Advice regarding forks?

Hi guys, been lurking here for a while and finally need to post so made an account!

I got my cb500s back in october, absolutely loving it so far, got it for £1000 and it needed some new shocks (got hagon's now) and a new front tyre with 15,000 miles. A steal I reckon!

Anyway, the bike has failed its MOT on 2 previous occasions for the fork seals - the left tube is pitted and obviously keeps wrecking the seal. What I want advice with is what do you think I should do? I could replace the seal, but it's likely to go again before I sell the bike (I'm keeping it til at least Sept 2013), or I could buy a new (or second hand) fork tube and replace it. I'm also thinking of stiffening up the forks whilst I've got them apart, as the nice responsive back end with my new shocks is let down by the wobbly front! How would I go about this? New hagon internals, or is it as simple as different weight oil?

So, what do you guys think? Thanks

Having a similar prob with mine, pitted just enough to make changing the seals a bit of a lottery. Having them re chromed / reconditioned was not much less than getting a new one. I got mine from David Silver for a little under 90 quid.

Hope that helps
S

As regards stiffening the fork action, tried using 15W oil in my fronts, and it worked a treat.

I dare say that upgrading the springs would do wonders also, but tried the oil route first as it was cheaper.

Right so new tube from david silver, new seals and 15W oil for now. The hagon internals are £80 from wemoto, £80 that I don't really have. Thanks for the advice

i've not gone with the Hagon internals option - it's a personal choice but i wonder, given the CB500 is far from a 'performance' machine, that it makes much discernable difference, others may disagree of course? go with the 15W oil and a serviced standard fork and you should be fine.

In terms of replacing the stanchions that would depend on how bad the pitting was. I managed to rub mine down with a very fine grit wet sand paper and now keep them clean and regularly wipe over with wd40 and all has been fine so far, they even look fine. The new seals are still intact.

I'll have to have a proper look at the extent of the pitting, I think it's below the dust seal because there's nothing obvious above it. How long ago did you change your seals and sand the pitting down?

It was 1500 miles and 8 months. So it's not a mega long time but like I say all seems good. The cost of seals is relatively low it's just the time stripping the forks if it doesn't work. You could use this strip to try replacing the oil with 15 weight. Then if the seals fail and/or you want new springs you can then re-strip the forks. Overall could save you bucks.

Hello,

The CB500 setup for handling is pretty budget but more than capable, in my personal experience with this great little machine i have found the standard rear shocks the best. My forks still have there original springs (81000 miles) but i have put in a 10mm spacer and replaced fork oil with 15w. Entering the famous gerrards bend at mallory park race circuit nearly flat out and coming out the otherside suggest they work well.

The only thing ive noticed that affects the great handling on these bikes is topboxes, screens and flat tyres..!!

Thanks for all the replies, gonna go with 15W fork oil, and hopefully clean up the tube - if it's knackered I'll grab another. No worries about new springs for now, only 16,000 miles on the clock!

Thanks again

kwackboy wrote:i have put in a 10mm spacer and replaced fork oil with 15w...

The only thing ive noticed that affects the great handling on these bikes is topboxes, screens and flat tyres..!!

Is that a 10mm spacer between the fork top capa and the top of the spring?

I definatly agree about the top-boxes, flat tyres etc...

eternally_troubled wrote:

kwackboy wrote:i have put in a 10mm spacer and replaced fork oil with 15w...

The only thing ive noticed that affects the great handling on these bikes is topboxes, screens and flat tyres..!!

Is that a 10mm spacer between the fork top capa and the top of the spring?

I definatly agree about the top-boxes, flat tyres etc...

Indeed.. between the cap and top spring....

Just a thought on fork refurbishment.

When I did mine 18 months ago I modified the fork slider to that used on the "R" models, i.e. tapped the bottom of the tubes and fitted M6 oil drain screws, all the tubes appear to have the bosses still cast in. Although it is obviously better to remove the forks and clean them thoroughly, being able to change the oil with the forks still on the bike can have advantages.

Chris

goulton wrote:Just a thought on fork refurbishment.
When I did mine 18 months ago I modified the fork slider to that used on the "R" models, i.e. tapped the bottom of the tubes and fitted M6 oil drain screws...

I had thought of this, given that I had also noticed the casting for the drain screw remained. You should post a picture of your modification - might inspire someone else to have a go!

Don't know if this picture will work but here goes.

The screw is an M5. I think the one used on the "R" model was an M6 and this could certainly be used as the boss on the casting is about 12mm in diameter but I was being cautious with the amount of metal I tapped out.

I would not recommend this unless you have the fork leg completely stripped and can properly wash out the swarf before re-assembly.

P.S. Another reason I used M5 is that it is similar to the drains screws on my Yamaha XS-650 and they drain OK.

Looks good to me!

Another pennyworth.
I fitted hagon progressive front springs with 20w oil and reduced the oil gap to 140mm.
The forks still have full travel but with the updated springs the front feels lots more planted.
I also have Hagon rear shocks which again match the front.
As previously mentioned the CB500 is basically a commuter bike but little improvements in the suspension makes a massive difference.
Been round Oulton park and Anglesey and never had a problem with my suspension.
Just a bit of advice on the stanchions,if you are stripping the forks to fit new seals,then spend a couple of quid and fit some rubber gaiters,these keep the majority of the muck off the seals during the winter.

Murray wrote:.
Just a bit of advice on the stanchions,if you are stripping the forks to fit new seals,then spend a couple of quid and fit some rubber gaiters,these keep the majority of the muck off the seals during the winter.

Agreed......especially in the winter...

Araldited the left tube in the end, the pitted wasn't too deep but quite widespread. Pulling the old seal off the tube over the pitting was horrible!

It's lovely now, the original springs were at the perfect length according to the haynes manual and the 15W oil makes them a little stiffer. So much better than before, especially as most of my oil had leaked out anyway!

May look at getting some gaiters, but I have them back together now

EDIT: also should say, that drain bolt is very nice! Shouldn't be changing my fork oil for ages so having to take the forks out of the yoke isn't the end of the world anyway

Well done that man! I'm helping my bro sort the forks on his Daytona some time soon, I think it'll be another araldite job on the pitting.

Araldite is your friend :)