smart51
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| posted on 24/1/06 at 10:48 AM |
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shifting between 1st and 2nd on a BEC
If I use all the revs in 1st gear it is quite difficult to engage 2nd. I have to declutch and wait for the revs to drop so that the speed is right
for 2nd before trying to engage. Trying to make a quick shift makes slight clicking noises from the box until the revs are right and then it goes
in.
1st to 2nd shifts at slower engine speeds are no problem, as are shifts between all the upper gears. Clutchless upshifts work fine in all the other
gears too.
Is this caused because of neutral being between 1st and 2nd? Is it because 1st and 2ns are further apart than the other gears? Is there a special
technique that I am missing?
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RichieC
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| posted on 24/1/06 at 11:36 AM |
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There is normally a noticable difference between 1st and 2nd because of N in between. If there is any wear on the dogs in the box this will be more
noticable as there will be less liklehood of a clean engagement.
I think Im right in saying, you change forks from 1st/N onto 2nd/3rd. Again, if there is any significant wear this transition may not be as smooth as
youd wish.
I rarely used the clutch going up on any of my bikes, from reasonably slow speeds to the other end of the scale.
The biggest difference betweem ratios is 1st - 2nd, the ratios then "smooth" out:
98-00 R1 ratios:
1st 12.87442
2nd 9.1210314 = 3.75 step
3rd 7.42755 = 1.69
4th 6.6006161 = 0.82
5th 5.94204 = 0.66
6th 5.5211455 = 0.42
Hope this is of help, I guess any or all of these could gcause this
Kind rgds
Rich
Rich
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Hellfire
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| posted on 24/1/06 at 12:21 PM |
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I haven't noticed any problems going from 1st to 2nd on either Blade or ZX12R engine, other than it being clunky at low revs (using clutch)
which is just a bike engine trait.
At high revs, 1st to 2nd gear goes in just as smooth as other gears on clutchless upshifts.
Does it accelerate quickly and smoothly once you're in second gear?
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uklee70
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| posted on 24/1/06 at 12:33 PM |
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My r1 mini first to second was quite a clunk
I think R1's are known to be a like this
Lee
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smart51
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| posted on 24/1/06 at 12:33 PM |
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It accelerates well in all gears. I spent much of saturday afternoon on small windy lanes accelerating from 30 to 60 in 2nd before slowing for the
next bend and accelerating again.
At angine speeds upto maybe 5000 RPM, there is no problem shifting from 1st to 2nd, apart from it being a bit clonky.
If I rev upto 10,000 or 11,000 PRM, it won't go into 2nd until the revs drop by about 3000 or so, which is then the right speed for 2nd gear.
It is only a problem when doing flying stats or going into 1st gear hairpins, but then thats part of the fun.
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Paul G
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| posted on 24/1/06 at 01:42 PM |
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I know when I was testing mine on the road (R1 indy not SVA'd yet) I always seemed to get quite a big clunk and a shudder when going first to
second at all revs, all the other gears went in smoothly. I was a bit worried about it as it didnt feel right but was concentrating on getting
through the SVA first
Paul
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carnut
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| posted on 24/1/06 at 02:37 PM |
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If youve been giving it a lot of stick (ie flat shifting 1st to 2nd) you may have chipped the corners off the dogs. I did this to 4th gear but on the
over-run side while changing down. Only way you can tell if this is it though is to pull the engine apart or take the sump off and filter out to
look for bits of metal.
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JoelP
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| posted on 24/1/06 at 06:58 PM |
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id vote for the clutch dragging, especially bearing in mind the shims you added. Have you considered removing them and doing a quick blast to compare?
Obviously your clutch will slip again, but it might solve the clicking etc.
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ChrisGamlin
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| posted on 24/1/06 at 09:23 PM |
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Agreed, sounds like clutch drag to me
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progers
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| posted on 25/1/06 at 08:00 AM |
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If it turns out to be clutch drag, try reducing the washer you put under the coil springs from 2.5 mm down to something less than 2. The sump washers
I used were around 1.5mm.
- Paul
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smart51
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| posted on 25/1/06 at 08:26 AM |
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nice idea with the clutch but it has always been difficult to shift from 1st to 2nd, before I fitted the clutch spring shims and before I fitted the
barnet pressure plate.
My first few trips to SVA and things I drove it very gently but it has always been tricky. I assumed it was bad technique at first.
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ChrisGamlin
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| posted on 25/1/06 at 05:53 PM |
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If its always been like that then it could possibly be a bent selector fork 
I would double check the drag thing first though
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