So I am experiencing the front wheel tucking under on low speed steep descents and dumping me on the deck. What I have altered is, Muller the back wheel and left the flip chip in its lower setting because I thought it would be better for recent Alps trip. I got thrown off three times yesterday so I thought I would ask what you guys think? Original head angle is 63°. From my mechanic days it seems like the caster angle is wrong?
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Geometry experts please!
- Thread starter Bones
- Start date
- Thread starter
- #32
63° is the original angle with the 29" wheel fitted. And I have only just altered the bars. The forks have just had a factory tune so I am using some compression on them, unlike the original setup with both compression wound off.
Edit. I have raised the shock in that photo to the higher setting as well.
Last edited:
steve_sordy
Wedding Crasher
Same place as everyone else.
But from there the brake hose should go between the fork and the wheel to get to the caliper.
steve_sordy
Wedding Crasher
Consider it a bonus learning!Ah right, I will tweak it. But I don't think it will sort out my crappy riding position though
+1 on each of these points.
I think easiest way for you to get a decent set up on the bike is to go to a good quality mtb bike shop and get a proper bike fit. Then you should only have to tweak from there.
Ps. Mega to hear you're riding mtb at 78! Props!!
Plummet
Flash Git
OK,
The bike looks good.
I reckon there's 3 things that can cause over the bars.
1, Technique. This is the primary reason. You need to look at technique. It could be a dead sailor thing. IE it gets to a certain steepness and you freeze up and haul on a handfull of brake.
2, Fork set up too soft and or not enough compression dampening. This will cause fork dive and make going over the bars easier. Try more compression dampening and or more air pressure in the fork.
3, Not enough brake power. This sound counter intuative. But if you have more power then you can control more speed earlier and have less change of needing to grab a handle full later. Try a 220 rotor on the front.
I've just changed my meat bike to 220mm from 200 and even though i didnt think i needed 220. i can feel the extra control 220 provided. With the 200 i would speed up sooner and have to counteract by grabbing more handfulls.
Side note. This ergonomic grips will not be helping steep riding at all. Change them out for some round ones that will allow you to rotate your hands around the grips as the steepness increases.
- Thread starter
- #39
Point 1 definitely
Point 2 the fork does not dive and has enough LSC dialed in to support it.
Point 3. I had 220 rotors in the Alps and it's low speed where I am folding the front.
Point 4, I will refit some standard grips. Those on are only cheap ones to try and relieve some hand pain but they don't work for me
Thanks though for your thoughts
Point 2 the fork does not dive and has enough LSC dialed in to support it.
Point 3. I had 220 rotors in the Alps and it's low speed where I am folding the front.
Point 4, I will refit some standard grips. Those on are only cheap ones to try and relieve some hand pain but they don't work for me
Thanks though for your thoughts
Just to check a few points as we all get lost and end up projecting and coming up with out own visualisations.
Is this just Downhill or also on the flat at times ?
If it's Downhill, I take it your dropper is down, but you're seating to reduce fatigue ?
But you're washing, never when pedalling, only descending, dropper down, but often seated ?
If all that's correct, then I'd say that seated descending will actually cause more, rather than less fatigue. You can't use your arms and legs to position and move your body to the trail and you'll be getting bucked more than you should - your arms and legs are massively more suspensive than anything the bike can give. Working in unison delivers wonders, depending on one or the other is hugely inefficient and ultimately tiring when descending (and scary).
Contrary to other advice (I agree with what they're saying, but think they're visualising for them, not you). I'd have low speed compression set fully open. Let the front take the hits and absorb them, keeping the bike stable and then letting the rear do it's stuff effectively, so you're happy standing (in a relaxed way - you don't need to sit doing most things in life !) I'd speed up re-bound one click to start with as the fork might be slowly wallowing into it's travel and your nose is getting low.
We don't know the exact corners or the lead in, so we have to guess what's happening upto that point.
The exception to this fits more with Plummets suggestion above, if you're braking in a way that almost bottoms out your suspension due to terrain and braking, if compression is too slow for he terrain/technique, then turning and releasing the brake, then re-bound could extend the fork too quickly and wash you out - that's less likely though.
Then you need to look at other things if it's not that. Are you still feathering the front brake into the turn ? Are you looking through the exit (this all affects body position - which won't adjust correctly when seated).
If it's none of that then it's new bike day, because a new bike always feels better at first ..
You can also try flip chip in high. Whilst it's counter-intuitive, it will naturally put a little more weight forwards and I don't think the fork angle in the degrees were talking about is going to be the issue unless it was happening at 60kph+ Bringing the contact point a few mm closer will help if you're rearward weight bias.
Is this just Downhill or also on the flat at times ?
If it's Downhill, I take it your dropper is down, but you're seating to reduce fatigue ?
But you're washing, never when pedalling, only descending, dropper down, but often seated ?
If all that's correct, then I'd say that seated descending will actually cause more, rather than less fatigue. You can't use your arms and legs to position and move your body to the trail and you'll be getting bucked more than you should - your arms and legs are massively more suspensive than anything the bike can give. Working in unison delivers wonders, depending on one or the other is hugely inefficient and ultimately tiring when descending (and scary).
Contrary to other advice (I agree with what they're saying, but think they're visualising for them, not you). I'd have low speed compression set fully open. Let the front take the hits and absorb them, keeping the bike stable and then letting the rear do it's stuff effectively, so you're happy standing (in a relaxed way - you don't need to sit doing most things in life !) I'd speed up re-bound one click to start with as the fork might be slowly wallowing into it's travel and your nose is getting low.
We don't know the exact corners or the lead in, so we have to guess what's happening upto that point.
The exception to this fits more with Plummets suggestion above, if you're braking in a way that almost bottoms out your suspension due to terrain and braking, if compression is too slow for he terrain/technique, then turning and releasing the brake, then re-bound could extend the fork too quickly and wash you out - that's less likely though.
Then you need to look at other things if it's not that. Are you still feathering the front brake into the turn ? Are you looking through the exit (this all affects body position - which won't adjust correctly when seated).
If it's none of that then it's new bike day, because a new bike always feels better at first ..
You can also try flip chip in high. Whilst it's counter-intuitive, it will naturally put a little more weight forwards and I don't think the fork angle in the degrees were talking about is going to be the issue unless it was happening at 60kph+ Bringing the contact point a few mm closer will help if you're rearward weight bias.
- Thread starter
- #41
Ok start again.
The mullet setup was because I needed a new rear wheel and I have run a mullet bike for the last 6 years+ I assumed because of the flip chip it was an option for that frame.
Now it was riding ok with the chip high.
Due to a recent Alps trip I dropped the chip to low, fitted the riser bars. Stuck a 220 rotor in the front and fitted a brand new standard assegai tyre on the front.
The forks have been a nightmare to sort out and it's taken three goes for silverfish to sort out by fitting it new damper and air shaft under warranty. Plus a factory tune so I don't need to run them fully open on compression now. The forks are setup very well and working well now.
I folded the front nearly every day in the Alps and I was blaming the tyre and also braking too hard.
Back home and replaced the tyre with an hillbilly T9, put the 203 rotor back on.
Still folding the front.
They have been low speed steep sections where it's happening.
Yes I've been sat down so poor technique but low position of the flip chip made me think it's a geometry issue as it seemed fine before I dropped it.
Now I have raised it but can't try it as I'm away in Portugal wed for a week with a hire bike.
The mullet setup was because I needed a new rear wheel and I have run a mullet bike for the last 6 years+ I assumed because of the flip chip it was an option for that frame.
Now it was riding ok with the chip high.
Due to a recent Alps trip I dropped the chip to low, fitted the riser bars. Stuck a 220 rotor in the front and fitted a brand new standard assegai tyre on the front.
The forks have been a nightmare to sort out and it's taken three goes for silverfish to sort out by fitting it new damper and air shaft under warranty. Plus a factory tune so I don't need to run them fully open on compression now. The forks are setup very well and working well now.
I folded the front nearly every day in the Alps and I was blaming the tyre and also braking too hard.
Back home and replaced the tyre with an hillbilly T9, put the 203 rotor back on.
Still folding the front.
They have been low speed steep sections where it's happening.
Yes I've been sat down so poor technique but low position of the flip chip made me think it's a geometry issue as it seemed fine before I dropped it.
Now I have raised it but can't try it as I'm away in Portugal wed for a week with a hire bike.
Welcome to the internet
Thanks for the re-hash - it helps !Does the wife know ?
As for the rest .. I can see how your head hurts .
Especially with the tyre change. The only physical difference left then is the bars....
- Thread starter
- #43
Easiest way is to go back to original and put it all down to a bad move regarding the bike.Welcome to the internet
Does the wife know ?
As for the rest .. I can see how your head hurts .
Especially with the tyre change. The only physical difference left then is the bars....
Biggest problem now is getting my body to move around more and alter how I've got used to riding ebikes
Easiest way is to go back to original and put it all down to a bad move regarding the bike.
Biggest problem now is getting my body to move around more and alter how I've got used to riding ebikes
There are no bad moves.
We're always trying to improve things. Some work, some don't. Some work one day .. and not the next.
But it does sound like you need to get jiggy with it !
Plummet
Flash Git
On steeps forearms and wrists roll back in roll back in relation to how far back you are leaning....
Forearm and wrist angle should be the same.
Thanks for sharing ! Nice ride. Top notch on your climbs !
I think you were just a bit unlucky there. You went ever so slightly too far right, which moved your bars close to the large rock and put your front wheel on the right of the line :
Then you compensated, but slightly over compensated.
Which put you to the left of the line and put you on the off camber wet slippy stuff :
I think being seated really screwed you up. If you'd been up you could have adjusted the line and the bikes angle by leaning the bike whilst keeping yourself upright. Likewise, when you did end up on the left, you could have moved your body weight/weighted the right pedal more - to keep the bike up. It looks like when you realised you were on the left and knew it wasn't good that you probably locked the front (tyre doesn't look like it's turning) rather than letting it roll and going with it.
Glad to see you were ok though.
You looked confident everywhere else, maybe the bars have moved your body position slightly so you have momentary lapses in confidence ? Or it was just one of those things - you can't always be perfect !
14:58 was just that evil little stone and lack of momentum.
- Thread starter
- #49
Thanks for disecting the ride and glad you enjoyed it .
The washout was quite possibly wrong line and my body position but it gave an idea of what's happening since I altered the rear shock position.
It's looking like 63° head angle is about the limit of the frame for stability.
I've never looked at geometry before and had no idea what mine was or infant what reach it is
It's always climbed well and I'm putting that down to my skill
Yes that last tumble was embarrassing but it helps the video content.
.The washout was quite possibly wrong line and my body position but it gave an idea of what's happening since I altered the rear shock position.
It's looking like 63° head angle is about the limit of the frame for stability.
I've never looked at geometry before and had no idea what mine was or infant what reach it is
It's always climbed well and I'm putting that down to my skill
Yes that last tumble was embarrassing but it helps the video content.
Plummet
Flash Git
That crash is all technique driven.
You were too slow into the feature you needed to start further back and roll in at a speed that kept you more stable.
Mentally you psyched your self out before you started, rode Deadman sailor stiff, because of the slow roll over the rock your front wheel went offline and it was all over from there.
Also there was too much breaking over the rocks. That put you offline too. Brake less over features that send your wheels off line.
This is all technique and confidence driven not bike set up driven.
I suggest practicing being looser on the bike. Session sections of track that are difficult. Do it 10 or 20 times until you have it dialed. Try different lines to get it dialed. Then move onto the next bit of track that's difficult.
Each time you tick off a bit of difficult track ridden you have improved slightly and can add that into your skill basket. Next bit of track that looks similar will be easy.
Sessioning is something the kids do well but us old bastards do poorly. We tend to just keep on riding and the next time we ride that bit of track we ride it poorly and the cycle of no improvement continues.
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