Puzzling questions

[kecup]

Hi to everyone,

this is concerning the Sport 1100i, thought to ask here since the bike is reasonably similar to V11.

The problem: I had two strange accidents recently - low sided my 1997 1100i two times, both at low speed during braking. The bike is a bit damaged and so am I, but more painful is not knowing why this happened. Hence the post in here.

Accident no 1: Went slow in a line of cars when suddenly the car in front of me decided to stop, I start braking, not much emergency, but suddenly the front wheel locked and I got a immediate left-hand tank slapper and ended on the ground. It was on a bit of a wet surface so I blamed it on this, although it felt weird. Just the front wheel broke the traction a bit fast. Anyway, repaired the broken shifter and continued riding. Not much other damage, no apparent fork problem, no weird handling afterwards.

Accident no 2: Riding at some 30mph, when I saw someone at distance crossing my path, start braking, again no emergency, dry conditions, perfect surface. I got a very quick, again left-hand tank slapper and low-sided, this time with a bit more damage to the bike and myself. THis was very surprising since it should absolutely not happen.

Bike and my conditions: 1100i 1997 Sport, 20K miles, recently serviced, plenty of front tire (do not know the age of it though - bought the bike with it few months ago), steering damper put on "no resistance". When bought the bike there was no signs of previous accident on it at all. I have 2 other bikes - Monster 1000s and S4R. I ride almost daily for at least 15 years, brake mostly front end, always leaning forward to put a weight on front end. During my history of riding I has some accidents but never something so strange as this.

Questions: What can be the cause? Hardened tire, bad forks? Design? I had a 2004 LeMans before and noticed the bike has a slight tendency for a left-hand tank slapper when hitting a bump or so. I need your imput:) Pavel

[Tom M]

I'd check the entire bike if I crashed twice for no apparent reason! Did the front wheel lock up both times? If so I'd check the front brake system first. After that, forks, steering head, steering damper, frame, all motor mounts, swingarm bearings, wheel bearings, etc.

 

It's certainly not a design issue or we'd probably all be dead by now

[Guest ratchethack]

Pavel, glad you're OK. I applaud your interest in nailing down the cause of these similar crashes. Wise move.

 

Since your bike is over 10 yrs old with very low mileage, I would begin by discovering the age of your tires first, since this is unknown, and it could quickly make this an open-and-shut case. You can rule tires out by noting a few things, including make, model, and pressure you're running F/R, which if you mention this here, might be a dead give-away by itself. Most (I think all?) tire mfgr's date code them on the sidewall. It might be obvious. If not, a tire dealer can help you with the date code. I'd also suggest making sure the sizes are properly matched to the wheels while you're at it. If you're able to rule the tires out as a cause, the possibilities widen up considerably from that point on, but in any case, you'll get plenty of highly qualified, knowledgeable help here.

[gstallons]

You don't use ArmorAll or ANY type or spray on your tires?

[badmotogoozer]

Both times when braking, pulls hard left. Screams brake problem to me. Especially the left front. Pull the calipers off, check for debris, check rotors are not bent/warped/damaged, check condition of brake pads, pull in brake lever and check if all pucks move (don't pull hard enough to move the pucks very much - risk shooting them out completely), you should be able to press them back in with your hands slowly, check the alignment of the calipers and rotors, and the caliper mounts. If free floating rotors on the 1100i, check that the rotors have some in and out flex at the float points.

 

good luck!

[kecup]

I'd check the entire bike if I crashed twice for no apparent reason! Did the front wheel lock up both times? If so I'd check the front brake system first. After that, forks, steering head, steering damper, frame, all motor mounts, swingarm bearings, wheel bearings, etc.

 

It's certainly not a design issue or we'd probably all be dead by now

 

 

The wheel locked both time, quick and unexpectedly when not so hard braking. The brakes work nice, plenty of pads, rotors changed for brand new recently. We will of course go through the whole bike during the restoration but the first accident happened with no damage to the bike. Steering damper was set on loose and head bearing checked normal during the service few days ago.

[kecup]

Pavel, glad you're OK. I applaud your interest in nailing down the cause of these similar crashes. Wise move.

 

Since your bike is over 10 yrs old with very low mileage, I would begin by discovering the age of your tires first, since this is unknown, and it could quickly make this an open-and-shut case. You can rule tires out by noting a few things, including make, model, and pressure you're running F/R, which if you mention this here, might be a dead give-away by itself. Most (I think all?) tire mfgr's date code them on the sidewall. It might be obvious. If not, a tire dealer can help you with the date code. I'd also suggest making sure the sizes are properly matched to the wheels while you're at it. If you're able to rule the tires out as a cause, the possibilities widen up considerably from that point on, but in any case, you'll get plenty of highly qualified, knowledgeable help here.

 

 

Thanks for answer. I feel even if the tire is old (could not find any codes on it) it still should not be so dangerous, since this happened w/o any warning. I desperately need to know what was this or I am not sitting at this thing again. I rode bikes with bent forks before, including my monster for 500km right after a 60mph crash that left front forks misaligned by 2cm down at the hub. In all cases the front end behaved strange some ways but it was predictable and started slowly. My latest experience is completely weird. It is my 4th guzzi and I really want to keep it forever, but can not ride something that is that dangerous.

[kecup]

You don't use ArmorAll or ANY type or spray on your tires?

 

never

[raz]

Good advice already given: check calipers etc.

 

For what it's worth I locked my front good in maybe 40-50 km/h once and it was still stable enough that I never went down. I was very unexperienced at the time after 14 years without a bike (which is why it happened in the first place). So I'm thinking if it was just a bad tyre, you should not get a tank slap and go down.

[kecup]

Both times when braking, pulls hard left. Screams brake problem to me. Especially the left front. Pull the calipers off, check for debris, check rotors are not bent/warped/damaged, check condition of brake pads, pull in brake lever and check if all pucks move (don't pull hard enough to move the pucks very much - risk shooting them out completely), you should be able to press them back in with your hands slowly, check the alignment of the calipers and rotors, and the caliper mounts. If free floating rotors on the 1100i, check that the rotors have some in and out flex at the float points.

 

good luck!

 

 

the rotors were changed few weeks ago, must have some 300miles on them. Plenty od pads. Brakes work nice. On low speed trials on the parking lot, both legs on the ground, after the crashes, I found no tendency of the steering to move left when slamming brakes. The chance is that the calippers are dirty and do not move freely, so there is some build up of the pressure needed to cut them lose, in this case they would bite hard suddenly without warning. But this is pure speculation. Thank you for answer.

[kecup]

Good advice already given: check calipers etc.

 

For what it's worth I locked my front good in maybe 40-50 km/h once and it was still stable enough that I never went down. I was very unexperienced at the time after 14 years without a bike (which is why it happened in the first place). So I'm thinking if it was just a bad tyre, you should not get a tank slap and go down.

 

 

Thanks for answer, I agree on the bad tyre. I ride almost everyday for many years and so far thought I can brake the front wheel with confidency - maybe an illusion:). Under hard braking on my monsters I can tell when the traction is giving up quite nicely, based on the front end feel and the sound of the tyre. The guzzi has quite different feel (my leg can tell:), just have to find out what this is - love the bike and want to keep it for good.

[Skeeve]

Both times when braking, pulls hard left. Screams brake problem to me.

 

 

Check for possible fork binding [braking, fork compresses, binds on one side, twists, things go south rapidly...] and of course, the tire age thing. Look for the DOT # impressed in the side of the tire [all the other codes are embossed/raised lettering.] The last three digits of the DOT # are the week [2 digits] and year[1] when the tire was made, eg: DOT XXXXXX521 was a tire made the last week of 2001 [or 1991, but that's just ridiculous! Or is it?.. ]

 

Best of luck!

[Guest ratchethack]

Thanks for answer. I feel even if the tire is old (could not find any codes on it) it still should not be so dangerous, since this happened w/o any warning.

From your last posts it looks like you don't think tires or brakes could be the culprit.

 

Coupla thoughts.

 

A few years back, a guy had just purchased a PO'd 2000 Sport and posted here with a "mystery crash" somewhat similar to yours, except for the fact that that he said he wasn't braking at the time of the crash. According to him, it happened on a straight section of road with a slight ripple in the pavement. He was absolutely convinced of a fundamental flaw in the design of the moto, due to a widely circulated Old Wive's Tale about a "handling problem" with the "short frame" Sports (which never had any basis in reality).

 

This guy could not (or would not) be disabused of the fallacy of the Old Wives' Tale. He was convinced that "something about it" (never identified) had bucked him off! Else, how to explain riding along peacefully one moment, and suddenly he's doing the macadam backstroke as it went spinning down the road in front of him?!

 

A little Q & A, and it quickly became apparent that he hadn't the first clue how (or if) the suspension had ever been set up properly, nor had he the foggiest idea why it might be important, nor (like you) had he been using the steering damper at the time. He sold the bike -- as I would, too -- IF I were as convinced as he was that it was haunted by mysterious demons, rather than considering that my own lack of knowledge could be the most serious problem!!

 

Now I'm not suggesting that you don't know what you're doing, my friend! (How would I have any idea at this point?) Nor am I implying that you have a suspension problem, nor am I implying that not using your steering damper caused this! But they're all certainly potential contributing factors, unless of course, among a host of other things, you have your chassis set up properly (sags, spring rates, preloads), per the usual recommendation of the Pro's. It's usually a combination of many factors of this kind that conspire with certain variables on the road to create an inherent handling problem. If you're interested, there are many posts on suspension setup and discussion about the correct use of steering dampers here that might shed some light on this.

 

Hope this helps.

[kecup]

From your last posts it looks like you don't think tires or brakes could be the culprit.

 

Coupla thoughts.

 

A few years back, a guy had just purchased a PO'd 2000 Sport and posted here with a "mystery crash" somewhat similar to yours, except for the fact that that he said he wasn't braking at the time of the crash. According to him, it happened on a straight section of road with a slight ripple in the pavement. He was absolutely convinced of a fundamental flaw in the design of the moto, due to a widely circulated Old Wive's tale about a "handling problem" with the "short frame" Sports (which never had any basis in reality).

 

This guy could not (or would not) be disabused of the fallacy of the Old Wives' Tale. He was convinced that "something about it" (never identified) had bucked him off! Else, how to explain riding along peacefully one moment, and suddenly he's doing the macadam backstroke as it went spinning down the road in front of him?!

 

A little Q & A, and it quickly became apparent that he hadn't the first clue how (or if) the suspension had ever been set up properly, nor had he the foggiest idea why it might be important, nor (like you) had he been using the steering damper at the time. He sold the bike -- as I would, too -- IF I were as convinced as he was that it was haunted by mysterious demons, rather than considering that my own lack of knowledge could be the entire problem!!

 

Now I'm not implying that you don't know what you're doing, my friend! (How would I have any idea at this point?) Nor am I implying that you have a suspension problem, nor am I implying that not using your steering damper caused this! But they're all certainly potential contributing factors, unless of course, among a host of other things, you have your chassis set up properly (sags, spring rates, preloads), per the usual recommendation of the Pro's. If you're interested, there are many posts on suspension setup and discussion about the correct use of steering dampers here that might shed some light on this.

 

Hope this helps.

 

done some kilometrage on 3 other guzzis before so do not believe much in tales, no complaints about the design. I guess anything can be the cause, among the variables here, including their combination. Old tyre and dirty brakes most likely. But we will give it a thorough research when we start restoring the bike. Recent events will speed up the process a bit. Suspention settings were checked, seems they are factory. But banalities need to be ruled out first I agree. Know very well how stupid hurts - from the 2stroke 175cc era back home long time ago:)

[gstallons]

k,

Do you have access to a non-contact infrared thermometer? If so look at the temp. of the front rotors after (or a couple) one hard stop. The temp of the rotors should be within 10 degrees of each other. If one caliper is sticking or stuck the temp. will be a lot higher.

I don't know what temp. these rotors will be, automotive rotor usually stay below 150 deg.