Author Topic: xbr 500  (Read 2473 times)

guest564

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Re: xbr 500
« Reply #30 on: June 23, 2014, 08:01:24 PM »
I say try it and see how it feels to you. The racer was a good bike, tatty and built on a tight budget but it did well in its day. A large number of parts came from others upgrading their bikes at the end of the season. A spare engine, cam, the Astralites and the ignition all came quite cheap from other racers, other bits came from breakers. The HRC cam and the fork springs were among the bits I bought new.  Sadly its currently scattered around the South in various storage locations.

Propellor

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Re: xbr 500
« Reply #31 on: June 25, 2014, 05:49:27 AM »
I say try it and see how it feels to you. The racer was a good bike, tatty and built on a tight budget but it did well in its day. A large number of parts came from others upgrading their bikes at the end of the season. A spare engine, cam, the Astralites and the ignition all came quite cheap from other racers, other bits came from breakers. The HRC cam and the fork springs were among the bits I bought new.  Sadly its currently scattered around the South in various storage locations.

Couldn't agree more. For road riding, if it feels good and you enjoy it, then I guess that's pretty much all that counts. For racing, broadly speaking, lap time is king. If whatever you tweak brings the lap time down then it goes!

For my own part, I just enjoy thinking about these contraptions we ride and trying my best to figure out the truth (that's right kids, I enjoy it!). I really, really enjoy riding em too.

Going back to spring rates and particularly bottoming out under braking, how about adjusting fork oil level? Admittedly this is a risky tactic unless you are super methodical and have loads of spare time. Also, overfill and your ride will become harsh, as well as the increased risk of oil leaks probably.

Another tactic might be to use 2 stacked springs of different (straight) rates. Playing around with the rates and free lengths will give a wide range of different results. A tubular spacer up the inside of the softer spring would theoretically allow modification to the place in travel where the overall rate would increase by locking out the spring. Not sure if an audible clonk would occur? Anyone ever tried this?

BMW's elastogran (sounds like some kind of geriatric super hero) was an ingenious solution to providing on board, easily adjustable spring rate. So there are ways.

I wonder if/how they do it in moto gp?
BEIGE is all the rage

guest564

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Re: xbr 500
« Reply #32 on: June 25, 2014, 09:06:15 PM »
My old 1988 VFR750 had two stacked springs in the front forks, at least it did have until I changed them for WP springs, I think that they were both progressive but the top, shorter spring was quite soft and it did have a habit of standing on its front wheel under heavy braking.
Changing the fork oil only really changes the damping but increasing the level reduces the amount of air in the fork and does change the springing very slightly, I don't recall what level I ran but I did go a little higher on the oil grade to 12.5W by mixing oils.

Moto63

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Re: xbr 500
« Reply #33 on: June 25, 2014, 09:45:12 PM »
Evening again propellor and rhinoman ,
This has got to have been the most interesting and informative thread that's been on this site since I joined up approx 12 months ago. It,s almost like a good book that you don,t want to end, it,ll be a shame when you,ve both exhausted the subject, but again cheers to you both for expanding my grey matter.  Oh just one other thing, I hope you had a fruity end can on the VFR  rhinoman be a shame not exploit the sound of that lovely v4. 

Propellor

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Re: xbr 500
« Reply #34 on: June 26, 2014, 05:24:57 AM »
Flattery will get you everywhere propellor I,m sure  LOL

I rest my case, m'lud.



(Ps. Cheque is in the post)
BEIGE is all the rage

Propellor

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Re: xbr 500
« Reply #35 on: June 26, 2014, 06:02:25 AM »
http://rideapart.com/2008/10/details-bmw-esa-ii-electronically-adjustable-suspension/

I like the ingenuity behind the principle, but not the idea of electronic control. Can't see why it couldn't be done very easily manually.
BEIGE is all the rage

guest564

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Re: xbr 500
« Reply #36 on: June 30, 2014, 09:17:05 PM »
I had the stock cans and then a Motad stainless system - a fruity can would have given me a headache on long trips, I did 216,000 miles on that bike before someone stole it and wrote it off.

guest564

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Re: xbr 500
« Reply #37 on: June 30, 2014, 09:18:14 PM »
http://rideapart.com/2008/10/details-bmw-esa-ii-electronically-adjustable-suspension/

I like the ingenuity behind the principle, but not the idea of electronic control. Can't see why it couldn't be done very easily manually.

That looks like the modern, more complex, version of the old air caps - I expect its a lot more reliable.