Cheap track bike mods??

[mossy1200]

Sounds like you had fun.
Photos required if you have any.

[yamaha_george]

Just done first track day done at Rockingham, It went great, i certaInly wasn't outclassed by newer stuff.

The mods so far are:-

1. Stiffer fork springs from Yamaha Georges contact (o.85kg/mm) the biggest single improvement, although i think one of them may be binding in the tube
2. Running 15wt oil in the forks
3. Set of braiDed front lines
4. 520 chain conversion with 15/47 ratio - worked out cheaper than replacing the standard knackered chain!!!

as well as this i cleaned out the carbs, rebuilt the brakes, changed the oil etc etc.

Im pretty happy with what ive got for the money. my r6 shockj kit is on the way and ai cant wait for that!!!

Tatty,
You need to check that spring if it is in fact too big in diameter and rubbing in the tube (as opposed to "binding" by going solid when fully compressed.
Measure the stantion inside diam ACCURATELY with verniers and then lock them in position and check the spring coils outer diam. My mate had a spring that varied by 0.01 inches and that rubbed we took it back and they swapped it for a new one. No arguments they are good people that way.

[tattysteve]

Just done another day at Snetterton, for those that dont know tracks in the UK, Snetterton is the "Fastest place in Uk motorsport" and has two massive straights. So obviouly I got nailed by all the brand new litre bikes twice a lap but then got to scithe past them through the corners or on the brakes. It was frustrating and rewarding at the same time.

I managed not to crash but had a MASSIVE moment in the last session, i'd decked the pegs out which unsetttled the bike a bit, got on the gas to early (trying to hang on to a fireblade) and had a huge slide, the revs roared up and the rear came all the way round, it felt like it was happening in slow motion, and i was sure i was about to be launched into the sky but eventually the bike shook its head and the rear got back in line. Fooking scary though, i let the blade get away from me then on

Ive sorted out the fork springs issue, it looks as though where the forks have been bent, and then straightened (at some point over the last 2 decades) they have left a tiny crease on the inside of the stantion, and the springs i got made up were slightly over 32mm, so they made a new 31.5mm outside diameter set and fanny's your aunt.

I put reelrazors r6 shock kit on, its nice to have some damping but even with the preload at max i cant get the rider sag below 50mm!! looks like ill have to get a spring compressor and slip a nylon spacer in there.... If anyone has any advice about what type of spring compressor is best that would be helpful. I'll let you know how i get on.

I was the only FZr on track but 2 spectators came up to have a chat about fzr projects they have going on, and reassure me that the bike drinking 700ml of oil in the day isn't anything to panic about because of the nature of the track.... I spent alot of time at 12K!!!

In the end i gave up clutchless upshifts, the bike has just ticked over 37000miles and was regularly missing gears and finding neutrals.........

I have some pics this time but havent got them hosted anywhere yet so cant post them up yet. Booked at Mallory park for next week!

[yamaha_george]

J
Ive sorted out the fork springs issue, it looks as though where the forks have been bent, and then straightened (at some point over the last 2 decades) they have left a tiny crease on the inside of the stantion, and the springs i got made up were slightly over 32mm, so they made a new 31.5mm outside diameter set and fanny's your aunt.

I put reelrazors r6 shock kit on, its nice to have some damping but even with the preload at max i cant get the rider sag below 50mm!! looks like ill have to get a spring compressor and slip a nylon spacer in there.... If anyone has any advice about what type of spring compressor is best that would be helpful. I'll let you know how i get on.

I have some pics this time but havent got them hosted anywhere yet so cant post them up yet. Booked at Mallory park for next week!

Tatty ,
well done,
RR has spring compressors I have a set on standby as I am still travelling, if you need them pronto ask RR to move them to you. When You finish with them you can post them to me and I will pay you then .

The spacer is best made of the teflon chopping block material and needs to have a steel washer the same size as the spring over it next to the actual spring.
The theory goes (for advanced rider can feel it) that the spring will actuall twist & move the steel washers on the teflon as the spring twists as it si shortened and the reduction in force needed to overcome the friction at spring ends is now cosiderably lessened. so pre load works better !!!


you can post your pictures by uploading from your computer direct to the site, as I do when I am doing WIKI how-to's for other guys.

[tattysteve]

The Theory sounds good to me......... I have a degree in this somewhere.....

Is it OK to make the teflon spacer and the steel spacer as a 'c' section so that i can compress the springs and then slip them over the damper rod? Or is it better to do the job properly and make complete spacers - for which I will have to remove the spring completely, am i right in thinking that this is straightforward once the spring in compressed.

I better get my dremmel out!!!

im keen to get this done pretty soon so might just bite the bullet and get a set rather than wait for them to come across the Atlantic

[reelrazor]

Is it OK to make the teflon spacer and the steel spacer as a 'c' section so that i can compress the springs and then slip them over the damper rod? Or is it better to do the job properly and make complete spacers - for which I will have to remove the spring completely, am i right in thinking that this is straightforward once the spring in compressed.

The OEM spring keepers are c-shaped. If you stack any up, just try to stagger the ends so the openings aren't lined up. It is my opinion that with the short stroke(45mm) compared to the spring length (153mm) that the twist issue really isn't an issue. Yamaha uses a nylon washer, bare, at the top of the stock FZR shock-I know mine had 17,000miles and 11 years on it and has no wear to speak of.

At my local hardware store I can buy these:


They are 50mm i.d. , 70mm o.d. and real close to 4mm thickness.

here's another view:


Dremel the inside diameter to 53mm, and use sidecut pliers to cut a section out:


If the shock is still mounted on the bike you can use a tie-down strap to fully compress the rear end and then use a couple of hose clamps across a couple of coils to compress the spring, undo the tie-down strap and you should have enough spring compression to slip the spacers in.

[mikev]

Bob's yer uncle!

(I have nothing of substance to add)

[tattysteve]

Thanks for the pics RR, i should be able to get onto that on Monday, and will let you know how I get on

Here are some pictures of me on track, making no apologies for rather dated yellow leathers........ All the cool kids wear yellow leathers.

I managed to steal some yellow and black warning tape from somewhere so at least i co-ordinate!!

[yamaha_george]

The Theory sounds good to me......... I have a degree in this somewhere.....

Is it OK to make the teflon spacer and the steel spacer as a 'c' section so that i can compress the springs and then slip them over the damper rod?

im keen to get this done pretty soon so might just bite the bullet and get a set rather than wait for them to come across the Atlantic

Tatty,
C section is fine just make sure they are close to size round the rod (not rubbing) and the steel washer has the opening in the opposite direction to the teflon would make sense (YMMV as i have not done this with C's just completes in the past)

[tattysteve]

I got the spacers in and now get good sag values with the preload adjuster smack bang in the middle, perfect. CAdwell PArk becon on Thursday and then i think ill leave it for the year. I need to earn some money and it seems to just be raining here (England) all the time at the moment, so i my take my Aprillia to Europe!