Canyon bike incorrect head angle ???

stubs

jairaj wrote:

I don't agree with you here, I have u turn adjust forks and can definitely feel the difference between +/- 1 degree. I'm not saying the bike suddenly become un-ridable but I do feel the steering quicken up when running a steeper head angle and vice versa.

I would imagine (supersonic might know better) that the main impact of shortening the fork with U turn would be an increase in front end weight distribution as the bike rotates forward about the rear axle.

I did have a hardtail with U Turn Recons and I played with it at first but after about 2 or 3 rides I just left it in the 100mm position and forgot about the U Turn. A good gadget but mehh in operation a bit like adjusters on your brakes in my opinion.

supersonic

Both really - are some subtle effects: the wheelbase (and front centre) shortens, the BB drops, the seat (and of course head) angle increases and your weight is positioned further forward.

However this is just for altering fork length - alter the headtube or use an angleset (to decrease head angle), and things change a little differently: the head angle slackens, but the seat angle steepens, meaning seated riding has your weight further forward. BB lowers, and wheelbase and front centre increase too.

Glenn 10

At present I have a bit of extra air in the fork but it only uses about 100mm of travel out of 120mm. This helped but is obviously not ideal . I experimented with dropping the back but I was getting alot of peddle strikes. I don't want to have the bb lower.

I definitely need to work on my technique. Don't we all?

I think the weight being forward on the bike has probably a big part to play. I shortened the stem and have the saddle right back which helped with the feel of the bike. The short stem adds to the sharpness of the steering though. Maybe I do think too much about these things .

I would not rely on an angle finder but trigonometry is very exact. I have 17 years experience of taking precise measurements and I study engineering. Assuming that my method is sound in the first place then I believe I would be within 0.1degrees tolerance.

When the rear of the bike is said to have 120mm of travel, is this in the vertical plane.??

The Rookie

You still really need to remove the fork and use the headset bearing bores as the datum, it is possible (I agree unlikely) that the bores and OD are not parallel.

stubs

The rear travel might be 120mm theoretical measured on the CAD drawings. I did a rough and ready travel check on my Nerve 2011 model by measuring seat height by marking it against the shed wall with a spirit level. Then taking air out of shock (I was servcing it) and pushing the saddle down till the shock was fully compressed. I measured 114mm of travel which is probably well within tolerance. Aluminium does funny things when it is welded and a frame iirc can end up an inch shorter after welding. The designer has to design the raw frame larger than needed to allow for this shrinking.

You can get headset crown races which raise the front end by increments of about 5mm or 10mm. I have never come across a 1.5 inch riser crown race but I have seen several 1 1/8th ones. Might be worth investigating.

edit: Just spoken to a mate who has used lathes in the past. He reckons if you could get hold of the right 2000 series aluminium bar stock making a new thicker crown race would be simple for a competent machinist.

stubs

The Beginner wrote:

You still really need to remove the fork and use the headset bearing bores as the datum, it is possible (I agree unlikely) that the bores and OD are not parallel.

Not totally unlikely some frames have the headtube machined off centre to give thicker material at the rear for better welding.

adamfo

stubs wrote:

The rear travel might be 120mm theoretical measured on the CAD drawings. I did a rough and ready travel check on my Nerve 2011 model by measuring seat height by marking it against the shed wall with a spirit level. Then taking air out of shock (I was servcing it) and pushing the saddle down till the shock was fully compressed. I measured 114mm of travel

I thought the Canyon lever ratio was 2:1. 60mm shock travel equals 120mm suspension travel.

stubs

adamfo wrote:

stubs wrote:

The rear travel might be 120mm theoretical measured on the CAD drawings. I did a rough and ready travel check on my Nerve 2011 model by measuring seat height by marking it against the shed wall with a spirit level. Then taking air out of shock (I was servcing it) and pushing the saddle down till the shock was fully compressed. I measured 114mm of travel

I thought the Canyon lever ratio was 2:1. 60mm shock travel equals 120mm suspension travel.

Its not an exact science, there is a lot of bearings and links in the back end (I should know I replaced all 8 sealed bearings and cleaned the 2 plain bearings a few weeks back) Wouldnt take much in the way of manufacturing tolerance to add up to 6mm missing on the travel. The 120 mm might also be measured without a shock in place and shocks have bump stops inside I think.

supersonic

Some manufacturers measure travel by taking two points: end and start, and measure the direct distance. Others may measure the curve. Others may take the average leverage ratio and multiply by shock shaft displacement. Others may take vertical displacement. Then we have errors.

But one thing is for sure - with a sus system like this, the rear axle path is a lot more vertical than the fork.

I do have a lot of sympathy with the OP here. I do wish that manufacturers were more upfront on how things are measured and what parameters. However I stand by my earlier comments, and echo those of others, that the stable platform desired will not be achieved with a 69 compared to 70 degree head angle. A different type of bike is needed.

Glenn 10

The Beginner wrote:

You still really need to remove the fork and use the headset bearing bores as the datum, it is possible (I agree unlikely) that the bores and OD are not parallel.

The fork is running parallel with the outside of the head. Canyon use the outside of the head to take their measurements. The angle of the fork is what really counts .The fork needs to be on to determine the orientation of the bike frame in relation to the ground.

Stubs,
Using your measurement the bike dropped by about 114mm at the back. Using 70.3degrees and a 120mm fork, the front would drop 113mm vertically (all being equal) The bike will drop close to to parallel to the ground. It definitely won't drop by 30mm more on the front.

Supersonic,
You may be right about the actual effect but I would like to see for myself.

supersonic

It is not the angle of the fork for the reasons I gave earlier - it is the head tube angle. Forks on 26er bikes typically have 46mm of offset, either built into the crown or dropouts. This means forks can have the legs at different angles to the headtube, but the axle and fork trail will be the same.

The most accurate way would be to remove the fork, ensure the bb is 5mm lower than the rear axle and then measure.

lbalony

Wow. I thought I was a tough customer.

Depends on what engineering tolerances they are manufactured too. There is always going to be slight differences. Say they allow:

-/+0.5 then your fancy instrument has a tolerance of -/+0.5, this quickly makes up the slight difference of roughly 1.

1 degree is going to make any noticeable difference.

How long have you had the bike? Sounds like you have not got something set correctly. i.e. shocks, cockpit, sags etc. My Nerve was murder to get comfortably set up and working in harmony with me. Took a lot longer than on my new bike. But once it was set for me after many times of tinkering after rides it was amazing.

If you're after a fix as you think this is the answer to your issue. Fit an angle-set or try running the bike with lower rear shock pressure and higher front just to replicate the head angle you want and then try and descend on it. Might give you an idea of what that 1' feels like. But then you'll have to factor in the other alterations you have made.

What do you do for a job though? You sure you don't work for a rival bike company? I would buy another Canyon again no problem. In fact I actually regret getting my new bike. But I will more than likely be getting another Canyon again once this one is tired.

Huckfinn

OP I have a nerve and it can be a little scitish on fast technical descents afan forest, brechfa etc, (but it is a xc bike not a trail bike) never on easy fast descents like on the south downs. I find shifting my body weight back over the wheel increases the stability further. I would be interested to see what canyon have to say.

adamfo

lbalony wrote:

Wow. I thought I was a tough customer.

Depends on what engineering tolerances they are manufactured too. There is always going to be slight differences. Say they allow:

-/+0.5 then your fancy instrument has a tolerance of -/+0.5, this quickly makes up the slight difference of roughly 1.

1 degree is going to make any noticeable difference.

Even cheaper digital angle finders have an accuracy of 0.1 % so that's not a problem.
Also watch the trigonometry section of the OP's video. The head angle can be derived from distances.

https://www.youtube.com/watch?v=BBDbTir ... ata_player

I'd like to know the angle of the top section of the steerer tube.

Mass produced alloy frames welded on a jig do distort in the welding process and are nudged back to tolerance.
With that in mind I looked at the new all carbon Nerve. This is laid up in a metal master mould and cannot be out of tolerance. Canyon quote 69.5% degrees. The two German mountain bike mags measured it at 69% and 69.1.
This suggests both magazines use a slightly different measuring method than Canyon. On other bikes the figures they publish are often, but not always, slacker than Canyon's and those of other manufacturers.

supersonic

Even cheaper digital angle finders have an accuracy of 0.1 % so that's not a problem.

Assuming the finder is in the right place.

Also watch the trigonometry section of the OP's video. The head anngle can be derived from distances.

And again, assuming the member is in the right place. I cannot be certain both are, especailly when the OP is using the fork legs (as it seems) as the datum point, when they are not always in the same plane as the head tube or steerer

Glenn 10

Supersonic
We are getting our wires crossed somewhere. The fork is parallel with the head. I am not saying it is in line with the head. If you draw a line from the axle to the crown the angle would be different but if you draw a line through the centre of the legs it is at the same angle to the ground as the head is.
I don't agree about taking off the fork. If the bike is rotating about the back axle ,any discrepancy in bb height will be magnified at the head as the radius of the turning circle gets bigger. The bb offset of this bike is closer to 8 or 9 mm and not 5mm stated on the Canyon website. I would be very difficult to accurately position the bike relative to the ground without the fork on. Why do you think my method is flawed?

Ibaloney
I will either get an angle set or ideally a longer fork If I can afford it. I covered your points about bike setup in earlier posts. I have the bike since Sept last. Do you thinks i should ask Canyon for a job.?

Huckfin
I totally agree with you but the bike is marketed as a trail bike. If the angle was off by the same amount in the other direction it wouldn't have bothered me.
Maybe Canyon might respond to this post.

supersonic

Canyon state a 5mm drop in their measurement - why not use that and measure? Again, Canyon do not explicitly state parameters (the frame could be measured with this 5mm drop), but I would jig it and try it. I would definitely take out the fork, jig it, and use the inside of the headtube to measure from. I'm not saying the fork is or is not in line with the haed tube either, but it may not be parallel - how do you know? It could be, but have you seen Fox tech drawings, or are you relying on your measurements? Either way, nobody measures head angle here.



Taking the forks and shocks out the equation could be a good move, as crown ta axle can vary even in the same model, and even a mm or two on the shock shaft can make big differences. Try the 5 mm bottom bracket drop. It may even measure steeper, further bolstering your case.

Glenn 10

Sorry my last post was late off the mark.
Adamfo
Thank you for pointing out the alternative trigonometry method.
The angle of the top section of the steerer would be difficult to determine.

Supersonic
I think i see what your saying now. Im using the fork as it's easier to see the line of it on the video. In person you can see that the measuring tool is also in line with the front face of the head. The face of the head is what canyon use. In this case it also is in line with the fork. The angle finder confirms the measurement. If the tool is set to 69 degrees the difference in totally obvious.

Edit
I am only interested in the head angle of the fully assembled bike.

adamfo

Michael Staab is the Canyon mountain bike product manager. The Op could try contacting him.

http://www.youtube.com/watch?v=Z0JKgUom47s

lbalony

Glenn 10 wrote:

Supersonic
We are getting our wires crossed somewhere. The fork is parallel with the head. I am not saying it is in line with the head. If you draw a line from the axle to the crown the angle would be different but if you draw a line through the centre of the legs it is at the same angle to the ground as the head is.
I don't agree about taking off the fork. If the bike is rotating about the back axle ,any discrepancy in bb height will be magnified at the head as the radius of the turning circle gets bigger. The bb offset of this bike is closer to 8 or 9 mm and not 5mm stated on the Canyon website. I would be very difficult to accurately position the bike relative to the ground without the fork on. Why do you think my method is flawed?

Ibaloney
I will either get an angle set or ideally a longer fork If I can afford it. I covered your points about bike setup in earlier posts. I have the bike since Sept last. Do you thinks i should ask Canyon for a job.?

Huckfin
I totally agree with you but the bike is marketed as a trail bike. If the angle was off by the same amount in the other direction it wouldn't have bothered me.
Maybe Canyon might respond to this post.

Dont know if im right or what but: today was inspecting my mate canyon steerer and the inner bored out surface does not seam parralel with the out as its tapered! Just a thought!

nicklouse

and even then with all these talk of measurements. First find out how they take there measurements before anything else. the measurement on the drawing may not actually be related.

and the twitchyness you feel might just be new bike jitters and stiction.

stubs

Or might just need some more damping. The Nerve back end is pretty lively and in my experience needed more rebound damper than felt right to me at first.

Glenn 10

I have already been in contact with Canyon about this issue. I recieved an official report from them which shows the head angle being measured from the outside of the head with an angle-finder.
For this reason It is appropriate to use the outside of the head to take measurements.

supersonic,
I don't have a bike jig. My only concern is the geometry of my bike in an assembled state but to follow up on your point I crunched some figures.
If everything pivots about the rear axle and the bb is raised to match the Canyon spec of -5mm offset, the front wheel will raise by 13mm approx. In the real world that would mean that the fork would have to be lengthened by 14mm. The resulting head angle would be 69.6 degrees. This is about half way between the angle of my bike and the spec. A 150mm version of my fork would be a perfect solution.

This would also correct the seat tube angle and the wheel base length.(the seat tube is out by a similar amount to the head and the wheelbase is shorter than the spec.) It would bring the whole bike back in line with the specification.

stubs

You havent got the AM version of the frame by any chance have you. It looks very similar.

adamfo

stubs wrote:

You havent got the AM version of the frame by any chance have you. It looks very similar.

Doubt it, the old AM is listed as slacker @ 68.5%

http://web.archive.org/web/201205042101 ... tml?b=2566



Nerve XC (supposedly 69 degrees)



current AL+ 67 degrees

adamfo

Glenn 10 wrote:

I have already been in contact with Canyon about this issue. I recieved an official report from them which shows the head angle being measured from the outside of the head with an angle-finder.
For this reason It is appropriate to use the outside of the head to take measurements.

Are you sure your not talking to the Canyon monkey rather than the organ grinder ?

This is my Nerve 29er. The external headtube angles bear no relation to the fork angle.





I've got a digital angle finder, just waiting for some new button cells. I'll take the stem off and measure the steerer tube angle.

Glenn 10

stubs wrote:

You havent got the AM version of the frame by any chance have you. It looks very similar.

It's definitely the 120mm XC frame. The seat tube has no kink in it.

adamfo
Thank you for the images. It is clear that the angle finder would give a false reading on your bike for reasons stated in previous posts. (the front face of the head tube is not parallel with the bore) The XC has 95mm of straight tube before it tapers out.
I don't want to name people but I don't think that the main guy I was talking to was a monkey.

supersonic

Out of interest, what do you measure the eye to eye length of the shock as?

Northwind

Measure the fork not the bike, takes away any room for eccentric bores, confusion over tapers, etc etc. Fork stanchion as fork legs aren't always simple shapes.

bennett_346 wrote:

On it's own i think you'd struggle to notice 1 degree of change.

2 degrees in my Hemlock (head angle doohickey) made a massive difference. 1 would make half as much

Glenn 10

supersonic wrote:

Out of interest, what do you measure the eye to eye length of the shock as?

Eye to eye is 190mm (189.5mm if you are anal like me)

Northwind wrote:

Measure the fork not the bike, takes away any room for eccentric bores, confusion over tapers, etc etc. Fork stanchion as fork legs aren't always simple shapes.

bennett_346 wrote:

On it's own i think you'd struggle to notice 1 degree of change.

2 degrees in my Hemlock (head angle doohickey) made a massive difference. 1 would make half as much

If we are using rough measurements, one and a half degrees would be more appropriate which is accually 3/4 of massive. (very large maybe? )