SetUp - Race Reps versus Heavy Weight Bikes - ZRX1200
Discussion
Spoke to previous owner, good friend, he reckons 5W fork oil and air gap 160mm???
Tried to tweak rider sag front and rear as advised.
Forks:
Maximum rider sag possible - no preload - 58mm - 55mm = 1 1/2 turns in from fully out.
Shocks:
Tried backing off preload monitoring shock rod but despite lots of adjustment could not get it below 30 out of 90 so reverted to the standard way of measuring - vertical above rear axle to tape suitably positioned. Max rider sag, minimum preload, 43mm, so tweaked to 40mm.
It would appear measuring rider sag using shock rod unreliable just good for monitoring useage.
A difference of 15mm between front and rear must be too much - took bike out before it got too dark - felt every bump, bouncing about all over the place, unstable on the bends - nightmare. Definitely a backward step - cannot increase rear rider sag perhaps reduce front back down to 45mm?
Tried to tweak rider sag front and rear as advised.
Forks:
Maximum rider sag possible - no preload - 58mm - 55mm = 1 1/2 turns in from fully out.
Shocks:
Tried backing off preload monitoring shock rod but despite lots of adjustment could not get it below 30 out of 90 so reverted to the standard way of measuring - vertical above rear axle to tape suitably positioned. Max rider sag, minimum preload, 43mm, so tweaked to 40mm.
It would appear measuring rider sag using shock rod unreliable just good for monitoring useage.
A difference of 15mm between front and rear must be too much - took bike out before it got too dark - felt every bump, bouncing about all over the place, unstable on the bends - nightmare. Definitely a backward step - cannot increase rear rider sag perhaps reduce front back down to 45mm?
Steve Bass said:
Where are you measuring the 43mm? Above the axle or on the shock?
Typically, rear suspension travel is around 130mm so 43mm isn't too far out of the ballpark. IS your preload adjuster full in or full out in the rear to achieve the 43mm?
Having discovered the hard way that using coil strut unreliable - reverted back to correct way above axle to point marked by tape on seat, directly above.Typically, rear suspension travel is around 130mm so 43mm isn't too far out of the ballpark. IS your preload adjuster full in or full out in the rear to achieve the 43mm?
Reduced preload until could not increase rider sag any more and it would appear the coils were not far from no longer being held in place securely.
Coils are very easy to remove on these shocks, no compressor required just wind out preload until coil loose enough to come away from lower support which is then removed and coil then dropped off below. in reverse position coil with support underneath and wind preload until trapped by adjusting ring above and lower support.
Very busy this weekend especially Saturday and missus needed a day out today so got to the bike late today.
First thing sorted today - noticed height adjusted on Ohlins so took them back down to factory settings do not want to take a chance with geometry.
Measured rear shock coils weight off - 230 mm as per spec, then refitted and wound preload on reduced length by 10mm. Strangely that released another 13mm rider sag at rear now max available 56mm - adjusted to 45mm.
Left rebounds front and rear at one third available and set compressions to 50%. Get out on the bike tomorrow.
First thing sorted today - noticed height adjusted on Ohlins so took them back down to factory settings do not want to take a chance with geometry.
Measured rear shock coils weight off - 230 mm as per spec, then refitted and wound preload on reduced length by 10mm. Strangely that released another 13mm rider sag at rear now max available 56mm - adjusted to 45mm.
Left rebounds front and rear at one third available and set compressions to 50%. Get out on the bike tomorrow.
First run felt what can only be described as soggy, wallowing around bends the only bonus was that, despite feeling every bump, it was soft enough to be comfortable. The only time ridden it softer was when I removed all damping as an experiment - bouncy castle.
Next run I also tweaked rebound damping to 50% - started to be uncomfortable again all the bumps. Tweaked rebound back down to third available and then increased compression from 50 to 75% - awful over the bumps.
Next run I also tweaked rebound damping to 50% - started to be uncomfortable again all the bumps. Tweaked rebound back down to third available and then increased compression from 50 to 75% - awful over the bumps.
Roads are so uneven round here that comfort with sufficient control and confidence around the bends is key for me. Enjoyment for me riding bikes revolves around bends - straight bits are only stretches of road that link bends. I have the greatest trouble trying to work out what is causing my woes so of course, you ate right, only methodical route stands a chance its just knowing which direction and which adjustment to make.
Another two hours of daylight taken advantage of today. First warm up run, with two gallons fuel added, with rebound(R) and compression(C) settings front(F)/shocks(S) 50%, followed by runs as below:
............. Front..................................,Shocks..............
(R)Out of 15...(C)Out of 18....(R)Out of 60.......(C)Out of 24.
(F)(R)..........(F)(C)...........(S)(R)..............(S)(C)
8................. 9 ................ 30.................... 12 Initial run, v bumpy,bouncy cornering.
6................. 9 ................ 22.................... 12 Much worse, v uncomfortable thru bars.
7................. 9................. 26.................... 12 A little better but perty poor.
12.................9................. 46.................... 12 Better but not great.
12.................7................. 46.................... 11 Definitely improved - last run of day.
Initial rebound experiments not good reversed plus changed direction, small gain, needed compression tweek to feel better. Front definitely pings back at some rate after braking will revisit perhaps increase damping midrange between 50% and 12 clicks out. Last run felt more balanced over long bumps, appeared to rise and fall closer together. More work to come. Looks like big changes but Ohlins have huge adjustments possible so have tried to scale small changes on front to match.
............. Front..................................,Shocks..............
(R)Out of 15...(C)Out of 18....(R)Out of 60.......(C)Out of 24.
(F)(R)..........(F)(C)...........(S)(R)..............(S)(C)
8................. 9 ................ 30.................... 12 Initial run, v bumpy,bouncy cornering.
6................. 9 ................ 22.................... 12 Much worse, v uncomfortable thru bars.
7................. 9................. 26.................... 12 A little better but perty poor.
12.................9................. 46.................... 12 Better but not great.
12.................7................. 46.................... 11 Definitely improved - last run of day.
Initial rebound experiments not good reversed plus changed direction, small gain, needed compression tweek to feel better. Front definitely pings back at some rate after braking will revisit perhaps increase damping midrange between 50% and 12 clicks out. Last run felt more balanced over long bumps, appeared to rise and fall closer together. More work to come. Looks like big changes but Ohlins have huge adjustments possible so have tried to scale small changes on front to match.
Edited by oldninjaron on Wednesday 30th September 07:23
Edited by oldninjaron on Wednesday 30th September 08:17
Edited by oldninjaron on Wednesday 30th September 17:01
Edited by oldninjaron on Wednesday 30th September 17:01
Edited by oldninjaron on Wednesday 30th September 17:02
Edited by oldninjaron on Wednesday 30th September 17:09
Edited by oldninjaron on Wednesday 30th September 21:14
Edited by oldninjaron on Friday 2nd October 07:09
Edited by oldninjaron on Friday 2nd October 07:09
Edited by oldninjaron on Friday 2nd October 07:10
Edited by oldninjaron on Friday 2nd October 07:11
Edited by oldninjaron on Sunday 4th October 21:53
Two hours again, warmed up with settings from yesterday, thankfully still promising.
............. Front..................................,Shocks..............
(R)Out of 15......(C)Out of 18.......(R)Out of 60..........(C)Out of 24.
(F)(R)...............(F)(C)...............(S)(R)................(S)(C)
12................... 7 ................ ....46.................... 11 Initial warm up run - still fine.
11................ ...7 ................ ....42.................... 11 Instantly uncomfortable - reversed.
12................ ...6 ................ ....46.................... 10 Any balance prior gone - bad.
12................... 7 ................ ....46.................... 10 Unstable.
12................... 7 ................ ....46.................... 11 Back to start.
11................... 7 ................ ....46.................... 11 Not as good as start, back to start
After yesterday felt optimistic, felt on the flat sharp bumps felt softer and longer bumps felt front and rear close to rising and falling together - still felt pretty soft. My main concern is the bumpy bend once you a hit a bump it sends the bike into some sort of oscillation almost wallowing - not sure whether it is side to side or even back and forward then settles. It looks like happy with front end quite fast and I have tried to slow down fork compression to see if I can get some control over bumps on corners.
Throughout this challenge I keep trying to get bike front and rear rising and falling at same rate but have rarely managed it in the garage, pressing hard just behind petrol cap - the only time it sort of happens when bouncing on front seat but doubt it is at centre of gravity.
............. Front..................................,Shocks..............
(R)Out of 15......(C)Out of 18.......(R)Out of 60..........(C)Out of 24.
(F)(R)...............(F)(C)...............(S)(R)................(S)(C)
12................... 7 ................ ....46.................... 11 Initial warm up run - still fine.
11................ ...7 ................ ....42.................... 11 Instantly uncomfortable - reversed.
12................ ...6 ................ ....46.................... 10 Any balance prior gone - bad.
12................... 7 ................ ....46.................... 10 Unstable.
12................... 7 ................ ....46.................... 11 Back to start.
11................... 7 ................ ....46.................... 11 Not as good as start, back to start
After yesterday felt optimistic, felt on the flat sharp bumps felt softer and longer bumps felt front and rear close to rising and falling together - still felt pretty soft. My main concern is the bumpy bend once you a hit a bump it sends the bike into some sort of oscillation almost wallowing - not sure whether it is side to side or even back and forward then settles. It looks like happy with front end quite fast and I have tried to slow down fork compression to see if I can get some control over bumps on corners.
Throughout this challenge I keep trying to get bike front and rear rising and falling at same rate but have rarely managed it in the garage, pressing hard just behind petrol cap - the only time it sort of happens when bouncing on front seat but doubt it is at centre of gravity.
Edited by oldninjaron on Wednesday 30th September 21:46
Edited by oldninjaron on Thursday 1st October 22:43
Edited by oldninjaron on Friday 2nd October 07:15
Work got in the way today so only had one hour of daylight available.
Testing the theory that my front end instability on bouncy bends could be down to too much compression damping at the forks:
(F)(R)Of 15......(F)(C)Of 18.........(S)(R)Of 60.......(S)(C)Of 24
12................... 7 ................ ....46.................... 11 Start
12................... 14................ ....46.................... 18 Felt much improved on bends.
12................... 7 ................ ....46.................... 19 Could be slightly better, rear harsh.
Tomorrow fuel top up need to see if that has an effect but promising - went for large change (C) front and rear as limited time for runs - pleased with results so far, plenty adjustment to try between start and finish settings.
Testing the theory that my front end instability on bouncy bends could be down to too much compression damping at the forks:
(F)(R)Of 15......(F)(C)Of 18.........(S)(R)Of 60.......(S)(C)Of 24
12................... 7 ................ ....46.................... 11 Start
12................... 14................ ....46.................... 18 Felt much improved on bends.
12................... 7 ................ ....46.................... 19 Could be slightly better, rear harsh.
Tomorrow fuel top up need to see if that has an effect but promising - went for large change (C) front and rear as limited time for runs - pleased with results so far, plenty adjustment to try between start and finish settings.
Edited by oldninjaron on Friday 2nd October 07:08
Edited by oldninjaron on Friday 2nd October 07:12
Edited by oldninjaron on Saturday 3rd October 09:03
After previous days successes needed to check not upset by filling up tank - needed 3 gallons this time out of 5, putting in some mileage and time here. Forks still relatively stable on bumpy corners, thankfully.
Checked rider sag on forks just out of interest - reduced to 51mm, since last measurement despite fuel up, got to be red herring. Check it again when I have a mo - without damping.
Last night as still a bit harsh at rear, reduced shock(S) compression(C) bit by bit, working on assumption if rear too slow hitting the bumps rather than absorbing them on compression?
(F)(R)Of 15......(F)(C)Of 18.........(S)(R)Of 60.......(S)(C)Of 24
12................... 14 ................ ....46....................19 Start
12................... 14................ ....46.................... 20 Upsetting stability
12................... 14 ................ ...46.................... 21 Worse.
12................... 14 ................ ....46....................19 Back to start.
Unless I am missing something here, I seemed to have reached limit of compression damping at rear unless I need to reduce front even more, as well to attempt to maintain stability but with 18 clicks available forks and 24 shocks, always going to be a suck it and see experiment. "Telltails" on forks and shocks indicate a good 40mm available forks, still not sure if internal stops fitted, 10mm above shock stop.
Hopefully later today going to decrease some rebound damping on rear as rear still feels harsh, not sure if rear is squatting causing front to ride higher, may have to reduce fork rebound damping also to maintain stability?
More ramblings from a fella who is prone to learn the hard way tomorrow all going well - keeping shiny side up and as much rubber on the deck as possible.
Checked rider sag on forks just out of interest - reduced to 51mm, since last measurement despite fuel up, got to be red herring. Check it again when I have a mo - without damping.
Last night as still a bit harsh at rear, reduced shock(S) compression(C) bit by bit, working on assumption if rear too slow hitting the bumps rather than absorbing them on compression?
(F)(R)Of 15......(F)(C)Of 18.........(S)(R)Of 60.......(S)(C)Of 24
12................... 14 ................ ....46....................19 Start
12................... 14................ ....46.................... 20 Upsetting stability
12................... 14 ................ ...46.................... 21 Worse.
12................... 14 ................ ....46....................19 Back to start.
Unless I am missing something here, I seemed to have reached limit of compression damping at rear unless I need to reduce front even more, as well to attempt to maintain stability but with 18 clicks available forks and 24 shocks, always going to be a suck it and see experiment. "Telltails" on forks and shocks indicate a good 40mm available forks, still not sure if internal stops fitted, 10mm above shock stop.
Hopefully later today going to decrease some rebound damping on rear as rear still feels harsh, not sure if rear is squatting causing front to ride higher, may have to reduce fork rebound damping also to maintain stability?
More ramblings from a fella who is prone to learn the hard way tomorrow all going well - keeping shiny side up and as much rubber on the deck as possible.
Edited by oldninjaron on Saturday 3rd October 23:23
(F)(R)Of 15......(F)(C)Of 18.........(S)(R)Of 60.......(S)(C)Of 24
12................... 14 ................ ....46....................19---Start
12................... 14................. ....50....................19---Feels riding higher at rear, not too ......................................................................-------bouncy, might be something in this?
11................... 14 ................ ....50.................... 21--Interesting, flighty at front, too .......................................................................------much rebound?
12................... 14 ................ ....49....................19---Unstable?
12....................14......................48....................19---Worse, bouncy cornering
12................... 14................ .....50....................19---Try first change again.
12................... 14 ................ ....46....................19---Start
12................... 14................. ....50....................19---Feels riding higher at rear, not too ......................................................................-------bouncy, might be something in this?
11................... 14 ................ ....50.................... 21--Interesting, flighty at front, too .......................................................................------much rebound?
12................... 14 ................ ....49....................19---Unstable?
12....................14......................48....................19---Worse, bouncy cornering
12................... 14................ .....50....................19---Try first change again.
Edited by oldninjaron on Sunday 4th October 08:43
What a strange challenge this has been, things have not necessarily turned out quite as expected - perhaps a lot of preconceptions or misconceptions. I am not saying that bike is perfect but its not bad at all. Made a few adjustments today before the weather broke.
............. Front..................................,Shocks..............
(R)Out of 15...(C)Out of 18....(R)Out of 60.......(C)Out of 24.
(F)(R)..........(F)(C)...........(S)(R)...................(S)(C)
12................14 ................ 46.................... 19 Initial run.
12................14 ................ 50.................... 19 An improvement.
12................14................. 51.................... 19 It gets better.
13................14................. 51.................... 19
It could be some time before next run but need to run with this for now. If settle on this I will be amazed at just how little damping required?
............. Front..................................,Shocks..............
(R)Out of 15...(C)Out of 18....(R)Out of 60.......(C)Out of 24.
(F)(R)..........(F)(C)...........(S)(R)...................(S)(C)
12................14 ................ 46.................... 19 Initial run.
12................14 ................ 50.................... 19 An improvement.
12................14................. 51.................... 19 It gets better.
13................14................. 51.................... 19
It could be some time before next run but need to run with this for now. If settle on this I will be amazed at just how little damping required?
Edited by oldninjaron on Monday 19th October 07:16
Before adjusting forks rebound, given that front end really plush on test route, used Ohlins shock height adjust option at rear - equates to approx 10mm increase of shock length. Only had time for one run did seem to affect turn a little but would need some more time to test.
Got home, wiped off the bugs, but while oiling chain noticed rear tyre in a bit of a mess, looks completely goosed down the centre on a patch approx 1/4 of circumference and about half the width. Tyre has small cracks across the tread perpendicular to wheel travel!!!!
Current tyre Metzeler Roadtec Z8 190/50 ZR17, inherited from previous owner on a 6in wheel - standard normally 5.5. I have a 190/55 ZR17 of same make and model - I have know idea why he fitted 190/50 rather than 190/55 because standard on 5.5 wheel is 180/55. I am sure this will affect how bike handles anyway just based on its shape and height.
One thing I did notice, although predictable for some time, is how bike handles round slow bends over bumps, feels like front is bouncing side to side - I could be wrong but particularly noticeable round right handers - equal settings left and right forks, fork brace fitted, equal standard heights fitted in triple trees - now that does bug me????
Got home, wiped off the bugs, but while oiling chain noticed rear tyre in a bit of a mess, looks completely goosed down the centre on a patch approx 1/4 of circumference and about half the width. Tyre has small cracks across the tread perpendicular to wheel travel!!!!
Current tyre Metzeler Roadtec Z8 190/50 ZR17, inherited from previous owner on a 6in wheel - standard normally 5.5. I have a 190/55 ZR17 of same make and model - I have know idea why he fitted 190/50 rather than 190/55 because standard on 5.5 wheel is 180/55. I am sure this will affect how bike handles anyway just based on its shape and height.
One thing I did notice, although predictable for some time, is how bike handles round slow bends over bumps, feels like front is bouncing side to side - I could be wrong but particularly noticeable round right handers - equal settings left and right forks, fork brace fitted, equal standard heights fitted in triple trees - now that does bug me????
50 BHP more - now that would be heavily modded engine.
My Spec:
ZZR1200: Cams, valve springs, pistons and barrels.
ZZR1100D: Igniter, carbs and six speed gear box.
Skimmed head, lightened balanced crank.
Akropovic headers connected to twin, GSXR1000, Arrows cans.
Maxton modded forks, Ohlins shocks.
6 in rear wheel - ZX7R sourced.
Nissin 4 pots front.
ZX9R front mudguard.
Apparently 147 BHP at rear wheel - but this was according to previous owner - he has a newer ZRX12 with very similiar spec. All the mods make it as useful low down as a ZZR12/11 but eyeball vibrating stomp in theory, IMHO, all the way up to approx 11500 revs and thats without RAM air. It has immense torque so cracking top gear roll on and people wonder why I need it to handle. She is still pretty heavy though.
My Spec:
ZZR1200: Cams, valve springs, pistons and barrels.
ZZR1100D: Igniter, carbs and six speed gear box.
Skimmed head, lightened balanced crank.
Akropovic headers connected to twin, GSXR1000, Arrows cans.
Maxton modded forks, Ohlins shocks.
6 in rear wheel - ZX7R sourced.
Nissin 4 pots front.
ZX9R front mudguard.
Apparently 147 BHP at rear wheel - but this was according to previous owner - he has a newer ZRX12 with very similiar spec. All the mods make it as useful low down as a ZZR12/11 but eyeball vibrating stomp in theory, IMHO, all the way up to approx 11500 revs and thats without RAM air. It has immense torque so cracking top gear roll on and people wonder why I need it to handle. She is still pretty heavy though.
Gassing Station | Biker Banter | Top of Page | What's New | My Stuff