Wow and LOL.
|
|
|
Trial & Error - Playing with my CBR600RRA suspension
- Thread starter dragenn
- Start date
Wow and LOL.
Caboose - At this point no names. You guys are out for blood and that just the end of it. Just know he has built many custom bikes of ALL types, has his own top tier drag bike, and services his own team of track bikes. He got more then enough experience to set me right. He did my previous bike and it was great. If he has advice im taking over you guys any day, no offense but ive seen his roaster already. Im on good term with him ( note to some members, if you find a good mechanic pay him well. It work in your favour over time ), and l always have a list of question when l see him. I just dont call him up on a whim to bother him. It's out of respect for his time. So expect me to talk about this en devour. I just wont mention any of your names out of respect too.
So on with a mini update.
If you want the biggest bang for buck. It'll have to definitely be a good set of tires. So for the members that brought that to my immediate attention, take a bow. You some good advice to pass on. Fighting with my suspension to make up a mediocre set of tires, took more a lot of effort and didnt automatically fix my issues. I also will "observe" never mismatch your tires, for what you save in cash expect to lose in handling. I got my bike from a stealership so l happen to come across a strange combination, not to mention overly glossy tires that are annoying to break in.
On the other hand a good set up will keep the wheels planted properly giving you more confidence in what you do. Before putting the bike away l soften the preload and compression damping and managed to get the bike feeling better. In retrospect l figured a stiffer set up would help me ride the bike harder, but l went a little too stiff. I can also confirm one setting at a time helps. It's easy to read what you did wrong.
So on with a mini update.
If you want the biggest bang for buck. It'll have to definitely be a good set of tires. So for the members that brought that to my immediate attention, take a bow. You some good advice to pass on. Fighting with my suspension to make up a mediocre set of tires, took more a lot of effort and didnt automatically fix my issues. I also will "observe" never mismatch your tires, for what you save in cash expect to lose in handling. I got my bike from a stealership so l happen to come across a strange combination, not to mention overly glossy tires that are annoying to break in.
On the other hand a good set up will keep the wheels planted properly giving you more confidence in what you do. Before putting the bike away l soften the preload and compression damping and managed to get the bike feeling better. In retrospect l figured a stiffer set up would help me ride the bike harder, but l went a little too stiff. I can also confirm one setting at a time helps. It's easy to read what you did wrong.
Here's a quick trouble shooting guide. There easy to find and follow once you start to get a hang of the typical terminology you'll have to learn to progress.
Lack of Rebound
Symptoms:
• Forks are plush, but increasing speed causes loss of control and traction
• The motorcycle wallows and tends to run wide exiting the turn causing fading traction and loss of control.
• When taking a corner a speed, you experience front-end chatter, loss of traction and control.
• Aggressive input at speed lessons control and chassis attitude suffers.
• Front end fails to recover after aggressive input over bumpy surfaces.
Solution: Insufficient rebound. Increase rebound "gradually" until control and traction are optimized and chatter is gone.
Too Much Rebound
Symptoms:
• Front end feels locked up resulting in harsh ride.
• Suspension tucks in and fails to return, giving a harsh ride. Typically after the first bump, the bike will skip over subsequent bumps and want to tuck the front.
• With acceleration, the front end will tank slap or shake violently due to lack of front wheel tire contact.
Solution: Too much rebound. Decrease rebound "gradually" until control and traction are optimized.
Lack of Compression
Symptoms:
• Front-end dives severely, sometimes bottoming out over heavy bumps or during aggressive breaking.
• Front feels soft or vague similar to lack of rebound.
• When bottoming, a clunk is heard. This is due to reaching the bottom of fork travel.
Solution: Insufficient compression. Increase "gradually" until control and traction are optimized.
Too Much Compression
Symptom:
• Front end rides high through the corners, causing the bike to steer wide. It should maintain the pre-determined sag, which will allow the steering geometry to remain constant.
Solution: Decrease compression "gradually" until bike neither bottoms nor rides high.
Symptom:
• Front end chatters or shakes entering turns. This is due to incorrect oil height and/or too much low speed compression damping.
Solution: First, verify that oil height is correct. If correct, then decrease compression "gradually" until chattering and shaking ceases.
Symptom:
• Bumps and ripples are felt directly in the triple clamps and through the chassis. This causes the front wheel to bounce over bumps.
Solution: Decrease compression "gradually" until control is regained.
Symptom:
• Ride is generally hard, and gets even harder when braking or entering turns.
Solution: Decrease compression "gradually" until control is regained.
Adjustment Locations: Rear Shock
Rebound adjustment (if applicable) is located at the bottom of the shock. Compression adjustment (if applicable) is located on the reservoir. Spring prelude is located at the top of the shock.
Shock: Lack of Rebound
Symptoms:
• The ride will feel soft or vague and as speed increases, the rear end will want to wallow and/or weave over bumpy surfaces and traction suffers.
• Loss of traction will cause rear end to pogo or chatter due to shock returning too fast on exiting a corner.
Solution: Insufficient rebound - Increase rebound until wallowing and weaving disappears and control and traction are optimized.
Shock: Too Much Rebound
Symptoms:
• Ride is harsh, suspension control is limited and traction is lost.
• Rear end will pack in, forcing the bike wide in corners, due to rear squat. It will slow steering because front end is riding high.
• When rear end packs in, tires generally will overheat and will skip over bumps.
• When chopping throttle, rear end will tend to skip or hop on entries.
Solution: Too much rebound. Decrease rebound "gradually" until harsh ride is gone and traction is regained. Decrease rebound to keep rear end from packing.
Shock: Lack of Compression
Symptoms:
• The bike will not turn in entering a turn.
• With bottoming, control and traction are lost.
• With excessive rear end squat, when accelerating out of corners, the bike will tend to steer wide.
Solution: Insufficient compression. Increase compression "gradually until traction and control is optimized and/or excessive rear end squat is gone.
Shock: Too Much Compression
Symptoms:
• Ride is harsh, but not as bad as too much rebound. As speed increases, so does harshness.
• There is very little rear end squat. This will cause loss of traction/sliding. Tire will overheat.
• Rear end will want to kick when going over medium to large bumps.
Solution: Decrease compression until harshness is gone. Decrease compression until sliding stops and traction is regained.
Mark Thompson has spent the past 20 years racing motorcycles and managing Race teams and riders. He now runs the Trackbikes Website along with a number on Internet Ventures
Lack of Rebound
Symptoms:
• Forks are plush, but increasing speed causes loss of control and traction
• The motorcycle wallows and tends to run wide exiting the turn causing fading traction and loss of control.
• When taking a corner a speed, you experience front-end chatter, loss of traction and control.
• Aggressive input at speed lessons control and chassis attitude suffers.
• Front end fails to recover after aggressive input over bumpy surfaces.
Solution: Insufficient rebound. Increase rebound "gradually" until control and traction are optimized and chatter is gone.
Too Much Rebound
Symptoms:
• Front end feels locked up resulting in harsh ride.
• Suspension tucks in and fails to return, giving a harsh ride. Typically after the first bump, the bike will skip over subsequent bumps and want to tuck the front.
• With acceleration, the front end will tank slap or shake violently due to lack of front wheel tire contact.
Solution: Too much rebound. Decrease rebound "gradually" until control and traction are optimized.
Lack of Compression
Symptoms:
• Front-end dives severely, sometimes bottoming out over heavy bumps or during aggressive breaking.
• Front feels soft or vague similar to lack of rebound.
• When bottoming, a clunk is heard. This is due to reaching the bottom of fork travel.
Solution: Insufficient compression. Increase "gradually" until control and traction are optimized.
Too Much Compression
Symptom:
• Front end rides high through the corners, causing the bike to steer wide. It should maintain the pre-determined sag, which will allow the steering geometry to remain constant.
Solution: Decrease compression "gradually" until bike neither bottoms nor rides high.
Symptom:
• Front end chatters or shakes entering turns. This is due to incorrect oil height and/or too much low speed compression damping.
Solution: First, verify that oil height is correct. If correct, then decrease compression "gradually" until chattering and shaking ceases.
Symptom:
• Bumps and ripples are felt directly in the triple clamps and through the chassis. This causes the front wheel to bounce over bumps.
Solution: Decrease compression "gradually" until control is regained.
Symptom:
• Ride is generally hard, and gets even harder when braking or entering turns.
Solution: Decrease compression "gradually" until control is regained.
Adjustment Locations: Rear Shock
Rebound adjustment (if applicable) is located at the bottom of the shock. Compression adjustment (if applicable) is located on the reservoir. Spring prelude is located at the top of the shock.
Shock: Lack of Rebound
Symptoms:
• The ride will feel soft or vague and as speed increases, the rear end will want to wallow and/or weave over bumpy surfaces and traction suffers.
• Loss of traction will cause rear end to pogo or chatter due to shock returning too fast on exiting a corner.
Solution: Insufficient rebound - Increase rebound until wallowing and weaving disappears and control and traction are optimized.
Shock: Too Much Rebound
Symptoms:
• Ride is harsh, suspension control is limited and traction is lost.
• Rear end will pack in, forcing the bike wide in corners, due to rear squat. It will slow steering because front end is riding high.
• When rear end packs in, tires generally will overheat and will skip over bumps.
• When chopping throttle, rear end will tend to skip or hop on entries.
Solution: Too much rebound. Decrease rebound "gradually" until harsh ride is gone and traction is regained. Decrease rebound to keep rear end from packing.
Shock: Lack of Compression
Symptoms:
• The bike will not turn in entering a turn.
• With bottoming, control and traction are lost.
• With excessive rear end squat, when accelerating out of corners, the bike will tend to steer wide.
Solution: Insufficient compression. Increase compression "gradually until traction and control is optimized and/or excessive rear end squat is gone.
Shock: Too Much Compression
Symptoms:
• Ride is harsh, but not as bad as too much rebound. As speed increases, so does harshness.
• There is very little rear end squat. This will cause loss of traction/sliding. Tire will overheat.
• Rear end will want to kick when going over medium to large bumps.
Solution: Decrease compression until harshness is gone. Decrease compression until sliding stops and traction is regained.
Mark Thompson has spent the past 20 years racing motorcycles and managing Race teams and riders. He now runs the Trackbikes Website along with a number on Internet Ventures
Good.
It seems like you might finally be directing your questions to the right person.
Like l said, l've compiled a decent list of things to ask, and was "brutally corrected" via this forums. He got more patience and understanding when dealing with me because l listen and he knows im no pro. I dont go often so l wanted some practical experience as well, so l can relate easier to what he'll have to say.
Well, it might not have been pretty, but it looks like you are on a path of getting someone more knowledgeable to help you out, and that's good. The troubleshooting symptom guide that you posted is good, also, just be aware that there are more things to adjust than just the damping.
Rear ride height affects (directly) the swingarm pivot height, which affects the swingarm down-angle, and that affects the amount of anti-squat that the rear suspension provides when accelerating out of a corner.
Not enough rear ride height/not enough swingarm down-angle/not enough swingarm pivot height are all different ways of saying the same thing, and the effect is lack of rear traction when rolling on the throttle while leaned way over. Generally only meaningful when riding on the track, but WHEN you take the bike to the track, boy does this ever matter (and it's one of the reasons that I never recommend for anyone to lower their suspension).
Too much rear ride-height/down-angle/swingarm pivot height wants to make the front wash out when accelerating out of a corner. It's causing the front end to lose grip.
Front ride height too high leads to heavy steering and makes the bike want to stand up mid-corner. Front ride height too low leads to instability and the bike wants to fall in (and slide out). The rear ride heights affect this, too, but when you combine the need for rear anti-squat with the need for a certain rake/trail combination for the tires that you are using, it ends up that there is only one solution for a given set of tires - the combination of front and rear ride heights that gives correct anti-squat and the correct rake and trail for the front end for the tires that you are using. Changing the tires will change this because of the different profile ...
Then there's trail (triple clamp offset), then there's spring rates, then there's the balance between front spring rate and oil level in the forks, and on and on and on ... It ain't simple ...
Rear ride height affects (directly) the swingarm pivot height, which affects the swingarm down-angle, and that affects the amount of anti-squat that the rear suspension provides when accelerating out of a corner.
Not enough rear ride height/not enough swingarm down-angle/not enough swingarm pivot height are all different ways of saying the same thing, and the effect is lack of rear traction when rolling on the throttle while leaned way over. Generally only meaningful when riding on the track, but WHEN you take the bike to the track, boy does this ever matter (and it's one of the reasons that I never recommend for anyone to lower their suspension).
Too much rear ride-height/down-angle/swingarm pivot height wants to make the front wash out when accelerating out of a corner. It's causing the front end to lose grip.
Front ride height too high leads to heavy steering and makes the bike want to stand up mid-corner. Front ride height too low leads to instability and the bike wants to fall in (and slide out). The rear ride heights affect this, too, but when you combine the need for rear anti-squat with the need for a certain rake/trail combination for the tires that you are using, it ends up that there is only one solution for a given set of tires - the combination of front and rear ride heights that gives correct anti-squat and the correct rake and trail for the front end for the tires that you are using. Changing the tires will change this because of the different profile ...
Then there's trail (triple clamp offset), then there's spring rates, then there's the balance between front spring rate and oil level in the forks, and on and on and on ... It ain't simple ...
Is this why you've been touting what my angles are. Sorry still havent sat down and got around to it. I been way too busy, having trouble getting the boys together, and the weather is ******.
Thats a pretty big chunk to take it. I follow up some research on it. I have taken some initiative to learn the value of proper tire pressure and understanding the mechanic's behind spring rate.
Nice post and l can actually understand what your talking about. SCORE!!!!!!!!!
Except on GSXR's, lol!
I should let you take my 400 for a rip at the next round, you'll see what I mean. You'll probably go off the track on the INSIDE of corner one ...
Background: This is an an endurance-racing situation in which the bike in question is comfortable for its owner but not for the 2nd rider (me), and I suspect that the 3rd rider actually isn't as comfortable on it as she could be if the steering effort were lower. I actually suspect that having lower steering effort would be better for all concerned, but aside from knowing it's somehow related to geometry, this one has me stumped.
I can feel what you mean about the front not wanting to be dropped down on that bike, but the steering is bloody heavy compared to what I'm used to (heavier than my 400, heavier than my ZX10R even with that bike in long-wheelbase drag-racing configuration and with buggered tires on it!) And the GSXR's don't have a reputation for being heavy-steering bikes, either. I spent a track day on one at Calabogie (2004, generation before yours) and I don't recall the steering effort being out of the ordinary. But, the tires were different (still Dunlop, but a different model). The YZF750 that I rode last year in the last endurance race felt like a slightly heavier FZR400 with a lot more power (but again, the tires were different, as was the whole bike).
I have not had a chance to ride my friend's street GSXR of the same generation as yours, thanks to the crap weather.
Tire profile? I know from the ZX10R that I want a pointy sharp-steering front tire profile, and I hated the more rounded BT016's on that bike. I have the UK Dunlop GP Ntec's on the ZX right now, with the 190/55 rear that's meant for the 600's, and those steered and gripped very well at Deals Gap last fall. Michelin Pilot Power has worked well on that bike, too. Never tried Pirelli.
Trail? The "feel" that I get from the FZR is the tire contact patch, the "feel" that I was getting from the GSXR felt like all gyroscopic effect. If this is what's underlying, it's a bugger to change (triple clamps with a different offset - expensive experiment!) and I sure have no way of predicting the outcome of *that*.
For the original poster, this is a snapshot of what goes on behind the scenes at the racetrack ... You'll note that the "clickers" aren't even on the radar screen in this discussion. The tires, and the geometry, and the spring rates and preload settings, all come first ...
|
|
|
|
|