Full Suspension Tuning guide?
 

I was just curious if anyone know any in depth tuning tutorials of full suspension bikes. I looked on google today, but really came back empty handed. :'(

Thanks

Ming

Different bikes have different tuning parameters depending on their design. Your bike should have come with a manual describing how to properly set up your suspension. However, there are a few generic tips that go so far as to say things like "you'll want to back off the rebound rate if your bike does <this>". There are plenty of these webpages on the Internet and quite a few books in your bookstore. Here's a pretty decent webpage to get you started.

Too many variables to count. Personal preference, style, type of suspension, type of shock and the various controls on them. Its a trial and error type of system

Thanks for the information. I am an engineering student, so I am trained to want to understand how exactly things work, and how to achieve the best performace from a product :D

Too bad I can't turn off my brain even when I go biking lol

Ming

I understand completely. I am an IT guy and spend my days disecting everything. Problem with people vs machine...ALWAYS comes down to preference. :)

Lots of books and stuff around the web as pointed out. My simple(ton's ; ) method is to adjust the front and rear susp until the desired total sag (with me fully on the bike) is equal across the bike; the front doesn't nose down or up relative to the rear. Then I make minor tweaks to the front and back for personal preference on the trail.

Ned Overend (Championships:5 Nationals and one World) gives some guidance in his book. It goes some thing like: use firm settings for smother turf and softer settings for the rough stuff. With proper settings you should bottom once in a while on the rough trails, otherwise you're not using the whole travel range.

Overend's book is the best technique guide out there. You can often pick up a like-new used copy from Amazon for just a little more than the price of a magazine. His Video is very good also. I refer to the book often and especially when I make my "pilgrimages" to the N Georgia mountains and Moab.

Al

Yeah. His book is great. My FBS, knowing I was a big fan of his arranged to have me meet him at a local function. They also gave me a copy of his book for being a good customer and Overend signed it. The book is great for both beginners and experienced riders alike.

Thanks a lot for the suggestion! I will have to purchase it once school is over. Time is difficult to come by during a semester through Engineering :D Also, it is getting very cold in Canada, so I wont be going out much :mad:

If you have your fork set so soft that it bottoms out once in a while, wouldn't most suspension bob too much on climbs?

Just curious

Ming

It could, depending on how good you are at "spinning circles". I have have an easy to reach lock-out on my fork, but I never use it. I don't bob because I've practiced spinning circles at up to a cadance of 110; I cruise at 95 on my road bike. Overend has a good section on that too.

Other factors would include rebound and compression damping settings on the Fork. On my Fox fork, I also have a low frequency bump-threshold setting as well.

Al

I am fairly good at spinning without bobing because all the spinning classes I do at the GYM :D It is only when I am very desperate for power if I come off the saddle and stand up.

After a few more rides, I have a few more questions. I took my bike to Hilton Hills last weekend, which is a rock garden :eek: During that ride, I had my rear shock set at 160psi and I only used about 3/4 of the travel. My intution tells me that I should run the shock at a lower pressure. Today, I went for a 2 hour ride on some rocky trails with my shock at 120psi. This time, I actually used about 7/8 of the rear travel, but there is way too much pedal bobbing. I have been told by some friends that I should be running approximately 1psi for every pound of body weight. I weigh about 190lbs, and I usually wear a backpack with all my emergency gears inside, so how come I am NOT utlizing all the travel at 160 psi??

The other question is about my SID. I have the postive air chamber set at 160psi, and the negative one set at 150psi, and the pure delite system at 20psi. The rebound setting is half-way. Initially I wanted the fork to be active over small bumps, but when I ride over rocks about 2-3 inches high, the fork deflates and then quickly comes up and tops out. It kinda makes a loud slapping noise when I go over such bumps. Do you guys have any recommdnations on how to fix this??

Thanks a lot

Ming!

Seven eighths is close enough. Who knows how accurately your shock is specked, Ming. I suspect my 4" fork has less than 4". Sounds like your pressure is way too low though.

I use about 205/210 psi on my Fox rear and 70 in the Fox front for my local (N Florida) trails. I get close to full range in the rear (about 3.6"). The front, I get typically 3" or a little more (out of 4), but I like the feel with 70, so I leave it there. I'm about 200 lbs with pack/water/clothes and it's about a 29 lb bike. In the N Georgia and S North Carolina mountains, I go closer to 225 rear and 75 front. The trails have bigger bumps, but mostly you just go faster due to the steeper down hill sections. I also get off the saddle on the rougher sections for better control and to protect the bike.

Too make sure we are on the same wave-length, "spinning circles" is not "spinning". Spinning circles (as I remember Overender's explanation): after you push down on the pedal and near the bottom, you pull your foot back as if you were trying to scrape gum off your shoe, then you pull your leg up; actually, you drive your knee toward the handle bar, then begin the cycle again. The objective of that last part is to off-load the weight of your leg from the other leg as the other leg drives down and not to pull up hard on the pedal. Overend says to concentrate on the pulling the foot back and the driving of the knee towards the bars; the pushing down part will take care of itself.

I guarantee, if you can spin circles well, you won't bounce. Since I've owned my full suspension (about a year and 700 miles), I've had to improve my pedaling since a full suspension gives more feedback than a hard tail, which is good IMO. I've had to become a better biker; choosing that rout rather than "locking out" front or rear. However, I've never tried as low a pressure as you and I'm not nearly as good as Overend looks in his video.

One of the reasons I like Fox and there are many reasons, is I only have to mess with one air pressure. I have no knowledge of your kind of set-up.

Al

I pumped my rear back up to about 160 psi, and I'm going for another good ride this weekend :D If the 160 psi isn't enough, I guess I should go up even more because my pressure is so much lower than everyone is recommanding.


I usually weigh the same with all my gears, except my bike weighs in about 24lbs. Also, I still pick the smoothest line because I rode a rigid bike for so long, and I tend to ease the bike over obstacles. Maybe that is why I am not using all the travel it offers. I love the extra stability the full suspension offers for high speed downhills runs. Can't wait until the racing season next year to try out my bike!



I understood what you meant before :) Basically, I meant to say I have a fairly consistant and smooth pedal stroke. Also, the spinning instructors makes us pratice standing climb with no bob. That also helps me out to smooth out the stroke. Nonetheless, the above explaination was very helpful, and I'm sure it will further improve my stroke technique. Thank you for taking your time to type all that.


I initially was looking for a bike that came with a Fox Float up front. However, the deal I got on my rocky mountain was too good to pass up. I'll most likely upgrade to a Fox Float F80x when my SID blows up on me. As of now, I'd like to learn how to properly tune the SID for my riding style. However, i guess more flexiability means more headaches for the user. :(

Which fox fork do you own and how do you like it so far? My SID works pretty well over bumps, but it is not nearly as plush as my friend's Manitu Black, or the Fox Forks I've tried at the bike show. A friend of mine just upgraded from a SID SL to a Float F80X, maybe I'll ask him for a test ride. How is the Fox for maintaince? Also, if you rebuild your own fork, how difficult/expensive is the process?

Thank you very much

Ming

I'd keep your fork. I'm sure the better ones of the major brands all work fine. After all, it's mostly the rider that makes the difference. The only reason I wound up with a Fox (Float 100 RLC) is that Specialized put a cheap Manitou on the bike to meet their list-price target. The rest of the bike is first class, so they went with a junk fork. I knew that, but the bike was well discounted (previous year's model) and the shop bought back the hydraulic brakes (I put my old Avid cable actuated disc's on it) and the pedals.

In trying to make that fork work, I learned that the Manitou tech folks don't know their products and aren't all that anxious to help. The damper unit I needed on warranty was out of stock for four months. Pity some guy who sent the shock to the factory to get it fixed. He's out of his brand new bike for four months.

I rode undamped that long. Not all that safe, especially on a fork with a lot of flex to boot. You never could be totally sure which way you were going next. Then they never told me you needed a special tool too install the new damper unit. They just mailed it too me with no advice (I asked for it) on how to install it. Even the closest Specialized bike shop sends the forks back to the factory. They won't touch one.

I had to modify a top tube (reversed the taper to not cut the o-ring seal) with a grinder to do it. Poor design IMO. Then after a while, the front wheel took a cant to the left. Good on right turns.

I'll never own anything made by Manatou again. I have found that the Specialized tech folks are not much better. Their main goal is to get you to go away.

That's fine as I do all my own work except wheel lacing. By the time the front fork destructed, I had several dealings with Fox on the rear shock for seals and maintenance advice. Their tech folks really know the product and they really want to help. RockShock was the same some years back. Another big plus is that you can mail order all parts you need directly from Fox and their turn around time is very short. That's important to me as I often go off for up to 6 weeks at a time to bike and I may need parts fast.

The Fox Web site has good info on repairing/maintaining their products. They told me that everything is owner replaceable except the bushings (they center the tubes) which is a factory job.

Customer support, reputation and those oversize tubes are the reason I went with Fox.

How do I like It? I can't imagine a better ride and handling than a FSR suspension with Fox air front and rear. Of course you have to consider that this is my first full suspension bike and only the third fork I've owned. Not much of a sample size.

Al

Thank you very much for the informing post!! My Instinct is my first suspended bike, and I am trying to get used to its riding characteristics. Also, my SID also the first front fork I've owned. I'm very overwhelmed by its maintaince schedule (changing oil for every 40 hours of use, and rebuild the pure DeLite syste every 100 hours of use). My friends have been telling me that they were rebuilding the SID worldcups after every race!!! However, I guess the racers do have more budget and requirement for their equipment to work in perfect condition compared to us. I will also need to purchase some new tools and learn how to rebuild the fork myself because I am really not willing to dish out 50-100 dollars for every 40 hours of riding.

After some hours of searching on mtbreview.com, I found out that many 2003 SIDs have a defect in their pure delite system. When rebound is turned on, the fork would clutter and sound like the bike has a loose headset. This is exactly the problem I'm experiencing. Looks like I'll need to send my fork back to Rockshox for repair after 3 rides :mad: Hopefully my friend will lend me his bomber for the last few rides of the year :)

Thanks again for your advice!!!

Ming

If that's the fork I think it is, a friend of mine has a Sid. He races from Florida to California and states in between. He's told me he much prefers to ride a Fox Float 100, but for racing he needs the light weight. The Fox requires the air chamber oil changed and the bushings measured for wear every 200 hours or annually.

Al

I just changed that on the fox's site. This is soo much better than every 50 hours of riding on my SID. I may end up getting my friend's old Dir Jumper II for around 100 bucks, and use that for training. Then save my SID for races :)

Good/bad idea??

Ming

Since the wife and I have 9 canoes between the two of us, two bikes sounds rational to me.

Al

Lol...9 Canoes...no wonder why your nick name is Al.Canoe :)

I meant getting my friend's old fork and use it in place of my SID since my old bike is a rigid bike and it is much too small for me :)

Ming

I just took my bike out for a spin after school, and I think I got my SID setup properly! The cluttering is gone, and the fork is much more plush than before! I think it's either I did something right or the fork has broken in.

I am going for a longer ride on Sunday and we'll see how it does :)

Ming