Harsh Cer Forks.

The last card in the deck is these new softer springs arriving tomorrow, I have the rear wheel off for a new tyre and while I was there pulled the chain guard for a blast and paint so hopefully, by next weekend I will know if I have wasted my time or not.
 
Certainly sounds like softer springs will increase your travel, Vince. I'd persevere until you feel you've done everything you can, now that you've sunk the big loot into it. Race preppers since time immemorial have been modding std stuff to get the best out of it.

Sure, you reach a point like CK and I did where you go with modern suspension, but there's a lot to be said for getting the best out of what you have. If we all abandoned ship on modding forks, noone would even bother fitting emulators, and they are tried and true.

I personally went modern because I have felt stiction ... and I hate it. One of the reasons I'll go with suspension upgrades is that I reckon the SF frame is inherently very stiff, low and in many ways resembles modern frame design. I just need ot steepen that steering head to match the modern offset triple clamps to bring trail into usable realms!! I LOVE this stuff!  :P :P :P
 
Glad to see this thread still rolling 😂. Will be interesting to see how my forks behave after the bingle and the new triple clamps!

My shitty fork performance was solved by a spacer between the NZ valvy thing and the return hole! Works well at the track at least!
 
One of my first dirt bikes was an XT 500 Yamaha, I wanted long travel suspension on it so I acquired the frontend of a later model Yamaha 2 stroke and its alloy mono-shock swingarm. I got a couple of twin shock mounts welded onto it and fitted a pair of remote reservoir Ohlins and got 11 inches at the rear. I mucked about with the other frontend, steering stem and that got me 300mm at the front but it was racked out to hell so it went to the local motolinner bloke who pulled the frame rack in as much as he could and it ended at 27 degrees from 34. That bike went great till it caught fire and burned to the ground. So this isn't new to me.
 
This post is for people who want their original bikes updated to as good as they can get within the prettywell original framework.
Anyone could come on here and criticize all the work people do with engines and tuning and make the same comment "why don?t you just buy a modern bike". It is what we do.
Click to expand...
Get off your high horse Tippie. It wasn't a go at people on the forum, just stating a different point of view. I personally believe that updating a bike is fine, emulators, shocks, ignition, tyres etc., done it myself but I reckon there is a limit to how much a bike should be changed from how it left the factory. On the other hand I am amazed by the lengths some take to keep their bike(s) totally original.
I'm of the opinion that modifications should be limited to keep them safe and reliable and that any other changes should be changes that would have been done back in the day.
Just an opinion ;)
 
I doubt that lower rate springs will increase fork travel by much. The distance that the wheel moves up and down over bumps is determined as much (if not more) by the shape of the bumps and the fork damping as it is by the spring rate.

Best way to get more suspension travel is to find a bumpier road and ride faster!  :D
 
How far back or up do you sit on your Pantah Vince? i.e. are they std handlebars or more upright (and with risers perhaps?)? could be you don't have enough weight over the front wheel to make the suspension work properly: another reason to of for softer springs...
 
That makes sense, I have modified the seat by removing the front bit of the removable pillion section so I can fit a bit better and have clipons with risers up as high as I can get them. That would affect the bikes front-back balance but it still has these solid at 80mm forks. The new springs haven't arrived as yet, I am sweating on them making a big difference.
 
I am heavy, maybe 300psi. The pain continues, I discovered why this Pantah seems to have no top end power, someone reduced the rear sprocket from a 40 to a 38. I had ordered a rear tyre and wanted to paint the chain guard so when the tyre arrived I was going to do the sprocket swop, I ordered one and it arrived the next morning, then it I almost broke my alan key and my 12-volt rattle gun wouldn't touch the sprocket bolts. I had to visit a mate to pull it and even then it took a 3/4 drive air rattle gun to loses them. So all really to fit the wheel and I notice the bike shop has fitted the tyre backwards. I told them what side the chain was on as well. So hopefully Monday the softer fork springs will arrive and the tyre will be reversed and the bike might turn a wheel and I will finally know whether the missing 50mm of fork travel has come back.
 
Vince said:
The pain continues, I discovered why this Pantah seems to have no top end power, someone reduced the rear sprocket from a 40 to a 38.
Click to expand...
Hate to rain on your party, Vince, but the gearing might affect top end in high gears, but if it won't produce power at revs in any gear it's nothing to do with the gearing! I fitted a one tooth bigger gearbox sprocket to that little 250 I rode to Sydney last year - still flies at revs in every gear, just a bit sluggish in 6th up a hill (below 8,000rpm!)
 
Telling them what side the chain is on is expecting them to work out the rotation direction themselves. Seems to be beyond some of the tyre fitters to do that. ::)

When I take a wheel to a shop to have a tyre fitted, I always grab a felt tip pen and put arrows on the rim showing the direction of rotation, so it eliminates that step in their thought process. All they have to do is match the arrows on the rim with the arrow on the tyre. They couldn't possibly fuck that up, could they? 

Well, yes. They could fuck it up. Even with the arrows on the rim, it pays to check before leaving the shop. On one occasion I went to pick up a wheel from a shop, and the tyre arse about. I told bloke behind the counter. He called the mechanic over, and the mechanic called the guy who actually fitted the tyre. He looked about 16 years old, and had just started work there a couple of days before. It wasn't his fault though. They'd shown how to operate the tyre changing machine but forgot to tell him that tyres had a direction arrow on them! The kid said he thought I'd put arrows on the rim so I knew which way to put it back on the bike.

He'd done about 8 tyres since they put him on that job. The probability is that 50% of them would have been arse about.  I suggested that they call those customers and ask them to check the arrows on their tyres, but I dunno if they ever did. 
 
Yes, I get that, it was geared to the moon though. It took a fair bit of clutch slip to get off the lights and with a cold engine that was a pain in the arse. The top end effect was flat accelerating above 5k and a bigger gap between gears. There was a discussion on the Pantah Face Fuck page on gearing that worked and what I had,
15 x38 was too tall by all accounts. It's now 15 x40, not a major change but it's only a 600 and I hope this will work to the engines strengths. Doesn't help I am 125kgs as well. The tyre fitter was the shop's OWNER, and he is who I told about the chain side. I have known him for 30 years, okish bloke even if he still tries to sell me bikes I dont want all the time.
 
Dellortoman said:
Telling them what side the chain is on is expecting them to work out the rotation direction themselves. Seems to be beyond some of the tyre fitters to do that. ::)
Click to expand...

I have my own tire machine ...... and I have messed up on at least one occasion. Thankfully ..... having my own tire machine means I can fix my own fuckup.

I'm pretty sure it was one of those look at the tire ..... yep that's the right way ....... lube the tire with soap ..... then flip it over and lube the other side. Number one way to mess up tire install.

Once you do it once ...... you won't do it again. Sorry for the kid who didn't get trained properly. Hoping he turns out to be one of the ones who's a thinker.
 
helicopterjim said:
I have my own tire machine ......
Click to expand...
So you obviously know about the dot that indicates where the valve aligns (to aid balancing), Jim?

Bicycle tyres are nearly all directional these days as well. I know correct fitment from tread patterns without trying to find the arrow these days.

Vince, once you get your 120mm of travel (keep 10mm for emergencies  :D , give it to a dyno person. You just might find a whole shedload of missing power!
 
You must log in or register to reply here.
Back
Top