Bigger front sprocket

[fordlatch41]

I have just upgraded the front sprocket on my 2001 to a 16 tooth item, also upgraded to the 12mm thick nut and new lock washer as it still had the old 9mm nut fitted, the vibration at 70 mph was driving me mad which is why I decided to change the sprocket. So now it revs at about 700 rpm lower, doesn't seem to have affected the performance by much if any, but now is super smooth up to almost 80 mph. Just thought I would put it out there chaps.

[daviee]

have you tried balancing the carbs it help smooth it out i get very little at 70 mph just a thought ,,

[Disorderlypunk]

i think matt7chunk also runs a 16t
ive just pulled my 14t off and put back my 15t, was good fun for accelerating off the line and hooligan fun but my recent 120mile trip used much more fuel and lost a lot of the top end
might try a 16 if i go for a massive ride down south as most of it will be on the motorway anyhow

[fordlatch41]

have you tried balancing the carbs it help smooth it out i get very little at 70 mph just a thought ,,

Yes I did them last night actually, it's defo a mechanical prob on these machines, a proper tingling through my feet at 6250 rpm

[Triggergee]

Mine vibrates a fair bit at that rpm too so much so that for the missus sake I've wrapped a bicycle inner tube around the pillion handle, don't know if my carbs need balancing but I've just bought a Morgan carb tune so I'll know soon enough. In the interest of serving the community I've just ordered a +2 17 tooth sprocket and will let you all know how it feels. Should do good things for fuel consumption and hopefully keep the other half quiet.

[limax2]

Very common for these 600's to have a bit of a vibration patch round about the 6,500 mark. Correctly balanced carbs helps but may not eliminate it completely.  It's unfortunate that it happens to be at the sort of speed when you want to just cruise down the motorway within the legal limit.
Triggergee.  It will be interesting to know how you find the 17 tooth sprocket. Hope you can back off the chain adjustment enough not to have to alter the chain.

[Disorderlypunk]

legal limit -whats that ??? (the kids like me passing the school at 70mph on my back wheel)
im 5 notches back on my 15t and was nearly at the back on my 14t
i have a feeling if you go 17 it will be a remeasure and longer chain so your stuck with it once riveted or throwing money away
i think we are at 110 links standard

[matt7chunk]

i think matt7chunk also runs a 16t
ive just pulled my 14t off and put back my 15t, was good fun for accelerating off the line and hooligan fun but my recent 120mile trip used much more fuel and lost a lot of the top end
might try a 16 if i go for a massive ride down south as most of it will be on the motorway anyhow

Indeed I do, interested to hear about the 17t also, might be to much of a change though considering that's like the equivalent of losing 4 off the rear if I'm correct?

[Disorderlypunk]

there is more maths to it the bigger the change but the general consensus is 1 tooth is effectively 3 teeth on the rear
was talking to my father today about switching back to the 15 and he said he thought it wouldnt last long given the difference in riding conditions here
if your up and down the motorway all the time and not spending much time town riding a 17 wouldnt be a terrible
14t   3.43 /1
15t   3.2   /1
16t   3      /1
17t   2.82 /1
cant remember the primary reduction but you can see that is a serious change

[Triggergee]

Didn't really think about chain length.. idiot. I've got four notches/lines to play with but I'm not sure that will be enough. I may or may not buy a new chain if it doesn't fit. Is there a cheap way to lengthen the chain?

[Disorderlypunk]

if you go D.I.D you can buy extra links which of course need a rivet tool to fit, if you already have a d.i.d then a rivet remover can be used to remove old and replace more links

[darrsi]

have you tried balancing the carbs it help smooth it out i get very little at 70 mph just a thought ,,

Yes I did them last night actually, it's defo a mechanical prob on these machines, a proper tingling through my feet at 6250 rpm

Just take into consideration that the rear wheel alignment might cause mild knocking at speed if it ain't quite right.
Even spinning the rear wheel in reverse on the centre stand can show this up, and you can also hear if it's not true.
Don't totally rely on the swingarm markings.

[Disorderlypunk]

funny you should mention that after i have spent an hour killing myself over that today
with the wheel in the air it was shaking around like mad but when under pressure no problem at all
without a laser alignment tool its hard to be sure but them lines are the best we have - they are made in a pretty accurate JIG but as time passes we lose alignment through bearing wear etc

[Triggergee]

if you go D.I.D you can buy extra links which of course need a rivet tool to fit, if you already have a d.i.d then a rivet remover can be used to remove old and replace more links

I've got a sealey chain tool although like a tit I snapped the one of the pins on its first use as I didn't notice the the chain rivet wasn't fitting through the anvil and kept cranking on the ratchet until it pinged... and a JT chain, 530 Z3? maybe so I'll have a look tomorrow to see if I can get extra links for that.  Wonder what rpm it would be at on the motorway at "legal" speed limit

[fazersharp]

Mine vibrates a fair bit at that rpm too so much so that for the missus I've a bicycle inner tube

WTF is your mrs doing with a vibrating rubber inner tube. ------------- Had to say it before that idiot Tommy said it.

I dont notice any vibe other than at about 3500k - its the buzing fairing/bulb fitting. My cure is not to pootle  around at 3500k

[darrsi]

Mine vibrates a fair bit at that rpm too so much so that for the missus I've a bicycle inner tube

WTF is your mrs doing with a vibrating rubber inner tube. ------------- Had to say it before that idiot Tommy said it.

I dont notice any vibe other than at about 3500k - its the buzing fairing/bulb fitting. My cure is not to pootle  around at 3500k

If you shout "La la la la" in your head you can't hear feck all, bike's fine. 

[darrsi]

Don't try the movie though, LA LA LAND  really was shite.

[tommyardin]

Mine vibrates a fair bit at that rpm too so much so that for the missus I've a bicycle inner tube

WTF is your mrs doing with a vibrating rubber inner tube. ------------- Had to say it before that idiot Tommy said it.

I dont notice any vibe other than at about 3500k - its the buzing fairing/bulb fitting. My cure is not to pootle  around at 3500k

Bit rude 

[fazersharp]

Mine vibrates a fair bit at that rpm too so much so that for the missus I've a bicycle inner tube

WTF is your mrs doing with a vibrating rubber inner tube. ------------- Had to say it before that idiot Tommy said it.

I dont notice any vibe other than at about 3500k - its the buzing fairing/bulb fitting. My cure is not to pootle  around at 3500k

Bit rude 

[darrsi]

funny you should mention that after i have spent an hour killing myself over that today
with the wheel in the air it was shaking around like mad but when under pressure no problem at all
without a laser alignment tool its hard to be sure but them lines are the best we have - they are made in a pretty accurate JIG but as time passes we lose alignment through bearing wear etc

Are you on about letting the wheel spin in gear with engine running on the centre stand?

[Disorderlypunk]

yeah i was cleaning the chain and decided to just start her up and let her spin the wheel on the paddock stand as i sprayed the hose at it to remove the cleaner and it was bouncing all over the place- turns out it was just riding the front sprocket a bit - its fine when its under load

[darrsi]

yeah i was cleaning the chain and decided to just start her up and let her spin the wheel on the paddock stand as i sprayed the hose at it to remove the cleaner and it was bouncing all over the place- turns out it was just riding the front sprocket a bit - its fine when its under load

It's the momentum of the wheel gaining speed but the chain won't let it go faster than the engine speed, which causes that shuddering effect.
Get quite a few people freaked out by it when it happens, but as you say just a very tiny bit of throttle levels it out.

[Triggergee]

17 tooth sprocket arrived today, big bastered... as soon as it stops raining I'll attempt to fit it and let you all know my opinion.

[His Dudeness]

I've a theory that it's the exhaust resonating at 6k that causes the problem. I just need someone mad enough to go flying up the road with no exhaust to test the theory

[Disorderlypunk]

I've a theory that it's the exhaust resonating at 6k that causes the problem. I just need someone mad enough to go flying up the road with no exhaust to test the theory

done it - for some reason people kept looking at me