Triumphrat

Treehugger · 07-14-2005

I'm no major mechanic and when it comes to fault diagnostics Im pretty touchy feely so let me explain the problem.
riding into work yesterday I noticed a fait tap noise "tock tock"
1. I only hear it when i'm accelerating. at the same speed without accel there is no noise.
2. It's a faint noise and doesnt feel through the bike, although I think I an feel the tapping through the leftside foot peg through my foot but very faintly.
3. The tapping doesnt really speed up even when I do, only very slightly and is about 2 taps a second at 40mph.
4. there is no loss of power
5. no noticible performance/handling difference.
6. I think its starting to get a bit louder (the tapping) or it may be because I'm tuned into it now.

with that timming between knocks could it be chain related? I've looked at the chain and havent noticed any rubbing. I'm all ears for suggestions, many thanks in advance. It doesnt seem wheel related as the taps dont correspond to the speed of the wheels.

Ghoti · 07-14-2005

You say tapping does not correspond to wheel speed, but the chain and wheel speed are directly related. Is it engine speed related? If so, forget about the (final drive) chain.

Could be chain rubbing on the stand or something. As you accelerate the slack part of the chain will be at the bottom. Holding a speed it will be even(ish) top and bottom. Under engine braking the slack part moves to the top. May just be too much slack in the chain or an unevenly worn chain.

Could also be a stiff link, but I don't really understand how this would only show in acceleration.

Another thing to check are the sprockets and alignment of rear wheel (make sure it is straight to the frame).

Ghoti · 07-14-2005

Another thing...

Have you got any aftermarket 'bits' down near your left peg like a chain oiler (scotoiler/lubeman etc), hugger, etc.

Check them also.

Treehugger · 07-14-2005

no aftermarket bits, except exhaust. I thought about the slacking of chain because of accelarating. I'l look closer at the chain after work today and check alignment, all seemed to be correct last night...
if the chain was rubbing surely it would make a constant sound? rather than paced out?

Ghoti · 07-14-2005

Quote:

if the chain was rubbing surely it would make a constant sound? rather than paced out?

Not if you have an unevenly worn chain and it just happened you checked it at the tight spot so it is too slack at the slack spot. Then it would only hit something when the slack bit of chain was at the bottom and it would be clear when the tight bit was at the bottom.

[I'll re-type that in English when I know what I'm saying - it almost makes sence!]

Treehugger · 07-14-2005

whot yu men? I undastud that fin

i get it i'll take a look, if anyone has any other experiences or advise feel free

Will · 07-14-2005

I am scratching my head on this one. A tap a couple of times a second with no relationship to engine or road speed makes no sense. Is it rhythmic? If not, it could be a loose shock absorber mount or something like that. Do you have anything on the bike that could flap in the wind and whack a pert of the bike? That is really a stretch, but I can't think of much else right off.

Treehugger · 07-14-2005

it does have some relation to speed as I mentioned it does speed up slightly as i do but not but not by much at all. Could it be tracked to a part before gearing? the final drive moves faster ie wheels. I have been riding upto 40-50 around town and havent really thrashed it revs or speed. I would say it bears better relation to revs than speed. because im keeping my revs at a steady 3-5K...

JayR · 07-14-2005

Without looking at the manual (so forgive me if its a stupid suggestion!) could it be the cam chain/belt? Under acceleration the engines working a bit harder then it is at a constant speed which could account for the knocking....

Have you had a look at the rubber strip along the swing arm that protects it from the chain - can't for the life of me remember the name of it, just in case it's something as simple as that!

Will · 07-14-2005

One thing to do is pull off the cover over the countershaft sprocket and see if there is anything stuck in there. It gets pretty guzzed up in there if you don't clean it every now and then. Come to think of it, it gets pretty guzzed up in there anyway!