500 K cafe racer conversion - build thread

[Ewan 500 K1]

you are working hard Ewan,

 I suggest you get it on the road,run it for a while,get used to the feel.bed the tyres and brakes in ,
then explore the handling,

I guess you have some great bike roads around you,

go and have some fun

you're right of course John ... but intrigue & curiosity meant I spent some more time on rake and trail today. I decided I wasnt happy with the broom handle .. to much scope for variation in the figures so made a telesopic version which was then fixed to the tripe T in line with ,and parallel to, the headstock. Much more rigid and stable. Pics 1 to 3 below show this. The 4th photo shows how I measured the sides of a right angled traingle to calculate the rake.  So .. after much repeated measuring and using three different trail and rake calculators .... I've got some averages of averages:

Old shocks with straight triple T :  Trail = 97.9mm (3.9 inches)    Rake = 23.8 degrees

New longer shocks with straight triple T : Trail = 90.5mm (3.6 inches)  Rake = 22.7 degrees

So still showing a one degree reduction in rake with the new shocks and now a 7.4mm (0.3 inch) reduction in trail. I think I'll get a steering damper to be of the safe side.

[Ewan 500 K1]

another (vastly improved, simpler and more accurate) method of finding out what the trail is ...thanks to turbo guzzi and johno on the US site's high performance & racing forum

Step 1. find out what the rake angle is by sitting a bubble protractor / digital protractor / inclinometer against the fork tubes , OR  by taking  a high definition photo from a long distance, camera at mid bike height, importing it into a cad or vector graphic program and anlalyisng it. .

Step 2. Use my new calculator ... there's a screenshot of it attached to this reply below the pictures and a downloadable version attached to my next reply.

Note .. this only works if the triple T has zero rake itself and neither it nor the forks are bent in any way

Also for a 500 four a  one degree change in rake translates to a quarter inch change in trail ... so if using a bubble protractor it needs to be able to measure to say within 0.5 degrees and the bike will need to be on a perfectly level surface

[SteveD CB500K0]

I've added .xls and .xlsx file types to the "allowed" list Ewan. Nobody has ever tried it before!

Steve

[Ewan 500 K1]

I've added .xls and .xlsx file types to the "allowed" list Ewan. Nobody has ever tried it before!

Steve

cheers Steve , calculator link at foot of this reply

[Ewan 500 K1]

Have had it confirmed that stock fork offset is 45mm

[Ewan 500 K1]

Another rake / trail calculation. (Edit .. this was with original rear shocks on. The photo says "new shocks" top left, but that was a mistake !)This time I took some photos of the bike. First placing the bike on a plank of wood. Then printed out the photos and drew a centre line on the fork and using the plank as the horizontal drew a line along its edge. Then I  used a decent protractor to measure the castor angle (angle A in the attached photo). Out of four different photos (2 of each side) the castor angle was consistently between 65 and 66 degrees giving a rake angle (R on attcahed photo) of 24 to 25 degrees and a calculated trail of 93.2 to 99.5mm ...... a much more acceptable result that using the crude pole measuring methods above.  Just waiting for a mate to loan me an inclinometer to measure the angle of the forks to the horizontal now to see how that compares. .... . Just need to to put the new rear shocks on and use the photo/protractor method to see how the  standard shock result compares with the longer rear  shock result .. and repeat using the inclinometer method.

[Norniron]

Here here oddjob,lifes too short and so is the summer

[Ewan 500 K1]

ye cannae hurray a murray ... not planning to be on the road till 2014 

[Captain Snakebite]

Just a quick question Ewan.
Early in the thread you mentioned Morris Minor hubs? Are there Minor bits that go onto a 550?
Cheers,

Owen

[matthewmosse]

The 550 rear brake lining can crack up sometimes giving a nasty feeling brake and need for a new hub, or if you have a lathe then you machine out the cracked steel liner and insert a mini or morris minor drum - takes a wee while and some care but I've done it on my 500/4 sidecar outfit and that has seen quite a lot of milage since. I think that will be where morris minor bits will have come into it.

[Ewan 500 K1]

The 550 rear brake lining can crack up sometimes giving a nasty feeling brake and need for a new hub, or if you have a lathe then you machine out the cracked steel liner and insert a mini or morris minor drum - takes a wee while and some care but I've done it on my 500/4 sidecar outfit and that has seen quite a lot of milage since. I think that will be where morris minor bits will have come into it.

yep !!

[Ewan 500 K1]

Another gripping episode from my Rake & Trail measuring shenanigans. First off, I've modified reply #133 on the previous page .... it wasn't the new shocks that were on when I did that first manual protractor / photo method at all.. it was the old shocks. I realised that when I went out to the shed today to take some more photos of the various combinations of rear shocks and Triple Ts to apply the manual protractor method to.  So ... I took photos with new shocks and old bent Triple T, new shocks new straight Triple T , old shocks and new Triple T and old shocks with old bent Triple T. Four photos of each combination. Results were inconsistent with variations of up to one and a half degrees for the rake calculations for any one configuration.   

However the Digital Protractor ( A.K.A. the inclinometer) arrived today (see first picture below) and this really has given consistent results (see third picture below),  ... it was absolutely consistent in the change effects that both the new shocks and changing the Triple T had on rake and trail and this gives me loads of confidence in the figures. So thats me done and dusted with rake and trail measuring you'll all be glad to know. Its been an education for me at least  .

So, I now reckon (with confidence) that..

1. A one degree change in rake = a reduction in trail of more or less 6.5mm (quarter of an inch)

2. For every 10mm increase in rear shock length there is a 0.48 degree reduction in rake and a 3mm recuction in trail.

and with a bit of acceptable tolerance that..

3. With the new longer shocks I've got a rake of 23.5 degrees giving a calculated trail of 91mm (3.64 inches). Stock figures are 26 degrees rake and 102.5mm (4.1 inches) trail.

Also got hold of a bargain basement GSXR steering damper today... might be a wee bit on the short side for a stock 500, but as I'm putting 10mm extra on the steering stop so that the ace handdlebars dont bang off the tank I reckon it should do the job. Just having trouble locating a suitable frame clamp (29mm) for the damper, anyone got any ideas .. maybe best bet is just to use a 30mm one ?.

Next up then ...

• Stripping back to bare frame again and getting a wee bit of welding done to one of the passenger footpeg mounts and the steering stop

• Make up my mind whether I want the frame silver or gloss black, then getting it powder coated

• Ordering my rear sets now that the Italians are back at work

• Make up my mind if I want to drill some holes in the front sprocket engine casing

• Bit of alloy polishing refresh

• Stick it all back togeather

• Bit of a tune up service

• Refine the rear light set up

And then we're ready to roll I hope.

[Ewan 500 K1]

Yeah but yer got a moose loose aboot yer house 

a perfect opportunity tae respond wae a "jings, crivens, help ma boab"

[matthewmosse]

Sidecar mounting clamp onto the frame for damper? bit heavy.... Fabricate something from tube cut open withh a hacksaw with drilled 'ears' added with weld.

[Ewan 500 K1]

Sorted on the steering damper clamp front , got a 30mm one from Dennis Trollope Racing at http://stores.ebay.co.uk/Dennis-Trollope-Racing . He's quite a bit cheaper than others for the same clamp. Although the 500 frame measures 29mm in diameter, the 30mm clamp tightens on fine. Not too happy now with the GXSR damper though. On the good side it bolts straight into the hole on the bottom of the 500 lower yoke. On the down side it does not allow the steering to go full lock to lock, this isnt really a problem for me as I intend reducing the lock to lock distance to stop the ace handlebars hitting the tank anyway. What I'm less happy about is the height the GSXR damper needs to sit at ... it sits too high and spoils the lines of the tank (see photos) Going to order an NHK ODM 500 damper from Dennis Trollope instead now which should sit better.

GSXR Dimensions
Mid point to eye (extended)  150mm
Mid point to eye (closed) 85mm
Travel 70mm
Body Length 128mm

NHK ODM 500 Dimensions
Mid point to eye (extended)  227mm
Mid point to eye (closed) 141mm
Travel 85mm
Body Length 154mm

so .. if any one wants to buy a used GSXR damper , its yours for £25 + P&P