Best front damper for a race scooter

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tony
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They have to be set up and made right. The parallelogram layout allows suspension travel under braking. Basically all we are doing he is stopping the caliper from 'winding' up the suspension under braking. Problem is if its made slightly wrong the suspension will go solid and its goodnight ! :P
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Don't those bolt-on anti-dive brackets spin around or move? I can't see how they wouldn't with the force on them. I see that one goes past on the side, but even if the bar across from the caliper plate hit perfectly in the middle of the fork there would still be a tendency to spin around the fork to one side, thus twisting the bracket on the fork and skewing the caliper plate angle. Experience?

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mark
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my bracket is grub screwed from the back as well
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frank sanderson
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Some of my Rant below might be of help FROM A THREAD IN GENERAL CHAT.also pics of early version of single disc showing how slim calliper carrier is they are now slotted like on pic showing dampers fitted .
Over the time we have been fitting outboard suspension to various scoots we have changed the source type and length of shocks used . some of the earlier shocks were quite a bit harder and a bit longer than the ones pictured on Les and fattys front ends which are about as hard as a MB or taffspeed uprated internal spring set up .the shocks that are fitted on les and fattys are modified by us before selling ,they are not just a shock out of a box and are only available through us .There is also a further mod to add a softer setting but we tend to find they are fine as they are . Once a scooter moves outside its std speed range like most of our conversions do ;) A different set of stds need to be attained It has taken us the best part of 5 yrs to come up with this set up that can cope with higher speeds and suspension demands . What a lot of folk dont realise is that we designed this set up so the mounting points for your supension are further apart so the front end becomes a lot more stable by having a wider track. Any one that has had any of our conversions done in the past can now retrofit these softer shocks to there scoots if reqd. Also as mentioned these shocks are not a very expensive item probably costing no more than a good internal set up however coming soon for tech nuts are some new shock options manufactured in the EU by quality companys that will be quite a lot more expensive but of much higher technical spec . These will be able to be directly fitted as replacements on our set ups.
Dont want to go on but as you may know we have done loads of anti dive conversions and during the development period we have as with the shocks found out what does and does not work . We did try an adjustable link bar with olive mounts similair to knowledge but found that once you have found out what works you dont need adjustment and that the threaded shaft of the olive joint was not up to the constant pressure exerted on it . the weakest point of the shaft is at the base of the thread so eg an olive joint with an 8mm thread is less than 6 mm at the base of the thread the same ratio applies to all sizes also the main point for stresses to occur is at the v base of the thread that is why you dont see sharp corners on stressed items.Every time you put on your brake its like hitting the linkage beetween the calliper carrier and fork leg with a hammer. this is why you find the hub retaining link on lambretta std suspension bent to a different shape to the non brake retaining one this is also why we prefer to have a solid mounting on the fork leg as with time clamp on brkts even when dowelled to try to stop movement cannot stand up to these constant pressures ,these are only my opinions but I tend to err towards safety as a priority.
Also we use steel components not alloy as the comparitive strength factor of steel to alloy is why all the alloy ones you see seem to be very thick and bulky and we only need to use 6mm plate this also makes the items virtualy the same weight .Another problem is finding the space for the linkage on the spindle do not for example fit 2 LH links as I have seen used as you will have unequal pressure on the spindle the leverage being much higher on one side than the other.
With everything we do we put development and testing before putting a product on sale so that the customer can be assured the product is safe to use. It does not seem fair that companys like us that can spend sometimes years on R&D can just have there products copied and sold on be they one off body designs or mechanical parts by unscrupulous people in the UK and abroad just chasing profit with no regard to safety or comebacks if the products they make and sell fail .
One good thing to come out of the credit crunch is its now as expensive to buy inferior far east copies as the real deal.
hope this helps dont want to rant, if advice on anything mentioned is needed just give me a bell I am happy to help.Lots of stuff discussed to see @ http://www.lambrettainnovation.co.uk
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simon k
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anyone tried the set up Charlie Edmunds runs on his race scoot? bitubo's with the spring removed and what looks like nolethane bushes
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frank sanderson
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we usualy have the Bitubos you mention in stock but charlie adapts them to suit his needs its not only removing the spring they can be tuned internaly with different oils and other tweaks so his prob wont be the same as std ones . The big alloy ones have the ability to have the damping rate changed at will a lot easier for the man on the street !
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simon k
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have been following the damper debate closely. and really wanted something trick on my street racer. however have decide on standard escort dampers,progressive springs & SD anti dive to begin with.am happy with this set up on an inboard disc and confident that the innovations hub will deliver. if the dampers turn out to be the weak link then i may upgrade around original damper brackets.
do the Bitubo's dampen on compression as well as rebound?
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soulsurfer
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Good choice, I'd be very surprised if you feel the need to upgrade. The only thing further I would recommend is the tubeless wheel hub version.
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simon k
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yep that's the one i have soulsurfer, lovely bit of kit ;)
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I'm having a bit of a crisis of confidence about my anti-dive. I've followed my own rules (actually, it was Rob at JB's "rule") of using a parallelagram, but some how it just looks like the parallelagram will squash-up under braking, and the torque arm between the caliper and the forks will not resist the rotation of the fork link about it's own (front) pivot.

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I attach an unblemished version, so an obliging contributor might add some more lines to the drawing to assist me.
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What do you think?
Martin
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