Triumphrat

TB-T100

There is one issue that I think warrants a discussion here. How much of the Front dive is caused by the stock springs, and how much caused by insufficient riding skills?

Often members on this site suggest that progressive fork springs is the best or close to the best mod that one can do on a Bonnie. The reason given is the Bonnie's tendency to front dive, when braking.

BUT, my impression is that the front dive issue is 90% an issue of brake-technique. With braking the way I was taught
- relaxed arms and shoulders
- sqeezing the tank with my knees
- tightening the muscles in my legs, lower-back and stomach
(This way the weight is "anchored" to the seat, so to speak.)
the front dive is minor.

With "wrong" braking:
- stiff arms and shoulders
- weight on the handlebars
the front dive is huge.

This makes me think that maybe some of those who complain about the stock springs really should work on their braking technique. Now, I'm not pointing the finger at all those who change the spring, as there can no doubt be riders who are conserned about the "last 10%".

What do you think: How much of the front dive-issue comes down to riders with insufficient riding skills?


My personal disclaimer: I am not a very experienced rider. After an 18 year hiatus, I returned to biking this Spring when I bought my T100. This Summer my T100 and I have done 13 000 kms. And I have not changed the front springs. I have however read widly about riding-technique (book worm?).

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'04 T100 Black and White (because that is the only colour to wear with a Dinner Jacket)
AI removed, TORS
engine dresser bars, grab rail, flyscreen, Triumph leather panniers and tank bag

lovin' ev'ry minute of it

sweatmachine

I think it is due to the stock springs.

Heavier fork oil will help as well, 15 or 20 wt.

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alright alright alright

Bonnie cafefighter!

mag10

change to a progressive type spring it will really help with the fork dive. good 15 W oil and good seals are a must as well.

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see my wicked black speedmaster

bonnieblackinfl

I say that it is 90% springs and 10% rider. Someone shouldn't have to change the way that they ride to eliminate that much dive.

Greg

PAAS

When you brake there is weight transference onto the front end of the bike, the harder you brake the bigger the effect. This will naturally cause the front forks to compress, how much will depend on the stiffness of the forks. I don't really see how your riding posture has any effect on this physical phenomenon, unless you move to the pillion seat every time you break to negate the effect!

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Paul.

Herts. UK
Opal & Tangerine 05 T100 (865cc)
(Previously Ducati Monster S4 and numerous UJMs)

uzidzit

The bike is set up badly, The only thing to remember is to let the weight transfer before you really clamp them on but a progressive squeeze rather than a quick clamp on the takes care of that( you also need to get in the habit of keeping the power on and using the brake and throttle together to keep the suspension settled, in the turns), given the layout of the bonnie you can,t lock in as tight with your lower body as on a sport bike, so you may have to pickup a little arm push, you do have the right idea with the lower body.

Now to the bike, the Bonnie comes with damper rod forks and mushy springs, and the only way to prevent the dive is to putter around and hardly use the front(bad idea), if you want well behaving front end you need to get correct rate linear springs, and cartridge emulators (valves). you can bring this front end up to modern standards easily but it takes a little work to get the setup dialed in, but it is not difficult. The progressive springs make the front end feel better but do nothing for the very poor dampening qualities of the stock fork tubes, the valves let you set the rebound dampening with fork oil selection and the compression dampening with the valve adjustment. the reason for the improved feel with springs alone if they are progressive, is that they firm up as the forks dive, this feels like an improvement and it is but you wind up with a loss of performance in hard cornering as the spring rate becomes too stiff to allow the suspension to keep working, when the turn gets bumpy it will still seem really disconected if the dampening was not improved as well.

Damper rod fixed orifice forks really work backwards in terms of what you want in a really good fork they dive badly when slow speed loads are applied, and firm up to almost solid when high speed loads are applied, this is due to the resistance of fluid flow through an orifice, which goes up by the square of the speed of the fluid. what you actually want in a fork is the fluid to flow faster as the work is applied faster, that is what the valve does.

I will try to help out if you have questions setting up a front, pm me

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"Peter, It seems like you have been missing a lot of work recently, well Bob I wouldn't say that I've been missing it"
ENOUGH, go out and ride!

mistermellow001

At some speed point, whatever riding techniques contribute to fork dive become academic, as g-forces will overcome even the most thunderous of thighs and other muscles. Put it this way, why should a bike require a rider to compensate for something that could be mechanically remedied?

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Guy

stretch1

As Mr Blair once put it, "Suspension Suspension Suspension".

Get ta 80, 85 on a B road, on't power, my Thruxtons as skittish as next door's cat face'in me Staffordshire Bull Terrier! talk about shakes its head. (Lodzafun)

Best regards Stretch

thekiwi

Uzidzit said it all, A straight wound spring will give a better ride than a progressive spring , it will be stiffer in its initial travel but has a softer overall rate.
Have fitted Racetech springs & valves to my scrambler & it makes the world of difference. Fitted lighter springs to the valves as the forks were initially quite harsh & it is better now. Will next try a lighter oil 10wt . It takes time & effort but it is well worth it .
I can't understand why Triumph dont fit some half way decent suspnsion to these bikes , they are not budget bikes so why do we get budget suspension that most guys seem to uprate. I am sure we would all be happy to pay a little extra for a bike that was a little better set up, not Ohlins/WP Just better that the 60s style stuff we get now

VITAL Before you start with any suspension mods get a mate to help you check out your static sag & start from that point, increasing preload to fix sag problems is not the solution, change springs

road_dog

Honestly TB? I think you're hoping for someone to convince you there's no need to upgrade your fork springs. I think 90% of the fork dive is due to the weak OEM fork springs and the need is real. I upgraded mine, and to say it's a drastic improvement would be an understatement.

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Phil (road dog)