Breva 1100 fork springs

[egschade]

I'm doing my spring prep work now on my '07 B1100 which will include a fork oil change. I've read about going to a slightly heavier weight oil - which I probably will - but I'm also thinking at 220# in my gear plus some stuff in the bags I could go with stronger fork springs. The front end dives a lot on anything more than mild braking and to get the sag right, I'm near max pre-load on the adjusters.

I've not found any threads on upgrades and am uncertain what to look for. Would B1200 sport springs do the trick or better to go aftermarket? Any advice will be greatly appreciated!

[guzzisteve]

I have installed these in customers bikes, they work.

http://www.guzzitech.com/store/product/norgebreva-fork-kit/

[toma nova]

I also bought heavier springs from Todd Eagan for my 1200 Sport.  Send him your weight with gear / luggage and he'll let you know the correct rate.  I went from stock to 10W fork oil, made a big difference. I posted a tech write up on GuzziTech with photos and specs.

[EvanM]

Another  :+1 for the Matris kit. Put that in, along with 20wt oil, and the front end is amazing. Night and day better than before.

[egschade]

I have installed these in customers bikes, they work.

http://www.guzzitech.com/store/product/norgebreva-fork-kit/

I see that I can order just springs for about 30% the cost of the kit. I'm not that aggressive a rider so if I go with springs and some heavier oil will I really miss the full kit?

AND, if I go with the full kit will my sock need upgrading as well?

Thanks for the info BTW. Internet search was pretty useless.

[balvenie]

          You could try just talking to the IKON people near you, before putting your money down. Their fork srings alone have transformed my Cali ;D

[guzzisteve]

If you're happy w/rear shock why change it. Try just the springs & 15 weight oil. I just do what the customer wants.
My 98EV still has stock suspension, just heavier fork oil. I don't load it up w/lots of gear. Just tent, sleeping bag and a change of clothes. Always traveled light.

[EvanM]

I see that I can order just springs for about 30% the cost of the kit. I'm not that aggressive a rider so if I go with springs and some heavier oil will I really miss the full kit?

Yes. In my opinion you will anyways.

As for the rear, I upgraded mine, but I could have done without doing that.

[cheekieduckie]

Thought I'd share my recent work on the fork springs on my 2007 Breva.
I bought the bike with about 3500 miles and it currently has a little over 5k.  I made sure I rode it 'some' before tweaking.

The front suspension I found a little soft in terms of mid-corner wallow but yet harsh when it came to sharp edge (expansion gap type) bumps on the highway.  It seemed to (in my mind at least) to demonstrate the symptoms of soft low-speed compression with hard high-speed compression damping.  Or maybe I was just trying to talk myself into getting Racetech cartridge emulators

Anyway, I thought to take it one step at a time.  Using Racetech's calculator and my 275lb heavy mass, I determined I needed a fork spring rate upwards of 1.05kg/mm.  FWIW, it looks like the Matris kit comes with 11.5N/mm (1.17 kg/mm) spring so it seemed like I was in the same ballpark.  This info came from http://www.guzzitech.com/forums/threads/breva-norge-fork-mods-1200-sport-info.8213/
http://japan.webike.net/products/21827041.html

The ID of the springs is 38mm and I picked FRSP S3732110, a 1.1kg/mm spring.
The original sag was 38mm w/6 turns out.  The original spacer/spring length was 205+280 mm = 485 mm
I cut the new spacer to 165mm.  Add the spring (315mm) and washer (1.8mm), the new stackup came to 482.5mm
The new spring didn't have a taper to it and so sits on the outside step of the preload adjuster, giving it another 2.5mm boost.

I filled it with 10wt Belray @ 400cc.  I drained approximately 480cc from each leg.

Here's a good link describing the process:
http://www.guzzitech.com/forums/threads/breva-v1100-fork-oil-change.2202/

Once re-assembled, I found I had to back the preload adjusters to 10 turns (was 6) to achieve the same sag.  I'm guessing this is due to the increased spring rate.  There was about 15 turns on the adjusters @ 1mm increment per turn so it didn't bother me too much.

Unfortunately I did put fresh PR4s on the bike as well....not an entirely controlled experiment.

Why the weird spring kit? It was also sized for my Futura...so that was a contingency in case this went horribly wrong   

I've had it back out and in search of bumpy spots and curves with undulation.  So far I like it (only 50 or so miles).  It does appear a tiny bit harsher on low-speed compression but much better composed on high-speed bumps.  Overall less pumping of the handlebars and pretty happy around corners.

Just thought I'd share my 2 cents.

Ken

[guzzied]

I installed the Matrix fork kit into my 2014 Norge as everyone said it worked great. Well for the price of the kit, I didn't find it worked much better than stock. Yes, the fork spring was much stiffer 11.5kg for my 220 lbs. with full gear. The bike still had too much fork dive for my riding style. So what comes in the Matris kit, fork springs, fork spring spacers, adjustable spring preload adjusters and plastic orifice's to control the fork oil which Matris states to use 10wt. The front fork sag is between 28-30mm. with the preload adjusters backed all the way out, the fork dive was better but I wanted it better, I pulled the forks again and changed the fork oil to 15wt, went on a 500 mile trip and while it is better, I would still prefer less fork dive. My next plan is to install the Race Tech Emulator and Race Tech springs as I feel the 11.5 kg springs are too stiff for my weight. To me, I feel the Matris fork kit is a band aid fix. Just put stiffer springs in with the stock 15wt or heavier 20wt fork oil and save yourself some money.

Just my thoughts, Mike

[cheekieduckie]

Mike
Thanks for sharing, I think I'm headed toward the emulator path too.  I haven't disassembled my forks yet (not sure what the top of the piston looks like), but I'm thinking about trying FEGV S4301 and adapting as needed.
For what it's worth the FRSP S3732xxx series is available from .85 to 1.2 kg/mm.

Ken