What fork springs? brand and type.

[barwel1992]

looking for some fork spring about £70-80 but haven't a clue what to look for apart from i know i need 90kg fork springs according to racetech

i can get K-tech for £80 but not sure about any others ? and what fork oil would i need? 10w ? and what size spacers would i need, and how much oil is needed per fork leg ?

im 108kg with just t shirt and boxers (racetech say weight without gear)

looking to get these done soon :)

[dizzyblonde]

Hagon Prgressives.

whats 108 kg in stones.....you skinny then?

[TazDaz]

Hagon Prgressives.

whats 108 kg in stones.....you skinny then?

Unless he's 8ft tall, I'm going to say no! :)

17stone or so.

[dizzyblonde]

lol, I'm old, I don't do kilos ;-)

Thats a bit heavy then :-)

[Specialone]

Well im 6'1" and quite built and weigh about 100 kilos which is about 15 stone 8 pound.
So yeah quite heavy lol

[barwel1992]

all right all right i like pies ...... lmao, trust me im losing it lol 20min run every other day about 2.75km

anyyyy wayyy i keep seeing progressive springs are not any good and to go with linear

btw im just under 17stone was 16 start of last year

[barwel1992]

ok so going to go with linear 90kg (reading most of the spring threads say that they are best (correct me if im wrong))

now what most suggest 12.5w MOTUL oil for the front but have head that 15w is ok as well ? 1 litter will be enough for both sides apparently but how much each side exactly ?

and then spacers do you use the standard spacers or cut new one, i have no idea if spacers are included ? and what length would i need to use ?

[embee]

I fitted K-tech linears in my curvey SK1 and they were direct replacements for the OE, used std spacers. Don't know if that'll be the same for the K3, the suplier should be able to advise.

As for oil, it depends a bit on the make/type, have a gander at the white table halfway down here (http://www.peterverdonedesigns.com/lowspeed.htm) which lists the viscosities and VI for a load of oils. As a general guide you want an oil with a high VI, in other words the viscosity isn't highly sensitive to temperature.

I've switched to Silkolene PRO RSF, and so far I'm very happy with it. The actual viscosity you use will depend on the weight and the spring stiffness, but I'd guess something round 40-45cSt at 40C would be a start. I use PRO RSF 7.5W which is 37cSt and similar to most 10W oils, but I'm 76kg and use 0.8kg/mm springs. Pick an oil in your chosen range and give it a try.

[barwel1992]

^ thats complicated :\ lol

and the k-tech ones say direct replacment on the k3 so that's that sorted :)

now just the oil thats confusing me to death lol

[barwel1992]

ok so looking again at the motul oil 15w seems to have ok number of 77.90 at 40c with my weight in mind i supose i would need heavy oil

PS never going to be less than 16 stone, as i do weights as well so muscle will add weight eventually

[Specialone]

PM Ralph, he's just done his springs, he did say he maybe should have gone for progressives in the end as his linear ones are a bit hard.

[barwel1992]

hmm ok :/ with kit on i weigh a tone lol so i think the 90kg one will be ok and i will be taking pilion as well

[barwel1992]

now its just the oil, keep seeing 20w oil been used (SVrider recomend it) but i think the motul 15w oil will be enough ? looking at that chart

[Spanner Man]

Good morning all.


Go for Hagons & use their recommended oil, & oil level. I've supplied hundreds & never had anyone who wasn't happy with them.


Cheers.

[BigBaddad]

Save your cash and stop eating all the pies.......hope this helps.

If not any of the big names should be fine it's all a matter of preference, I agree with Spanner Man about Hagons, not heard a bad word said against them. But most people would feel a vast improvement over 10 year old standard fodder being replaced by a good spring and new oil.

I have Bitubo linear springs and 15wt oil in mine and they're great for me and I'm no light weight. But what works for me, might not for you. My rear shock is up to the max and forks dropped by 3mm. Linears can feel hard but my frontend is loaded up. Progressive springs in idiot speak have a stiff end and a soft end, they're designed to soak up the smaller bumps on the road, but you'll get a bit more initial dive. Most people find linear spring too harsh for the road. If you are planning on riding with a pillion stick with progressive. I feel linears work best if you really load up the front end. Having a pillion would shift the weight backwards and your bike won't handle.

But best go to a company with as much info as you can about the type of rider you are and the roads you ride, be honest your surname ain't Rossi. These guys deal with lots of bikes, how many people on here can boast the same. You may find with a stiffer front end your tyres will get worked harder. Good tyres will work better because of this, bad ones may feel worse.

[cbay]

LINKY (http://forums.sv650.org/showthread.php?t=148588)

Have a read there, might help ^^^^^

[dizzyblonde]

anyyyy wayyy i keep seeing progressive springs are not any good and to go with linear



Its personal preference.

I have both progressive and Ohlins linear in my bikes. I prefer progressive.

I seem to recall someone saying progressive were more for road than linear anyway, I may be wrong.
I have 15w in with my Hagons, and even though some may think thats a bit harsh for my ten stone weight, I actually like them that way, The linears did have 12.5 with them, but in an oil change we put in 10w and I bloddy hate that, so will be going for a higher grade when they get played with next.

[barwel1992]

thanks all :)

ok looking at hagon and they dont list the sv in the fork spring section ? also are the progressive springs Dependant on your weight like the k-teck's been .90kg springs for my 108kg weight

[dizzyblonde]

I got my hagon stuff from Wemoto.
Plus if you ring Hagon, they are helpful.

[simesb]

ok looking at hagon and they dont list the sv in the fork spring section ? also are the progressive springs Dependant on your weight like the k-teck's been .90kg springs for my 108kg weight

No - they're a compromise spring for all riders.

FWIW, I fitted K-tech progressives and was very impressed. Soft enough for comfort when about town, but with much improved feel on track. (new fork oil will have had something to do with this too)

[barwel1992]

No - they're a compromise spring for all riders.

ohh right ok thanks

FWIW, I fitted K-tech progressives and was very impressed. Soft enough for comfort when about town, but with much improved feel on track. (new fork oil will have had something to do with this too)

hmm the k-tech ones are linear, they dont seem to have any progressive ones at all so im presume they dont do them any more ?

these are the ones for my bike and my weight LINK (http://www.k-tech.uk.com/product_detail.php?id=2228)

ohh and with the hagon springs wont they still be to soft for my 17stone lard ass ?

[simesb]

hmm the k-tech ones are linear, they dont seem to have any progressive ones at all so im presume they dont do them any more ?

My mistake - I meant to say Hyperpro.

ohh and with the hagon springs wont they still be to soft for my 17stone lard ass ?

Not necessarily. Only you know how you ride and how much you load the front. Suspension is a black art, and while there may be rules of thumb, what works for one rider may not work for another.

At the end of the day, the stock springs in the SV could charitably be described as adequate; almost anything you fit with new oil will feel like an improvement.

[barwel1992]

ok thanks :)

i have a fast paced riding style usually quite smooth, i don't load the front that much into most corners, but the ones that i do load at the moment bottoms the fork out

im tempted by the hagon's because of the price but i think im leaning more towards the K-tech because i have progressive springs in my push bike and im not a fan of how the operate (bad comparison i know) so all in all im leaning towards the linear

[simesb]

i don't load the front that much into most corners, but the ones that i do load at the moment bottoms the fork out

Are you sure? Have you tried zipties to actually measure the travel used?

[barwel1992]

yeh im sure as there's a gathering of dirt residue at the top of the forks about 1.5cm from the bottom yoke like its all been pushed up from the lower part of the stantions, it could have something to do with the raised tail and dropped front putting more weight on to the front end

im going to go and fit my calipers back on and do the zip ties and see what happens and report back

[barwel1992]

Are you sure? Have you tried zipties to actually measure the travel used?

hear you go, this was a run to my shop about 3 mile round trip with some fast low islands

and yes i know my bottom yoke is rusted :smt091

http://i357.photobucket.com/albums/oo16/barwell1992/26032010396.jpg

EDIT not bad quality for a phone pic

[simesb]

Quite a bit of travel used there...

FWIW, when I had the progressives in I had to wind the preload almost right out to get the right sag which indicates that they are stiffer than stock.

[Nobbylad]

I had Hagon progressives, they were a massive improvement on stock, but nowhere near as much as the Gixer front end.

[barwel1992]

hmm dilemma, im thinking about getting the hagons now just because of price, but think the -tech ones would be more suited for my weight

nobbylad what size spacers did you have to use ?

[Nobbylad]

Can't remember, Flymo would know. TBH - after I did the Hagons, the front end was WAY better than it ever was, but then I kept thinking I could have spent the £80 towards a Gixer front end.

In the end of the day, I bought 3 x sets of Gixer forks and each time I bought one, I decided to sell them on again because I didn't want to shell out loads to upgrade the front end. The 3rd set I bought, I got a complete front end and ended up making money after selling my SV bits (which paid for a Halfords Pro socket set amongst other things).

If your patient and are prepared to shop around, you'll pick up the bits you need. I guess it's all about being prepared to take your time. Hagons are a good, cheap, quick upgrade though.

[barwel1992]

i rely dont have the cash for a gixer front :( otherwise i would definitely get one

[Nobbylad]

I made money on mine. I think CheGuevara did too. If you're patient, know exactly what bits you need, it can be done for even money, or maybe about the same cost as new springs/emulators.

[embee]

All this debate about progressive/linear, what matters is the spring rate or stiffness. You could fit "progressives" which have just the right range of rate for you, or you could fit some which were completely in the wrong range or way too progressive etc.

One "advantage" of linears is that you know what you're getting, if it says 0.8 or 0.9kg/mm then that's what you've got. Who's seen a stiffness spec for any progressive springs? There must be some around but I've never seen any supplier give a data sheet.

Personally I think the OP should go with the 0.9 linears, seems to be spot on for what he wants. I don't find any disadvantages with the linears I have even though on paper they are slightly stiffer than I need, it just feels firm and well controlled but in no way harsh.

[barwel1992]

^ thats whats bothering me about progressive springs, so im going with the k-tech linear springs (.9kg) with 15w motul oil, and 58 or 54mm spacers with a 130mm air gap :)

[barwel1992]

right then, ordered springs and oil, decided to go with 10w motul instead of 15w if i decided the 10w is not enough then i will put 15w in but im sure any thing will be better than what i have now :)

then i will set the sag on the rear end as well

[yorkie_chris]

You go for the .90 springs? I would say those or even .95s.
With travel you're using there that looks like you'd be into the oil locks so effectively bottomed out.

[barwel1992]

went for the .90's as im losing weight at the moment (looking to lose a stone) so didn't want them to be to stiff, just wating for a PM from ralph regarding fork spacers (he sead he will give me some and i can cut them down)

or can some one link me to the corect pipe on B&Q's site (i cant find it)

[yorkie_chris]

See what length they arrive at, compare it to free length of spring in manual.

[barwel1992]

ralph has the same springs and Icanopit who did ralphs springs sead the k-tech springs are 12mm shorter than stock he made up spacers (3 sets) of 58mm (+/- 4mm) he sead he was using 36.2mm OD and 31.6 ID tube id bet the spec in a shop would be 36mm OD and 32mm ID but i cant find any

[barwel1992]

ok so i have 10w oil and im thinking (now after ordering it :rolleyes: ) that i could have done with 15w (k-tech dont sell 15w though) so you lot think think 10w will be ok or should i get some 15w ?

[yorkie_chris]

Try it. It is mostly for rebound. I think 15w would be better.

[barwel1992]

ok because im lazy i will get some 15w and go with that, cant be bothered removing the forks again after refitting them

[barwel1992]

what static/rider sag should i have ?

[DarrenSV650S]

17

[barwel1992]

17mm, hmm that a fair bit different to what else i have read EG 30mm static and 40mm rider sag :/

but also have heard 20mm static and or 30mm rider so a tad confused

[DarrenSV650S]

41

[davepreston]

giving the lad ramdom numbers will just get him hurt, barwel the only way to do it is for someone else to adjust it while your on there then quick ride and re adjust

[yorkie_chris]

20mm static, then try it.

[barwel1992]

thanks lads

just cut the spacers, still waiting on replacment abba stand kit

[barwel1992]

job jobed :D

static sag is 20mm and rider (no gear) is 35mm so it should be about 40mm with me in gear

feals fu*king hard compared to the stock springs :) will test it out tomorrow (might drop the rear wheel off first though)

Its only take me a month to get my abba stand fitting kit from M&P :|

[Troy]

feals fu*king hard compared to the stock springs :)

When I first tried out my new, stiffer springs, I thought there was no way they could be "right", judging by how stiff it felt sitting in that garage. I only had the OEM SV springs to compare it to though... Should be good! :-D

[dizzyblonde]

Stiff is good ;-)

[-Ralph-]

Barwel, how are you getting on with them? What length spacer did you cut in the end and where is your preload set?

[barwel1992]

haven't tried them yet will do in a bit

and ralph preload is 1 1/2 turns in from fully out although not sure they are supposed to be that far out so might wined them in a bit, and i went with 58mm spacers with a 130mm air gap

i have to say it was definitely a 2 man job, bike kept tipping forward when removing and refitting the fork's so roped in the gf to lean on the back of the bike while i torqued all the bolts up :P

[yorkie_chris]

Preload adjuster doesn't matter as such.

That spacer you made determines internal preload i.e preload with adjuster all the way out. Total preload is internal preload plus however much you tighten top adjuster.


It is 2 man job because you must have been using wrong stand.

[barwel1992]

^ i was using a abba stand and a car jack under the the front (didn't have any thing else)

YC do you know how much fork can be sticking out of the top yoke ?

[yorkie_chris]

Jack must have been in wrong place then, should be rock solid like that.

You can drop them a long way safely, like 20mm IIRC. However far you drop them you need to remove top caps and let the forks sink down afterwards to check the mudguard or tyre does not hit any other parts of the bike.

[barwel1992]

ok cheer will give it ago

and hmm i placed the jack on the flat part next to he oil drain bolt, wrong place ?

[yorkie_chris]

block of wood on the jack, right behind the oil filter.

[barwel1992]

ahh ok at least i know for next time :)

thanks

[yorkie_chris]

Or drill some rawbolts into floor so you can strap back down.

[barwel1992]

i could but dont think my dad would let me do that

[-Ralph-]

haven't tried them yet will do in a bit

and ralph preload is 1 1/2 turns in from fully out although not sure they are supposed to be that far out so might wined them in a bit, and i went with 58mm spacers with a 130mm air gap

i have to say it was definitely a 2 man job, bike kept tipping forward when removing and refitting the fork's so roped in the gf to lean on the back of the bike while i torqued all the bolts up :P

OK, let us know how you get on.

I'm using 54mm spacers, air gap as standard, and my preload is about the same as yours. You might find there's a bit too much preload there with the longer spacer, I set it three turns in and had to back it off by 1 1/2 turns to get a more comfortable ride over drain covers and bumps. I'm going to re-measure static sag, change back to the standard spacer if I need to, and test ride again, and if it's still too hard for my liking, I'll try a 12.5w oil.

It may be an idea to meet up and have a short test ride of each other's bikes to compare notes. Maybe at Bassets pole or the Waterman when they get started.

[barwel1992]

only have 10w oil so will see how that goes to :)

will test it out if there to much preload i will make some smaller spacers

[-Ralph-]

only have 10w oil so will see how that goes to :)

will test it out if there to much preload i will make some smaller spacers

Well my bump absorption issue is probably the compression damping and not the pre-load, but I want to make sure sag/preload, etc is OK before changing the oil. Change too many things at once and you get in a muddle. I would definitely be interested to know how you get on with the 10w oil as I think 15w is too heavy.

We are the same weight, on the same bike with the same springs, but possibly different preferences about how we want it to feel.

[yorkie_chris]

What spring rate you got ralph? Too fast rebound can feel harsh too.

[-Ralph-]

What spring rate you got ralph? Too fast rebound can feel harsh too.

0.9kg/mm. You've just made me stand on the scales and I'm not happy!! 104 kilos (16st 4). F***ing Easter chocolate! :mad:

[barwel1992]

WOW that is all that i can say lol

ok its not all i can say, went on a quick ride through town centre down some dual carriageway and on some of the back roads also hammerd it over some speed bumps

general town riding is a lot smoother no jarring when hitting pot holes no load clunk ether and no harsh rebound (the oil i took out was like water)

dual carage way i was on is very unsmooth and the front seemed to cope very well and kept prety plush at XXXmph

speed bumps, well i wanted to see if i could bottom the forks out so hit some speed bumps at about 50mph (the big type) and the forks didn't bottom out my travel marker is about a inch lower than the bottom yoke befor with the old springs it was 1/4 and that was with just road riding

on the twistes the front seemed a lot more planted

i need to do some more open road riding but so far its a hell of a lot better

apart from one thing ...... the steering seems slow i think its because before the bike was sagging about 50mm under its own weight so i have gained about 25mm of front end height slowing the steering down so im going to pop the fork caps off at some point and fully compress the springs to see how much i can push the forks up through the tripples without having clearance problems

[barwel1992]

0.9kg/mm. You've just made me stand on the scales and I'm not happy!! 104 kilos (16st 4). F***ing Easter chocolate! :mad:

u think thats bad ....... im 16st.12 again put 2 pound on in 2 weeks :mad: :(

[-Ralph-]

general town riding is a lot smoother no jarring when hitting pot holes no load clunk ether and no harsh rebound (the oil i took out was like water)

dual carage way i was on is very unsmooth and the front seemed to cope very well and kept prety plush at XXXmph

OK, sounds like I definitely need a lighter oil.

[barwel1992]

let me ride it a bit more first though just in case i decide the oil is to thin

just so you don't waste time and money :)

[yorkie_chris]

What brands are you both using?

[barwel1992]

im using motul 10w factory line (bit crap on that chart of ures)

[yorkie_chris]

What do you mean crap? Thicker oil does not equal better.

The 22.3cSt one?

[barwel1992]

yup thats the one

and i ment its crap compared to some of the other 10w oil's ;)

[yorkie_chris]

That's not how I'd define crap.
Viscosity @ 40 deg is one factor in a huge number of them, VI performance, wear, additive package... all need considering.
Maybe that crap oil is actually great compared to maxima or something because it keeps its viscosity after 2000 miles.


There isn't really good or crap in suspension... they're all factors which can be manipulated.

Take an example, you compare some ohlins springs @ 1.0kg/mm for you to say WP springs at 0.7kgmm for a 125 GP bike. Does that make the WP springs crap?


Personally I think that oil is very light for stock forks and you should use something around 35-40cSt@40deg

[-Ralph-]

What brands are you both using?

http://www.sportsbikeshop.co.uk/product_images/motul_forkoil_medium_heavy_15w.jpg

[barwel1992]

you should use something around 35-40cSt@40deg

thats what i was meaning by crap :rolleyes: :)

[-Ralph-]

Somebody point me to the fork oil table again?

[barwel1992]

i cant find it ether and ralph i do know the stuf you have has a very high cst@40 rating

[yorkie_chris]

http://www.peterverdonedesigns.com/lowspeed.htm

[barwel1992]

well the 15w motul expert has a 77 cst@40c

[yorkie_chris]

A different site reckons it is 57cSt.

[-Ralph-]

well the 15w motul expert has a 77 cst@40c

OK, did you get that from another source as I can only see Motul Comfort on the table YC just posted.

What does that cst figure mean? Is that my problem?

[yorkie_chris]

I think motul make a number of oils with similar ratings. Source I have is not confirmed reliable either.

Best bet is to email motul.


Barwel be careful with that table, just because it is same maker and same SAE rating (5w, 10w, whatever) does not mean it's on about the same oil.
Look at silkolene... they make "fork oil 5W" and "Pro RSF 5" which are both nominally 5w but quite different oils.

[-Ralph-]

OK, found a PDF from Motul

http://www.motul.com.au/product_line_up/fork_brake_others/images/PDF/FORKOIL_EXPERT_BLEND_CHART.pdf

15w = 57.1
50% 15w + 50% 10w = 45.1
10w = 35.9

It also says Factory line Medium 10w is 35.9 as well.

The peterverdondesigns page says damper rod forks should use 34

So I think I'm going to buy a bottle of the 10w and try that, then if it's not thick enough I'll buy another bottle of 15w and do a 50/50 mix.

[barwel1992]

Barwel be careful with that table, just because it is same maker and same SAE rating (5w, 10w, whatever) does not mean it's on about the same oil.
Look at silkolene... they make "fork oil 5W" and "Pro RSF 5" which are both nominally 5w but quite different oils.

yeh i know because the fork oil i have "factory line" has a lower cst than the other motul comfort stuf

and searching for motul comfort brings back nothing so i presumed it was motul expert

[yorkie_chris]

I don't see why you press point when motul website proves your assumption was wrong.

[barwel1992]

i was just answering what you wrote

:-s

no need to blow a head gasket now is there :smt019

[yorkie_chris]

"I presume" is in the present tense, which implies you still presume despite being proven wrong. Seems a little odd.
Who is blowing gaskets, I do this for fun :-P

Anyway it would be prudent to state if something isn't clear. People aren't too friendly if you advise them based on assumptions and guesswork and they then go and spend their money on the wrong thing.

[barwel1992]

there fixed it for you :D