Log in

View Full Version : Crashed my new bike because the brakes locked up on their own


James87
24-07-12, 05:00 PM
Hi all,

Ive had a scare on my new bike, in fact quite a big scare so I thought I’d share it with you all and get some views and opinions as to what went wrong.

I’ve recently passed my DAS and have spent a good month looking at/trying different bikes. I didn’t firmly know what it was that I was going to get but the SV650 kept popping up. I looked at several half faired versions, which has some OK looks but something was missing. So I turned my focus elsewhere.

Whilst looking at another bike which I thought that I liked (er6n), I saw a lovely little black ‘07 naked SV sat amongst a bunch of verocious looking 1L sport bikes, I knew I was there to look at the ER6 but could not stop staring at the SV.

It turns out the only thing preventing me from really ‘falling’ for the previous 650’s that I looked at were the questionable looks, riding position of the S model. After having a go on this one however I knew this was the one. On top of the fact that there wasn’t a scratch on it and it had done 3000 miles with FSH, It had a few extras too such as a quill exhaust, tail tidy and Renthal bars which sweetened the deal at (3k).

So the next day I rode it home, and it was perfect! I had a sore face for a few days afterwards from grinning so much. This journey was about 30 minutes of riding. no dramas

So a week later, after being kept round the side of my house under a bike cover I finally found the time to take it out on Sunday to enjoy the amazing weather, I thought id take a trip to Hein Gericke in Farnborough to look at some kit as the bike trousers that I have are unbearable in the heat.

I was heading back the way I came after finding nothing that I liked in my size, and thought id ride through town as against the dual carriageway to get used to the ‘biting point’ on the clutch with the inevitable stop starting of urban riding. The bike seemed okay at this point but pulling away at junctions etc the bike felt quite laboured, kind of like when you pull away in too high a gear. I put this down to my inexperience and getting lost in the gears. Once I got moving again everything was okay.

I was travelling into the centre of Farnborough and was doing about 35 in a 40. I was on about 4.5k revs, nothing silly, as a noob I enjoy taking things easy. Nothing in front, a couple of cars a way behind. The bike started to feel extremely laboured, the next thing I know the front is violently going all over the place and then im on the floor sliding across the road. I wasn’t expecting to drop the bike going in a straight line. And I must say it happened very quickly, I took a whack to the head so now im looking at replacing the helmet, and im a slightly bruised. Jacket is a bit scuffed, and the trousers tore at the pocket. Thankfully im fine, investing in good kit paid off and no cars were coming the other way as I ended up on the other side of the road.

To say I was completely shocked is an understatement.

My initial thought was “did I hit some oil?” no. The road was clean.

There were a couple of nice people that appeared (not sure where from) that helped me pick up the bike and get it off of the road, they must have been the people in the car behind. They were just as flummoxed as I was as to what had happened. So we looked over the bike to try and work out what happened.

This is what we noticed:

There was a very potent burning/hot smell from the front brakes, I guess it smelt a bit like burnt plastic..
There was a lot of ‘bluing’ on the discs themselves as what happens to metals when exposed to a lot of heat.
There was an immense heat coming from the front wheel. I had my hand about 12-15” away and could feel a lot of heat coming from the front.
The tyre had blistered in the centre and slightly off to the side where I went over. (I’ve seen this on my dads back tyre after a track day – not sure if blistered is the correct term?)
My front brake lever was jammed behind the throttle cables. (impossible to say if this was a result of the crash or if this was like it before as the end of the lever is missing)
The brakes were rubbing making the bike hard to move around (until we managed to free the front brake from the cables)

My conclusion:

Somehow the breaks jammed/locked and it knocked me off

This scared the s**t out of me. Thankfully the garage I bought it from are going to repair everything and set it right like for like, for free.
Just as well because if this happened on the dual carriageway/if it was slightly busier on that road, I might not be here to tell you all this wonderful tale

So at the end of this rather large post/essay the question that I want to know is what the hell? Has anybody heard of something like this before? Can anybody think why the brakes might have locked up?

Thanks in advance,

James

Spank86
24-07-12, 05:07 PM
Sounds like they were sticking.

Bibio
24-07-12, 05:10 PM
well if they are going to repair everything for free then that to me is an admission of guilt.

sv_rory
24-07-12, 05:10 PM
if the seals have let dirt in it will cause the pistons in the calipers to lock up, the other thing is how long has the bike been sat there without the brakes being used?

sv_rory
24-07-12, 05:11 PM
well if they are going to repair everything for free then that to me is an admission of guilt.


I agree, You would think that brakes would have been checked before a sale went ahead

Elliott
24-07-12, 05:16 PM
well if they are going to repair everything for free then that to me is an admission of guilt.
Where there's a blame there's a claim. Get your gear paid for.

SuzukiNess
24-07-12, 05:16 PM
well if they are going to repair everything for free then that to me is an admission of guilt.

what i thought

sv_rory
24-07-12, 05:18 PM
Where there's a blame there's a claim. Get your gear paid for.


Absolutely!

Small Clanger
24-07-12, 05:20 PM
Were both discs blued? I may be wrong but I would have thought that, if both were affected, there would be a problem with the master cylinder or hoses but if only one was blued, it would be the corresponding caliper at fault.

Would that make sense?

sv_rory
24-07-12, 05:21 PM
Were both discs blued? I may be wrong but I would have thought that, if both were affected, there would be a problem with the master cylinder or hoses but if only one was blued, it would be the corresponding caliper at fault.

Would that make sense?


Mine did a simlar thing but it was both disks, a master cylinder repair kit sorted it

appollo1
24-07-12, 05:34 PM
perhaps the bike sat for a long time before you purchased and the dealer failed to give it a check before sales.

did it come with a new MOT? if there was a problem with the brakes i would have thought that they would have spotted that at the MOT!!

Dave-the-rave
24-07-12, 06:37 PM
Glad to hear you're OK James. Having the sh*t scared outa ya means you're alive. :cheers:

maviczap
24-07-12, 07:02 PM
How about pads being put in the wrong way round in one caliper? After a certain amount of time they'll get so hot they'll weld to the disc rotor?

But sticking pistons/brake system is more likely, but it won't be the first time pads have been put in the wrong way

monkey
25-07-12, 03:59 AM
Wow!

I can't picture how the brake lever got jammed behind the throttle cables but in my mind at the moment I think something has made its way loose/was initially loose and it's caused the brakes to be slightly touching until they got so hot that they locked. The fact that all seemed well and then you noticed it labotomy would support my theory.

I'm interested if both discs were similar too.

I really can't see that a 3000 mile bike would have brakes so crudded up and/or sticky to cause this.

Glad you're ok and hope it doesn't put you off.

chezvegas85
25-07-12, 05:21 AM
Glad your ok, also figuring its worth chasing up for compo, at least for the price of the gear..shiny new lids etc dont come cheap after all

Specialone
25-07-12, 06:20 AM
That could've ended a lot worse, glad you're ok dude.

As bib said, the dealer knows he's responsible as it's still under the minimum 3 months warranty (?), bike wasn't fit for purpose.

They know they could be sued over this hence them sorting it, I'm not in to all this blame culture but I think it's reasonable to ask for your lid and any gear that you damaged should be replaced by them.


Good luck :)

James87
25-07-12, 07:03 AM
Hi all, thanks for all of the responses,

The bike is already back at the garage i bought it from, although i do remember that both discs were 'blued' i cannot confirm right now. so i agree that it could be something other than the calipers such as the master cylinder.

One thing i neglected to mention is that it also has braided hoses on the front and im starting to wonder if they were not fitted correctly. But it worked fine when riding it home the week before..

It had its last MOT at the end of May and passed.

Ive attached an image of the lever stuck behind the cables, it took some to release it. but as said before it is impossible to say that this was the cause because it has been impacted as can be seen by the broken end..

Im going to make them go over the entire braking system as im definitely not inclined to get back on it until they get to the bottom of this.

thanks again

yorkie_chris
25-07-12, 08:24 AM
There was no need for this to end in a crash, next time it feels laboured like that stop and find out why!

How about pads being put in the wrong way round in one caliper? After a certain amount of time they'll get so hot they'll weld to the disc rotor?

But sticking pistons/brake system is more likely, but it won't be the first time pads have been put in the wrong way

Not really possible looking at the SV pads.

Wow!

I can't picture how the brake lever got jammed behind the throttle cables but in my mind at the moment I think something has made its way loose/was initially loose and it's caused the brakes to be slightly touching until they got so hot that they locked. The fact that all seemed well and then you noticed it labotomy would support my theory.

I'm interested if both discs were similar too.

I really can't see that a 3000 mile bike would have brakes so crudded up and/or sticky to cause this.

Glad you're ok and hope it doesn't put you off.



All it takes is for something to touch the master cylinder to the point where the transfer port closes.
This makes the brakes a sealed system.
Then the fluid expands due to heat, which applies the brakes a bit, creating more heat... which... yeah you work it out...


The cables touching the lever could cause this.

Sir Trev
25-07-12, 08:39 AM
Ive attached an image of the lever stuck behind the cables, it took some to release it. but as said before it is impossible to say that this was the cause because it has been impacted as can be seen by the broken end..



Looks to me like the lever pivot has been badly bent pushing the lever itself into the cables. Make sure the dealer replaces the r/h switchgear assembly as the thing will be very weak after that sort of distortion.

Glad you're OK of course.

jambo
25-07-12, 10:24 AM
There was no need for this to end in a crash, next time it feels laboured like that stop and find out why!


All it takes is for something to touch the master cylinder to the point where the transfer port closes.
This makes the brakes a sealed system.
Then the fluid expands due to heat, which applies the brakes a bit, creating more heat... which... yeah you work it out...


The cables touching the lever could cause this.

I'd agree with this.

This has also been seen with some after-market brake master cylinders, levers etc. If the brakes are not coming all the way off they will start dragging which will get worse until the braking force is stronger than the grip the front tyre can offer. By this time you have usually been fighting against it with some enthusiasm, for some time.
Lesson learned, if something feels nasty, take 3 minutes to pull over and check. Better to be a little late than land on your back side.

I helped pick a curvy SV off the deck a while ago that had managged the same issue with corrosion building up on the calipers as mentioned here, either way the brakes were not fully releasing, and eventually locked the front wheel.

Glad you're OK!

I'd question everyone's sudden enthusiasm to demand the bike shop pays for all your gear. I'd say they're trying to make things right, and the fault may not have been obvious when the system was cold. But it's worth an ask surely.

Jambo

James87
25-07-12, 12:31 PM
I agree, I probably should have stopped riding :(

It was only the 2nd short outing since passing my test and my inexperience led me to believe that i was in too high a gear when it started to labour coming out of junctions etc, when i got going again it felt fine which backed up this assumption. then lo and behold 400m down the road it laboured again, front went mad and i was on the floor all in what seemed to be about 2 seconds!

Naturally Ive very quickly learnt never to assume anything! :o

The owner of the garage was genuinely mortified that this has happened, and really wants to put things right. he is getting me a new lid as well, I'm not fussed about the jacket as its only got a few scratches on it, the trousers will need to be replaced but its a small price to pay as i was looking at getting different ones anyway.

I just want to be sure the bike is OK to ride before i get back on it, although I'm fine, i don't want to make a habit of it.

Im going to get him to fully service the brakes and replace all those controls on the right.

All in all though, the crash bung saved most of it so happy days:

jambo
25-07-12, 01:16 PM
Sounds like about the best result you could get from what could have been a rather nasty situation :thumbsup:

Once again, main thing is that you're fine. Don't let this put you off, and enjoy the summer while we've got it!

Jambo

monkey
25-07-12, 01:35 PM
When I said noticed it labotomy I meant to say noticed it later. I can't believe it wasn't queried?!

Nice bike mister!

yorkie_chris
25-07-12, 03:45 PM
Im going to get him to fully service the brakes and replace all those controls on the right.

The switchgear will be right unless obviously damaged.

It is the master cylinder which should be carefully checked.

Also check the routing of throttle cables, I seem to remember the cables coming off at the top on pointy. This is not critical... they can point wherever as long as they don't interfere with other things.

rictus01
25-07-12, 04:41 PM
whilst it could have been caused by mechanical or component failure or even bad maintenance I have my doubts (of course post accident it's hard to say), however I've had similar in the past and it was down the "comfort braking", novice or fairly new riders have a habit of riding the brakes, this builds up heat, they tend not to even realise they are doing it, but over a protracted period it can lead to the conclusion, what you perceive as light pressure maybe enough to cause them to drag.

Cheers Mark.