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The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> Pulsing at the brake lever on braking
Post Info TOPIC: Pulsing at the brake lever on braking
TTRfan


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Pulsing at the brake lever on braking
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We had a customer who asked if I had any ideas of what can be causing pulsing at the brake lever on braking.

He had tried a couple of used discs thinking one might be warped and also changed pads but the symptoms remained. 

I had come across this once before and, after a lot of head scratching, managed to track down the cause - a bent front axle evileye

It is hard to understand what forces could bend a front axle but that is what had happened. Replacing the axle cured the pulsing.

I suggested this as a possibility to our customer who put his axle in a lathe and found it oscillated! 

He decided to have a go at straightening the axle and kept checking it after some judicial walloping in the vice then rechecking it in the lathe and finally got it running true. He took the bike for a test ride and 80% improvement.

Back at his  workshop, he fitted one of our wavy discs and that totally sorted it wink

Hope that may help someone!

Brian



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Cubber


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TTRfan wrote:
I had come across this once before and, after a lot of head scratching, managed to track down the cause - a bent front axle evileye

It is hard to understand what forces could bend a front axle but that is what had happened. Replacing the axle cured the pulsing.


 Brian, bending the front axle would be a possibility, in my opinion, judging by the results of at least one of my "offs". confuse

I was amazed at the resulting mess of my forks, especially after this "off" when descending Bike Breaker, 192-237. bleh

The forward momentum, steep drop and my ineptitude sent the bike smartly down the chasm.
When I eventually picked it up the handlebars pointed more or less forwards but the front wheel was pointing severely to the left.

I had to loosen the yoke and axle clamps to straighten everything well enough to ride out.
Had the fixings been a little more secure locked I can well imagine a bent axle being the result. blankstare

Image.jpg

This was looking up the lane after I'd straightened the bike - remember - I was "supposedly" coming down the lane! biggrin

The bike had performed a forward roll, landing facing up the lane.

Plenty of forces, angle of dangle, velocity and gravity I'm sure could damage it alarmingly.

But as it was, on that day, my ego was more damaged than the bike. wink

Martyn

 



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Paul C


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I had this symptom. It was a very slight leak from the fork seal. An almost invisible drip of oil worked its way down onto the disk.

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petenz


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I bent the front axle on my XT660R....
didn't notice it till I tryed to unscrew it so
I could remove the wheel..
it has a CR USD front end with a 20mm hollow axle..

The only off I think that could have done it
was a good 80/100kph high side.... I'm now keep a look out
for shut gates just around blind corners...
could have been real nasty ..was doing 120k ... before I scubbed
a bit of speed off...



-- Edited by petenz on Wednesday 17th of February 2016 09:07:03 AM



-- Edited by petenz on Wednesday 17th of February 2016 09:11:06 AM



-- Edited by petenz on Wednesday 17th of February 2016 09:11:50 AM

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pricey


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Best photo ever petenz. Cracked me up.

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