maxton) and given I’m putting the 920 motor in, I wanted it to be right !

Glen, they’re not cheap, I’ve forgotten exactly but shocks were nearly £500 and forks nearly £1000 by the time I’d done opting for the adjustability and having fancy plastic bushes made and blah, blah. The more basic ones are cheaper, and would probably be perfectly fine if I’m honest with myself!

I think it’s important to note that my bike handled fine on the road, the shortcomings only showed up on the track, when pressing on a bit.
 
Al you may have a point about the damping, I’d not thought about that but it does sound logical / possible.

And whilst I agree that it is very often the case that ‘front end issues are caused by the rear’ it wasn’t the case this time. The front wheel was visibly bouncing up and down. It only happened around Gerard’s which is a LONG sweeper (technically it’s taken as two bends). So in this case, I know I had issues at both ends, and each end was possibly also effecting the other!

It occurred to me that as I only do few track days these days, I could waste the next 3-4 seasons on incremental trial and error problem solving... or I could bite the bullet and do it right (Maxton) and given I’m putting the 920 motor in, I wanted it to be right !

Glen, they’re not cheap, I’ve forgotten exactly but shocks were nearly £500 and forks nearly £1000 by the time I’d done opting for the adjustability and having fancy plastic bushes made and blah, blah. The more basic ones are cheaper, and would probably be perfectly fine if I’m honest with myself!

I think it’s important to note that my bike handled fine on the road, the shortcomings only showed up on the track, when pressing on a bit.

Unfortunately, you can usually only get a bike set up right by racing it. Even if you attend practice days, you often don't find all the bugs. When I was racing regularly, my bike was usually pretty good. These days, I cannot even ride at a practice day without finding major problems. When you are actually racing, your mindset is usually different from what it is on a practice day. On a practice day, I am never so determined, so the bike does not get stressed to the limit. For me, after 4 race meetings in a year, my bike and I are usually spot-on. But these days, you would have to be a millionaire. If I go to a practice day, after 5 laps I am usually up to about 90% of race speed, but that last 10% never happens.
Public roads are often smoother than race tracks and in any case there are laws against riding your bike there at a level which would approach it's design limits. To me, I cannot understand why anyone would ever buy a Ducati sports bike and ride it on public roads - it is a shocking waste of something which is really beautiful. Some of the kids in Victoria love to ride their road bikes at Phillip Island, I suspect they really do not know what they are doing. If you don't race regularly, that can be very dangerous. On some of those smooth high speed bends, you only need to twitch to go wrong.
 
Springs fully compressed.
Bike running wide exiting bends.
Backside passing buttons!
Picture tells the story.
Maxtons were too short for a MK2.
Chris
fitting new Falcon alloy rear shocks
 
And springs too soft Chris?

I think that bright red paint is too heavy.

That’s why folk have bare frames innit ?

BTW you’ve got some loo roll stuck on your back...
 
But being serious for a mo’...

Pics like that shows the value of track side photographers... big time.

You can see from your pic that those shocks being too short and / or too soft have totally screwed up the design intent of the geometry of the chassis!

Without the pic you might have been chasing your tail trying to figure out what was wrong for a whole season. Or more!
 
Hi Nige

Correct on all points. When I saw the photographs I was thrilled. The bend leads on to the back straight, the camber goes away from you & being a car track it has big rumble strips & a trench the other side! I could not keep the bike off the rumble strip.
Soft springs, shocks an inch to short? Driving hard compressing the back end & the bike walking, not evil just not not holding its line. I believed the rear tyre might have been on it's way, but the photo says it all.
I don't think about the handling now, she wears an old pair of Koni's. The Maxtons are on the MK4 that uses a shorter shock, with the springs one up on adjustment.
Chris
Ps duct tape repair to gravel rash. Loo paper elsewhere!!,
 
That frame looks to have less rake than 27 degrees. If it is one degree less, might make it tend to run wide coming out of corners. The Manx Featherbed frame has a rake of 24.5 degrees and extremely short yoke offset, and they tend to not run wide as you power out of corners, but come back on line as you give the motor more stick. Your yoke offset looks very similar to mine. I think the after-market featherbeds use 26 degree rake and 18 inch wheels and steer very neutral. Changing from 19 inch to 18 inch wheels on a Manx featherbed, makes the bike tend to run wide.
Does your bike tend to understeer as you brake, or get hard to tip in ? If it does, it will probably tend to run wide when powering out of corners. Mine stays neutral as I brake and tends to tighten it's line as I power out. The problem might be, that I suspect that one day, my bike is going to high-side me as it wheel-spins coming out of corners. It feels really great, but that is often a bad sign.
 
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With a road bike, it is supposed to become stable as you brake and the rake steepens, and stay neutral as you accelerate out of corners and the rake becomes shallower. The problem is you just cannot ride that sort of bike very quickly through corners, because you cannot get back on the gas early enough. That is probably why when you watch an on-board video, most guys are forced to back-off when halfway around corners. When I was racing years ago, I never thought about such things - I simply adjusted to the bike. With the Seeley, I just found out by accident, and scaring myself.
If you think about it - if you are running wide, it is not natural to gas the bike harder. The usual response is to brake or at least back-off, then the bike becomes more difficult to turn.
 
If your shocks are too short, you have probably shifted the mid-point of the steering geometry. The steering would be too unstable, both going in and coming out. You want the shocks shorter as you come out of corners, not going into corners. Going in, you want the bike to rock forward and steepen the rake until the bike becomes neutral steering. Then rock backwards and oversteer as you power out. With my Seeley, I had the experience where the bike did not stay neutral as I braked - as I braked it tended to stand up. Then when I braked hard going into a corner during a race, it actually stood up and turned the wrong way, throwing me off balance. I turned it on again to get it to the grass and drop it, and it came back under control. Then I dramatically reduced the yoke offset and all became lovely. So you figure it out. You need to be conscious of what your bike is doing as you brake and accelerate in corners. What I have been saying is obviously not what most guys believe happens.
 
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Bike handles like a dream. Look at where you want to go & it goes there. Drive it through the bends as hard as you like. Brake as hard as you like. Standard set up as per the way Colin Seeley made it. Just a bit orange.
When I ran my Rob North for the first time it handled well but ran wider on the bends, it didnt just go where you wanted like the Seeley. However once I got it up to speed & gave it the berries, it was spot on. You just had to run it as it was intended to be used.
Chris
 
Colin Seeley's bikes and the Featherbeds were obviously developed over many racing miles. When I bought my Mk3 Seeley, it had been used to house a heavy 750SFC Laverda motor and had Ducati 450 fork yokes which had about 70mm of offset. After I had the problem, I fitted TZ350 Yamaha yokes which have about 30mm of offset.
I have a magnetic base protractor which I stick to the fork stanchion. But I can never replicate the conditions at the front of the bike which occur when I am actually riding it. My suspension travel is about 2 inch, front and rear, and the wheelbase is about 54 inch. So the difference between the two rake angles (and consequently the trail) when braking and accelerating is 3/5 ths of bugger all - but it is critical.
My other project is a 600cc two stroke - a modified H1 Kawasaki motor in an Egli replica frame. I use RGV250 Suzuki wheels and front forks. The early RG250 had an 18 inch rear wheel and 17 inch front, but I use the later RGV set-up with two 17 inch wheels. Between the two arrangements, Suzuki specify half a degree difference in rake . If I get it wrong, it can really stuff me. That half a degree can be extremely dangerous.
Before I had the Seeley, I would simply adjust to whatever bike I rode. Now I think differently. I never previously rode a bike which gave me such confidence. When it self-steers in the right direction as I power out of corners, I can give it so much stick and so early, that it is obscene. It is not me, it is the bike - it never runs wide as long as I keep accelerating. On high speed bends, it is just bloody rude. You simply brake slightly before them then give it everything right through the bend. When I ride it, I sometimes think 'I should not be doing this', it feels wrong- but it is quick.
 
Do you have any photos of the problem, as I am considering the same set. Have been waiting until he gets his source back for chrome springs.

I'll be (hopefully) taking photos on Thursday evening partly to help me decide how to get around this problem.

So far, I've had the following thoughts:
1. dump the chainguard
2. cut a hole in the existing guard
3. make up a simple guard from folded sheet metal of glass fiber
4. move the top shock mount outboard by 7mm
5. find an existing guard and modify
 
Number 1 sounds simplest Steve !

Simple is good :)
First step though is removing the standard guard to see how much space there is. I notice that you were using the steel body shocks, which are rather smaller in diameter, that makes a big difference.
 
My Falcons were alloy bodies Steve.

Maybe you’ve got a posher version with more adjustability or something?
 
My Falcons were alloy bodies Steve.

Maybe you’ve got a posher version with more adjustability or something?
No, you're perfectly correct, same ones as I have. I was confused (blinded??) by the Maxtons, which do seem slimmer in that area :)
 
Hi Nige

Correct on all points. When I saw the photographs I was thrilled. The bend leads on to the back straight, the camber goes away from you & being a car track it has big rumble strips & a trench the other side! I could not keep the bike off the rumble strip.
Soft springs, shocks an inch to short? Driving hard compressing the back end & the bike walking, not evil just not not holding its line. I believed the rear tyre might have been on it's way, but the photo says it all.
I don't think about the handling now, she wears an old pair of Koni's. The Maxtons are on the MK4 that uses a shorter shock, with the springs one up on adjustment.
Chris
Ps duct tape repair to gravel rash. Loo paper elsewhere!!,
Surely not old tyres Chris?!
 
Hi Peter
Just brought a set of scrubs, just to be told they are ancient lol
Speak soon
Chris
Are you about in April?
 
Many old tyres return to giving grip after being used a bit. These days, the young guys are very tyre dependent, so rain becomes a leveller. I use Battlaxe tyres, and when I first got them, they meant nothing to me because I was riding so far within their safe limits. My riding style has been conditioned by pain. In the old days you only had to have the slightest change in mental state and you were down.
 
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