View Full Version : best front fork springs?
Gaz.sv650
19-03-11, 02:10 PM
hey i am going to get some new springs for my front end just wanted to know what you guys think i am looking at either hyperpro or maxton? any others? whats best?
thanks
Any of them will be fine, the manufacturer is less important than getting the correct spring rate. K Tech (http://www.k-tech.uk.com/rr_springs.php) also do springs for the SV650.
Gaz.sv650
19-03-11, 03:00 PM
what spring rate whold you say i have no expriance with this? i weigh 10 and a half stone if that helps ha
The Racetech Calculator (http://old.racetech.com/evalving/SpringRateCalculation/dirtspring.asp?brand=Suzuki&yr=03-07&ml=SV650S&formuse=form1&SpringType=Fork&bikeid=510) suggests 0.85
I'm 12st and have the k-tech linear 0.85 springs, just about right for me, I'd reckon they'd be fine for you too. Way better match than the OE springs anyway.
I use Silkolene PRO RSF fork oil, one of the better spec oils IMO (very high viscosity index VI, which means it doesn't change as much with temperature). Personally I find the PRO RSF 7.5W suits me in the SV, but be aware that the nominal viscosity of that is more like a typical 10W oil (around 35cSt@40C). Check out the viscosity table in the bible here (http://www.peterverdonedesigns.com/lowspeed.htm).
I've had race tech and ohlins springs in my old curvy, couldn't really say there was a difference except that the ohlins springs cost about a tenner more.
Gaz.sv650
19-03-11, 10:28 PM
ok thanks 8.5 it is and think i will go with the ktech is like toxic said there a tenner less :D
andrewsmith
19-03-11, 10:33 PM
I'd Pm sv650racer and see if she'd get them any cheaper as mine were few pounds cheaper inc postage
yorkie_chris
19-03-11, 11:48 PM
At 10.5 stone if you are doing mostly road I would go for .8s
coolevilangel
19-03-11, 11:57 PM
are ohlins any good for the 650? or the thou in my case
Theyve got a massive sale on at the mo
yorkie_chris
20-03-11, 12:00 AM
Springs are springs. Just get the right rate and they're fine.
What makes you think the thou is undersprung? They're not half as bad as the 650
coolevilangel
20-03-11, 12:04 AM
Springs are springs. Just get the right rate and they're fine.
What makes you think the thou is undersprung? They're not half as bad as the 650
Am just thinkering lol
Im a hefty 100kg on the thou and under heavy braking it does lurch, so looking at poss options.
What rate spring would do?
K-tech are a joke. The have a 10% variance so your 0.8's could be 0.9s and vise versa.
I ordered 0.9 to replace 0.85's and for a 0.87 and a 0.88.
When I phoned to complain, I was told it didn't matter what was written on them due to the 10% variance and that they'd be "OK". They couldn't have cared less about it and basically wanted me off the phone. I'll not spend a penny with k-tech now.
So I bought racetec's. More expensive but what they say is what they are. (+/- 3%)
and you see "Mr Couldn't give a ****" at K-tech? There are these things called forums, where people spread news about bad service and unacceptable variance in a "precision" product.
C
K-tech are a joke. The have a 10% variance so your 0.8's could be 0.9s and vise versa.
10% of 0.8 is not 0.1.
I ordered 0.9 to replace 0.85's and for a 0.87 and a 0.88.
Say again? If you mean you measured your 0.9 springs at 0.87 and 0.88 then they are within about 3% of the nominal value. Chances of you noticing the difference is very tiny.
Gaz.sv650
20-03-11, 10:10 PM
hey thanks for the tip you got a link for the ohlins sale?
Gaz.sv650
20-03-11, 11:47 PM
Anyone know the 650 stock spring rate?
Electro
21-03-11, 12:01 AM
Good old Maxton, when i collected my .95`s the owner stated they were both tested and matched at .95. Dunno about othe spring costs but £96 inc vat for the maxton springs and spacers was good enough for me. £8 for the oil and bingo, sexy forks :)
andrewsmith
21-03-11, 07:55 AM
Anyone know the 650 stock spring rate?
Stock 0.73, or in English an 8-9 stone rider
kaivalagi
21-03-11, 09:10 AM
Are progressive springs not worth a mention? Alright they're a bit more but if your weight can vary quite a bit throughout the year or you might take a pillion now and then they wouldn't be a bad choice, no? Twinshack have the true progressive Hyperpro springs for £94 (http://www.twinshack.co.uk/prods/290.html)
Twinshack have the true progressive Hyperpro springs for £94 (http://www.twinshack.co.uk/prods/290.html)
I have Hagon progressive springs in my forks, how do the hyper pros differ?
kaivalagi
21-03-11, 09:34 AM
I have Hagon progressive springs in my forks, how do the hyper pros differ?
Hagon are not progressive, they're dual rate that operate very closely to what progressive would...I'll try and dig out the discussion on it here...
If you look at pics of the hagon springs you'll see 2 distinct wind rates, whereas the hyperpro's vary along the length
I don't have either, I will be purchasing soonish, so I'd like to think I am unbiased :thumbsup:
Hyperpro springs pic: http://www.moorespeedracing.co.uk/user/products/large/hyper-pro-progressive-springs.jpg
Hagon "progressive" springs pic: http://shop.wemoto.com/pictures/springs/hagonsprings.jpg
All this is what I have read and am led to believe, I would love to be proved wrong cause I'll buy the cheaper Hagon springs is they're the same
Too late for me, I have the Hagon's already, for road use, with a Hagon rear shock, they seem fine.
Are progressive springs not worth a mention?
As long as you fit progressive damping to go with them...
kaivalagi
21-03-11, 09:50 AM
As long as you fit progressive damping to go with them...
Seriously, for road use is it such a concern?
They seem like the best all around choice to me when the forks you have don't have all the bells and whistles like the newer tech sports...
Voidoids
21-03-11, 10:35 AM
Hi everyone, I found this and other fork spring topics very informative, so I thought I'd share my experiences before and after a hagon front fork spring/oil change...on a '55 SV650S
I was experiencing less than perfect stability in corners, too much dive during braking, a tendency to run a little wide as a result. Not confidence inspiring. I has real issues running on rutted tarmac (lots of that around Cornwall at the moment!) with the bike tracking badly, especially under hard braking downhill. I got paranoid that my 9yrs off motorcycles had took it's toll on my confidence levels!
I fitted the hagon progressives, and recommended oil. The original oil was in my opinion badly deteriorated, more so in the left fork that the right - water contamination??
Had a good ride out on Sunday, and the results were startling. I'm approx. 13-1/2st all up, with a standard shock at the rear - on position 4. Used the re-sprung forks on position 3.
I rather expected the diving problem to be improved, and, of course the damping. What I was most surprised about was the total elimination of tracking, and the improvements in straight-line at speed. The handling has been DRASTICALLY improved and it's good to know that it wasn't my imagination at work!
Whilst I'm not a racer, and my bike may have been a bad example of badly decayed oil, I have to say that the upgrade was worth every penny.
Hope this helps the discussion.
10% of 0.8 is not 0.1.
No, its .08. I can do maths :)
So if you order 0.8 you could be getting anything from 0.72 to 0.88
Say again? If you mean you measured your 0.9 springs at 0.87 and 0.88 then they are within about 3% of the nominal value. Chances of you noticing the difference is very tiny.
I ordered .9 springs and received 0.87 and 0.88 to replace 0.85 springs.
80 quid to have them nearer the old springs than the target. So I phoned them and was told that it didn't matter becasue there was a 10% variance on what was written on the springs anyway.
So I sent them back. and Bought racetecs... in 0.95 (to make sure)
C
yorkie_chris
21-03-11, 07:30 PM
bingo, sexy forks :)
Plus some $$$ for emus and about 6 trips to Halifax :-P (sorry!)
Are progressive springs not worth a mention? Alright they're a bit more but if your weight can vary quite a bit throughout the year or you might take a pillion now and then they wouldn't be a bad choice, no? Twinshack have the true progressive Hyperpro springs for £94 (http://www.twinshack.co.uk/prods/290.html)
Truly progressive?
Personally I don't like them. From heavy braking the front seems to ping up, but going to a heavy 20W oil made them do weird stuff. No happy medium.
There's no problems with spring rate if your weight varies, not like you're going to put on 10 stone is it. And the forks hardly notice a pillion.
Seriously, for road use is it such a concern?
They seem like the best all around choice to me when the forks you have don't have all the bells and whistles like the newer tech sports...
Depends how fast you like to go on the road really.
Personally I think having suspension as good as possible is more important on a road bike, and I dislike the road/race separation people have in their heads. On a racetrack if you fall off, you don't die.
What is "all around" choice? Nobody seems to try and understand all or even any of the things at play beyond reading the bumf :-P
Progressives from either manufacturer are better than stock. Hyperpro ones have feature that you can add preload and change spring rate range. But do you really want to do that?
I don't like how they don't release information about their springs. I want to know what I am using so if you get issue x you can narrow it down to variables a b or c, if you have unknowns in there you are blind.
kaivalagi
21-03-11, 07:56 PM
Truly progressive?
Personally I don't like them. From heavy braking the front seems to ping up, but going to a heavy 20W oil made them do weird stuff. No happy medium.
There's no problems with spring rate if your weight varies, not like you're going to put on 10 stone is it. And the forks hardly notice a pillion.
I'll read some more me thinks before I do anything...
TBH I am umming and arring as to whether I should start on the SV mods or just trade it in for something with fully adjustable suspension, better calipers and a more perky engine and be done with it...
Depends how fast you like to go on the road really.
Personally I think having suspension as good as possible is more important on a road bike, and I dislike the road/race separation people have in their heads. On a racetrack if you fall off, you don't die.
Gotcha, that's the sort of stance that has got me thinking that rather than trying to make something of the SV that isn't all that great I should just bite the bullet and get something that's bang on in the first place....
I think this whole thing comes back to the other argument I read about, either the bike limiting you in the longer term or you limiting the bike....I am starting to think having a bike that can performance past my abilities will be best....especially as I improve as a rider.
edit: Apologies for taking the thread off on a tangent a little, it's just that a little explanation and justification would be a nice to read when suggestions on what's best are being posted...I was asking genuine questions and it looks like I need to get my head around the fundamentals myself before I'll be satisfied rather than posting lots of what if's...sorry. The next question I need to ask myself is even if I get the front suspension sorted out for me will the brakes be the next limiting thing....trouble is I don't know 100% until I get there, if I get there....might be better just to not mod and upgrade the whole bike!
yorkie_chris
21-03-11, 11:10 PM
Gotcha, that's the sort of stance that has got me thinking that rather than trying to make something of the SV that isn't all that great I should just bite the bullet and get something that's bang on in the first place....
Why not make the SV something great? All you need is a good rear shock and a set of cartridges up front.
No such thing as a bike that's bang on in the first place.
Every stock bike has compromise, they need to work with fat blokes, thin blokes, corners, drag racers, muppets attacking the settings etc. etc.
yorkie_chris
21-03-11, 11:21 PM
I think this whole thing comes back to the other argument I read about, either the bike limiting you in the longer term or you limiting the bike....I am starting to think having a bike that can performance past my abilities will be best....especially as I improve as a rider.
edit: Apologies for taking the thread off on a tangent a little, it's just that a little explanation and justification would be a nice to read when suggestions on what's best are being posted...I was asking genuine questions and it looks like I need to get my head around the fundamentals myself before I'll be satisfied rather than posting lots of what if's...sorry. The next question I need to ask myself is even if I get the front suspension sorted out for me will the brakes be the next limiting thing....trouble is I don't know 100% until I get there, if I get there....might be better just to not mod and upgrade the whole bike!
There is no such thing as "limiting", there are people who will get a stock bike around a track faster than next bloke on a fully sorted one. The only limit that matters is that you AND the bike are better than the situations you put yourself in, which comes down to roadcraft and observation.
However your cornering skills are dependant on confidence in the bike, which comes with suspension and tyres. And having confidence and good setup will mean you can pull yourself out of the sh*t when observation breaks down (which it inevitably does on occasion).
Some other skills, like smoothness, are really well honed on a stock bike, as to corner well on a stocker you need to be really good at making the weight transfer just right.
Put spot on suspension on there, and you can be very gibbon like in the application of controls, while getting absolute feedback from the tyres giving you confidence you're not booking a short stay in the highside hotel (nice view but the foods sh*t).
Or just the lack of any phantom "aaahhrg I'm going to run wide" feelings which are probably the biggest limitation of stock kit.
But are we getting philosophical on a thread which should be technical?
On another note if you go from stock to some progressives, while they might not be the best option, they are probably 50% of the improvement.* Linears probably 55%. Well set up cartridges, 90%. Emulators when working absolutely perfectly on a good day, 90%.
*Which is why you go "wow" when you first try them and why people think they're ace, because they're much better than stock. To quote Paul Thede "the best you've ridden is the best you know".
kaivalagi
21-03-11, 11:37 PM
Thanks YC, you went out of your way with that explanation, very much appreciated!
I ordered .9 springs and received 0.87 and 0.88 to replace 0.85 springs.
80 quid to have them nearer the old springs than the target. So I phoned them and was told that it didn't matter becasue there was a 10% variance on what was written on the springs anyway.
So I sent them back. and Bought racetecs... in 0.95 (to make sure)
C
The point I was making is that the springs that K-Tech sent you were within Racetecs tolerances.
So I am a DIY lover,changing the fork springs for stiffer linear seems the way forward but are there cartridges that fit the stock forks.I am not wanting to do the front end swaps but do get the bike running wide on ripply roads when cranked over so would like to try something.Not convinced about emulaters.
Gaz.sv650
22-03-11, 09:49 PM
phoned ktech yesterday and they said i will need 0.9's so hopefully they will be on the bike by the end of the week think i might as well strip down the forks and give them a good service well i have them half apart anyway what have you found to be the best oil? i like putoline all of there stuff has seemed to be very good for me
yorkie_chris
22-03-11, 10:13 PM
So I am a DIY lover,changing the fork springs for stiffer linear seems the way forward but are there cartridges that fit the stock forks.I am not wanting to do the front end swaps but do get the bike running wide on ripply roads when cranked over so would like to try something.Not convinced about emulaters.
Yes there are a couple of ways to do it
Yes there are a couple of ways to do it
ok searching found the cbr6f3 97/98 showa forks work any others?
I understand that the cartridges also need modded to my weight.A mates got modified blade forks on his 95 cbr6 and vtr forks on his vfr shimmed etc so recon he could help me along :cool:
But,all this in mind.Will a stiffer spring slow tip in,I am sure I read a soft spring makes for too fast a tip in?I need a .85/.9 spring for my weight but already have the forks through the yokes a bit to speed turning on the standard springs,to the point that the front tire drags you slightly into the turn at say a roundabout.
So a stiffer spring may mean moving the forks up the yokes more ,to get the same tip in and then the ground clearance is reduced and stabilty under power say coming off of a humped back bridge on full throttle may be reduced?
yorkie_chris
23-03-11, 06:47 PM
Spring rate doesn't affect tip in, dynamics of geometry affect tip in, which a stronger spring is one factor of.
Yes you need to revalve them really.
If you are coming off a humpback bridge at full throttle then forget front end setup, it makes no difference when airborne.
Spring rate doesn't affect tip in, dynamics of geometry affect tip in, which a stronger spring is one factor of.
Yes you need to revalve them really.
If you are coming off a humpback bridge at full throttle then forget front end setup, it makes no difference when airborne.
does when you land,front shakes :reaper:,will stronger springs will make that worse?
Gaz.sv650
23-03-11, 09:28 PM
springs came today :D chuffed with them well worth it for the price stops better and even on a pretty much bold front tyre (woops) i can feel better front end grip thanks again for the help guys
Sorry for reviving an old thread but was reading about upgrading my front fork springs. I'm 105kg and have been saying that cornering makes me nervous on my sv650s k3. My friend had a go on it yesterday and I tried out his daytona 675 and it is worlds apart. He said the forks feel awful like either the oil in them has deteriorated badly or something like that. I then started reading about the front suspension on here and it seems I'm probably far to heavy for stock front springs and would be better suited to 9s n/mm does anyone here have any knowledge in whether I should change the oil and springs or just change the oil to a heavier viscosity?
dont try and compare the cartridge forks in the 675 to damper rod forks on the SV as they are two completely different types of suspension. adding springs and fresh oil wont turn a sows ear into a silk purse.
yes you are waaaayyyy to heavy for the standard springs but springs and oil alone wont suddenly transform the SV forks. it will make them better but wont cure the design of damper rod forks and they will still bounce up and down like a kangaroo due to the non existent dampening, in fact you might make things worse so be very very careful what oil you put in them. if the oil is too heavy you will lock them up and the front will rattle your teeth out, too light an oil and you will bounce about all over the place. there is nothing you can do apart from fit emulators to help keep the forks under better control. fitting emulators requires a fair bit of work to be done to the damper rods.
Hi thanks for the quick response. I appreciate I can't make my bike perform like the daytona I just want the bike to not dive so much and be a little firmer when cornering. I have had my bike a fair few months now and do about 300 miles a week on it at present I just take it easy round corners and it has done me fine so if I get some slightly heavy springs luke the .9 ones the racetech calculator suggests and some 15w oil will it still be an improvement?
nutzboutbikes
03-09-15, 03:29 PM
Hi thanks for the quick response. I appreciate I can't make my bike perform like the daytona I just want the bike to not dive so much and be a little firmer when cornering. I have had my bike a fair few months now and do about 300 miles a week on it at present I just take it easy round corners and it has done me fine so if I get some slightly heavy springs luke the .9 ones the racetech calculator suggests and some 15w oil will it still be an improvement?
Yes the correct spring rate for your weight will be a big improvement the standard ones are very soft, 15w oil is good for road riding.
Right thanks also I read I don't want progressive springs or are the hyperpro okay?
nutzboutbikes
03-09-15, 03:41 PM
Stick with linear springs bud, have a look here http://www.brooksuspension.co.uk/
That's where I've been looking thanks. I watched a video on youtube and it looks an easy job too
nutzboutbikes
03-09-15, 03:50 PM
Yes its a pretty straight forward job, my advice is just take your time, do one fork at a time and make sure the air gap is the same in each leg
i would not recommend you use 15w oil, its too heavy and wont flow through the orifices properly which will give you a harsh compression. stiff suspension is bad and will cause rapid wear to your tyres as the carcase will be taking more brunt. mind you this all depends on the brand of oil you use as they are all different cSt for a given weight, some might say 15w but will me more like 10w.
nutzboutbikes
03-09-15, 04:39 PM
i would not recommend you use 15w oil, its too heavy and wont flow through the orifices properly which will give you a harsh compression. stiff suspension is bad and will cause rapid wear to your tyres as the carcase will be taking more brunt. mind you this all depends on the brand of oil you use as they are all different cSt for a given weight, some might say 15w but will me more like 10w.
I didn't notice that 15w oil makes the suspension harsh I felt it help to combat the pogo effect, oil level or air gap has more effect in my opinion, I use 17.5w oil for trackdays which seems spot on and stops the bike going into a second down stroke after being compressed which is what your looking for.
I didn't notice that 15w oil makes the suspension harsh I felt it help to combat the pogo effect, oil level or air gap has more effect in my opinion, I use 17.5w oil for trackdays which seems spot on and stops the bike going into a second down stroke after being compressed which is what your looking for.
thats ok on a smooth track but start hitting potholes and its a different kettle of fish. the SV has very week check valves that leak like a sieve thats why you find heavier oil better but at the expense of fast compression. oil level only works on the last 1/3 of the stroke and on damper rod suspension its not that aggressive.
what 17.5w oil did you use?
wideguy
03-09-15, 06:02 PM
Sorry for reviving an old thread but was reading about upgrading my front fork springs. I'm 105kg and have been saying that cornering makes me nervous on my sv650s k3. My friend had a go on it yesterday and I tried out his daytona 675 and it is worlds apart. He said the forks feel awful like either the oil in them has deteriorated badly or something like that. I then started reading about the front suspension on here and it seems I'm probably far to heavy for stock front springs and would be better suited to 9s n/mm does anyone here have any knowledge in whether I should change the oil and springs or just change the oil to a heavier viscosity?
As you've heard here, get springs to suit your weight. It's worth it and you have to take them out to replace the oil anyway.
Since your bike is 12 years old, there's a possibility there isn't much oil left in the forks, which will certainly make the damping poor.
The air trapped above the oil in your forks is a progressive spring, so you can get additional spring by adding more oil, but too much will reduce the travel.
nutzboutbikes
03-09-15, 06:11 PM
I used 15w oil in the forks when the bike was a road warrior and found it to be ok, as with most things it personal preference but will do no harm, I have seen a lot of people say that 20w is ok for a track bike however I found it a little on the slow side.
I use Rock oil and aimed to get a cst number of around 60.
wideguy
03-09-15, 08:09 PM
I used 15w oil in the forks when the bike was a road warrior and found it to be ok, as with most things it personal preference but will do no harm, I have seen a lot of people say that 20w is ok for a track bike however I found it a little on the slow side.
I use Rock oil and aimed to get a cst number of around 60.
I prefer suspensions on the firm side for my weight. I'm pretty good at staying loose on the bike if the road turns bumpy, and it's great when the road is smooth.
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