Spring choice considering after trip riding time
I've got a F650 Dakar which I'm kitting out for a few overland trips.
I've just ordered some emulators and springs from Race Tech taking into account the roughtly 50kg of luggage and things I'll have to carry.
They hooked me up with some stiff springs to cope with this weight but mentioned that I wouldn't really want to use these springs when riding without luggage. I'll be using the bike in between long trips for like weekends away and stuff.
No big deal. I'll just get the stock springs shortened or change the spacer length and change them over each time I plan a trip with full luggage which won't be very often for little weekends away.
The thing I'm wondering now is how do people deal with this with their rear shock. I'm also getting an Ohlins shock for the same weight. Do people get another lighter spring with it to cope for the bike in normal conditions get the springs swaped and re-conditioned (or whatever they do to it) and simply change it back when they do another large trip?
If you're getting a second shock, get it with the softer spring for your weekend riding. Changing shocks is a lot easier than changing springs.
Just a thought
To be honest, I can't really see what you are going to achieve - more or less as the last post said.
For instance, 50Kg = about the weight of a (light) pillion passenger = can be adjusted on the preload (just as for "one-up riding" changing over to "two-up riding"). So long as the shock does not bottom out all is well, and I am guessing that you are overlanding one-up.
I adjust the preload regularly with my wifes F650GS, depending on 1 or 2 in the saddle and it has not bottomed out so far.
After that, have as many shocks as you can afford and change them often!
A fully adjustable Ohlins will be very nice indeed.
I put a heavier spring on my XT for my luggage. Even without any preload, its pretty stiff.
On the road, this is actually an improvement (as long as the front is also stiffer). Its like riding a supermoto :thumbup1:
No good for offroad though.
50kg can be adjusted on a stock shock by using pre-load but you then have limited travel and a harsher ride.
I agree with Dave. No need to change shock or spring to accomodate different riding/load. With the right spring choice and increased damping in the first place you should be able to do well either loaded or unloaded by simply adjusting preload, compression and rebound damping to suit load. The preload
adjustment will be the most significant when adding 100 kgs.
If you buy an Ohlins (I wouldn't) or a Wilber's (I would) you can adjust preload remotely. Unloaded you would back preload off all the way to allow a more compliant/plush ride with the lighter load. If you get the right spring, unloaded you would have almost NO preload dialed in.
So the idea is to get a spring that is stiffer than stock and but would handle
your load. But I would not go too crazy. As Dave points out, the stock bike can handle a passenger....maybe not perfectly, but adequately.
So go stiffer but set it up so that when unloaded and preload is backed off, the bike will still ride nicely. With a quality, fully adjustable shock, it should handle great with the big load too. Just remember, no matter what suspension
mods you make...a fully loaded bike is still a handful and will never, ever match the nimbleness or performance of an unladen bike.
The easy way -
Compress the entire shock with spring (you don't need to full compress it - just enough to be able to dissassemble it). You could do this while it is on the bike .. just lean on the back of the bike so it goes down. (assumes you have acess to the spring for the next step) You could make a temproy jig to do this ... bolt one end of shock to bench .. other end to a leaver (2x4 bit of wood) fix short end of leaver to bench .. compress shock wj=ith leaver ..
Place retainers on to the spring so it cannot extend .. like the commpresion tools above .. but without the compression being required.
Extend shock .. leaving spring part compressed ..
Remove spring retainers
remove spring .. I'd leave it compressed if you need to reinstall it a little later ...
Re springs .. and weight .. Most of the luggage weight will be on the rear of the bike .. Where you have passengers sit .. so
Humm basically a compromise .. if you had a fixed weight then one spring weight would be perfect .. but you have to chose where you want the 'best' to be .. with luggage or without .. or you can go part way and have teh 'best' when only partially loaded .. too strong when there is only you and too weak when you have teh luggage .. most people tend to settle towards best for the majority of there use .. You will have to make a choice. One way or the other .. changing springs all the time would get to me.
This subject has cost me a lot of work during the years.
IMHO a tuned suspension is one of the best modifications you can do to your bike! The difference between a “working suspension” and a “tuned suspension” is huge!
Most bikers don’t stress this so most bikes come with crappy suspension.
The front on the Dakar is not very good, I have never tried the race-tech solution but it might make it better.
As Frank Warner says the weight from the luggage is mostly in the rear so make sure you don’t make the front end to hard – a lot of people do that.
For me (and maybe others) it’s not right to compare luggage with a light passenger. When I drive with a passenger I change my driving style, it becomes much softer. When I drive with luggage I still want to drive a bit hard and I go places where I could not go with a passenger.
I don’t think there is a standard answer for your question, but maybe my experience with other bikes might help. These examples are from paralever bikes and they are a bit easier to adjust:
R80GS standard (with WP rear):
-Front was like most other bikes (okay, but not great)
-The spring in the rear was too soft when driving with luggage
-Compression damping (rear) was not working well with luggage
-Driving with luggage and a passenger was not nice.
Tried a stiffer spring (rear) and got problems with rebound, changed back.
Spacers in the front helped a bit.
R80GS Øhlins rear (stiffer spring):
-Much better then the WP I was able to tune the rear pretty good with/without luggage and it was also pretty okay to carry a passenger and luggage.
R80GS with cartridge front (this is what Race Tech tries to achieve):
-Better handling all over
R80GS rebuilt to R100GS HPN Rallysport:
-Front handles everything
-I can set up the rear for all kinds of driving (luggage, passenger++)
When I drive solo I have almost no preload (rear). During the winter I will probably make a light subframe with another exhaust and this will reduce the weight with 15-20 kg, not sure if the spring can manage that….
…… So what does this mean? It means that it’s not easy to tell if one setup can handle all your needs in the way you prefer…
A lot off people don’t adjust their suspension at all, maybe they increase preload a bit when they have luggage. I think this is a huge mistake – you have paid for the components and should use them!
Øhlins (and maybe others) have some good guides for adjustment. Some shocks are easier to adjust then others.
I also think it’s important to remember that the suspension requires service:
Front: Clean, oil-change and check every second year
Rear: Overhaul 30-50kkm
Holy crap, this is confusing. Firstly, let me start by saying that I still don't know how a bike should behave as these are usually such finetuned experiences that I usually blame on my rider skill. All I know if when the thing bottoms out or when it dives when hitting the brakes. (Any tips would be much appreciated.)
I understand that pre-load affects the stiffness of the ride because of the simple fact that a spring requires more and more pressure the further it compresses. But when a stock suspension is designed for a average weight of a single rider (90-100 kg), I effectively add half of that to the suspension. So I thought spring rate would come into play a bit.
I would have to agree that I should not start ordering a shock for the 150kg's I'll chuck on it. The thing is, when you order one they ask you for your weight, your luggage weight, how often you ride with that weight and your riding style.
So what do they really want from us? Should I tell 'em that I use the weight hardly at all, or should I simply give them a lesser luggage weight.
The main reason I want another shock it because I simply don't trust the stock to survive the trip. But I also hear very good stories on them over at F650.com.
I ride one up.
Also, do you guys measure the sag all the time to find the pre-load? Or just once with luggage and once without and remember the settings?
ps: Race Tech gave me .8 springs while some other guys got given .9. How much gear would those guys ride with?
Another thing which confuses people: If you cut a spring it gets harder.
Well..... That sucks. I'm currently in the UK saving money for this trip with my bike in storage in Australia. I've got a month to sort it all out (including finishing off my luggage and some other things) so I hope they'll get it right for me in the first instance.
So, after some of you having done this thing before, did you notice that you should have quoted less weight? Or more. I'm going with Ohlins.
I don't like the idea off 'sacrificing' travel by winding preload onto the spring for the normal riding condition, because I would need to sacrifice more for riding with luggage. (I got that right, didn't I. pre-load = loss of travel because the coils get closer together. I'm a real noob when it comes to suspension.)
Yes, it is a confusing subject, or it has the potential to be so - so many permutations!
What I was trying to say is the KISS principle - keep it simple, stupid (ignore that last word!!).
There are loads of views and opinions around and you are getting some great advice in the previous posts.
Here is a link that summarises things; I have found it useful because it is written in a KISS manner - for instance I like the way that it is broken down into steps (called days in the text, but it does not have to be whole days IMO).
Thing is that you can spend a lot of time adjusting the suspension; in this link it suggests taking things steadily and experimenting bit by bit (or was that another site?!).
Ohlins also have advice for suspension setup, on various websites of theirs in different countries and I expect there are others to be found in a web search - not sure, but there may be some stuff in this HU website as well.
Motorcycle Suspension Set-up
Oh yea, on your last point, you need some sag to allow the suspension to operate in the "opposite direction" to the usual i.e. it "expands" as you un-weight the bike - this is covered in the link article here. So, some preload is "good".
Good luck with your travels and the suspension fine tuning.
As for developing a good "seat of the pants" suspension rating system, well this just takes time and really helps to ride other bikes for comparison. Took me years to get a sense for this. The goal should be to have the bike work well in a wide variety of situations. You can rarely get it perfect everywhere
and you wouldn't know perfect in any case at this point. So, best rely on good advice from other experienced riders of F650's.
taller bike. Stock suspension is designed to carry two people, not solo rider.
Stock suspension is often of the progressive type to allow the bike to work in a wide load range, but rarely is ideal. Hope this is not too confusing.
Spring rate MOST DEFINITLEY comes into play.
seals when used hard on a loaded bike off road.
So Ali's advice of servicing should be taken seriously.....I have seen many Ohlins leak oil...both on street/race bikes and dirt bikes. The good news is an Ohlins trained tech can rebuild it in an hour (or less).
There should be an ideal race sag range for your bike.
Most dual sport bikes/dirt bikes have an ideal race sag range between 3 inches to 4 inches. On your Dakar, probably closer to 3" ? (from say...95 mm
to 105mm ?)
Remember you have two sag numbers, static sag and race sag. For you, race sag is the important one. When the bike is without any luggage for solo riding,
your sag number should be at the minimum. When loaded it should not exceed the maximum in the range. Do you know how to measure race sag? Very simple but you need a helper.
(front and rear) based on your weight and luggage weight. Don't forget to add in the weight of your racks, empty bags, tools carried, water....all of it.
But much of that figure comes down to what the stock spring rates are and how much measured sag they have. Front sag is trickier....in fact dialing in the front end is tougher overall...and its kind of a personal thing.
For touring I don't like it too stiff but I don't want too much dive either and I want to be able to manage sand or rocks at good speed. A properly set up front end makes all this much nicer when spring rates/set up is correct.
Takes a bit of experimenting and trial and error to see what you like.
One of the advantages of a quality cartridge fork is all the adjustments it comes with. The Race Tech emulator gives you the ability to adjust preload which allows you to fine tune the forks to your liking. (sort of...poor man's solution really)
On my bike (no fork adjustments at all) I have to pull the fork caps and change spacers or oil or springs. I went on the experiences of other riders carrying similar weight and I got lucky. New Eibach springs have made a 100% improvement on my DR650. Same on the rear. Would Cartridge forks be better? Of course, but as of now the bike is working very well. I am happy.
All you really need to know are two numbers: Fork Spring rate and Rear Spring
Rate. The rest is fine tuning.
Thanks for all the advice guys. I've got a much better idea on what to look for now.
I'll have to rent a few bikes from time to time to get a feel I reckon. Won't be able to do it before I go though, but I'll do the measuring sag and stuff. At least high end stuff is completely adjustable.
The F650 is kitted out with Showa suspension and tend to fall apart after 20000kms if not before.
Have you read that webpage that I posted? All the basics are in there.
I agree with your idea of hiring bikes, but if you can borrow your buddies bikes for nothing, so much the better!!
If you go to any bike shows, try the new models on display for their suspension movement - can't always do this depending on how they are supported, but if you can "bounce" the front or back of expensive new bikes, such as a Ducati, you will get an idea of what good suspension feels like, while static at least.
Ref the 20000 km Showa suspension, you don't say what kind of riding you expect to do, apart from 1 up, distances to be covered and what miles the bike/suspension have done but,
Don't worry, be happy, you are learning!!:rolleyes2:
Properly tuned high end Showa suspension is the equal or better of anything out there. After all, how many world class MotoCross/SuperCross bikes run Ohlins or WP? (Keeping in mind that Honda OWN Showa, KTM own WP....and Yamaha own Ohlins!!:eek3: ) On about 90% of Yam race bikes....(dirt/enduro) you see KYB suspension, not Ohlins. Moto GP is another story. Honda MotoGP run Showa.
Both KYB and Showa have more experience in off road type suspension than anyone...including Ohlins. And remember, these days Ohlins' number one
customer....is NASCAR! :rofl: (a good friend works for Ohlins)
Set the bike up for the max weight and go. After you're done (in a year or more) you can change back. Changing fork springs is easy, a shock spring (depending on bike) can be a pain.
Crash bars, racks, bags and tools are not stock fitment, so you have to figure that in within the grand scheme. Also figure fuel weight if running a much larger fuel tank (Tourtech).
Like Walkabout points out, if you're only ever riding roads, then you're suspension will not have to be so stiff or perfectly tuned. If you plan to ride in challenging off road environments....at speed... then firmer is better for that much weight. Hope you rear sub frame can hang in. Also, shock mounts have broken on the F650 on overloaded bikes.
|All times are GMT +1. The time now is 18:44.|