Scratching the exhaust in right curve

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Martin_CZ
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Scratching the exhaust in right curve

Beitrag von Martin_CZ » Sonntag 30. September 2007, 22:55

Hi, would not think that this could happen to me, but...

... today I've scratched my Bulldog's right exhaust pipe (the part below engine) in a sharp right turn, going uphill. I was quite fast, and suddendly there was the ugly sound of asphalt scratching the metal and the bike lost its grip on tyres. It moved some 20 centimeters aside before I managed to get grip again. Bike was loaded with 2 people.

I would expect the footrest to go in contact with road first, but definitely not exhaust :-( Anybody having similar experiences? If not, watch for the right curves....

Regards, Martin.
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WullDee
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Beitrag von WullDee » Montag 1. Oktober 2007, 09:48

Hi Martin,
This never happened to me, but it sounds that you are riding the original fork springs.
By default, they use to be too soft when riding a bumpy curve.
Try adjusting the default value of your fork springs (doing this using the blue adjustment screws at top of the fork).
I have the original ones (still) installed also and my fork is adjusted to two visible rings.
Die linke Hand zum Gruß,
Waldi

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Axman
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Beitrag von Axman » Montag 1. Oktober 2007, 12:27

Hi Martin,

the scratching of the header-pipe in right hand curves, especially with a passenger, is a known problem.
The fork springs are way too soft and turning the blue preload * won´t help you very much (in my case it didn´t help at all. As I am a little on the "heavy" side, I scrached the exhaust on my very first outing!!)

A very good remedy for this is changing the fork springs for progressive ones from www.wilbers.de While doing this change the fork-oil too (the standard fork-oil from Belgarda is very low quality) Wilbers will provide you with a complete kit - Springs and oil - for about 100€ . Dependingt on your weight you should try 10 or 15 wgt. oil You´ll experience a much better ride with very good roadholding and absolutely no more fear of scratching the exhaust and thus getting levered off the road :shock:

Regards

Axman
...es ist ein Zeichen von Intelligenz seine Grenzen zu kennen..

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Martin_CZ
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Beitrag von Martin_CZ » Montag 1. Oktober 2007, 19:17

Well, good news that I'm not alone with my trouble. I think that I've set up the front fork on the start of this season about the same as you, WullDee, but it happened anyway. OK, for sure I think I never have done that curve so fast, but I must admit that the confidence in bike's handling is a little bit gone. If you say, Axman, that progressive springs will just do fine, I think I will spare €100 during the wintertime. Any chance to get it at Louis? I happen to be there quite often (nearly every 2 weeks I'm in Frankfurt on business).

Thank you both for answer.... this site really seems to be the place no.1 to look for BT-related info!

Martin

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Axman
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Beitrag von Axman » Montag 1. Oktober 2007, 22:59

I really don´t know whether Louis has Wilbers-Fork-Springs for thr Bulldog on stock. But I´m sure they can order them for you. And remember to order the complete kit : springs and fork-oil.

Regards

Axman
...es ist ein Zeichen von Intelligenz seine Grenzen zu kennen..

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Bully79
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Beitrag von Bully79 » Dienstag 2. Oktober 2007, 11:12

Hi Martin!

In the past I had the same problems with scratching the exhausts in right curves as you.

After I have changed the fork springs and -oil the problems were gone. The Bulldog driveability will also be multiple better after this procedure.

Best regards

Frank
Was wäre das Leben, hätten wir nicht den Mut, etwas zu riskieren? (Vincent van Gogh)

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nippo_
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Never happened to me (Aufbergbremser??)

Beitrag von nippo_ » Mittwoch 3. Oktober 2007, 17:55

Hallo guys,
my 2005 and I scraped only the right footpeg so far - on Misano racing track.
I weigh between 72 and 75 kilos depending on how much beer I drink... maybe I am quite light compared to the average bulldogger? Or maybe I simply brake too much before the curve (hence the german title)
:wink:


Anyname

Beitrag von Anyname » Sonntag 7. Oktober 2007, 00:33

i've read some reportes on this happening to others and it worry's me, but it never happened to me, and my tires are almost at the limit on the sides. The past week i unfortunately let my bike fell to the ground on the right side while i was stopped (it feel very slowly since i fought till the end to not let it feel) it was almost like curving stopped :) and even then the exhaust curve underneath the engine dind´t touch the ground at all.

I know that the suspensions were "open" but they were not fully open, wasn't the exhaust supose to touch the ground in this case, has anyone else had this experience.


Anyname

Beitrag von Anyname » Donnerstag 11. Oktober 2007, 15:26

Apparently no one had the same experience good for you.

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Axman
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Beitrag von Axman » Donnerstag 11. Oktober 2007, 16:40

Hi Anyname,

why don´t you complete your "Profil" so that we know, who we are dealing with??

As to your question, why the exhaust header didn´t scrape when your bike fell over, thats an easy one : the exhaust only touches the ground when the suspension is fully compressed...or nearly so...and that only happens if you are riding the bike!!

So, if you ride into a curve at speed and tilt the bike over, nothing happens...yet :o but should there be a bump in the course of the curve or should you be forced to tilt the bike a little further, the suspension compresses even more and then...if you are lucky it only makes an ugly noise and even uglier scratches onto your header-pipe (look at Martin-CZ´s picture) if you are unlucky the header-pipe crunches so hard into the ground that it levers the bike off the road...and you with it:shock:

Oh,and by the way, your weight matters too...if you only weigh 50 kilos you´ll probably never experience this problem. But if you are of "normal" weight or even a little on the heavy side, it´s not a matter of "if" but a matter of "when" this is going to happen..

Good luck

says the Axman
...es ist ein Zeichen von Intelligenz seine Grenzen zu kennen..


Anyname

Beitrag von Anyname » Freitag 12. Oktober 2007, 12:20

Best luck to you all.


sully22252

Beitrag von sully22252 » Mittwoch 14. November 2007, 13:04

Hi all

My mark 1 Bulldog already has progressive fork springs fitted, but I thought after reading the above posts it would be wise to also fit them on my Mark 2. I bought a pair of Wilbers springs but when I took the old ones out, to my surprise it already had progressive springs fitted as standard, so presumably Yamaha were aware of the problem and made this modification on the Mark 2. Just thought I should post this to save people wasting money!

Regards
Chris

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Axman
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Beitrag von Axman » Mittwoch 14. November 2007, 18:04

Hi Chris,

maybe I didn´t describe it correctly, but the standard springs on the Bulldog are progressive too (MKI or MKII doesn´t matter) but they are way too soft!! The progression has nothing to do with the strength of the spring or its pliability!!

So changing the fork-springs and the fork-oil on the Bulldog is definitely not a waste of money but added safety :shock:

Regards

Axman
...es ist ein Zeichen von Intelligenz seine Grenzen zu kennen..

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