What's happing at the rear of my FS when I am cornering?
xCatch22x
Posts: 36
Hello all,
I have a Boardman Team FS that I have just finished setting up the suspension on, well basic settings anyway.
On my way out tonight for a blast around westwood (my local woods) I used a couple of fast ish downhill road sections that gave me some strange feedback through the backend. This is my first FS bike so I am not entirely sure what was happening. It's nothing that worries me, I just want to understand what the bike is doing.
The feeling is as if the back end is oversteering as if I have rear wheel steering.
I'm not new to setting up suspension as I am well practiced on my old Yamaha R6 and I never had anything like this happening there. I know it's a different ball park, but the principles are the same.
These are what I think could be possible causes.
1) Geometry that is different to my HT bikes that I have owned before.
2) Rear shock compressing while cornering - needs more air
3) Wrong rebound setting - probably too fast a setting
4) Slack back end due to design
Any ideas people?
Wayne.
I have a Boardman Team FS that I have just finished setting up the suspension on, well basic settings anyway.
On my way out tonight for a blast around westwood (my local woods) I used a couple of fast ish downhill road sections that gave me some strange feedback through the backend. This is my first FS bike so I am not entirely sure what was happening. It's nothing that worries me, I just want to understand what the bike is doing.
The feeling is as if the back end is oversteering as if I have rear wheel steering.
I'm not new to setting up suspension as I am well practiced on my old Yamaha R6 and I never had anything like this happening there. I know it's a different ball park, but the principles are the same.
These are what I think could be possible causes.
1) Geometry that is different to my HT bikes that I have owned before.
2) Rear shock compressing while cornering - needs more air
3) Wrong rebound setting - probably too fast a setting
4) Slack back end due to design
Any ideas people?
Wayne.
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Comments
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I take it everything is bolted together correctly?
Could be the rebound being too fast
Tyre pressures? Low pressure might make the tyre squirm on the rim
Adjust one thing at a time & see what works to eliminate it.
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1) Geometry alters every time the suspension is compressed.
2) Normal, it needs as much air in it to give you the desired amount of sag.
3) Set rebound for offroad riding rather then road.
4) Possibly
5) You are not used to a sus rear end (it's not a r6), so give it more time to get used to it.
6) Tyres and tyre pressure, a knobbly off road tyre ain't got much contact with the road when cornering...imagine your r6 with a moto x tyre on it...loose back end...large portion. Too soft a pressure and it will slide.0 -
Is it not just that your used to having less traction at the back with a HT and the FS is giving you more traction and therefore feeling like oversteer? Just takes time to get used to maybe?0
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stu8975 wrote:1) Geometry alters every time the suspension is compressed.
2) Normal, it needs as much air in it to give you the desired amount of sag.
3) Set rebound for offroad riding rather then road.
4) Possibly
5) You are not used to a sus rear end (it's not a r6), so give it more time to get used to it.
6) Tyres and tyre pressure, a knobbly off road tyre ain't got much contact with the road when cornering...imagine your r6 with a moto x tyre on it...loose back end...large portion. Too soft a pressure and it will slide.
Thanks for that mate. I have sag at 25% front and rear and works nicely off road so I suppose the road stuff could just be ignored as it's mainly off road that I will be doing. You know, the lazy drive to location, ride, and drive home!
As for tyres and pressure, the other bike I have is a Boardman Team HT with exactly the same setup inc tyres and pressures etc. The same route on that bike does not produce the same effect.
The compression interests me more as it would in effect shorten the wheelbase whilst compressed if my thinking is right. I may try some more pressure in the rear shock and maybe a little more gate just to see if this helps.
Just been and checked the bike for loose components and everything seems fine. Doing a flex check on the back end shows very little movement.
I will report back when I have some results.
Thanks again, both of you.
Wayne.0 -
Probably body position and riding style, when the back end unweights there will be a lot more going on you'll get used to it. Saying that there will be some more flex in the rear end, my teocail had some flex in the rear end, but changing to a halo tornado rear wheel with spindocor hub stiffend it up giving more consistant contact, putting a bolt through axle has made it even better, so maybe there is flex in the hub which is more noticable on an FS.-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
Mongoose Teocali
Giant STP0
Why are MTB economics; spend twice as much as you intended, but only half as much as you wish you could afford? :roll:0 -
You could just be going into the corner a lot faster than you are used to on your HT. If it has a bumpy approach you will naturally back off on the HT but possib ly not even notice the bumps on the FS.
When I got my Commencal after not having ridden FS for a while it felt a bit odd I think the extra weight of the shock and links puts more weight on the back end than a HT.Fig rolls: proof that god loves cyclists and that she wants us to do another lap0 -
Once the suspension is compressed, it normally makes the wheelbase longer - in nearly all full sussers anyway.
If you hit a corner at speed with your weight back, the suspension will compress from the force. When riding off road, this is good, it allows much sharper turning, almost as though you were riding a berm - this makes the experience much different to a HT.
I'd say that is all that's happening and you just need to get used to having a bouncy back end!
(Once you get the hang of it, its much better - in my opinion!)0 -
I think Bails was the closest with wheel flex but I'm going one further and saying its frame flex, try this, ride diagonally up a driveway entrance, you'll feel the rear end self steer as it meets the gradient am I right, Whallaa, frame flex, had the same problem (not really a problem as you get used to it ) on my 04 Epic, just had a look at a FS boardman and yes all those skinny tubes and four bar rear suspention will flex somewhat, If it really bothers you buy an Orange five with a maxel swingarm, almost zero flex and a dirty big smile at the bottom of each run, but honestly after a 100 or so km you wont even feel any flex and youll be having a blast..........all
...at........work
fun..................&
..no.............no
.....is......play0 -
Had this problem on my FS changed the tyre's to something with thicker side walls to stop them rolling in corners and its made the back feel planted.0
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A few reviews I've read score the Boardman Team FS down for rear end flex, could well be that.0
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Wayne, what's it like around Westwood? I'm always in Greno/Wharncliffe, but I'll give it a go up there if it's decent.0
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I used to do a lot of riding around Westwood - quite a few short but twisty trails in the woods above the dam. If you cros over into Parkin Wood there is a jump spot and a custom made trail too.0
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PS Wayne, if you want me to check your bike over, feel free to PM me and I will service it for you for nowt.0
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Thanks, Super...I'll have to have a look.0
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It is short and sweet, and I usually link into a longer ride. But some big bomb holes in there, and some rooty stuff too.0
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It is short and sweet
Like me, mate!
To be honest, this year it feels like I'm riding better than ever, but I seem to be carrying injuries for some reason. I've been trying to push myself harder, and perhaps I've paid the price. It's frustratng, because I know I can ride better that I have previously (not hard that), but I'm struggling with a knee problem that it now limiting my riding!0 -
I know the feeling lol. Whilst my health is getting better, I need to pace myself. Sometimes I just dawdle around the woods lol, gasping.0
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supersonic wrote:PS Wayne, if you want me to check your bike over, feel free to PM me and I will service it for you for nowt.
Thanks for the offer my friend. I am ok with servicing/building bikes but may need some input on the suspension and linkages as they are new to me. What I'm wondering about most is if there are any better bushing kits that could be used if it is indeed rear frame flex.
Westwood is ok for a bit of XC stuff and I like bombing down the "white path" to what used to be the ocar pond at the five arches!
The bomb holes/bell pits are good fun and very steep too with some good techinal bits near the outcrop area.
Where is Parkin Wood? Across the bypass towards the golf course?
Wayne.0 -
Not sure of any upgrades for the bushings, but I can try and evaluate the flex. A little flex is not always a bad thing.
Yep, that old path is a good little blast! Lots of loose stuff, and those ruts can catch you out lol. Last time I was there there was a big tree that had fallen accross.
Parkin wood is the one that is in the middle Station Road/Thorncliffe Rd/road upto J35a and Warren lane. If you take the other path to the east before the arches you come out on the road to the motorway, then cross over straight into the wood.0 -
