Can excessive fork dive affect braking - Tiger 885

[Frosties]

Hiya fellas,

Looking for some advice on my trusty battleship.
When new, the fork dive on the Tiger ('98 carbs) was described as excessive and still is compared to the Fazer or indeed a modern day adventure style bike like a V Strom thou. This was probably due to the manufacturing era of "these bikes ARE dual purpose". Now whilst I like the fork dive to a degree, mainly because it ensures maximum tyre compression and contact area under a hard panic brake, the dive is excessive and you do get thrown forward a fair degree, not to mention the braking is down on the Fazers ability (110 section tyres, EBC HH pads and braided hoses on both bikes - bur smaller discs on Tiger with additional 40kg weight). Currently over road imperfections it also feels a bit harsh on poor rutted surfaces so wouldn't want to increase this.
Not sure if I have progressives fitted (doubt it) but the oil certainly hasn't been changed in around 30k miles so requires changing soon. The fronts are also non adjustable apart from choice of springs/spacers and oil weight.
The question is - will I gain more braking efficiency if the front is tighter or not. If I won't gain braking power then will leave the springs as is.
Any advice as always much appreciated
Cheers

[nick crisp]

[Noggy-esque post alert!]  :pokefun  :lol

You won't lose braking power with excessive fork dive I don't think. What I think you will have, is more weight transfer to the front, which puts the front tyre under more load, which could be an issue, especially on a poor surface. Suspension is about keeping the tyres in contact with the road. Also, you'll have to brake earlier for corners and give the suspension time to settle before committing with too much dive. I also think the brakes will give you better feel if the suspension is keeping things under control.

I would upgrade, either with fresh/thicker fork oil, and/or better springs, simply because the bike will be much more enjoyable, and somewhat safer to ride than with loads of dive.

Just my thoughts, but always open to learning if I've got it wrong (again  :rolleyes :lol ).

[/Noggy-esque post]

[BBROWN1664]

mainly because it ensures maximum tyre compression and contact area under a hard panic brake

The opposite is true. If the load is being taken care of by the forks, the tyre isn't being planted on the road as hard. Less dive = more load on the tyre as the tyre walls will have to do the flexing instead.

If the front is more stable, you will get more confidence.

[Dead Eye]

I don't know... the force required to compress the suspension has to come from somewhere so I'd say it would have a limited effect on braking - to what degree I have no idea. I don't think it would make a big enough difference in actual braking power, but it may make it feel much better from your perspective. However, I'd expect it to sort of ruin the ride comfort as well...


BBROWN1664 got in there just before me


Nick, only just realised that you posted and not noggy... damn good job on the noggy-ness of your post

[sadlonelygit]

can excessive fork dive affect braking...............no
you have brake discs of a given size and a maximum amount of hydraulic pressure generated by the master cylinder.
what it will affect is the steering (change of trail/rake) and at max compression the ability to absorb a bump shock.
measure the amount of travel used with a cable tie around the fork, if you are using all the travel then either preload the spring or fit a firmer one until you have @15mm travel left after max compression.
but tbh they're a pig on stilts anyway :rollin

[nick crisp]

mainly because it ensures maximum tyre compression and contact area under a hard panic brake

The opposite is true. If the load is being taken care of by the forks, the tyre isn't being planted on the road as hard. Less dive = more load on the tyre as the tyre walls will have to do the flexing instead.

Isn't that a contradiction? (Confused  :\ )

[Frosties]

Pure brilliance lads. :lol ..so who's right then, Nick or BBrown ??

[Noggy-esque post alert!]  :pokefun :lol

What I think you will have, is more weight transfer to the front, which puts the front tyre under more load,
I would upgrade, either with fresh/thicker fork oil, and/or better springs, simply because the bike will be much more enjoyable, and somewhat safer to ride than with loads of dive.

Just my thoughts, but always open to learning if I've got it wrong (again  :rolleyes :lol ).

[/Noggy-esque post]

My thoughts the same re springs and oil  :thumbup

However, BBrown says....

mainly because it ensures maximum tyre compression and contact area under a hard panic brake

The opposite is true. If the load is being taken care of by the forks, the tyre isn't being planted on the road as hard. Less dive = more load on the tyre as the tyre walls will have to do the flexing instead.

If the front is more stable, you will get more confidence.

So we have soft front = weight transfer = more front load . Me & Nick  :pokefun
Less dive = more load. BB  :pokefun
Deade Eye "I don't know... " many thanks for your honesty  :lol

For what it's worth, I can outride most bikes through the twisties on the Tiger better than I can on the Fazer - nice wide bars  :b but am sure spring and oil change will make it even better....certainly don't trim hedges with it 

[Frosties]

can excessive fork dive affect braking...............no
you have brake discs of a given size and a maximum amount of hydraulic pressure generated by the master cylinder.
what it will affect is the steering (change of trail/rake) and at max compression the ability to absorb a bump shock.
measure the amount of travel used with a cable tie around the fork, if you are using all the travel then either preload the spring or fit a firmer one until you have @15mm travel left after max compression.
but tbh they're a pig on stilts anyway :rollin

Makes sense fella.....just couldn't get it straight in  my head. Tend to do all my main braking before a corner and maybe adjust mid corner with rear brake, weight transfer or throttle so mullers those Fazer Thous in the twisties.

Will check the amount of travel I use.

Pig on stilts  :lol :lol . I actually love the look in a [Noggy style] Post apocalyptic, urban survival, cool, ride what you're happy with, everyone's different, you pays your money [End of Nog] way of putting it  :lol

[nick crisp]

[quote author=sadlonelygit link=topic=17525.msg201968#msg201968 date=1435831496]
can excessive fork dive affect braking...............no
you have brake discs of a given size and a maximum amount of hydraulic pressure generated by the master cylinder.
what it will affect is the steering (change of trail/rake) and at max compression the ability to absorb a bump shock.
measure the amount of travel used with a cable tie around the fork, if you are using all the travel then either preload the spring or fit a firmer one until you have @15mm travel left after max compression.
but tbh they're a pig on stilts anyway :rollin

Makes sense fella.....just couldn't get it straight in  my head. Tend to do all my main braking before a corner and maybe adjust mid corner with rear brake, weight transfer or throttle so mullers those Fazer Thous in the twisties. [/quote]

You still get your braking done before committing, even with less dive, but with a well-controlled front set up, you can brake later, harder, and flip it in with everything working to it's optimum still. If you brake and get a lot of dive, and then if you have a low rate of rebound damping, the forks will spring out again when the main braking force is removed, so unsettling the bike, too much movement just as you want to turn in.  ???

Will check the amount of travel I use.

So let me have another stab at this  :rolleyes. Once at full compression, the suspension has no further ability to adjust to keep the tyre on the road, and this is where the tyre risks becoming excessively loaded for the available grip? And I think I get the rake/trail change thing too - compression effectively steepening the steering angle, much like dropping the yokes down the forks, to give quicker turn in. But it still needs more travel available to deal with any bumps etc. So it's a compromise between the two - you need some compression, but it needs to be controlled (damping, spring rate), both in total amount of travel, and rate of travel.

This suspension thing is confusing, but getting the idea that it's about the ability to adjust for different situations, so you can't generalise about one thing or the other. And you can't treat compression damping or too weak springs as an individual thing, but have to look at the whole operation of the various functions of the unit together. This is why I don't mess around with settings myself  :lol

[Frosties]

You still get your braking done before committing, even with less dive, but with a well-controlled front set up, you can brake later, harder, and flip it in with everything working to it's optimum still. If you brake and get a lot of dive, and then if you have a low rate of rebound damping, the forks will spring out again when the main braking force is removed, so unsettling the bike, too much movement just as you want to turn in.  ???


That makes a lot of sense Nick, must be my riding ability that has been compensating for a soggy front  . That alone steers me towards progressives when I change the oil  :thumbup 


So let me have another stab at this  :rolleyes . Once at full compression, the suspension has no further ability to adjust to keep the tyre on the road, and this is where the tyre risks becoming excessively loaded for the available grip? Errrrr, totally beyond me that one :'( .  And I think I get the rake/trail change thing too (me also) - compression effectively steepening the steering angle, much like dropping the yokes down the forks, to give quicker turn in (yep, got it). But it still needs more travel available to deal with any bumps etc. So it's a compromise between the two - you need some compression, but it needs to be controlled (damping, spring rate), both in total amount of travel, and rate of travel Errrrr, I think so  :rolleyes .

This suspension thing is confusing, but getting the idea that it's about the ability to adjust for different situations, so you can't generalise about one thing or the other. And you can't treat compression damping or too weak springs as an individual thing, but have to look at the whole operation of the various functions of the unit together. This is why I don't mess around with settings myself  :lol  Good call  :lol

[nick crisp]

You still get your braking done before committing, even with less dive, but with a well-controlled front set up, you can brake later, harder, and flip it in with everything working to it's optimum still. If you brake and get a lot of dive, and then if you have a low rate of rebound damping, the forks will spring out again when the main braking force is removed, so unsettling the bike, too much movement just as you want to turn in.  ???


That makes a lot of sense Nick, must be my riding ability that has been compensating for a soggy front  . That alone steers me towards progressives when I change the oil  :thumbup 


So let me have another stab at this  :rolleyes . Once at full compression, the suspension has no further ability to adjust to keep the tyre on the road, and this is where the tyre risks becoming excessively loaded for the available grip? Errrrr, totally beyond me that one :'( .  And I think I get the rake/trail change thing too (me also) - compression effectively steepening the steering angle, much like dropping the yokes down the forks, to give quicker turn in (yep, got it). But it still needs more travel available to deal with any bumps etc. So it's a compromise between the two - you need some compression, but it needs to be controlled (damping, spring rate), both in total amount of travel, and rate of travel Errrrr, I think so  :rolleyes .

This suspension thing is confusing, but getting the idea that it's about the ability to adjust for different situations, so you can't generalise about one thing or the other. And you can't treat compression damping or too weak springs as an individual thing, but have to look at the whole operation of the various functions of the unit together. This is why I don't mess around with settings myself  :lol  Good call  :lol

Glad you agree, but I have been known to be wrong ya know  :eek

Funny how for years and years, I always just rode to my own (sometimes beyond  :lol ) limitations, and only bothered with the suzzies if they were obviously shot. This one has more serious mods in that department than I've ever had before, so now it's interesting to me to know why it works better, even if I'm not a good enough rider to explore it's limits. It's quite possible that if I gave it to someone who really knew what they were doing, it could be better still, but it still handles far and away better than anything I've had in a long while.


Hmmm...... :eek I have become Noggy  :eek  :rollin

And glad to hear you're a brilliant rider Frosties, someday we'll have to get together and you can show me how it's done - maybe in return, I can give you a little topiary lesson; you'd like that, wouldn't you?  :lol

[bigralphie]

I had one of these ,and they are bouncy on the front  :lol


I bought a kit from [color=rgb(84, 84, 84)]Jack Lilley Triumph[/color][color=rgb(84, 84, 84)][/size] I think which had up rated springs some preload spacers to sit on top of the springs and heavy fork oil [/color]
[color=rgb(84, 84, 84)][/size][/color]
[/size]But I don't think they still stock it now [size=small]

[Frosties]

[quote author=Frosties link=topic=17525.msg201990#msg201990 date=1435842329]

You still get your braking done before committing, even with less dive, but with a well-controlled front set up, you can brake later, harder, and flip it in with everything working to it's optimum still. If you brake and get a lot of dive, and then if you have a low rate of rebound damping, the forks will spring out again when the main braking force is removed, so unsettling the bike, too much movement just as you want to turn in.  ???


That makes a lot of sense Nick, must be my riding ability that has been compensating for a soggy front  . That alone steers me towards progressives when I change the oil  :thumbup 


So let me have another stab at this  :rolleyes . Once at full compression, the suspension has no further ability to adjust to keep the tyre on the road, and this is where the tyre risks becoming excessively loaded for the available grip? Errrrr, totally beyond me that one :'( .  And I think I get the rake/trail change thing too (me also) - compression effectively steepening the steering angle, much like dropping the yokes down the forks, to give quicker turn in (yep, got it). But it still needs more travel available to deal with any bumps etc. So it's a compromise between the two - you need some compression, but it needs to be controlled (damping, spring rate), both in total amount of travel, and rate of travel Errrrr, I think so  :rolleyes .

This suspension thing is confusing, but getting the idea that it's about the ability to adjust for different situations, so you can't generalise about one thing or the other. And you can't treat compression damping or too weak springs as an individual thing, but have to look at the whole operation of the various functions of the unit together. This is why I don't mess around with settings myself  :lol  Good call  :lol

Glad you agree, but I have been known to be wrong ya know  :eek

Funny how for years and years, I always just rode to my own (sometimes beyond  :lol ) limitations, and only bothered with the suzzies if they were obviously shot (also guilty as sin on all my bikes). This one has more serious mods in that department than I've ever had before, so now it's interesting to me to know why it works better, even if I'm not a good enough rider to explore it's limits (Noggy is  :lol ). It's quite possible that if I gave it to someone who really knew what they were doing, it could be better still, but it still handles far and away better than anything I've had in a long while. If you're happy with it then stick with it Nick.


Hmmm...... :eek I have become Noggy  :eek :rollin

And glad to hear you're a brilliant rider Frosties, someday we'll have to get together and you can show me how it's done - maybe in return, I can give you a little topiary lesson; you'd like that, wouldn't you?  :lol
[/quote]

You're not that far away from Wokingham Nick so yeah, would be up for a ride out one day.......once I've sorted the front out - can't have you winning. As for topiary lessons.....would only happen if I followed your line  :pokefun 

[Frosties]

I had one of these ,and they are bouncy on the front  :lol


I bought a kit from [color=rgb(84, 84, 84)]Jack Lilley Triumph[/color][color=rgb(84, 84, 84)] I think which had up rated springs some preload spacers to sit on top of the springs and heavy fork oil [/color]

[size=1em]But I don't think they still stock it now [/size]

Bouncy front is one way of describing it.......

I think when they named the bike they were thinking of one of these  :lol

[midden]

LATE ENTRY:: 
More weight over the front wheel resulting from the nose dive (forks compressing) helps the bike slow quicker.
Does your front often bottom out? Back wheel feel like it's leaving the road, skipping sideways?  If yes to either then compression is probably too soft.
But as you met ion it feels harsh over poor rutted ground (I presume you're still talking about the front)  this is indication of compression too hard.  Oh a contradiction.

Since you have no adjustment capability (does this include preload)  I would start at the cheaper option of renewing  the fork oil as this alone should give a smoother more controlled feel to the springs. Perhaps as many suggest use the next higher grade.

Also when riding give this a go...........DON'T PANIC  :eek

[Frosties]

LATE ENTRY::  [img alt=]http://foc-u.co.uk/Smileys/efocicon/cheesy.gif[/img] Better late than never fella  :thumbup

More weight over the front wheel resulting from the nose dive (forks compressing) helps the bike slow quicker. Ohh FFS....that's confused me now and Nick's going to relapse rethinking his hard work getting his head around this  :lol

Does your front often bottom out? Never. Back wheel feel like it's leaving the road, skipping sideways? Never - rider in total control    If yes to either then compression is probably too soft.
But as you met ion it feels harsh over poor rutted ground (I presume you're still talking about the front) Yup  this is indication of compression too hard.  Oh a contradiction. Errr yeah........i'm totally head fecked now :wall

Since you have no adjustment capability (does this include preload) None, Zip, Nada I would start at the cheaper option of renewing  the fork oil as this alone should give a smoother more controlled feel to the springs. Perhaps as many suggest use the next higher grade. Seen as i'm now confused I will do this as being the cheaper option and chuck 15w in  :rolleyes But if that oil change stiffens the front then I'm guessing less weight over the front which from above means I'm going to get reduced braking  :groan

Also when riding give this a go...........DON'T PANIC [img alt=:eek]http://foc-u.co.uk/Smileys/efocicon/shocked.gif[/img] 

I don't normally panic, but commute 50 odd miles from Wokingham to London every day and have to deal with those feckin cyclists that just pop out of traffic all over the place - all of them..TW@!  :grumble . Its the only time I panic brake and grab a handful and I do look for the bastards all the time......maybe I should slap some dodgy plates, save my brake wear and gradually reduce their numbers :angel

[nick crisp]

LATE ENTRY:: 
More weight over the front wheel resulting from the nose dive (forks compressing) helps the bike slow quicker.
Does your front often bottom out? [b]Back wheel feel like it's leaving the road, skipping sideways?  If yes to either then compression is probably too soft.

But couldn't this also be due to lack of rebound damping on the rear shock? (I'll have Frosties' head exploding before I'm through here  :b )

But as you met ion it feels harsh over poor rutted ground (I presume you're still talking about the front)  this is indication of compression too hard.  Oh a contradiction.

Yeah leave out the contradictions will ya, ya goat shagger  :lol

Also when riding give this a go...........DON'T PANIC  :eek

Yeah, hospital food ain't that bad these days, and hedges are soft 

[midden]

My main advise is to renew the oil working on the basis that over time it most probably has lost its full efficiency. So to replace with the original spec 10w should in theory return damping to its original. Perhaps by slowing or smoothing the dive without reducing it.    Going 15w could compensate any wear in the springs without going straight to the next problem of what rating spring should I go for. Which to me sounds like a minefield of opinions. Also since you found it springy when you first got it 15w may have helped then.  I think if it does end up feeling too firm you might get away with taking a little out of each stanchion (how say others on this)

I have two bottles of unopened 10w oil which I got on the panic of my weight  making the front jumpy but as yet haven't used it due to this argument of putting 15w in. I should be a real candidate for the heavier oil but I rarely bottom out, if indeed I actually have and I improved things by lowering the preload from hardest setting.

[midden]

[quote author=midden link=topic=17525.msg202007#msg202007 date=1435848525]
LATE ENTRY:: 
More weight over the front wheel resulting from the nose dive (forks compressing) helps the bike slow quicker.
Does your front often bottom out? [b]Back wheel feel like it's leaving the road, skipping sideways?  If yes to either then compression is probably too soft.

But couldn't this also be due to lack of rebound damping on the rear shock? (I'll have Frosties' head exploding before I'm through here  :b )
Absolutely but that just adds to confusion.  Question answered by dive essentially being good for breaking.

But as you met ion it feels harsh over poor rutted ground (I presume you're still talking about the front)  this is indication of compression too hard.  Oh a contradiction.

Yeah leave out the contradictions will ya, ya goat shagger  :lol

who let that one out the bag. More lover than shagger

Also when riding give this a go...........DON'T PANIC  :eek

Yeah, hospital food ain't that bad these days, and hedges are soft 
[/quote]

[slimwilly]

Nick did you see my forks dive on entry to that one bend,,oh so did yours ,oh and also PieEaters ,a hell of a lot of late braking going on there