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such is life
12-04-07, 08:25 PM
Hi all

I seem to be experiencing some vagueness in my front end, more noticeable when I am riding solo (two up it seems okay). The front tyre has around 3mm of life, tyres pressures seem fine. Low speed it does feel a little strange, hard to describe but it does seem right. The only explanation is the tyre, but as I said it has a fair bit of wear left in it.
Suspension settings haven't been touched since I have bought the bike, around 1000ks ago, and it was fine riding it solo then. Since then, I have been riding more two up.

I have scheduled it in for check over, but that won't be for another week and a half. May try a new front tyre on the front, the bike has around 4400ks, the rear was replaced at 3500.

Any similar problems with larger bikes out there ? Look forward to any suggestions.

cheers
G

planezrx
12-04-07, 09:25 PM
Maybe your rear shock had "bedded in"?
Try a touch more pre-load on the rear and see how that feels.
Cheers,
Pete
Disclaimer - I am not a suspension technician, so take my advice with a grain of salt.

such is life
12-04-07, 09:32 PM
Maybe your rear shock had "bedded in"?
Try a touch more pre-load on the rear and see how that feels.
Cheers,
Pete
Disclaimer - I am not a suspension technician, so take my advice with a grain of salt.

thanks for the advice, will check this out on the weekend when I have the time to do a little more investigating.
cheers
G

AlligatorCastrator
13-04-07, 12:41 AM
Maybe your rear shock had "bedded in"?
Try a touch more pre-load on the rear and see how that feels.
Cheers,
Pete
Disclaimer - I am not a suspension technician, so take my advice with a grain of salt.


G'day mate,

planezrx is true in what he states, plus the same can happen in the front, plus other areas of the machine as well. Here's a couple of things which do occur and why, plus one thing to maybe look at if the answer isn't to be found simply.

The "bedding in" of springs will happen with all sprung steel items. The main thing which alters on them is what is called the spring "harmonics".

When this goes, will end up (in the extreme) like many of the Honda Fireblades and the early 90's Kawa sporties. You may see how some squat at the rear and after a while, tend to "kick back" over even smallish bumps in the road, not tracking as they should, yet still work kind of okay over the slower undulations etc. This is because the initial sensitivity of the item has lost some integrity (only in relation to its function, not safety). Basically, it won't react to small and / or fast impacts, but will handle the longer slower ones.

Riders & some mechanics (who don't know better), keep winding on more spring, or compression / rebound damping adjustment to try to fix it, when what has happened is the "soft side progression" of the spring has fallen out of it's harmonic range. In other words, that part of the spring now doesn't spring so well ;) Solution, new spring.. ** Cheaper than getting the current one retempered etc.

Now, nothing THAT drastic is what is happening in your case, just the start of it, which is natural, then both front and rear will stabilise once they've settled down. Someone who knows suspensions will be able to take it for a brief ride, then advise on what to adjust. It only take a few km's to sus this out when there's an issue like this. To get it perfect requires a few runs with smaller adjustments, but the suspension guru will get it almost perfect in no time at all.

Finally, check the steering head bearings for any play. Sometimes, they aren't 100% seated from the factory and riding them settles these fully home, thus giving the slightest little bit of play, which will also make for a vague front end. If you have a decent mechanic at a reasonable rate, my advice is just get them to check and re-grease the bearings there. In the days gone by when I was around bikes a lot, many of the bikes I looked over, didn't have enough grease from the factory.

It is one thing I have always done when I give my bike the full once over. Greasing them there, means lots longer life for those bearings if they were a tad shy of grease from the factory.

Cheers, hope that was helpful in some way. Tod.

MIKER
13-04-07, 11:31 AM
^^
thanks for the info .. ;)

such is life
13-04-07, 11:46 PM
G'day mate,

planezrx is true in what he states, plus the same can happen in the front, plus other areas of the machine as well. Here's a couple of things which do occur and why, plus one thing to maybe look at if the answer isn't to be found simply.

The "bedding in" of springs will happen with all sprung steel items. The main thing which alters on them is what is called the spring "harmonics".

When this goes, will end up (in the extreme) like many of the Honda Fireblades and the early 90's Kawa sporties. You may see how some squat at the rear and after a while, tend to "kick back" over even smallish bumps in the road, not tracking as they should, yet still work kind of okay over the slower undulations etc. This is because the initial sensitivity of the item has lost some integrity (only in relation to its function, not safety). Basically, it won't react to small and / or fast impacts, but will handle the longer slower ones.

Riders & some mechanics (who don't know better), keep winding on more spring, or compression / rebound damping adjustment to try to fix it, when what has happened is the "soft side progression" of the spring has fallen out of it's harmonic range. In other words, that part of the spring now doesn't spring so well ;) Solution, new spring.. ** Cheaper than getting the current one retempered etc.

Now, nothing THAT drastic is what is happening in your case, just the start of it, which is natural, then both front and rear will stabilise once they've settled down. Someone who knows suspensions will be able to take it for a brief ride, then advise on what to adjust. It only take a few km's to sus this out when there's an issue like this. To get it perfect requires a few runs with smaller adjustments, but the suspension guru will get it almost perfect in no time at all.

Finally, check the steering head bearings for any play. Sometimes, they aren't 100% seated from the factory and riding them settles these fully home, thus giving the slightest little bit of play, which will also make for a vague front end. If you have a decent mechanic at a reasonable rate, my advice is just get them to check and re-grease the bearings there. In the days gone by when I was around bikes a lot, many of the bikes I looked over, didn't have enough grease from the factory.

It is one thing I have always done when I give my bike the full once over. Greasing them there, means lots longer life for those bearings if they were a tad shy of grease from the factory.

Cheers, hope that was helpful in some way. Tod.


Thanks Tod, very detailed. Will have a muck around the suspension settings on the weekend. Have it booked in in a week and a half's time, so will let the forum know what the problem is for future readers. Have called a couple of bike shops, one did say an owner had similar issues and was rectified by putting on the new Michelin Pilot. I have been running fairly high pressures, but as per manual 42/42. Both bike shops I called said 36/38. One did say the front tyre may had expanded ?, if it has been over inflated, i.e more than the prior owner had put in. I am pretty sure though, he ran them pretty high too.
Anyway, frustrating, you only got two wheels, so I would like it to be spot on, strange that it has been all okay:(
thanks again.

AlligatorCastrator
14-04-07, 05:44 AM
Hey mate,

If you want me to take a peek at it beforehand, let me know via a private message thingy. I'm out Albany Creek way. Am heading off for a smallish ride tomorrow (mum is going for her 2nd ride on the bike), I'll be back in the afternoon and should be around at least some of the day Sunday.

Now, about the advice? from one shop re: One did say the front tyre may have expanded ?, if it has been over inflated, i.e more than the prior owner had put in. I am pretty sure though, he ran them pretty high too.....

Well, when you race, vastly increased grip and loads mean that you tend NOT to use that slippery goo on the beads to help make fitting etc easy. You want the tyre to stay put once it is on there. So often, the practice is to way over-inflate the item at the time of fitting. Often to almost twice the pressure recommended. So in my mind, that is something someone would say when - they possibly don't know what to say, but feel the need to tell you some secretive thing, which no-one else knew about, so as not to seem , well..

Anyways, fitting a new tyre will always make a huge difference, though mainly to the bike shop's till receipts that day.. Unless the tyre is wearing badly and has obvious reasons to be causing this problem, it would be something like an internal issue in manufacturing, which would be warrantied.

Anyways, if you want me to take a quick look over it, drop on in. Like I said, msg me and I'll send you my contatc details.

Cheers, Tod.

PS. MEAN 1, thanks again for your complimentary comments. Cheers

MIKER
14-04-07, 07:53 AM
PS. MEAN 1, thanks again for your complimentary comments. Cheers

no probs :) ..

such is life
14-04-07, 06:05 PM
Hey mate,

If you want me to take a peek at it beforehand, let me know via a private message thingy. I'm out Albany Creek way. Am heading off for a smallish ride tomorrow (mum is going for her 2nd ride on the bike), I'll be back in the afternoon and should be around at least some of the day Sunday.

Now, about the advice? from one shop re: One did say the front tyre may have expanded ?, if it has been over inflated, i.e more than the prior owner had put in. I am pretty sure though, he ran them pretty high too.....

Well, when you race, vastly increased grip and loads mean that you tend NOT to use that slippery goo on the beads to help make fitting etc easy. You want the tyre to stay put once it is on there. So often, the practice is to way over-inflate the item at the time of fitting. Often to almost twice the pressure recommended. So in my mind, that is something someone would say when - they possibly don't know what to say, but feel the need to tell you some secretive thing, which no-one else knew about, so as not to seem , well..

Anyways, fitting a new tyre will always make a huge difference, though mainly to the bike shop's till receipts that day.. Unless the tyre is wearing badly and has obvious reasons to be causing this problem, it would be something like an internal issue in manufacturing, which would be warrantied.

Anyways, if you want me to take a quick look over it, drop on in. Like I said, msg me and I'll send you my contatc details.

Cheers, Tod.

PS. MEAN 1, thanks again for your complimentary comments. Cheers

Thanks for the offer Tod, may take the missus for a smallish ride tomorrow out dayboro way later in the day (I like my sleep ins), so perhaps we can meet up if you are going for a ride as well ? Will message you.

cheers G

blueZX14
17-04-07, 01:42 PM
Hi all from a nubie, I also have a zx14 with a vauge front end feel mostly on
corner exit. I think it is related to rear end spring rate (as I am not a small bloke) the factory suspension set up was WAY to soft and the bike squats badly under power even with the adjustments as good as i can get them. It may be time for a new rear spring but I don't know enough about suspension set up so the blue beast will be going to a race tuner soon. Anyhow good luck with your setup.