Glee Over Revving...Wheelspin or Clutch?

[Ambergnat]

Hi Chaps, I need some advice.  

I've been fixing and fettling the bike in anticipation of the West Wales trip, nothing major, but something I've done seems to have changed the behaviour of the bike, or something's worn to the point where it's letting me know its unhappy...

Changes Made in the last Fortnight:

1. New Back Tyre fitted (Pilot Road 4)
2. New Gel touring seat fitted (around 15mm higher than stock)
3. Longer Dog-Bones fitted (145mm) - lowering rear by 14mm
4. Dropped front forks by 14mm
5. Replaced Brake & Clutch levers (popped the cam on the old brake lever  - effing cheap chinese crap!)
6. Fitted foam hand grips (approx 5mm thick)
7. Fitted old shims behind rear brake pads (now the pads are worn enough to fit them)

Lowering the bike changed the handling completely for the better - the gel saddle was making things uncomfortably top heavy and I was on tip-toes all the time, even on one foot!

The Problem:

I used to be able to open the throttle from 5k in 6th and she'd take off like a scalded cat - even on the old death wing, but now - every time it give it some stick, she screams up to 7.5 or 8k, with no acceleration at all.

It doesn't feel like wheelspin, as the back doesn't slide or wiggle at all.  

The clutch seems to work perfectly at lower speeds, bites properly like it always has.

I can get to any (legal...+) speed with more 'careful' acceleration.

It's only when I give her some wellie she sits there and screams at me ... WTF is it?  

I was careful to run-in the back tyre gently, and on close inspection it doesn't show any surface tearing, scrubbing or ripping.

The only thing I've been doing differently lately is lifting & coasting down hills, which does mean re-engaging the clutch at speed in high gear - but I' always careful to match gears to the speed I'm doing and feathering the clutch/throttle for the smoothest transitions

I'm stumped...  Any Ideas?

[MartinW]

If the tyre was spinning or the chain was slipping I guess you would know about it, so surely it has to be the clutch?  

[V-Strom3]

Has the bite point changed with changing the levers?

[Ambergnat]

If the tyre was spinning or the chain was slipping I guess you would know about it, so surely it has to be the clutch?  

That's the only conclusion I came to - but if the clutch is going, why would it still work at low speed? - it's not loosened up noticeably since I got her and I can still ride the clutch at low speeds (crappy traffic etc...)

I've never heard of a clutch which would do that, but let go at speed... can they do that?

Has the bite point changed with changing the levers?

not massively - maybe slightly closer - but as they're 'shorties'  getting used to the different lever length may be affecting my judgement.

[Hondaman]

As above, do you have free play on the clutch lever?

[Ambergnat]

Absolutely None - it feels quite tight from the first mm

Also - when I boot it, the clutch is completely out/engaged

[mr_diver]

You need some play... Quite a bit when you look at the lever and move it to where you get tension on the cable.

If you are nailing the throttle you are asking for Max torque and with no free play at the lever will generate enough tension to let the clutch slip slightly.

In lower revs and around town you are not putting Max power/torque through the clutch hence no clutch slip.

I'm not sure about how much free play at the lever you should have but it does illustrate it for you in the owners manual.

[Ambergnat]

Aaahhh - now that does make sense.    

I can't remember how much play I had with the old lever, but I'm sure there was a bit.  I had no idea it could affect things so much...  

I rarely feel the need to nail it (as you can tell by the fuelly stats), but do occasionally get fed up with waiting behind idiots...

Too tired to faff around with it tonight, but I'll check out the manual and adjust things accordingly tomorrow.

Many thanks Mr Diver, most appreciated .

Just goes to show - Read the Manual!!

[Joe Rocket]

I agree with Mr Diver. It's less noticable in lower gears as the engine needs less effort to move the bike. In higher gears the engine will need a lot more torque to increase speed due to gearing ratios. If you have a push bike with gears you'll know how easily it is to ride in a low gear but try to go uphill in a high gear takes enormous effort. Hence if the clutch isn't fully engaged when you roll-on the power of the engine will overcome grip of the clutch plates and it will slip.

More free play is necessary. If you've got shorter levers then I'd suggest 10mm betwen lever and handlebar before you feel resistance through the cable.  

[Ambergnat]

Too tired to faff around with it tonight, but I'll check out the manual and adjust things accordingly tomorrow.

OK I lied, I was too bothered by it to leave it alone - had a quick look in the manual - freeplay should be 10-15mm at the lever.

Went out to adjust it and discovered that the cam lever, which I'd  set on maximum because of the size of foam grips - was catching on the hand guard, leaving the clutch always partially disengaged! - thankfully it appears to be only the existing free-play (plus a mm or two) which was taken up.  

Hence the slippage only happeneing nailing it at high speed...

That could have been a lot worse.

Thanks for the input chaps (especially Mr Diver ) - learned something new, and another thing to watch for...

I agree with Mr Diver. It's less noticable in lower gears as the engine needs less effort to move the bike. In higher gears the engine will need a lot more torque to increase speed due to gearing ratios. If you have a push bike with gears you'll know how easily it is to ride in a low gear but try to go uphill in a high gear takes enormous effort. Hence if the clutch isn't fully engaged when you roll-on the power of the engine will overcome grip of the clutch plates and it will slip.

More free play is necessary. If you've got shorter levers then I'd suggest 10mm betwen lever and handlebar before you feel resistance through the cable.  

Absolutely Joe, and thanks  ...... done and sorted...

And now for bed... :sleeping-yellow: up at 6 and getting' too to stay up... :violin:

[Joe Rocket]

Il n'a pas de quoi.  

(Translation: It was nothing/glad to be of help)

[mr_diver]

I trust my cheque will be in the post...
 

[Hondaman]

Get in the queue - after the rest of us that suggested the clutch ;)

[Ambergnat]

I trust my cheque will be in the post...
 ::

Get in the queue - after the rest of us that suggested the clutch ;)

so what happened to 'Advice is free' then eh?

 if you're at the meet - I'll stand you a beer (or two...) - advice on this site is always good - and always welcome - though I was half way there myself... (hence the title... )

... but it would have involved a lot of faffing around before I got there.

[Jacko]

All that high speed nailing might have taken a few thousand miles of the life off your clutch.

[mr_diver]

Juvecu had 110k on his Wee with the original clutch.
And that did a fair bit of clutch slipping offroad.

Mine had 60 with mega amounts of slipping offroad.

[Ambergnat]

Hopefully it wouldn't have taken too much off the clutch - it was only for two day's commute (total of 120 odd miles) and it only happened two or three times... after which I got a bit paranoid. :obscene-tolietpush:

She's done 47k, which is a lot for a 12 plate glee I know - but then I've done over 10k on her since I bought her and of Oct last year.

Also, the engine (and clutch) are relatively gently used - as it's primarily a commuter with the majority of road time in the 3000 - 5000 rpm rev range - it's only when I get on the big A roads and some numpty thinks he's an F1 driver that I feel the need to bugger off  - at speed - and she's rarely above 6500/7000 even then.

I've never redlined her - and have no intention of doing so.   :angelic-cyan:

I guess I'll find out at the next oil change - if there's a lot of crunchy bits in the bottom I'll know I've done some damage...

[UK_Vstrom650]

I'm sure it'll be alright  

[mr_diver]

Used to take mine to the red line all the time.

Running it through the full rev range is not so much an issue as over-reving it.

I've also done a fair bit of offroading on it where slipping the clutch is necessary and burning out the clutch a real possibility.
The strom's clutch is fairly heavy duty for the type of riding they tend to get used for.
The engine was designed to be ridding hard in a naked sports bike that will get ridden like it's stolen.

Changing the oil will likely not show anything as any bits of clutch friction material will float in the oil and get caught in the oil filter. Only heavier particles will sink to the bottom of the crank case and stay there until drained.