The dark art of suspension setup


I had been hoping all week that the weather yesterday wasn’t going to be as bad as predicted. It was as bad as predicted. As I just had the bike back together from having the shocks serviced I thought that I would pop out for a few hours and see how the bike felt. There were a number of things that I had changed since the last time I had ridden it (the day I broke my rib) and with a trip to the Isle of Man in 10 days time I wanted to make sure that I had everything setup right.

lickys_march7thcoffeeI went up to the Lickys and as I wasn’t really into pounding the miles today I hunted round for some new lines. I stumbled across 3 new lines that I hadn’t ridden before, one of them is almost certainly the best descent in the area. Nice mix of tight steep switch backs with a few jumps and berms thrown in for good measure. The rain had kept all but the most hardy dog walkers away so the place was pretty much empty. I stopped off in the visitors centre for a quick coffee and slice of cake. Two ladies were rather amused at just how covered in mud I was, one of them suggesting that I should go to the bath room as I had mud all over my face. Hahaha.

Over Christmas I had seen that On One were selling their own brand Chunky Monkey (2.4inch) and Smorgasbord (2.25inch) tyres at a great price. I have been riding with 2.1 and 2.0 mud tyres seemingly forever and decided that as the price was good I would pick some up for the coming drier weather. They had been sat in my tyre mountain for a while now unused, so yesterday I put them on to give them a run out. To start with I think it was totally the wrong conditions for them. They felt very sketchy and I started to lose confidence fairly quickly. They shed the mud OK but I didn’t feel they kept much grip. Quite often I felt both ends twitching around in places that I thought there shouldn’t be to much problem. I’m willing to concede though that part of the grip problem might be that I didn’t have the suspension setup right yet. chunkymonkey_smog_tyresI’m going to go back to the Fire XC Pro tomorrow that I’m used to and work on getting the suspension setup exactly I as I want it. I also found them very slow rolling and draggy. I have been riding my rigid a lot of late though so maybe it was just the extra weight of the bike plus heavier tyres at a low pressure. However it seemed to take a lot of effort to get up hills that have never been to much problem before. Possibly once they are worn in they may feel better but I was surprised as I didn’t think the tread was as big as say a Storm Control which is about the slowest rubber I had used before. In short the jury is still out on these tyres as I need to give them more time.

My Revelation 150mm RCT3 had had a full service and the dampening unit re-attached. I had thought that something was up with this as the full lock out didn’t seem to be doing much. However comparing how the “Threshold” setting feels now compared to how it did when new I think that it possibly was never working to full capacity before. The threshold now gives a very pronounced difference in feel. When on it means the first 2-4cm of travel is much harder to compress. This means that when there is “less force” put into the fork the compression is very small (if at all) but when a greater force is exerted the compression moves through this threshold and into the travel. Considering that the fork also has low speed compression I don’t really quite understand the idea that this is meant to stop “diving”. I would have thought that the stanchion would still dive past the threshold even at low speed when traveling across technical “stepping” type terrain. I would have thought that just having the low speed compression setting at full wack would give you a much better more linear response instead of “almost nothing” then normal response? The main use I can see for it is eliminating bob when climbing, as it seems to do this very well, like Pro Peddle on the Fox RP23.

motioncontrol_switchIn terms of numbers and settings here is how I started; the air pressures I left as they were coming back from Loco. This was:
+ve 105psi -ve 95psi (which gave me 20%-25% sag), RCT3 set to full open and the low speed comp at 6 clicks (middle position) and rebound at 6 clicks (middle position).

This setup didn’t bottom out for me, which is fine as I don’t expect to bottom out every ride (if at all actually) and specially not at the Lickys. I did feel however that the middle of the travel felt a bit soft, generally it was almost like the fork was too plush now in the first 70% of travel. I gradually tweaked settings until it felt more how I like it. I’m still not happy by any stretch but it was certainly better at the end of the ride compared to the start. I’m hoping that over the next week or so, tweaking and riding different types of terrain is going to get me to a place where I like how it feels.

By the end of the ride the settings were:
+ve 105psi -ve 105psi, RCT3 set to full open, low speed comp at 12 clicks (full on) and rebound at 9 clicks (3 off fastest rebound).

rp23_controlSo while all that was going on I was also trying to tweak the new Kashima Fox RP23 rear shock. Judging by how it feels certainly the rebound dampening control and Pro Peddle were basically not working before. I would hardly noticed any difference when changing the settings. It was comfortable to ride although I do think that maybe I just got used to it as opposed to it being the best setup for me.

I felt the pressure as it came from Loco was a little soft giving me sag at around 35%, I upped it to 200psi which made the sag around the 25% mark.

The first part of the ride at the Lickys is a climb as you make your way to the top of Beacon Hill, which was a perfect opportunity to check out the Pro Peddle. I went straight for setting 3 (full on) and started peddling. The comparison with how it previously felt is night and day. There was a big difference between on and off with “full on” removing all peddle bob. As someone who enjoys climbing I think this I’m going to like how the shock behaves  now. I think the air can spacer has worked to firm up the middle of the travel. It has lost some wallow in the middle and actually feels a bit stiffer even though the air pressure is lower than I ran previously. I’m not convinced it’s quite stiff enough but I will play with this over the coming weeks.

On the whole it was a good ride to start getting a feel for the differences. It was nice to find a few new great lines to ride at my local spot. Can’t wait to get out on Saturday and take another step forwards with my setup.

So, what do you think ?

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