Canyon bike incorrect head angle ???

adamfo

Bang on ! Canyon spec is 70 degrees on the 29er

Glenn 10

adamfo
That shows that bikes can be made as specified. It would be interesting to know if my bike is an anomaly or are all Nerve XC 9.0's the same.
(Note; to check the bike like this, the wheels/ground must be perfectly level)

adamfo

I've set the sag at 20% on my bike. Taking a reading whilst sitting on it slackens it by circa 1.3 degrees to a figure similar to the German bike mags. I guess they ratchet the bike down to simulate sag before taking measurements.

batmo

supersonic wrote:

measure the eye to eye length

Northwind wrote:

room for eccentric bores

I shouldn't stand for being called an eccentric bore whose eyes are too close together if I were you... :P

Glenn 10

adamfo wrote:

I've set the sag at 20% on my bike. Taking a reading whilst sitting on it slackens it by circa 1.3 degrees to a figure similar to the German bike mags. I guess they ratchet the bike down to simulate sag before taking measurements.

A few extra clicks of the ratchet front or back could change the whole geometry of the bike. It would be impossible to standardise this method of measurement. The simulated load and set up of the fork and shock would be completely subjective.

If your bike geometry changes as you say when you sit on the bike then you have more sag at the back.

A full suspension bike set to 20% sag on the front and back will drop by pretty much the same height in the front and back.
The resulting head tube angle would remain within a tenth of a degree of the unweighted bike. (a hard tail is a totally different story)


It was mentioned earlier that the front and back travel follow different lines but I will give you an example of how minuscule the difference is. Using a fork at 70.3 degrees with 120mm of travel and assuming that the rear of the bike has 120mm of travel which acts vertically. By compressing the travel by 20%, the fork will shorten by 24mm and the back will drop vertically by 24mm. The front will drop vertically by 22.6mm . That is a difference of 1.4mm which would make an indetectable difference to geometry after the bike is weighted. If the back travel is measured in a straight line from the uncompressed position to the fully compressed position, the difference between the front and back becomes even less. Same goes if the travel is measured in an arc.

supersonic

But it depends on the axle path, may not be true for other models. So when you say 'a full suspension' bike, you mean this one. I have a programme that models suspension, it can be quite pronounced.

stubs

You really are obsessing about fractions. I measured my rear travel at 114 vertically but the actual movement may be more some swinging arms particulary ones with extra links follow S shaped paths. 20% sag on the shock might not mean 20% vertical travel especially as I believe some frames the initial movement is backwards at an angle not directly down. I might mean up here my heads starting to spin

Ride it fiddle with the sitting position and try different front and rear damping settings. Dont assume that 20% sag is the right sag its just a setting to start from I think mine is about 25% going by eye.

Glenn 10

supersonic wrote:

But it depends on the axle path, may not be true for other models. So when you say 'a full suspension' bike, you mean this one. I have a programme that models suspension, it can be quite pronounced.

The point is, because we are only talking about the sag portion of the movement any difference in axle path would be tiny relevant to vertical movement. We are talking under 2mm. This varience front to back will make no perceivable difference.
All this confusion demonstrates that geometry measurements are best taken with the fork and shock extended fully.

stubs wrote:

You really are obsessing about fractions. I measured my rear travel at 114 vertically but the actual movement may be more some swinging arms particulary ones with extra links follow S shaped paths. 20% sag on the shock might not mean 20% vertical travel especially as I believe some frames the initial movement is backwards at an angle not directly down. I might mean up here my heads starting to spin

Ride it fiddle with the sitting position and try different front and rear damping settings. Dont assume that 20% sag is the right sag its just a setting to start from I think mine is about 25% going by eye.

I take my hat off to anybody who is still following this thread, it's not exactly light reading.(thank you all for your input) In the back of my mind I am hoping that someone from Canyon gets involved in this conversation and when there are no more stones left to unturn, they will have no choice but to except my measurements.

stubs
I have spent months messing with settings. At present I use around 20% on the front and 30% out back.

supersonic

Geo is best measured when the manufacturers give how they have done it ;-). As for axle path, it again, depends (front and rear), and it can make a difference, especially with longer travel machines and slacker head angles - it is small, but still on your measurement tolerance. Every bit counts ;-) A quick go on Linkage shows with a long travel Santa Cruz bike, running equal and appropriate sag front and rear, the head angle steepens 0.7 degrees from when fully extended. That certainly is a perceivable difference.

I have been trying to add reasons that could make differences, and how they are measured differently - no matter how small.

Your best bet from here is to threaten Canyon with trading standards if you still feel you have a case.

Glenn 10

supersonic wrote:

Geo is best measured when the manufacturers give how they have done it ;-). As for axle path, it again, depends (front and rear), and it can make a difference, especially with longer travel machines and slacker head angles - it is small, but still on your measurement tolerance. Every bit counts ;-) A quick go on Linkage shows with a long travel Santa Cruz bike, running equal and appropriate sag front and rear, the head angle steepens 0.7 degrees from when fully extended. That certainly is a perceivable difference.

I have been trying to add reasons that could make differences, and how they are measured differently - no matter how small.

Your best bet from here is to threaten Canyon with trading standards if you still feel you have a case.

I have a report showing how canyon measure head angle and there is no mention of sag, but let's analyse the s**t out of it anyway.

I accept your point for longer travel bikes with steeper head angles. This would increase the effect. I am surprised with 0.7 though. What is the front and rear travel, sag and head angle on the bike?

Do you think I have a case based on the specifics of my bike?

supersonic

I think you have a case. I think it is poor that all manufacturers do not state their conditions. As your bike does not seem to meet the specified angles, despite many different scenarios, then I would be tempted to take it further.

adamfo

The Mk I human eyeball is pretty good at detecting angles. Take a look at the fork angles on these 29ers:

72 degrees



70 degrees



68 degrees



If you run a protractor over publicity shots like these you generally get within half a degree of accuracy. With that in mind guess what this 2012 Canyon XC reads ?



2013 Nerve



Conclusion: AFAIK the Taiwan frame factory made 2012 Nerve AL frames with 70 degree head angles !

hard-rider

supersonic wrote:

But it depends on the axle path, may not be true for other models. So when you say 'a full suspension' bike, you mean this one. I have a programme that models suspension, it can be quite pronounced.

Sorry OT but may I ask what that program is called and does it only model suspension, i.e. shocks characteristics or the bike frame and linkages too?

supersonic

http://www.bikechecker.com/

Glenn 10

supersonic wrote:

I think you have a case. I think it is poor that all manufacturers do not state their conditions. As your bike does not seem to meet the specified angles, despite many different scenarios, then I would be tempted to take it further.

There isn't much I can do when Canyon refuse to accept my case because their blueprints say that the head angle is 69 degrees.

Conclusion: AFAIK the Taiwan frame factory made 2012 Nerve AL frames with 70 degree head angles !

This would not surprise me and may explain why Canyon refuse my case point blank even though my measurements are quite clear.IMO

bennett_346

Canyon: buy cheap buy twice.

supersonic

It's not just Canyon - many bikes tested at WMB are not as specified with the head angle.

bennett_346

I was more referring to the lack of customer support from them as a distance seller. Big brands you take it back to a dealer in the UK and they're mostly spot on with a replacement but Canyon seem to have a reputation for refusing to acknowledge issues from people in the UK because they're so far away.

supersonic

They have a UK centre now.

bennett_346

Yet clearly still seem not to want to acknowledge a massive amount of customer complaints. I stand by my original comment.

poppit

What are 'these massive amounts'? Have you personal experience with Canyon?

adamfo

bennett_346 wrote:

Yet clearly still seem not to want to acknowledge a massive amount of customer complaints. I stand by my original comment.

They were voted Brand of the year by the readers of the German mountain bike magazine. Beating the other large German brands like Cube, Ghost, Rose and the other International brands. The criteria included customer service.

adamfo

In the advancement of science I've deployed my goniometer :shock:





Looking at the hi-res image this 29er seemed a bit slacker than the claimed spec. of 70 degrees.

There is a useful shadow from two opposed flash softboxes running right down the middle of the fork.
This is straight so there is no distortion in this image.
My goniometer reads a tad under 69 degrees. I bet these Yellowstone frames come out of the factory in Taiwan at 69 degrees.

Quality control stickers with Chinese characters inside my Nerve 7.9 headtube.

97th choice

supersonic wrote:

It's not just Canyon - many bikes tested at WMB are not as specified with the head angle.

My boardman was 71.... Something degrees roughly, way over the stated head angle.

YeehaaMcgee

adamfo wrote:

In the advancement of science I've deployed my goniometer :shock:

What's your vertical reference? Are you considering lens distortion?
When you're talking half a degree, you have to be REALLY precise!

cooldad

Have you ever used it to measure the angle of your dangle?

adamfo

YeehaaMcgee wrote:

adamfo wrote:

In the advancement of science I've deployed my goniometer :shock:

What's your vertical reference? Are you considering lens distortion?
When you're talking half a degree, you have to be REALLY precise!

Grid overlay on my monitor provides the vertical. You rotate it so the bottom of the wheels line up. It's an expensive colour calibrated job.

The lens used looks to be a standard or mild telephoto. There is no measurable distortion. Download the bigger image off the Canyon website. Having said that some other manufacturers have press download sections where you can download proper hi-res images.

I agree accuracy is probably +/- half a degree. The Nerve 29er photo angles are exactly the same as I measured my own bike so there does seem to be some accuracy scaling photos within those limits.

adamfo

cooldad wrote:

Have you ever used it to measure the angle of your dangle?

Almost 180 degrees (in my younger days )

A medical goniometer is useful for roadies to set optimal saddle height by measuring optimal knee bend :idea:

adamfo

Holy thread resurrection. The new august issue of Das bike magazine measures the 2013 Nerve AL 8.0 at exactly 70 degrees. Same as my goniometer method. The OP's trigonometry video is correct.

rockmonkeysc

This is nothing, I met a lad who bought an earli Identiti Mogul with a head angle of 69 degrees, 4 degrees off the claimed geometry. It looked and rode terrible.