Author Topic: C5 Classic fork springs (Read 5848 times)

swingarm · **on:** March 15, 2014, 03:21:24 am

Hagon shocks and fork oil are a big improvement over stock handling but the front dives too much under brakes. Seems the stock springs are too soft. Unfortunately Sonic can't supply springs for the C5 any longer. Are there any recommended alternatives? Searching hasn't turned up anything definitive for the Classic (2009).

cheers

Professor · **Reply #1 on:** March 15, 2014, 03:51:09 am

Call Progressive Suspension in Hesperia California. They usually can help.

Ducati Scotty · **Reply #2 on:** March 15, 2014, 04:33:11 am

I tried the Sonics, they squeaked like crazy which is probably why they don't offer them any more. I forget the diameter of the RE springs but no one made a perfect match, so I got a slightly smaller diameter from Sonic. Sometimes it works, sometimes not. It didn't for me.

You can always take out the springs, do the math, figure out how many coils to cut off to get the spring rate you want and do it. You'll need to heat and collapse the last coil so it sits nicely but it's not too hard.

Honestly, just replace the stock oil with the proper amount of a good 10W fork oil. You'll be amazed at the difference.

Scott

swingarm · **Reply #3 on:** March 15, 2014, 05:27:50 am

Quote from: Ducati Scotty on March 15, 2014, 04:33:11 am

Honestly, just replace the stock oil with the proper amount of a good 10W fork oil. You'll be amazed at the difference.

Scott

Yeah the stock oil was awful. I replaced it with 10W. Might try some 15W instead.

As far as the springs go, I think the stock ones are too light and going with a heavier straight wound spring would do the trick. I had my last bike (XJ900S) done by ProMechA here so it may time to visit Peter again.

Thanks for the advice.

Professor · **Reply #4 on:** March 15, 2014, 07:32:17 am

If all else fails in terms of getting new springs. Go up in the weight of the oil and add a piece of metal tubing or PVC as a preload. All Progressive kits come with preload instructions. Easy to find on line. This is old, old technology.

Ducati Scotty · **Reply #5 on:** March 15, 2014, 02:55:16 pm

Also, get some good rear shocks. After I got some Hagon shocks for the rear the front felt much better. It's just that the rear now matched it much better.

Scott

swingarm · **Reply #6 on:** March 15, 2014, 04:45:05 pm

Quote from: Ducati Scotty on March 15, 2014, 02:55:16 pm

Also, get some good rear shocks. After I got some Hagon shocks for the rear the front felt much better. It's just that the rear now matched it much better.

Scott

Hagons are the best single upgrade I've done on this bike.

barenekd · **Reply #7 on:** March 15, 2014, 06:54:02 pm

+1 on the Hagons. Have you tried Racetech for springs?
As for the forks, mine improved so much after I got the sludge out and some 10W fork oil that I never worried about them after that.
As for preloading the springs with shims, The better deal is to cut some off to stiffen them, then worry about the shims. Shimming alone will just cause the coils to bottom out, as you're not actually changing the spring rate.
Bare
Bare

swingarm · **Reply #8 on:** March 15, 2014, 10:38:29 pm

I'm using the ProMechA articles as a guide
http://www.promecha.com.au/articles_index.htm

It's a challenge to improve this puppy. The only downer is having to remove the C5 forks to do anything.

Ducati Scotty · **Reply #9 on:** March 16, 2014, 12:48:36 am

I really like their "misconceptions" section.

Scott

swingarm · **Reply #10 on:** March 20, 2014, 08:54:22 am

Fitting new EBC brake pads seems to have solved most of the diving problem. The stock pads had only done 6000km and felt 'grabby'. Progressive application would go from slight braking to a lot with not much in between. It was hard to modulate braking in the wet or during cornering. Now there's the sort of feel you'd expect.

I'll leave these pads to settle in and go to 15W fork oil as a last resort. So far it's looking good.

Ducati Scotty · **Reply #11 on:** March 20, 2014, 11:41:01 am

Do you have the EBC part number? I'm due for new pads.

Scott

swingarm · **Reply #12 on:** March 20, 2014, 03:48:47 pm

Quote from: Ducati Scotty on March 20, 2014, 11:41:01 am

Do you have the EBC part number? I'm due for new pads.

Scott

FA228

They were convenient to get locally on the day. I don't know if the old pads were typical of stock part performance but these are much better in my case.

Ducati Scotty · **Reply #13 on:** March 20, 2014, 04:23:48 pm

Are those copper/semi-metallic or organic? I think they have FA228 (organic/kevlar) and FA228HH (semi-metallic).

Scott

swingarm · **Reply #14 on:** March 20, 2014, 07:26:22 pm

Quote from: Ducati Scotty on March 20, 2014, 04:23:48 pm

Are those copper/semi-metallic or organic? I think they have FA228 (organic/kevlar) and FA228HH (semi-metallic).

Scott

The standard oganic kevlar ones. I didn't like metallic pads when I tried them on other bikes but I'm not an aggressive enough rider to get heat into them anyway.

cheers

Professor · **Reply #15 on:** March 20, 2014, 07:44:03 pm

I have a new C5. I just replaced both from and rear suspension. I choose Progressive Suspension. Measure the rear shock eye to eye, order the shock in this length. Order springs that suit your weight. Progressive has figured the sag for the rear in the application. Progressive will give you the part number for the front springs and the amount of static pre-load comes with the kit.

swingarm · **Reply #16 on:** March 20, 2014, 07:56:50 pm

Thanks for the info. I've got 18kg Hagons on the rear which is just right for my weight. The front upgrade you've done is next on the list.

(if I don't become a heretic in the meantime, having lustful thoughts about the 690 Superduke I checked out yesterday)

Ducati Scotty · **Reply #17 on:** March 20, 2014, 08:22:20 pm

Quote from: swingarm on March 20, 2014, 07:26:22 pm

The standard oganic kevlar ones. I didn't like metallic pads when I tried them on other bikes but I'm not an aggressive enough rider to get heat into them anyway.

cheers

Agreed. Unless you're putting the bike on the track I'd rather have smooth modulation than maximum stopping power. They tend to beat up your disc too. I am keeping the metallics in mind if I add a sidecar though.

Swingarm, what diameter springs did you get from Progressive? When I contacted them they did not have the right diameter. I tried some slightly undersized springs from Sonic but they squeaked like an old gate hinge. Do you have the part number?

Scott

swingarm · **Reply #18 on:** March 20, 2014, 08:55:55 pm

Prof has done and recommends the Progressive upgrade on the front. I've done rear shocks (Hagons), 10w fork oil and brake pads. Surprisingly the pads have made a big real world difference. I might try 15w fork oil if I can be bothered with the effort, otherwise the Prof's Progressive spring upgrade looks like a goer. Sonic won't supply RE springs now.

Re metal brake pads - I found them too savage for normal road use, almost dangerous particularly on the rear of an elderly Suzuki GS850G and not much better on a Yamaha XJ900S. I can't see how a UCE (sans sidecar) has the grunt or weight to make them work properly even for a very determined rider.

Ducati Scotty · **Reply #19 on:** March 20, 2014, 09:05:28 pm

Quote from: swingarm on March 20, 2014, 08:55:55 pm

Sonic won't supply RE springs now.

I suspect that's because I had problems with them.

Scott

Professor · **Reply #20 on:** March 21, 2014, 10:05:56 pm

[Let me sort out the springs. I installed them, but they are stiff. Also a bit of a different diameter than the Indian springs. So, until I am satisfied, I'd hold my comments. Just am not sure right now.Rear shocks are fine. Dennis Kirk sells the progressive rear. There is no direct application for the Enfield. So, I had to measure preload for the first inch of travel, diameter and over all length.

swingarm · **Reply #21 on:** March 22, 2014, 01:43:54 am

I reckon I'll drop the idea of a front spring upgrade for now based on the collective experience of Scotty and Prof.

Professor · **Reply #22 on:** March 22, 2014, 05:13:39 am

I'm going to visit Race Tech this week so I'll let you know what they can do.

Professor · **Reply #23 on:** March 25, 2014, 01:39:04 am

Go to Race Tech on the net. There are Race Tech dealers/suspension shops who can help you. This is not beyond fixing. What we look for is catalog fix, here is part number, buy it and install. For the Enfield that won't work. More in depth work is required. Trust me GT owners will start this ball rolling.

The_Rigger · **Reply #24 on:** May 01, 2014, 09:40:12 am

Quote from: swingarm on March 15, 2014, 04:45:05 pm

Hagons are the best single upgrade I've done on this bike.

+1!!!