KMX Gears 3x8=21 ?

[Andrew1971]

Hi all
Got a little problem with my KMX. I have taken the two top chain tube's off because they were noisey.
So i take it out for a spin put it into 8th gear it was noisey me think's rear deraileur need's adjustment
I get home it's the chain rubbing on the frame. No matter i much i adjust rear deraileur it will alway's rub on frame in 8th gear only. So it rub's with or without chain tube on. Small design flaw !!.
So i can't use 8th gear hence 3x8=21 Has any one else got a simular problem with their KMX
Many Thank's
Andrew

 

[Lanky]

I would be thinking of a trip to Cowleys bike shop. Has it always been like that.

 

[numbnuts]

I have the Cobra and it's OK …....I think......... as I get no noise

 

[Andrew1971]

Yes. as iam getting better i have been getting into the higher gears that's when started showing up.
I have a couple of idea's now i had time to think about it.
@numbnuts how close is your chain to frame.
I bet i have the dodgy one. Look's like phone call to KMX and just fitted new tire's too and some other mod's too. Or fix it myself.
Many Thank's
Andrew

 

[numbnuts]

Yes. as iam getting better i have been getting into the higher gears that's when started showing up.
I have a couple of idea's now i had time to think about it.
@numbnuts how close is your chain to frame.
I bet i have the dodgy one. Look's like phone call to KMX and just fitted new tire's too and some other mod's too. Or fix it myself.
Many Thank's
Andrew

It's very close, but it's not rubbing, well the paints not marked

 

[Andrew1971]

Cheer's numbnuts for having a look. Look's like it's down to the metal on mine
Many Thank's
Andrew

 

[numbnuts]

Cheer's numbnuts for having a look. Look's like it's down to the metal on mine
Many Thank's
Andrew

You have the same cassette 32x11 make sure your back wheel is seated well in the slot as that would make the smallest cog lower down

 

[Andrew1971]

Hi numbnuts
Just went out and checked wheel fully in and guess what the new cassette I put on is
12-23 and still rubs
Many Thanks
Andrew

 

[Andrew1971]

A little update managed to get her a lot quiter but still rub's.
I going to put some tape over the mark on the frame and see what happens.
Many Thank's
Andrew

 

[numbnuts]

I think the only way you can stop it rubbing is not to use the lowest gear.
As I all ready stated mine is very close, but it doesn't rub and is very quiet.

PS can you post a photo please

 

[voyager]

stupid question here

have you tried to put a spacer washer on the spindle to bring the cassette away from the dropout

I will get my coat

regards emma

 

[e-rider]

reading this post it's hard to picture exactly where the chain is rubbing, but, it could be that the frame was designed for 7 speed cassettes and the 8 speed is just 1 or 2mm too wide - you might be able to adjust it out by playing about with the rear hub axle configuration

it does sound like the design of the frame isn't the best as well

 

[numbnuts]

I had another look at mine yesterday as I was cleaning it and I think it is down to them using box section for the chain stay and the tolerances are too tight = a design fault !!!

 

[Andrew1971]

Hi All
Some picture's

The bottom pic is of chain hiding the mark it made on the frame.
That's the result from the chain rubbing even more noisey with a 11t put 12t to stop it and did not.
Many Thank's
Andrew

 

[numbnuts]

Ouch that is tight, maybe get in touch with KMX and send them the photo