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Gas Gas Gearbox Noise


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#1 Roberto

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Posted 03 June 2008 - 07:24 AM

Here is the situation. I tried a 2006 GG TXT250 yesterday which is almost brand new. The engine sounded excellent but when I tried the bike, the shifter mechanism didnīt seem what a new bike should be. This bike only has about 500 km on it. Never used in trial and just for putting around the country. The shifter was very notchy, and the lever didnīt return smoothly. Between 4-5th, 5-6th the gearbox didnīt engage properly sort of chattering the gears as I shifted and engageing with noise sort of like when the chain slaps on the swing arm. This really got me thinking about how a bike this new could have such a gearbox problem. As I saw the post here about shaft adjustment, I was wondering if this could be part or all of the problem. Once in gear the bike didnīt seem to make any more noise than usual and 1-through 4th seemed relatively normal, just notchy and not very smooth. Any comments from the GG crowd?

#2 pancho247

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Posted 03 June 2008 - 03:45 PM

I have a 2008 250 Pro and i have a similar problem, the change between 4/5 is very clonky, 1-4 is ok, so is 5/6 but bit concerned if this is an early sign for an exploding gearbox?????

#3 Roberto

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Posted 03 June 2008 - 04:16 PM

Was your bike always like this? Or is this something that has just come up. This bike is absolutely new, I donīt think it has more then 300-400 kms on it. I donīt have any experience with GG trials bikes, I do with Enduros which always had very smooth shifting. Let me know what you think.

#4 pancho247

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Posted 03 June 2008 - 05:00 PM

yeah, the bike has been like it from day 1. i have had gasgas trials before not before the pro, had no issues then

#5 laser1

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Posted 03 June 2008 - 05:09 PM

In general, trials bikes tend to be clunky shifting bikes. They tend to be hard to get into gear, but also dont tend to pop out of gear either. What you describe could certainly be a sign you need an adjustment - you will need to try it to find out for sure. There are a few threads in the GG forum that explain the procedure and what to look/listemn for. I think JON did a write up on this, but not certain. Also, on pro models, the 1st gear and 4th gear shifts are especially clunky. You can find a Pro model transmission power transfer diagram here and makes it clear why it would be the case. http://www.trialspartsusa.com/diagrams/Pro...ion%20gears.doc

In terms of it being a relatively new bike - things like this can happen (especially with this sort of item ) and are one of the roles the dealers play in the supply chain.

#6 TooFastTim

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Posted 04 June 2008 - 12:49 AM

Just be firm (not violent) when changing between 4th & 5th and 5th & 6th. There's a huge gap in the ratios between those gears compounded by the rather clever selection mechanism that Gasser have patented (8 gears in a 6 speed box, as opposed to 12). It's normal.

#7 PeterB

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Posted 04 June 2008 - 02:05 AM

Hi Roberto,
What you describe, as Tim said, is quite normal for this particular motor. There is quite a clunk between 4th and fifth and this is nothing to be alarmed about. 1st through 4th is a little notchy I guess, but the gear lever should certainly return smoothly.
Bye, PeterB.

#8 Roberto

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Posted 04 June 2008 - 07:37 AM

Thanks for the info, Iīll let you know how things pan out after this weekend.





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