I have never changed sprockets on any of my bikes, but at Cartagena I swapped bikes with my mate for a session and his bike got a bit more drive out of corners, he said mine was lacking a bit of drive (I have a stock B1). Does it help much to change gearing?
If so what ratio suits the majority of tracks as the bike will only do trackdays? I got a 45 rear sprocket with the set of wheels I got for wets, which would be +5 over the standard rear, I can give it a try out to see the difference, but just wanted some opinions on whether it's worthwhile and what ratio is best?
Cheers.
On a B1 the best place to start is by changing to a -1 front.
Notes from my gearing changes on my b1...
14/42 at snett was too low (revving out on back straight)
14/42 was too low at cadwell for 2nd gear through hall bends
14/40 too high at Donny, 2nd gear bogging down out of Melbourne loop.
Quote from: Neil on March 28, 2014, 06:30:50 AM
On a B1 the best place to start is by changing to a -1 front.
As long as your chain has the adjusment left in it.
If not maybe +2 on the rear?
Quote from: 1-600-matt on March 27, 2014, 11:28:00 PM
I have never changed sprockets on any of my bikes, but at Cartagena I swapped bikes with my mate for a session and his bike got a bit more drive out of corners, he said mine was lacking a bit of drive (I have a stock B1). Does it help much to change gearing?
If so what ratio suits the majority of tracks as the bike will only do trackdays? I got a 45 rear sprocket with the set of wheels I got for wets, which would be +5 over the standard rear, I can give it a try out to see the difference, but just wanted some opinions on whether it's worthwhile and what ratio is best?
Cheers.
Everything is a compromise to some degree.
Stock gearing will not be much good for track use, the bike will fell very limp. Even my HP4 on road gearing feels very average. The ideal gearing will be something that allows you to use the "right gear" at the "right RPM" for a given corner exit without running out of RPM on the straights and importantly using as many gears as possible without needing to use them for tenths of second. See its not really straightforward.
We carry 15, 16 and 17 fronts with 42,43,44,45,46 rears for the HP4s and have already used most of them in testing !
Rule of thumb says 1 tooth front = 3 tooth rear. Keep in mind wheelbase and chain length requirements.
Personally, I'd start of at -1 +1 which will pep it up no end. You need rpm on a 600 (no midrange) if your riding any turn at <10K rpm it'll be as flat as a witches tit when you crack the throttle at the apex.
Finally, make sure its on a 520 chain and sprocket - its makes a big difference.
Quote from: Millhouse on March 28, 2014, 08:08:07 AM
Notes from my gearing changes on my b1...
14/42 at snett was too low (revving out on back straight)
14/42 was too low at cadwell for 2nd gear through hall bends
14/40 too high at Donny, 2nd gear bogging down out of Melbourne loop.
Why do I suddenly get the feeling you have been taking this trackday thing far more seriously than you were letting on?
(http://www.quickmeme.com/img/c5/c595586b491836bb2135fb603c2f4e5997ce0e2f8e41c30a81af650f568eaff8.jpg)
Quote from: mc101 on March 28, 2014, 08:49:02 AM
Quote from: 1-600-matt on March 27, 2014, 11:28:00 PM
I have never changed sprockets on any of my bikes, but at Cartagena I swapped bikes with my mate for a session and his bike got a bit more drive out of corners, he said mine was lacking a bit of drive (I have a stock B1). Does it help much to change gearing?
If so what ratio suits the majority of tracks as the bike will only do trackdays? I got a 45 rear sprocket with the set of wheels I got for wets, which would be +5 over the standard rear, I can give it a try out to see the difference, but just wanted some opinions on whether it's worthwhile and what ratio is best?
Cheers.
Everything is a compromise to some degree.
Stock gearing will not be much good for track use, the bike will fell very limp. Even my HP4 on road gearing feels very average. The ideal gearing will be something that allows you to use the "right gear" at the "right RPM" for a given corner exit without running out of RPM on the straights and importantly using as many gears as possible without needing to use them for tenths of second. See its not really straightforward.
We carry 15, 16 and 17 fronts with 42,43,44,45,46 rears for the HP4s and have already used most of them in testing !
Rule of thumb says 1 tooth front = 3 tooth rear. Keep in mind wheelbase and chain length requirements.
Personally, I'd start of at -1 +1 which will pep it up no end. You need rpm on a 600 (no midrange) if your riding any turn at <10K rpm it'll be as flat as a witches tit when you crack the throttle at the apex.
Finally, make sure its on a 520 chain and sprocket - its makes a big difference.
Cheers mark. As it works out -1 front is exactly the same as +3 rear... I have a spreadsheet!!
The question of geometry is my reluctance to change gearing, I will need some links in the chain to keep the back wheel where it currently is set. Putting in the +5 rear will move the rear wheel forward putting weight on the rear and taking weight off the front making it more likely to wheelie on corner exit, on the plus side it may help keep the rear in line on down shift.
But it seems that stock gearing is universally considered not to be the best for the track.
As for 520 chain, the B1 has a 520 chain as standard as far as I'm aware. But sounds like I need to get a few gears and some links for the chain so I can set the rear wheel in the swing arm where I want it.
I need to have a look at the chain and sprockets anyhow as they are all originals with 16k miles on the clock.
Cheers all.
Quote from: 1-600-matt on March 28, 2014, 03:43:23 PM
Quote from: mc101 on March 28, 2014, 08:49:02 AM
Quote from: 1-600-matt on March 27, 2014, 11:28:00 PM
I have never changed sprockets on any of my bikes, but at Cartagena I swapped bikes with my mate for a session and his bike got a bit more drive out of corners, he said mine was lacking a bit of drive (I have a stock B1). Does it help much to change gearing?
If so what ratio suits the majority of tracks as the bike will only do trackdays? I got a 45 rear sprocket with the set of wheels I got for wets, which would be +5 over the standard rear, I can give it a try out to see the difference, but just wanted some opinions on whether it's worthwhile and what ratio is best?
Cheers.
Everything is a compromise to some degree.
Stock gearing will not be much good for track use, the bike will fell very limp. Even my HP4 on road gearing feels very average. The ideal gearing will be something that allows you to use the "right gear" at the "right RPM" for a given corner exit without running out of RPM on the straights and importantly using as many gears as possible without needing to use them for tenths of second. See its not really straightforward.
We carry 15, 16 and 17 fronts with 42,43,44,45,46 rears for the HP4s and have already used most of them in testing !
Rule of thumb says 1 tooth front = 3 tooth rear. Keep in mind wheelbase and chain length requirements.
Personally, I'd start of at -1 +1 which will pep it up no end. You need rpm on a 600 (no midrange) if your riding any turn at <10K rpm it'll be as flat as a witches tit when you crack the throttle at the apex.
Finally, make sure its on a 520 chain and sprocket - its makes a big difference.
Cheers mark. As it works out -1 front is exactly the same as +3 rear... I have a spreadsheet!!
The question of geometry is my reluctance to change gearing, I will need some links in the chain to keep the back wheel where it currently is set. Putting in the +5 rear will move the rear wheel forward putting weight on the rear and taking weight off the front making it more likely to wheelie on corner exit, on the plus side it may help keep the rear in line on down shift.
But it seems that stock gearing is universally considered not to be the best for the track.
As for 520 chain, the B1 has a 520 chain as standard as far as I'm aware. But sounds like I need to get a few gears and some links for the chain so I can set the rear wheel in the swing arm where I want it.
I need to have a look at the chain and sprockets anyhow as they are all originals with 16k miles on the clock.
Cheers all.
Lets be clear - stock gearing is not for track use. A road bike with track gearing would get severely on your tits in a few dozen miles of road work.
I'd not worry about the wheelbase unless you front club running fast. Most people cant tell the difference in a bikes handling shortest to longest wheelbase - there is a difference but on stock suspension you'd be hard pressed to spot it significantly unless your seriously pressing on. Geometry (trail and rake) would be much more noticable to most track day'ers.
Don't over analyze, change the gearing in small increments and try it. If its more prone to wheelie that you dont feel comfortable with adjust your riding to suit and use your weight more or dab the rear brake to kill it off.
That needs a new chain. So fix the chain length problem when you change.
The +5 won't fit in with the current chain, I don't think there will be enough adjustment.
So looks like a new chain is in order along with a couple of sprockets.
Is there a favoured brand or brands?
Also, the wr250 chain is looking decidedly knackered. Any recommendations for chain and sprockets for an off-road bike?
Cheers.
Quote from: 1-600-matt on April 02, 2014, 12:11:00 AM
The +5 won't fit in with the current chain, I don't think there will be enough adjustment.
So looks like a new chain is in order along with a couple of sprockets.
Is there a favoured brand or brands?
Also, the wr250 chain is looking decidedly knackered. Any recommendations for chain and sprockets for an off-road bike?
Cheers.
Rental sprockets, tsubaki pro race chain...
Quote from: mc101 on April 02, 2014, 10:37:34 PM
Quote from: 1-600-matt on April 02, 2014, 12:11:00 AM
The +5 won't fit in with the current chain, I don't think there will be enough adjustment.
So looks like a new chain is in order along with a couple of sprockets.
Is there a favoured brand or brands?
Also, the wr250 chain is looking decidedly knackered. Any recommendations for chain and sprockets for an off-road bike?
Cheers.
Rental sprockets, tsubaki pro race chain...
Cheers mark.