Rake angle and grip

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Taffy
Active Visitor 100
Active Visitor 100
Posts: 326
Joined: Sat Aug 09, 2008 12:02 pm
Location: Soham, Cambs

Re: Rake angle and grip

Post by Taffy »

As this thread edges towards 10,000 (9,850 today) hits it is really sad to see so little has changed over these last 5 seasons. The sport is stood still technically.

viewtopic.php?f=10&t=15649&p=46637#p46637 this is a link to earlier perusing. Who said the Germans are dull, safe engineers.....not a bit of it!

In the UK there's been the use of extra wide 21" front rims allowing use of 70-100 front tyres instead of the choice of just TWO 20" front tyres. The Michelin Starcross V (5) being the top choice. This is a stunning tyre and is all the difference needed on its. (I have 2 rims left but can get more)

However some have tested this as a stand alone idea. IT CANNOT BE. the front end is raised 12.7mm/half-an-inch. this changes several factors.

Headstosk angle - but forget that. these others matter though...
The trail increases as the SC has 'tipped backwards'.
weight has come off the front.
the front shocks extend and the rear shock compresses.
braking on dry grippy tracks alters.

the answer is to get the outfit back to the same 'pitch' so measure the handlebars-to-ground before and get the same afterwards
this still leaves the loop pointing upwards slightly and a shorter shock.

to counteract this different shock holes should be available and the loop pivot should also have a second choice. TaSsyK.jpg
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This is the kind of Fork the future requires. The only people i could find to draw it were the Dutch and the only people who can bend it were the same Dutch family...
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another area worth a look is the idea of a wider rear wheel rim width - especially for a loam 'blue slick' track in those months June, July and August. The 140 Mefo, well the 140 anything were made for a minimum rim width of 3.5" (remember all measurements in imperial to put the Dutch off the scent) and up to 4.5". meanwhile you are all running 2.15", not even 2.5". The rider trying this idea needs to conquer rim locks and dodgy knees and then it will be go-go-go!!!!!!! :-D :-D :-D

Remember, the rear wheel has much in common with a CAR not a motorcycle.

another area of interest is the snow/ice tyre from the rally car world. their narrowest tyre is a 160 and very, very soft. the circumference is close to Motorcycle numbers (2m). The tread pattern could be ideal after gating. i hear you say gating is everything. No it isn't, a clear advantage somewhere on the track repeated 20 times will see most problems solved! if the race time is better then this would be still a good move.

Remember, :whistle: :whistle: :whistle: :whistle:
if you want to check someone else's trail, you merely go up to their outfit and go from lock to lock saying "what a nice bike!" but guaging how far the spine of the frame moves across your vision. I have checked ALL the nice bikes.........

Another great place to check them is when they are handed over to the FIM. the stewards are often asleep and you aren't arousing anyone as to what you're doing. when no one is upset, no one is hurt....are they? :dontknow: :dontknow:

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Stuart Brown's brake arm no longer runs parallel. this induces more squat. loading the front end. Nobody but nobody can touch browny on a dry loam track, his front end loading and grip sees him spraying the crowd with soil off the FRONT wheel. tyre and mousse deformation has a lot to do with this.

Image The above outfit uses stronger springs but with the same damping of soft springs. there is no give in the suspension and the tyre is doing all the work. a larger mousse/more air and suspension that gives easily on the face shims would be ideal here. it is only a small bump....

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The above outfit had this front eccentric for late 2018 i believe and all of 2019. is it a keeper...I hope so. on this day at Milton malser the eccentric is turned to 12 'o clock loading the front end and giving the rider one of his best results in the Uk during the season. The passenger with the idea didn't get to taste the glory. But well done Dave Keane -

Reminds me of a story about Dave. I was checking his suspension in 2017 and the front end was stretched to full length and pinging off everything. you'd have to agree that the suspension seemed rock hard. but on the downface of a table top the front end completely collapsed. I was now flumoxed. (Dutch; flummoxed). then I looked at the rear end. Dave had a 15 stone passenger and this collapsed the rear BUT also EXTENDED THE FRONT. lesson learnt in observing suspension; 'before you know-it-all' check both ends!!!

Taffy
I don't want a works bike I just want their address book! :?: :?:
here is a link to the SMCA web site for ya! http://smcagb.moonfruit.com/ :-D
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