[Gary]

Interesting with 710mm bar that puts you even further back.

well.. it's not really as simple as that.. I ride with my hands overhanging outboard of the lock-on collars whereas most riders with wider bars ride with their hands inboard of the collars and you have no idea how bent my elbows are when I ride.. but having said that I am more of a rearwards weighted rider

Didnt you had problem with balancing when it is so little room to move around or dont feel there is too much emphasis placed in rear, while not exaggerating elbows?

No. not at all, but my most used bike is a Dirt jump hardtail and feel comfortable riding that for full days XC too.

never been a fan of reach/stack, to me it's yet another stupid virtual measurement imposed on us with no real world measurements you can easily measure for yourself and not only that, it doesn't take into account an individuals preference for axle to crown measurement on a DH bike anyway.. I've been measuring bikes by downtube length instead (centre of lower headset cup to centre of BB) for years!

 

[Udi]

Gary -
A more useful measurement is the centre of top of headtube to centre of BB, as it takes the headtube length into account (something which changes hand to foot distance, and thus rider fit on a bike - measuring from the bottom of the headtube is inaccurate between different frames). This exact measurement coincides with the hypotenuse generated by reach and stack measurements, thus reach and stack are actually incredibly useful when combined. It is a shame that this third measurement wasn't part of the standard, as it gives an accurate indication of how a rider fits on a bike. Thankfully it is easily derived.

A medium Sunday is around 719mm for this measurement, which is actually a generous size for a medium. For those trying to make their bikes bigger, I found these things helped:
- Slacker cups to extend the WB (aside from just slackening)
- Increasing fork A-C (esp with 40) to extend WB, lowering bars to compensate if needed
- Wider bars increase hand to foot distance, can be rolled forward a little if needed to counteract shortened cockpit from slacker cups

 

[Tomasis]

I would love to see a photo of you holding that weird pose Do you mean extend elbows outward from body at both directions?

Re reach and stack, I'm aware of it though not long time ago. I remember Udi mentioned about measuring downtube.

To understand more of geometry, I usually check WB and CS with identical HA and BB to figure out how front triangle is configured. It seems that the current trend is to lower headtube (stack) with help of reducing downtube lenght and increasing TT when most already switched to slacker HA without affecting A2C height. All this changes increases WB yet retains rideability withoud dealing with crazy slackness of HA like Mondraker. Ride position changes from standing to being more "glued" on top tube thus improving COG.

I measured Enduro frame and got 69.5cm. How much did you got on Sunday? (I dont have access to that atm) . It might be time to start a new thread and ask for numbers of both old and new frames.

However, my intention is to have different bikes, one small and one big. It would be boring to have both long VPP bikes with slightly different stroke lenghts and it would be waste of money IMO If it feels stable on small Sunday on Ft Williams track, then it is fine.

 

[Tomasis]

There you are, Udi.

Is it not a bit contradicting with wider bars when it brings your legs closer to fork stanchions? Otherwise two alternatives are hard to do if one has other forks than 40 and still want retain rideability with 65 HA.

Re-measured as Udi suggested and got 740mm on Banshee Rune L frame. Not bad of Sunday M with 720mm.

 

[Gary]

A more useful measurement is the centre of top of headtube to centre of BB

Massively disagree

how can you use that measurement to compare two frames with different headtube lengths? You can't

 

[bengxe]

Hand to foot measurement matters a lot more than headtube length.

 

[Gary]

measuring hand position to feet position is utterly pointless.(far too many variables between the two points).

The measurement I use (and the one UDI recommended) gives BB spindle to steering Axis distance, I just find
udi's method less useful as it includes the extra variable of headtube length, making it yet another "virtual" measurement... urggghhh!!

 

[Gary]

I would love to see a photo of you holding that weird pose Do you mean extend elbows outward from body at both directions?

No. everyone bends their elbows, I simply meant you have no idea what degree of bend is comfortable for ANY stranger on the internet. therefore don't know how far their weight is back/forward by trying to judge from bar width

oh.. and BTW, where I hold onto my grips puts my hands apart by pretty much the exact same spacing a 780mm bar would for a rider who places his hands inboard of the outside lock-on collars..

 

[bengxe]

Obviously no one's literally measuring from their hands to either of their feet, but that distance is the most important factor in fitting a dh bike. As far as frame geometry goes, center of bb to center of the top of the headtube is the most accurate way to portray hand to foot distance. And your bars are too narrow for you.

 

[Gary]

as I already explained, No it isn't..

if all DH frames' headtubes were the same length, measuring to the top cup would be almost as valid a measurement but they're not.. bar height can be adjusted by 100mm easily on any DH frame with the use of differing rise bars/stems, spacers and top crowns so there's actually no need to bring bar height into the measurement at all. To size a DH bike all you really want is a measurement from the BB to a fixed point in the steering axis.. the only plausable fixed point to share between frames is the lower crown race (assuming you'll be running similar fork A-C length on each frame)
think about it?

And your bars are too narrow for you.

Thanks for your advice but I wouldn't still own a Sunday if I was moar interested in following fashion than riding what actually works for me..

 

[bengxe]

Lol. Keeping all your fingers on the grips isnt a fashion statement.

 

[Udi]

Massively disagree
how can you use that measurement to compare two frames with different headtube lengths? You can't

No, you're missing the point.
The way you measure is completely disregarding a component that matters in hand-foot distance. By all means keep doing what you're doing but it's inaccurate and useless as a comparison measurement between frames. A rider's 'fit' on a DH bike is purely dependent on hand-foot measurement, as you rarely sit on a DH bike. You seem to understand that, but disregard the headtube length by saying that you'll compensate for each frame being different by changing spacers or crown length.

Compensating for disregarding an important part of frame measurement does not make you correct. The idea is to compare how a bike will feel with an IDENTICAL setup - your viewpoint is the same as saying "let's ignore the head angle measurement because it can easily be changed with fork height and angle cups". The reality is, while many things are adjustable, any adjustment will reach limits, and what you really want to know is the frame's baseline. Hopefully you can understand that.

Most of all though, your measurement is completely useless because virtually no manufacturers provide it. My measurement on the other hand is now infinitely useful because every manufacturer provides a reach and stack measurement - do a simple sqrt(reach^2+stack^2) and you can accurately gauge how well almost any DH bike will fit you without riding it. Obviously other numbers will affect how it actually rides.

 

[Gary]

since when does your pinkie finger give you any actual grip?

UDI, that's retarded, when you buy a new frame you should always set-up optimum bar height! are you saying you'll only ever buy frames with 127mm headtubes?
Seriously.. think about it, I can measure any frame in seconds and have a good idea if it'll fit me, with your method, you need to measure headtube length aswell, then think about how the difference in HT length affects your dumb "Virtual measurement"
Just because manufacturers don't specify Downtube length, doeasn't mean it's not the most useful measurement.. they don't list "UDIs BB-127mm headtube top" measurement either

 

[ScarredOne]

since when does your pinkie finger give you any actual grip?

It actually gives you a lot.

Finding the right sizing is a great excuse to test-thrash as many bros' bikes as possible in search of the perfect fit.

 

[Udi]

UDI, that's retarded, when you buy a new frame you should always set-up optimum bar height! are you saying you'll only ever buy frames with 127mm headtubes?

You don't get it. The whole point is that frames DON'T all have the same headtube length, which is why it needs to be included in the calculation of hand-foot distance. Your method does not take HT length into account which means that two frames may have the exact same "Gary" DT measurement but fit very differently.

when you buy a new frame you should always set-up optimum bar height! are you saying you'll only ever buy frames with 127mm headtubes?

Bar height changes as a function of HA, not just HT length as you suggest. Thus, having the same bar height on two frames has no direct correlation to HT length. However hand-foot distance, and thus rider fit on a DH bike directly correlate to reach/stack measurements - which include headtube length because that affects fit.

then think about how the difference in HT length affects your dumb "Virtual measurement"

It's not a virtual measurement. It's a measurement between two physical points on the frame. Yes HT length affects the measurement, and that is the point - because HT length affects sizing:

Compensating for disregarding an important part of frame measurement does not make you correct. The idea is to compare how a bike will feel with an IDENTICAL setup - your viewpoint is the same as saying "let's ignore the head angle measurement because it can easily be changed with fork height and angle cups". The reality is, while many things are adjustable, any adjustment will reach limits, and what you really want to know is the frame's baseline.

Seriously.. think about it, I can measure any frame in seconds and have a good idea if it'll fit me

If you can physically measure a frame, it's probably built into a bike you can just ride to test fit. The point of providing measurements is to be useful to someone without physical access.

Just because manufacturers don't specify Downtube length, doeasn't mean it's not the most useful measurement.. they don't list "UDIs BB-127mm headtube top" measurement either

They actually do provide my measurement, because as I pointed out it is directly derived from the reach and stack measurements. These are provided because they are indeed useful, contrary to your belief.

on a small Sunday with a 50mm stem and 710mm 30mm rise bars

You're 5'11 and riding a small Sunday? Even allowing for different preferences and body shapes, your bike is almost definitely too small for you. Nothing wrong with that, but I'll suggest that your idea of 'good fit' probably doesn't correlate with the majority here.

I too spent a long time (thankfully years ago) hanging my pinkies off the grips and claiming wide bars were a fad. Then I bought some, and on the first ride out I felt stupid for having ever doubted them. I gained more control (especially in slides) and also noticeably reduced pinky fatigue, which was an issue for me when they were sitting on the endcaps.

I'm a big fan of the stock Sunday as I believe it revolutionised a number of things in the world of DH, but to think that significant progression hasn't occured since then is delusional. In reality, tracks have become steeper and harder, while riders have become faster. Slacker angles, longer wheelbases, and wider bars (amongst many other things) are a logical response to these changes.

2005 called, they want you back.

 

[Gary]

You don't get it. The whole point is that frames DON'T all have the same headtube length, which is why it needs to be included in the calculation of hand-foot distance.

it really doesn't!
with zero rise stems and flat bars there's no way any DH bike has too short a head tube, and like I already said with the right choice of stem/bars/spacers/top crown there are enough options to raise the bars sky high if you wanted..

The way you're suggesting measuring BB to steering axis it's possible for a short frame with a long head tube to measure the same distance as a loinger frame with a super short headtube.. in otherwords it's totally useless!

Your method does not take HT length into account which means that two frames may have the exact same "Gary" DT measurement but fit very differently.

Oh FFS! this is like panto season

any two frames with the same H/A, BB height and chainstay length will fit exactly the same (while stood up) if my downtue measurement is the same.. headtube length is irrelivent as explained above!

If you can physically measure a frame, it's probably built into a bike you can just ride to test fit.

Sorry, but that's totally wrong, it's not difficult to take a tape measure to a frame or built bike to measure, any manufacturer/distributor or shop or private seller wil be happy to measure it for you if you simply ask nicely!

As I explained, I spend moar time on a dirt jump hardtail than most folk ever do on a DH bike and my preference for a short front end set-up and a playful DH bike rather than craving stability reflects this..

I've tried plenty bikes with super wide bars and i've tried riding with my hands inboard, I simply don't like (or need) either, it's personal preference and I've never experienced pinky fatigue.. sounds kinda effeminate TBH

2005?? ha ha.. we rode down near vertical chutes in quarries on rigid bikes with canti brakes in 1991.. nothing has gotten any steeper.. there certainly seems to be a whole lot moar worrying about it now tho.

 

[Tomasis]

I think to measure from bb to top of HT is much simpler as you could transfer bar/stem/shims setup from your older bike than guessing and fiddling with stuffs or even buy new ones. Know your stack and get done in several minutes.

I understand that downtube measuring (to bottom of HT) would eliminate eventual corroleations in order to choose a frame from different brands ignoring size of frames. Though it is not accurate as it affect A2C. How are you supposed to know if you read numbers of stack/reach by mfg sheets.

At the end, I prefer Udi's way so I dont NEED to know HT lenght every time.

 

[Dsunday]

I'm 5.10" and on a small sunday.
Its taken -2 degree cups and 780mm bars and 50mm stem to just about not feel cramped.

I usually ride tight tracks so its ok but when I was in NZ and open rocky fast places at high speed it wasnt too stable.

would love to try M or L

 

[Udi]

Gary -
What does your measurement tell you if you measure two identical frames (same TT), where one has a 62* HA and the other has a 66* HA? The DT length on the 62* bike will be longer, but in terms of fit, it will actually be identical (or slightly shorter). In this scenario your measurement suggests a longer bike, but in fact the rider will be slightly more cramped on the 62* bike. Use reach/stack and you are told the bikes fit the same, which is far more accurate. What HAS actually changed is the HA (and thus WB), both values are independently provided. Your measurement is neither useful nor neccessary.

it's not difficult to take a tape measure to a frame or built bike to measure, any manufacturer/distributor or shop or private seller wil be happy to measure it for you if you simply ask nicely!

Or you could just use the measurements they already provide.
You know how you said reach and stack were "useless"? You can derive your precious DT length from those "useless" measurements by simply using HT angle and length. Change the numbers to suit yourself (I used Reach: 400, Stack: 600, HTA: 65, HTL: 127, an approximation of a medium Sunday).

Click here to see it calculated

Of course you would be better off understanding why your measurement is not particularly useful and sticking to the standards that are there for a reason (reach/stack exist because of DH bikes, they are not useless measurements like you assume). HT length is provided as an independent variable so there is no reason you cannot derive everything you need to know from a standard reach/stack-included geometry chart.

2005?? ha ha.. we rode down near vertical chutes in quarries on rigid bikes with canti brakes in 1991.. nothing has gotten any steeper.. there certainly seems to be a whole lot moar worrying about it now tho.

You missed the part where I said "fast".
WC courses have become rougher and steeper on average, denial is delusion. I'd like to see you ride the original (circa 07-09, not current) Champery WC track on a rigid with cantis at any reasonable pace. In fact, do a run on that bike and your Sunday then compare times. Isn't the Sunday a fad too by your reasoning? A newer bike with a newer setup will be measurably faster.

Technical advancement and innovation do not conveniently stop at the time of your last bicycle purchase.

 

[Tomasis]

Click here to see it calculated

we have another Einstein here. Two Einsteins in Ridemonkey, not bad!

 

[Gary]

Gary -
What does your measurement tell you if you measure two identical frames (same TT), where one has a 62* HA and the other has a 66* HA?

I wouldn't even look for my tape measure as I wouldn't want either frame.. I like a HA between 63 and 65deg for Descending and 69/70 for a hardtail (XC or DJ)
That's part of my point Udi..
You of all will people know what ball park BB height, HA and chainstay lengths you prefer for each type of bike you ride.

The DT length on the 62* bike will be longer, but in terms of fit, it will actually be identical (or slightly shorter). In this scenario your measurement suggests a longer bike, but in fact the rider will be slightly more cramped on the 62* bike. Use reach/stack and you are told the bikes fit the same, which is far more accurate. What HAS actually changed is the HA (and thus WB), both values are independently provided. Your measurement is neither useful nor neccessary.

Sorry, but because of what I just said above, this ^^ is a massive amount of pointless waffle.
DH top-tube measurements quoted in mfg geometry charts for their DH bikes is almost always a "virtual" eff TT measurement that rarely even make any sense.. which was the main reason I started ignoring them and measureing downtubes for myself many years before "reach and stack" was even thought of..


Or you could just use the measurements they already provide.
You know how you said reach and stack were "useless"? You can derive your precious DT length from those "useless" measurements by simply using HT angle and length. Change the numbers to suit yourself (I used Reach: 400, Stack: 600, HTA: 65, HTL: 127, an approximation of a medium Sunday).
it's ok, I have a tape measure and common sense

Click here to see it calculated

Of course you would be better off understanding why your measurement is not particularly useful and sticking to the standards that are there for a reason (reach/stack exist because of DH bikes, they are not useless measurements like you assume). HT length is provided as an independent variable so there is no reason you cannot derive everything you need to know from a standard reach/stack-included geometry chart.

you clearly love maths Udi, knock yourself out working everything out back to front when all you actually need is a tape measure and an ounce of common sense

You missed the part where I said "fast".
WC courses have become rougher and steeper on average,

Have they?
Fort william certainly hasn't
PMB? nope!
Champery? nope..
Leogang?

if anyone can provide data for the average steepness and roughness of each years WC tracks my money's on you though

denial is delusion. I'd like to see you ride the original (circa 07-09, not current) Champery WC track on a rigid with cantis at any reasonable pace.

I'd like a bacon sandwich,.. mmmm... bacon!

do a run on that bike and your Sunday then compare times. Isn't the Sunday a fad too by your reasoning?

Can I use a blind fold too so we're sure it's not simply placebo effect?

A newer bike with a newer setup will be measurably faster.

Not with me on it it won't

Technical advancement and innovation do not conveniently stop at the time of your last bicycle purchase. [/QUOTE]
Damn! My last bicycle purchase was almost 2 weeks ago.

 

[Sandwich]

testes testes...let's not get combative gents.

 

[Gary]

ha ha.. it's ok there's nothing to worry about here.. we're both clearly fairly high on the autistic spectrum, It's just that I'm right and Udi's, well.. a bit less right

 

[csermonet]

Udi > Gary

It doesn't take a rocket scientist to figure out that headtube length INDEED does affect the fit of a bike. Plus Udi uses big words and equations, so he wins by default.


Originally Posted by Gary
2005?? ha ha.. we rode down near vertical chutes in quarries on rigid bikes with canti brakes in 1991.. nothing has gotten any steeper.. there certainly seems to be a whole lot moar worrying about it now tho.

Pretty much sums it up, really showing your age there. I don't expect you to understand what the current state of progressive mountain bike riding actually is, I'm surprised you even know how to use this internet thing. Shame on Udi for expecting you to know basic math and reading comprehension.

 

[bengxe]

If you dont feed it, it'll eventually go away.

 

[astoria]

popcorn!

Let's take that argument in a DH racetrack. My bet goes to Udi. Gary might be sluggish.

 

[ritche]

Hey, 5'11 here, riding a medium sunday with works component -2 degrees, fox 40, 50 mm stem, and high rise renthal bars,

the wheelbase is now 46.25 inches, it's the same wheelbase of a stock large frame.

BB is at 14.7 inches.

Loving the current set up --> LOW and LONG and MOAR of the front end!

I don't feel cramped, as I usually ride at the back of the bike.

The Last 2 dh races here, have super steep sections, it was stable.

I survived it but did not win ( maybe less on the brakes next time).

Add

Initially I thought Sam hill's sunday was customized, it looks like a medium (from the seat mast), but the wheel base is longer than stock medium, size is between a medium and large, I thought he had a customed longer down tube.

But DW mentioned here it was stock medium with angle changing head set reducer, this was 07, before angled headsets were available to the public.

 

[astoria]

Surprisingly, Hill runs 63.75 deg HA during those days. Far from a standard medium Sunday HA which is 65 deg. Could it be Hill has a longer DT on his medium Sunday?

http://www.madcatzracing.com/media_pdf/dirt-DT70_PRObikeHILL.pdf

 

[Schneidie]

Surprisingly, Hill runs 63.75 deg HA during those days. Far from a standard medium Sunday HA which is 65 deg. Could it be Hill has a longer DT on his medium Sunday?

http://www.madcatzracing.com/media_pdf/dirt-DT70_PRObikeHILL.pdf

Could it be that hill hasn't ridden a sunday since 2008?

 

[sundaydoug]

BB is at 14.7 inches.

Loving the current set up --> LOW

Sounds a tad high.

 

[astoria]

Could it be that hill hasn't ridden a sunday since 2008?

So what's your point?

 

[Rider15]

Sounds a tad high.

Agreed, are you sure you do not mean 13.7 ritchie? As im 99% sure the stock BB height was 13.9. Be impressive if you could increase the height by almost an inch.

 

[Tomasis]

What do you think of two options in terms of handling also reach?

1. 740-760mm bar, 60mm stem
2. 780-800mm bar, 40mm stem

I remember I tested both 50mm and 60mm and I felt more stability with 60mm. Reach was good, but it bothered me a bit when I sometimes touch legs against stanchions. It was uncutted Boobar bar (it is 790 Im thinking)

63 HA from 65 would increase that distance?

 

[msaman]

Installed the large Sunday and now flying in the wet
Instantly more comfy on the large.no more akward feeling in berms especially when you try to enter it later :O
The trial is rideable in the wet but obviously not that fast as in the dry and still my time was -2 sec faster : ))
Really happy with that purchase.

Lower HA equals shorter reach,but my advice is just try a bigger frame as judjing by your words you dont ride with your weight on the back wheel.

 

[Tomasis]

yo! with larger distance I do mean room between my legs and fork stanchions. Between S and M sizes it is only 1" difference so I thought that I could solve that difference by adjusting bar/stem/shims/HA and get feeling of M size in hand foot distance. Reach feels good with longer stem.

It is fun to experiment and learn more about it. If I had to purchase bigger frame, it will be no Sunday Instead I'd look for some fun, poppy frame. Thats for another topic.

However I want get good general idea of what Sunday frame stands for in terms of overall package when I ride it for a while.

Anybody experimented with lighter spring and stronger compression shim stack in rear shock aka Hill ? (of curiousity)

 

[ritche]

Sorry my bad, BB height is now at 13.7 from stock 13.9 inches,

also it comes with frequent pedal strikes!

 

[dan76]

So I just dropped a totem on my 6point build and I really like how it changed the bike. I'm looking at replacing the dhx 3.0 air with a coil, and from what I've been reading the rc4 sounds like the best choice for DW link. Would with setup work well for freeride/mini-dh? I also can't find any information on if the RC4 will fit my frame? How would the rc4 compare to the roco WC/vivid 5.1 for my setup?

Thanks

 

[Mukkiman]

[/url][/IMG]

Her is my baby it´s one of the 2008 Dirt Demo Sundays.
I run an old Manitou 6 Way with shimstack. Got someone a good shimstack for this shock?
Because i don´t want to rebuild it every week until i got the right setup.

cheers Mark from Germany
btw. i love this Thread

 

[Mukkiman]

[/url][/IMG]

Hello guys this is my Sunday Dirt Demo edition there are only 20 Sundays of this on this Planet <3
I run an old 6Way shock without SPV anyone got a clue of a good shimstack for it? because i don´t want to rebuild it every time until i got the right tune ^^

 

[GekoES]

HELP!!!!

I can't unmount this bolts on each side:

I have already unmounted the shock and but these two bolts don't come out and I want to remove the linkage, they are two bolts and a axle right? So i suppose that they should come out counter-clockwise but my hands hurt trying, they must be over tightened.

So, both bolts come out counter clockwise right? If I'm going to use all my strength I need to be sure of that.