Handling Problems

captainfly

Just out of interest is the Kenda Navegal on the front an OE (came with a bike) sort or is it an aftermarket one? I only ask because the OE navegal on my teocali is awful on anything remotely wet dropping the pressure just means no grip in the slipper stuff and loads of rolling resistance everywhere else. I thought I'd give 2.35 single ply Maxxis swampthing a try because of all the mud that is around.

simonp123

captainfly wrote:

Just out of interest is the Kenda Navegal on the front an OE (came with a bike) sort or is it an aftermarket one? I only ask because the OE navegal on my teocali is awful on anything remotely wet dropping the pressure just means no grip in the slipper stuff and loads of rolling resistance everywhere else. I thought I'd give 2.35 single ply Maxxis swampthing a try because of all the mud that is around.

No The Maxxix Ignitor was the original, but it has no grip on roots and rock, great on hardpack though.
The Nevegal is a DTC version.

CycloRos

simonp123 wrote:

They are not expets either I would add, but are more experienced.

Unfortunately you can't buy experience and it may just be that your mates are fitter more experienced riders.

As for the tyre issue the Nevegal DTC is a great tyre, tube or tubeless makes little difference to grip except if its leaking air :shock:

Try out some of the things people have suggested and see how it goes.

simonp123

Of course there is another thing possibly at work here. Is it that above a certain speed a 2.1 tyre just simply cannot provide the level of grip required to cope with a bike and a 17 stone rider?
Wouldn't explain my trouble picking lines, but may explain washing out at much lower speeds than say my 4 stone lighter brother, hmm.

I was just sat on the bike last night (now that i finally have my front tyre sealing) and notices how much tyre squash I get particularly on the rear even at close to 40 psi :oops:

paul.skibum

I don't think weight to tyre size should be a major issue but you could try a 2.25/2.3 on the front - a bigger front will give you more cornering grip (or so people on here have told me - not put in practice by motorbikes but hey ho).

But its an expensive experiment - £40 for a new UST front tyre!

simonp123

paul.skibum wrote:

I don't think weight to tyre size should be a major issue but you could try a 2.25/2.3 on the front - a bigger front will give you more cornering grip (or so people on here have told me - not put in practice by motorbikes but hey ho).

But its an expensive experiment - £40 for a new UST front tyre!

I wasn't thinking about going up in size, just that perhaps I am expecting too much from something that has a finite ammount of grip, and the heavier the rider the more force is applied to teh tyre whilst cornering, so theoretically my max cornering speed would be lower than a lighter rider.

Will put some of the advice into practice at the weekend hopefully.
I have my loger slightly lower (5deg instead of 7 I think) rise angle stem now, but will not put this on straight away.

Dirtydog11

As no one else has suggested it........... have a play with your fork settings.

Generally forks are designed for the average rider 80kg or so, 17 stone is not average.

Too much rebound or too little compression damping can cause the front to want to tuck.

Running too little low speed compression can cause the fork to dive under braking which in turn steepens the head angle.

Running to much low speed rebound with too little low speed compression can exacerbate the problem even further. The fork dives under braking and the rebound prevents it from returning to its initial position.

Now you've got even more to think about. LOL

simonp123

Dirtydog11 wrote:

As no one else has suggested it I will.

Have a play with your fork settings.

Too much rebound or too little compression damping can cause the front to want to tuck.

Running too little compression can cause the fork to dive under braking which in turn steepens the head angle.

Running to much rebound with too little compression can exacerbate the problem even further. The fork dives under braking and the rebound prevents it from returning to its initial position.

Now you've got even more to think about.LOL

Gah, you just had to didn't you :evil:

I have recently lowered the air in the fork to give about 25mm+ droop, so it is possible that I need to alter the rebound as I didn't change that.
Never sure how to set rebound, I know that the fork should not spring up too quckly, but how do you judge how slowly it should return? Setting it on a car is rather simpler.

Dirtydog11

simonp123 wrote:

Dirtydog11 wrote:

As no one else has suggested it I will.

Have a play with your fork settings.

Too much rebound or too little compression damping can cause the front to want to tuck.

Running too little compression can cause the fork to dive under braking which in turn steepens the head angle.

Running to much rebound with too little compression can exacerbate the problem even further. The fork dives under braking and the rebound prevents it from returning to its initial position.

Now you've got even more to think about.LOL

Gah, you just had to didn't you :evil:

I have recently lowered the air in the fork to give about 25mm+ droop, so it is possible that I need to alter the rebound as I didn't change that.
Never sure how to set I wrebound, I know that the fork should not spring up too quckly, but how do you judge how slowly it should return? Setting it on a car is rather simpler.

If you've dropped the air pressue (Lowering the effective spring rate) then the chances are you would need less rebound.


There are a couple of guides for setting rebound but none of them are particularily scientific.

The general advise is to set the rebound so that the fork is fully extended by the time you pull it of the ground from a compressed state.

I would start with the rebound wound off (this will allow the fork to return to its inital state quicker) and add a click or two as and when (if) you get top out.

skullthaw

try tightning and replacing the head set bearings if rusted they will rattle = twitchyness and morefriction = reluctant to turn

simonp123

I thought my knee was up to a gentle ride last night as the skin has re-formed in most places.
Went for a 40 minute gentle jaunt on a bridleway/towpath route, all seems well knee-wise just a little sore after the ride.

I did lower the rebound damping a touch so that the fork would rise quickly but not slam up into the palms.

Hmm bike felt very odd as soon as I got on the stony bridleway (which I have ridden many times) quite squirrelly and hard to pick/hold a line ate first, the rear seeming to move around quite a lot.
I think that the tubeless setup and the corresponding lower tyre pressures give the bike a very different feel. Previously with the tubed setup with 2 Ignitors I would run 50+ psi (tyre quoted 45-65 IIRC).
Once I got used to the extra movement and just let the bike move around a bit my confidence increased. There is certainly a more suspended feel to the bike.

As this was pretty non-technical stuff I couldn't learn much new, so hopefully will do that at the weekend. I won't look at changing the stem until I have tried more technical stuff as it is.
I did compare the new stem with the Kona one on the bike, and the rise angle looked very different. The new one has a 5deg rise and I thought the Kona one was 7deg, but the difference looks more than 2 degrees. I have seen the same frame used with a 5deg rise stem though so it shouldn't bugger than handling up completely. At least it is an easy thing to swap.

bungalistic

If you're having that much trouble with getting the right 'feel' and possibly just your own skill level I would suggest paying for an actual skills day or class. Everyone on here can only help so much, and without seeing you riding and seeing your position, speed, etc........... it is very hard to diagnose.

Either that or ride with other people who are a 'level' above you so to speak. Ask their advice and stop on sections that you have trouble with and keep trying them until you feel more confident hitting them at higher speeds.

simonp123

Just to add to the confusion, I don't think the "feel" was helped by the fact that I discoevered when climbing a hill coming back that the damned sadlle is tilting whne I shift my weight :x Have to tighten that up.
Rear gears also playing up, I can get it to change up reliably or down reliably, but not both, so some work needed there too.

CycloRos

First its the front grip, then its the rear grip, now its the saddle and gears.

There's more variables everyday!

simonp123

CycloRos wrote:

First its the front grip, then its the rear grip, now its the saddle and gears.

There's more variables everyday!

Isn't life like that?
The rear is just moving around, the actual traction is fine. The front grip issue I had is literally the front sliding.

Saddle and gears possibly results of 2 crashes? :roll:

Bit of a strip-down celan, check and tightening of everything required I think.

simonp123

OK, gears are sorted, and also the saddle which has bent rails that needed straightening, and also getting the seatpost clamp a bit tighter as the saddle was able to twist around!

Had more of a play with the fork damping and found that it was still set quite slow so the fork would nout fully extend by the time I lifted the front wheel afetr compressing the fork.

Spent a few hours riding round the trail at Croft Woods in Swindon which it turns out is great for practicing and skill learning. Top marks to the guys who have (and still are) created that. So much packed into a small space.
So, 3 laps of that (6Km a lap) and I was able to try quite a few things. Firstly having a front tyre that stays up does make quite a big difference! Also the front fork now seems to really be doing its job and has quite a smooth feel and the front feels much more planted.

The front end has a tendency to lift when powering round corners so I do think there is a weight distribution issue, though I was able to compensate as suggested here by leaning forward and getting more weight over the front. It did get uncomfortable after a while, so I will be trying the longer lower stem for sure.
One thing my brother spotted is that I was lening my body as well as the bike into some turns, as you would a motorbike rather than leaning the bike under me. Once I changed this I found the tighter turns much easier, though I did clip the odd tree with my shoulders from turning too sharply now

Anyway the botom line is that I think mostly I gained more confidence in the bike and myself. But also is handy to have someone point out things that you were not aware that you were doing. It is all about confidence at he end of the day. If you are confident that the bike will do what you ask it then you have the confidence to push your skills a bit. I now have some confidence that the front will grip when I turn which I think is the fork settings and the fact that the front tyre is holding pressure, simple but important things.

ratty2k

What tyre pressures are you running? A mate of mine sold some tyres on too quickly, but didn't know at the time that the recommended pressure on the sidewalls are usually too high...
Just a thought, I'm heavier than you my front is 30 psi, and the rear 35-38 depending on terrain...

simonp123

ratty2k wrote:

What tyre pressures are you running? A mate of mine sold some tyres on too quickly, but didn't know at the time that the recommended pressure on the sidewalls are usually too high...
Just a thought, I'm heavier than you my front is 30 psi, and the rear 35-38 depending on terrain...

I think they are around 35 front and 38-40 rear. Much less at the rear and I find that the rim bottoms out. I know the Ignittor on the rear says 45 -60 psi :shock: That is with a tube though.