Crash. Fix. Test. Tweak

[Steve]

Hi there.

I had a pretty major moment on my FZS600 a couple of months ago and whilst I walked away pretty much unscathed, I can't say the same for my bike.
I won't get into it, but the front end was totalled, and I'm sure if I'd been fully comp it would have been a right off.

I'm taking a level 2 IMI course in motorcycle mechanics and engineering so the whole thing was blessing in disguise. It's allowed me to indulge in my own little project whilst riding my 125 (YBR) to work and financing the whole operation.

So I'm now at the point where the bike is up and running, everything's going great, but the bike just doesn't feel quite the same. And why should it? Half of it's been pieced and patched from other Fazers! This might just be a confidence thing- I had a major accident and got lucky- so after that experience of course I'm going to have a new perspective on my ride. But to an extent the bike does feel different.

For one thing, the brakes (Brembo blue bolts, not changed post-accident) feel a lot softer, despite a thorough bleeding, and are slow to respond. For another, the forks (a replacement from another Fazer) don't respond all too well and I'm feeling a lot more from the road surface, from minor bumbs to grip.

Seeing as I've gotten this far with the bike, I figure I might as well go the extra mile and make the bike my own, investing in a few performance parts. So far I'm looking at the brake discs and radiator. This is where I'm stuck. What I'm looking for is a few recommendations from my fellow FOC-cers in regards to these aftermarket/ performance parts. What works for you? Are there any manufactured parts seen way above the rest? Are there any I should avoid?? Have you had a similar incident? Is what I'm feeling from the bike normal after a crash, or is there something I should be keeping an eye on in regards to the bike?

Any and all advice would be very much appreciated, so thanks guys and girls. Discuss! 

[darrsi]

Have you actually replaced your brake lines, if not they could have suffered damage in the accident which won't be visual?


And the forks you bought, did you change the oil in them yourself?

[kebab19]

Your replacement forks may have been tweaked eg had progressive fork springs fitted, which gives more road feedback but at the expense of making everything feel harsh as it transmits more shocks up through the arms.
Or your new forks may have a lot more stiction, in which case a blown seal or two may be imminent.

Did you have the frame checked to see if it was bent? Usually manifests as tracking excellently through a right-hand corner but awful through a left-hander, or the other way round.

Did you replace the steering head bearings as they often get trashed in a shunt / prang.

If you need fork stanchions / brake discs, All Bike Engineering (ABE) are usually pretty good and far cheaper than OEM Yamaha
http://www.allbikeengineering.net/

Are the brake calipers & brake discs off the same bike or is there a mismatch? Pads take a while to 'bed in' on new brake discs, never mind bedding in on worn ones

Why mention the radiator - is there damage to it or is the bike overheating?

Don't be dismayed, we'll get you all sorted out...eventually ;-)

[Steve]

 Thanks guys.
 
 I stripped the bike to check the frame and I couldn't find any breaks or twisting in the frame or around the headstock, but I did change the bottom yoke, as I figured all that force which was transmitted through the fork legs (snapping one of the stanchion tubes in the process) might have also affected the yoke. Better safe than sorry I guess. I also got new head bearings when I changed the yoke.
 
 I've not taken the forks apart since I got them but they do look quite used. I checked for dripping fork oil and the condition of the dust caps when I bought them, and it's all fine on that front. I also checked for pitting on the stanchion tubes and its all clear there too. I couldn't say what fork springs have been used but mine before the crash were standard progressive springs made by Yamaha.
 
 I'm thinking of ordering a hyperpro multi-progressive kit to integrate into these stanchion tubes and my previous fork legs from the crash, as they are still in fine working condition. This would also give me a chance to get some new fork seals.
 
 The brake discs and callipers are the same as I had before the crash. I mean to change the discs as when I put it up on the spindle for a static balance test, the discs had some wobble on both sides, indicating they are very slightly bent. Thinking the worst, I took the whole wheel down to my local tyre place for an integrity check and pointed out the fault, and it came back all clear. I was given some advice as to what to look out for in regards to braking issues and haven't had any issues so far (the bike's done about 30 miles since being fixed).
 
 It might be worth changing the brake hoses. On the outside they look fine but I hadn't considered any internal issues.
 
 As for the radiator, there's nothing wrong with it- I did a coolant pressure test and a boil test on the temperature sensor, and the whole unit is working fine- but the previous owner must have used a jet washer or something to clean it, as some of the cooling fins are bent and/ or twisted. I was a bit concerned by this but I've got the bike up to temperature and the warning light hasn't come on, so I think it's all good. That said, it wouldn't hurt to get a new one and have the whole bike looking that much better for it.

[darrsi]

I had BIG problems that eventually turned out to be a dodgy braided brake line, and they weren't leaking and looked fine visually so i would definitely change them if they don't feel right.


The forks may simply have heavier oil in them.
Since i changed mine from 10w to 15w it feels much firmer and controlled up front, but it will also magnify the feeling of the odd bump in a road.


I don't know which bike your forks came off but something to be aware of is the oil levels per year of bike.


98-99 bikes have more oil in them because they don't have adjusters.
00-03 bikes do have adjusters and will take less oil.


I have 98-99 forks on my 00-01 bike and it's natural to look for measurements for your year of bike in the book.
It's just something to look out for if your replacement forks are newer than your bike! 

[Foxwood]

If you get the Hyperpro kit, try finding newer fork caps too. 

[AdieR]

Although you say you've stripped the bike to check frame damage and couldn't find it, weakening isn't impossible even if it can't be seen (by the sounds of it, your bike took a fair thump), so it may be an idea to get it double checked (it won't need much of a twist in it to feel totally different).

You mention brake disc wobble - were the discs running true beforehand?

[Dave48]

I know you want to get your Fazer up & running ASAP  BUT before you start spending lots of hard earned cash-just get your frame professionally checked for alignment/geometry. Otherwise the best aftermarket parts wont be able to make the bike handle as it should. Not all damage is visible as AdieR suggests 7 it wont cost a lot to have it checked on a proper jig. Then, if all OK, you can start on the forks,brakes etc. On subject of brakes the performance gradually deteriorates from new so after checking brake discs for truth/runout/thickness/mounting holes/cracks etc then you can move on to pads,pistons,seals, master cylinder overhaul kits and of course your rubber brake hoses which even if undamaged in accident are now 13years old if original-Yamaha recommend changing these every 4 years but a 2-line front(race) and single rear in braided will set you back less than £85 & will never need replacing.Allow your new pads time to bed down on your discs-gradually & progressively increasing braking pressure over the first 100 miles. There is an old saying "Do it right-Pay once"! Good luck & let us know how it all goes.

[kebab19]

Did you torque the steering head bearings to the correct setting? If you did it by feel only it can be quite a bit out & as a result the front-end can feel horrible at any speed, on straights or in corners.

But is it the handling thats concerning you or a lack of confidence in the bike / your riding since the incident? I say this as you might be unaware of unconscious tension - you might be gripping the bars in a somewhat rigid way & as a result the bike doesn't handle as well as she should (or used to before the crash). Don't be insulted, but it may possibly be a mental problem and not bike damage at fault.

[Steve]

 Re: Kebab19, I was wondering if it might be a confidence thing. I've been taking the bike out on some nice easy rides- nothing stressful- just getting comfortable with the bike again. It was after all a pretty big crash and I wouldn't be surprised if my confidence did take a knock from it. That said I feel alright. I'm not pushing myself at all, just taking it easy. That said, I might be tensing up a bit before corners- I've felt myself doing so on one particular corner; practically identical to the one that I crashed out on. However, the bike just isn't responding the way it used to. Note, this might just be me. I'm considering taking the bike down to my local MOT tester to see if he might notice something I haven't, and likewise to see if I do have a fault or whether it is just me.
 
 At high speeds I can almost feel a bit of horizontal play somewhere on the front end- very, very slight play I should say- more so when on an incline. But like you said earlier, it might be down to these forks being more sensitive than my last, or indeed my mentality during the ride. Thinking the worst I checked the spindle, but that's all fine, and I redid all my torque settings against my Hayne's manual, just to make sure everything is right on that front.
Also my head bearings are all torqued up.
 
 Does anyone know of a frame specialist based in the East Midlands? Considering I wouldn't be able to notice any alignment issues or the like with my naked eye- short of it being really bad, I think it would definitely be worth getting my frame checked out by a professional.
 
 Re: AdieR, The brake discs were running true prior to the crash- I did some servicing on the bike at college about a week before the crash and the discs were fine then. Since my last post I've taken the bike out on some longer rides and the brakes are feeling a lot better than on my first test ride.

[darrsi]

Just a thought but could it actually be the rear shock that's giving you the wobbles?
If that's knackered it would make the bike feel a tad unstable, but as you had a front ender it may be throwing you off scent a bit?

[kebab19]

Fair enough, sounds like you head's ok, something needs re-aligned on the bike

As Darrsi says, could also be a rear shock or a even squared off rear tyre giving odd handling

[darrsi]

Another possible, you may have uneven fork oil.

[Steve]

I don't know how I've done it but the problem's sorted. All I had to do was remove both the fork legs, strip em, change the oil, check the seals and springs for damage (whilst the springs visually look fine they do have twice as many miles on them as the Fazer itself, so I'll be changing them for some multi-progressive fork springs early next month) and rebuild and refit the fork legs. No idea what the problems were caused by but I took all the advice on board and it's better than before, so thanks all!

The brakes are still a bit slow to respond but I'll be replacing the hoses and discs early next month also.

What's better is I haven't found any other issues or weird sensations coming from the bike as of yet. I was worried that the suspension and braking issues might be hiding something else but so far everything is running well- fingers crossed.

[Hedgetrimmer]

If the forks had been knocked out of alignment, it's possible that removing and refitting on it's own may have sorted it?