Trouble changing up gear

[davebullet]

I have a 2007 VTR250 which changes up into 2nd first time every time, but not always into 3rd, 4th or 5th. 50/50 - it takes a second pull with the foot to get it up into gear.

The only recent adjustments made to the bike where chain tightening and throttle freeplay. I haven't ridden the bike long enough before that to know what "normal" gear selection behaviour was like.

The chain was recently tightened (not by me but by someone who knows about bikes). I don't think the problem occurred before then. I was worried a too tight chain might cause thise, however the chain (without weight on the bike) still has slack according to manual tolerances (25-45mm). I weigh about 85Kg with gear on, so wonder with me sitting on, whether the chain is becoming too tight.

Any ideas please learned bikers?

Thanks,
David.

[awayatc]

Chain shouldn't affect it.
Do you actualy let go of the gearshift lever completely after shifting?....don't leave your foot against it..
How about checking your clutch? Does it start engaging after a little bit of freeplay/....or only halfway through pulling the lever?
You got enough engine oil?

[davebullet]

Chain shouldn't affect it.
Do you actualy let go of the gearshift lever completely after shifting?....don't leave your foot against it..
How about checking your clutch? Does it start engaging after a little bit of freeplay/....or only halfway through pulling the lever?
You got enough engine oil?

Thanks for the quick reply. I'm sure I completely drop my foot off the lever, but will double check on the way home tonight.

The clutch dis-engages pretty early on - after a little bit of freeplay (ie. before the halfway point when lever pulled). Engine oil was changed 1,000kms ago (last service at 6,000kms - bike quite low ks). Oil is probably a little overful - maybe that might affect it?

Thanks,
David.

[vifferman]

Chain shouldn't affect it.
Ack Shirley, that's not true. An overtightened chain can affect gearchanging quite markedly. However, Mr Davebullet did say that the chain was within the specified range of flea play. However(2), he did also say that the trouble started after the chain was adjusted, which is suspicious.

[davebullet]

I work in IT, so one of the questions I ask my customers (and apply to myself is - "did it used to work? - if yes, what has changed since then?")

One of my colleagues also said an overtight chain can cause it. I will plonk my big bum on the seat and ask my better half to check slack tonight. It's a bit hard to do that by yourself and without a centre stand.

Do you guys think an overfilled sump would be a problem re gear changing?

[T.W.R]

The clutch dis-engages pretty early on - after a little bit of freeplay (ie. before the halfway point when lever pulled). Engine oil was changed 1,000kms ago (last service at 6,000kms - bike quite low ks). Oil is probably a little overful - maybe that might affect it?



There should be roughly 3mm free-play in the cable at the lever, measured between the lever & the perch at the outer edge of the clutch.
being slightly over full of oil wont effect gear selection




One of my colleagues also said an overtight chain can cause it. I will plonk my big bum on the seat and ask my better half to check slack tonight. It's a bit hard to do that by yourself and without a centre stand.



A overly tight chain does effect gear changing just the same way as an overly slack chain does also. An overly tight chain has a detrimental effect on a host of items in the drive line

Find the tightest spot in the chain and adjust the to the prescribed amount of slack at that point.
Lean the bike over on the sidestand until the rear wheel comes of the ground get someone to hold the bike steady as you slowly rotate the wheel looking for the tightest point in the chain

[OutForADuck]

The chain does sound like the culprit... firstly back if off a little (more slack) and take a test ride. If changing improves then you need to look at why.

It may be that your chain is too tight or it may be because its too worn (sprockets etc). To check this test your chain tension loaded and after spinning the wheel (i.e. if different places - sprockets can become overalised or simply develop "ramps" on which the chains rides up the teeth).

Also check chain alignment. Shift from 1st to second can be easier due to wider gap in the dogs (nuetral in the middle) but the rest of the box might need some slack to slip out of gear.

The next thing is technique and as pointed out not leaving the shift lever alone between shifts is a common shift problem, Another quick tip might also be to start learing clutchless upshifts... I know from experience that the VTR250 shifts alot smoother when the clutch is not involved.

P.S. Happy to give tips on this if your at a loss of how to do it.

[ManDownUnder]

Check (in this order)
1) Clutch cable adjustment
2) Gearbox oil level
3) Clutch plate wear

[OutForADuck]

I work in IT, so one of the questions I ask my customers (and apply to myself is - "did it used to work? - if yes, what has changed since then?")

One of my colleagues also said an overtight chain can cause it. I will plonk my big bum on the seat and ask my better half to check slack tonight. It's a bit hard to do that by yourself and without a centre stand.

Do you guys think an overfilled sump would be a problem re gear changing?
Overfull sump will not affect shifting.. but you should correct it if it is much overfull... other nasty effects can be had from too much oil :rolleyes:

[vifferman]

Make sure you check the oil level as proscribed in the owner's manual. That is, if it says to check it after the bike has sat for x minutes, then do that. (F'rinstance, for the VFR800, it looks over full if it's been sitting a while, but the proper technique is to leave it 1-1.5 minutes after the engine's been turned off, then check the sightglass with the bike on a level surface.)

[martybabe]

An over tight chain will affect your gear change, look there first especially as you feel the prob wasn't there before, start with the obvious. Also did your mate make sure the rear wheel is aligned, if he's just gone on the marks they can sometimes be out which would again put a strain on the box and bugger up your handling.

Finally and I don't mean to sound condescending in any way, I have no idea how new you are to bikes but you do know your supposed to back off the throttle a tad as you change up, I only mention it because there are a lot of new kids on the block and it would fit your symptoms perfectly.

All the best, hope you get it sorted. :niceone:

[davebullet]

An over tight chain will affect your gear change, look there first especially as you feel the prob wasn't there before, start with the obvious. Also did your mate make sure the rear wheel is aligned, if he's just gone on the marks they can sometimes be out which would again put a strain on the box and bugger up your handling.

Finally and I don't mean to sound condescending in any way, I have no idea how new you are to bikes but you do know your supposed to back off the throttle a tad as you change up, I only mention it because there are a lot of new kids on the block and it would fit your symptoms perfectly.

All the best, hope you get it sorted. :niceone:

Not condescending at all. I am new to bikes and its quite possibly poor technique as well. I've read that a way to check alignment (although probably not overly accurate - but enough of a "guide") is to run two straight edges from opposite sides of the back wheel to the front - gap should be the same on either side of front wheel and edges should be parallel. I don't have a calliper so can only probably measure down to the mm with any accuracy).

The chain tightening was done with the same amount on either side. 1/3rd of a turn on both sides (ie. two nut "flats") so the amount of the adjustment was the same and also minor (not OTT)..

I'll check all the same.

I will pay more attention to throttle position on changing up - to at least see if the "strike rate" is more, less or same with more, less or the same throttle.

I appreciate the help guys. I'll reply tomorrow with how I go (win or lose!)

[davebullet]

Measured the chain slack last night.
Unloaded bike - 35mm
Partner on bike - 20mm
Me on bike (80Kg) - 15mm

Checked for tight spots and alignment. No obvious tightspots and alignment with some straight edges looked pretty good.

Loosened chain back to where it was - added about another 5mm of slack. Manual states 25-35mm (I was wrong when I said 25-45mm) but manual says nothing about putting a load on the bike before measuring. I think 25-35mm is therefore unloaded weight. But going on the above - the chain will get tight with a heavy person or a pillion.

Ensuring I drop my foot off the gear lever inbetween changes and don't rush it, it changed up fine this morning.

I put it down to maybe more my technique being at fault, but at least with the chain a little looser it should help.