A question about springs...

[amyroukai]

Hello to all and greetings from Athens, Greece.
Bought a gen 1 in November, late 2001 model. I have been reading about it here since, trying to get to know the bike and you have been a great source of information and ideas.

So far I had to change the tyres, brake pads, chain and sprocket, all due to natural wear. But the suspension is killing me. It spoils all the fun. Plus, it's impossible to carry a +1 because it bottoms out all the time. Tried to buy new springs from the local market, but the fazer was never a poplular bike here and no local garage has been able to help me. Tried White Power, Ohlins and Hyperpro reps wth no luck. Perhaps they don't care to order two more pieces, together with their regular orders... So I followed your footsteps and emailed a couple of people you have had good experiences with, but no reply... So I will post my question here, opinions are welcome.
I was looking at the old racetech spring rate calculator, now the new one as well. The old calculator gave 1.092kg front and 9.57kg rear. The new one, 1.077kg front and 9.16kg rear for the same weights.

So, according to them, I should get the 1.0kg front in any case.
According to the old calculator I should buy the 96kn/9.8kg
According to the new calculator I should buy the 92kn/9.4kg

I am going for the higher rate and not rounding it up to the lower rate because I usually have the top case on the bike, loaded with stuff and that's something the calculator's not accounting for. I also do a lot of two up plus luggage, so a little firmer is more welcome than a little softer. And that's why I thought, get the 96kn/9.8kg spring.
But I was recently talking about it with a friend who said don't go overboard with the spring, otherwise your rear suspension will not work, it will not compress enough. But here's two options from the same source and they are both "correct". And it got me confused. How big a difference will it make, choosing the harder spring over the softer one? Is there really a risk of having a suspension that will not compress enough when riding solo or when I take the old girl to the track? The difference in numbers seems small... But then again I'm a civil engineer, not a suspension technician. Any thoughts on the matter?

[eflyguy]

I have a 625 (lb) on the rear of my Gen I, and although I don't ride 2-up, that's how the bike was set up. Also have full luggage - leave them on as the rack is ugly and I use them for groceries and such. The bike rides great even riding solo.

I am no expert, but I am pretty sure you need to adjust the valving as well as the springs, otherwise they will not be able to dampen correctly.
..a

[amyroukai]

thanx for the info, however that wasn't my point. You are using a 11kg spring, so I guess you're a lot heavier than me.

I was just wondering if anyone knew how big a difference it would make to choose the stiffer spring, rather than the softer, given that the rates are not that different.

given that the shock is adjustable, I am certain that I will find a sweet balance with the compression and rebound settings. if an oil & gas change doesn't do the trick, then I will revalve the shock and forks.

[rswebscan]

I can't think of any reason you'd want a softer spring on the rear shock. The stock shock spring is rated for someone that is about 130 pounds. If you're riding 2 up, you're way overloading the stock shock spring.



Lee at Traxxion Dynamics in Atlanta, Georgia may have some suggestions for you. His boardname here is Sportryder.

[Wlfman]

Originally Posted by rswebscan

I can't think of any reason you'd want a softer spring on the rear shock. The stock shock spring is rated for someone that is about 130 pounds. If you're riding 2 up, you're way overloading the stock shock spring.



Lee at Traxxion Dynamics in Woodstock, Georgia may have some suggestions for you. His boardname here is Sportryder.

Corrected

on Lee, he can answer all your suspension questions.

[amyroukai]

Originally Posted by rswebscan

I can't think of any reason you'd want a softer spring on the rear shock.

From what I understand, there's a rate after which the rear spring is just too hard for one-up. Suspension is always a compromise. The same spring cannot support one-up and two-up (plus luggage sometimes) in the same, "good" way. So I want to use the hardest spring possible that will allow my suspension to function as it's supposed to while riding one-up and then compensate for the extra sag that comes with the second person with an increase of preload on the spring. It will not be perfect, but when it comes to such diverse weights on the bike, it never is. It will be a lot better than the current situation though. I now measure about 7 cm of static sag one up, instead of 2.5cm which is the theoretical "sweet spot". Half the rear travel is used up, before I start riding.

Yep, the factory spring is rated for a 40-45kg rider, I weigh 95kg (I think it's about 210 pounds). What I am trying to avoid is creating the opposite effect to the factory spring. Now it's too soft and the suspension compresses too much, I don't want the new one to be so hard as to not compress the suspension enough. Since the only source of info on what rate to choose for my weight was racetech's site, I used their numbers as a reference point. And I was thinking, 92N and 96N don't seem to be that different being just 4% harder (and White Power offers a choice of 85N or 95N rear as well, but the Greek dealer is reluctant to provide me with one, god knows why) so the 95N/96N choice seems "correct" for the rear. A more educated opinion on the matter wouldn't hurt, especially since I don't have the opportunity to test ride the springs before I buy, as I have read people do in the UK. Worst case scenario, 96N is too soft or too hard and I have wasted about 110$ plus shipping... I was just trying to avoid the trouble, if possible

I have seen sportyrider reply to threads, but never got a reply of my email to traxxion and it's almost been a month since I sent it... Plus, it doesn't make sense to ship my suspension to the US! Greek dealers may not want to sell products for some reason, but they will fit whatever springs I bring to their shop and check seals, bushings, change oil and gas etc.

[sportryder]

Originally Posted by amyroukai

... I have seen sportyrider reply to threads, but never got a reply of my email to traxxion and it's almost been a month since I sent it... Plus, it doesn't make sense to ship my suspension to the US! Greek dealers may not want to sell products for some reason, but they will fit whatever springs I bring to their shop and check seals, bushings, change oil and gas etc.

If you are 210 lbs you need a 600 lb/inch shock spring. If you ride above 5 on a 1-10 scale then you should also have the shock revalved by a professional suspension tech so the valving matches the spring. The stock spring is ~420 lb/inch. Maximum rebound damping on the stock shock is close to -600 lb/inch at 10 ips velocity. Not nearly enough to keep that stiffer spring under control.

Under my avatar picture is my email address. You want to get email to me, write to that address. If you do not send it to that address, I cannot guarantee I will respond since anything else is not me. Thanks.

BTW, no one company in the world has done as much work with FZ1 suspensions as Traxxion Dynamics has. The FZ1 owners on this web-site have provided the feedback over a large number of years so the company I work for can get it right for FZ1 suspension upgrades. Because of that, the FZ1OA web-forum could be considered the best source of information regarding suspension upgrades for the FZ1. Race Tech doesn't have this data nor does any other company in the world. These are straight-up facts.

[rswebscan]

Originally Posted by amyroukai

From what I understand, there's a rate after which the rear spring is just too hard for one-up. Suspension is always a compromise. The same spring cannot support one-up and two-up (plus luggage sometimes) in the same, "good" way.

That makes perfect sense. From your earlier post I read it as your were thinking about going harder or softer than the "stock" spring, but you were speaking of the "optimal" spring for the specific condition.

[rswebscan]

details, details

[barryc]

Originally Posted by amyroukai

Hello to all and greetings from Athens, Greece.
Bought a gen 1 in November, late 2001 model. I have been reading about it here since, trying to get to know the bike and you have been a great source of information and ideas.

So far I had to change the tyres, brake pads, chain and sprocket, all due to natural wear. But the suspension is killing me. It spoils all the fun. Plus, it's impossible to carry a +1 because it bottoms out all the time. Tried to buy new springs from the local market, but the fazer was never a poplular bike here and no local garage has been able to help me. Tried White Power, Ohlins and Hyperpro reps wth no luck. Perhaps they don't care to order two more pieces, together with their regular orders... So I followed your footsteps and emailed a couple of people you have had good experiences with, but no reply... So I will post my question here, opinions are welcome.
I was looking at the old racetech spring rate calculator, now the new one as well. The old calculator gave 1.092kg front and 9.57kg rear. The new one, 1.077kg front and 9.16kg rear for the same weights.

So, according to them, I should get the 1.0kg front in any case.
According to the old calculator I should buy the 96kn/9.8kg
According to the new calculator I should buy the 92kn/9.4kg

I am going for the higher rate and not rounding it up to the lower rate because I usually have the top case on the bike, loaded with stuff and that's something the calculator's not accounting for. I also do a lot of two up plus luggage, so a little firmer is more welcome than a little softer. And that's why I thought, get the 96kn/9.8kg spring.
But I was recently talking about it with a friend who said don't go overboard with the spring, otherwise your rear suspension will not work, it will not compress enough. But here's two options from the same source and they are both "correct". And it got me confused. How big a difference will it make, choosing the harder spring over the softer one? Is there really a risk of having a suspension that will not compress enough when riding solo or when I take the old girl to the track? The difference in numbers seems small... But then again I'm a civil engineer, not a suspension technician. Any thoughts on the matter?

Traxxions got your action Jackson, I'm so clever...

[amyroukai]

thank you Lee, an email's on the way.
my last email was addressed to "info@..." so obviously it never made it to you. Or maybe it was that I used my hotmail account and got mixed up with all the spam.

[amyroukai]

I was, yes. And now with his post, Lee has added more food for thought and I'm a little confused...

hopefully we will sort it all out via email. the "good" season's here, track days have been going on for a couple of months now and I'm just watching all the others have fun...

[Jared]

Lee is the man. I'd send it to him from Greece. He did the suspension on my bike and its a new machine.

[amyroukai]

Parking my bike for three weeks at minimum is simply not an option. I am looking into the possibility to buy a shock off ebay, ship it to Lee and have traxxion work on it and ship it to me, together with front springs. If it's not cost effective, I will just buy front and rear springs and have a local shop do the rest. It's a good thing I know some people who race, they can introduce me to the right people for the job. However, after reading all your recommendations and praises for Lee and traxxion, these guys should be damn good and I'd prefer to have them work on the bike. I will know what to do, shortly...

A big thank you to all of you guys! Will be back with impressions when I'm done. Ride safe!

[WDD]

I like the idea of having Lee re build the shock for you.

But there is another option. He can set up a band new Penski shock for you and mail it to you. It will cost more, but is a nicer shock.

You will save the $ of buying a used shock and of shipping it to him in the first place.

[amyroukai]

After talking to Lee quite a bit, I ended up buying a used shock off ebay like WDD said, had it delivered to Traxxion, Lee had it all prepped up and it will be on it's way to me soon, together with bushings and front springs.

Lee is as awesome as everyone here described. He bombarded me with so much tech talk I had to open up both the service manual and some online fork schematics and how-this-works articles so I could understand everything he told me.

Now I am waiting for the suspension to arrive...

Thank you all for the advice... And my preliminary thanks to Lee and Traxxion for being so customer friendly and going above and beyond the typical behavior I was expecting. I have to try the new stuff before I go ballistic praising them for their work...

[rswebscan]

What is really cool, is getting to watch him rebuild a shock in person. I got the birds-eye view 2 summers ago when he rebuilt my Penske

[amyroukai]

And now, the good and the bad news.

Got the shock a week ago, stripped the whole rear out, cleaned the linkage, took out the rear wishbone (or whatever you call it) and cleaned and greased the axle. There was minor corrosion in the dogleg screws but scrubbed it off with 2000 fine sandpaper, then packed everything with lithium grease and reinstalled. Rear sag was 35mm (I did the measurement alone, so I have to admit accuracy is not perfect, so maybe I am a few mm off).

First impressions were mixed. The bike was firm and strangely comfortable, except for the biggest of bumps. I was really amazed, I was expecting it to hop all over the place because of the hard spring, a 600lbs was installed. Two up, it was similarly composed, though didn't go on a long ride. Took a long-ish ride with mates on Saturday through some twisties and I was trying to find MY own new limits, the bike was planted exactly at the places I was expecting her to bob and weave like she did with the old stock shock... I was happy. Firm, planted and not jolting me with every little imperfection of the tarmac but giving me information of what's underneath my wheels. A "new" bike... Didn't have time to change the oil and install the fork springs though.

And then, I take my gf for a ride on Sunday. We decided to do a 400km ride, to finally enjoy riding without a bike that hits the bump stops all the time... And 10 seconds after I closed the garage door, a 77 year old comes into the road from my left, hits the bike and we're flying, landed on a freshly plowed field, without hitting any trees. Thankfully it was mostly bruises and a small (but deep) cut on my gf's calf. Instead of spending the day having fun, we spent it getting Xray-d and sewn up... It's a good thing I nagged about her wearing shoes instead of sandals and wearing her jacket even though it was 35 degrees C...

The Fazer's hurt (front and rear plastic parts, gas tank and the left frame protector, plus the "mushroom", streering, counter weight, mounts for the rear top case and the top case itself... and that's what I can see without taking her apart). So riding will have to wait until insurances work it out. Damn... Just when it was getting to be fun

Thank you Traxxion, thank you Lee and Dan... For doing what you promised to do and delivering on time, offering a good product.
I hope to enjoy your work soon.

[eflyguy]

Geez. Sorry to read that. Glad you're relatively unhurt, though!
..a

[rswebscan]

Man, sorry to hear about that. You learned the importance of gear the easy way I think....