# Why does 3cm of TT make such a difference?



## HelmutHerr (Oct 5, 2012)

After an expensive and painful journey with 61-65cm frames, I've learned that even though I'm two metres tall, a 57-58cm top tube is the right length for me to feel like I'm sitting properly on a bike, with full control, and not sitting way back on a saddle and reaching for the bars like I'm pushing a wheelbarrow.

Why do those few centimetres make such a big difference to the feel and fit of the bike? It's not something I can compensate for with stems and saddles: even with a shortened cockpit, it doesn't feel as right as a shorter bike with the same distances.

Is this what front centre is about?

I ask because I need a custom frame, but the builders I've consulted, while excellent craftsmen, aren't physiotherapists and won't necessarily be familiar with building frames to the weird proportions I need, so having as much knowledge as I can will help me with the input.

Any links to relevant articles would be welcome.


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## pvd (Jan 4, 2006)

The relationship your saddle and handlebars have to your bottom bracket is defined by your handicap or aggression level and by how you fit to them. Where the wheels are in relation to your center of gravity control how the bike can perform.

We don't use top tube length when talking about bikes because it isn't a driving parameter.


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## briderdt (Dec 14, 2012)

pvd said:


> The relationship your saddle and handlebars have to your bottom bracket is defined by your handicap or aggression level and by how you fit to them. Where the wheels are in relation to your center of gravity control how the bike can perform.
> 
> We don't use top tube length when talking about bikes because it isn't a driving parameter.


Where's the "Like" button?


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## Eric Malcolm (Dec 18, 2011)

HelmutHerr

Could you expand a little on your size. At 2m tall and a preference to a TT of 57-58cm suggests very long legs, but a short back, arm length average/long?

Something that you could do is measure the preferred bike and yourself draw yourself up as a 'Stickman'. With the contact points known, change the TT length by shortening/lengthening against the original drawing. Change the H/bar stem length to suit. You will notice that while your ride position does not alter, the Front Centre does. The FC will determine important things for a touring bike like stability. Touring bikes spend a lot of time on the 'straight ahead' mode of riding rather than needing a quick steering bike. Hence the preference to go longer. But you are uncomfortable with that position, so there will be more to understand about yourself and how you fit into your bike.

Eric


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## HelmutHerr (Oct 5, 2012)

pvd said:


> The relationship your saddle and handlebars have to your bottom bracket is defined by your handicap or aggression level and by how you fit to them. Where the wheels are in relation to your center of gravity control how the bike can perform.
> 
> We don't use top tube length when talking about bikes because it isn't a driving parameter.


Yet it's the one characteristic that seems to distinguish a bike that feels great underneath me from one that feels too large.

What do you mean by "aggression level"? On my hardtails I simply don't feel like I have full comfort or control, whether it's on a slow commute or fast single track. I used the wheelbarrow analogy in the OP because that's how it feels, or like I'm pushing the bars to move a tiller, rather than with some weight over the bars and controlling the bike with body English. From my understanding, that's the classic sign of a frame that's too large.



Eric Malcolm said:


> Could you expand a little on your size. At 2m tall and a preference to a TT of 57-58cm suggests very long legs, but a short back, arm length average/long?


That's it precisely. A very short torso on top of super long legs, but my arms are about average, so I'm propped up high on a saddle, way over the back wheel, grasping for the bars.



Eric Malcolm said:


> Something that you could do is measure the preferred bike and yourself draw yourself up as a 'Stickman'. With the contact points known, change the TT length by shortening/lengthenindg against the original drawing.


Do you know of an online tool that helps with that? Or if Bikecad can do it?

Here's my 22" 1x1 as an example of the cockpit I end up with, although I can tolerate a slightly lower bar these days:









The key question for me is whether I should be talking to the builder mostly in terms of front centre in order to describe what I want from the frame. As you can see, actually describing the deficits in fit on a normal frame is difficult, so knowing the technical details helps.


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## briderdt (Dec 14, 2012)

What the builder needs is your contact points, and how you want the bike to feel. The rest is up to them. Once you start dictating any other dimensions to the builder, you're going to end up with something possibly horrific, if they'll do the job at all. Trust the builder.


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## Walt (Jan 23, 2004)

There are plenty of framebuilders who are great at making things out of metal but are much less interested in geometry beyond basic fit/contact points. PVD is absolutely correct - the hard part is determining where the wheels need to end up to make the bike disappear under you. Getting to where you can sit on the bike comfortably is easy to do. Getting the bike to ride right is not (well, sometimes it is, but it's harder). 

Find an openminded builder who can explain to you in plain english why a design will work for you or not. If they can't talk coherently about what different front centers, trail numbers, chainstay lengths, or BB heights will do to the ride, walk away.

-Walt


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## HelmutHerr (Oct 5, 2012)

briderdt said:


> What the builder needs is your contact points, and how you want the bike to feel. The rest is up to them. Once you start dictating any other dimensions to the builder, you're going to end up with something possibly horrific, if they'll do the job at all. Trust the builder.


Yeah, I'm second-guessing too much, but a custom frame isn't something I invest in every week, and the CAD schematic that came back from the last builder consult was monstrous.

But I guess that if I'm a weird shape, my bike should be too!


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## HelmutHerr (Oct 5, 2012)

Walt said:


> There are plenty of framebuilders who are great at making things out of metal but are much less interested in geometry beyond basic fit/contact points.


That's my concern. The bike industry tends to treat everyone as a medium-height male. To the extent that tall people exist in the bike world, they're just zoomed-in medium people, and not the weird mix of proportions and weight and shape that tall people really are.

A retail manufacturer can't tailor sizes that way, but it seems to lead to an industry culture that doesn't encourage thinking outside the box on bike fitting.

Anyway, that's my pet peeve and not really germane.



Walt said:


> Find an openminded builder who can explain to you in plain english why a design will work for you or not. If they can't talk coherently about what different front centers, trail numbers, chainstay lengths, or BB heights will do to the ride, walk away.


There's three. Three custom frame builders within a day's drive of where I live, so not a buyer's market!

I mentioned above that I went for a consult with one, and his bikes are beautiful, but we didn't communicate well. I couldn't describe what I wanted, and I think he felt like I was asking him to guess. Hence this thread: so I can maybe gain some technical knowledge to make the next discussion more effective.


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## pvd (Jan 4, 2006)

HelmutHerr said:


> View attachment 991735


That bike is completely messed up. You should rent or borrow a 23" Trek Superfly 29er and fit that up first. I'll bet that you find it amazing compared to that POS.

Superfly 6 - Trek Bicycle


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## Walt (Jan 23, 2004)

Buying local is great but if you don't have a good local option you might look further afield. I don't think you want to just let a builder "work their magic" if they can't tell you why something will work (or not). 

-Walt


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## pvd (Jan 4, 2006)

Zinn is the place to start for big bikes.

Big Sur ST Custom Mountain Bike | Zinn Cycles website


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## Eric Malcolm (Dec 18, 2011)

This is a difficult topic to cover as it is ethical to detail a build with a builder and Walt is following that line. The Zinn looks to be a good place to investigate something suitable.

I am tall, but not in your category, you tower above me....

In one of my places of employ, the crew would all sit around the table and we would have our Smoko break, talking, face to face at the same level. When finished, and standing up from our seats, one person would rise very little, and I would keep rising to my full height. Strange feeling that. This workmate had short legs and a long back, either that or his legs forgot to grow. Then, while working in the LBS, during an age where the universal bike of the day was the Raleigh Twenty, fixed reach to the H/bars, had someone like me with a very long thigh, hit the h/bars with my knees if I stood up out of the saddle. It is difficult to assume normality.

If you were to look at the Trek, looking at its Specs, you have a likely max saddle height of 900-920mm from centre of BB to the top of the saddle. But, maybe the reach is a bit long for a short back, so it becomes a try and see.

Personally, with my own bikes, I threw the rule book out the window. I have a back that on 'normal' bikes would give me 1-1:30 mins of ride time before giving in. Biking has to be comfortable. No fun if it is not.

Development started with shaping a Handlebar to suit me. It gave me knee clearance. My wrists had good blood flow and numbing of the hands decreased. The re-angled hand position also allowed me to pull harder and I could move to and fro to alter the back angle. This added another 1hr to my ride time.

Then, I looked at my ride position and how it affected my back, and determined that I needed to align the spine so it sat straight. Tall people are inclined by disposition to arch the back due to the normalizing of the average.

A clean sheet was required in my design approach. I found that when I was riding on a Static trainer like you ride in a gym, if I pulled my self forward on the saddle, that I not only increased my cadence without actually increasing power input, that my back felt better. I added this finding to my design, and went more to a TT/Triathlon position. Set my Mule bike up so I could test my theories. It looked ridiculous of course, but achieved another 1hr of ride time. I then took my set-up (contact points) and drew up my personal bike. 4yrs later and no regrets.

I use a steep 75* seat angle, with my body rotated over the BB, ride on an ISM Adamo Breakaway saddle that puts me a further 50mm forward than a conventional saddle. This allowed me to free up space for a long Front Centre, and in combination with the H/bar that I made, I was able to create a ride that gives me pleasure. 

I mention this to give you hope, it can be done.

Eric


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## cmc4130 (Jan 30, 2008)

HelmutHerr said:


> After an expensive and painful journey with 61-65cm frames, I've learned that even though I'm two metres tall, a 57-58cm top tube is the right length for me to feel like I'm sitting properly on a bike, with full control, and not sitting way back on a saddle and reaching for the bars like I'm pushing a wheelbarrow.
> 
> Why do those few centimetres make such a big difference to the feel and fit of the bike? It's not something I can compensate for with stems and saddles: even with a shortened cockpit, it doesn't feel as right as a shorter bike with the same distances.
> 
> ...


So, exactly how high do you run your seat (measuring from center of bottom bracket up to top of seat surface) ?

I have my seat at 29.5" (749.3mm) from center of bb to top of seat. About 34.5" inseam and 6'1".

What's your inseam? Like actual (not jeans)?

It seems like adjusting stem length could be a big factor in the "reach" you're talking about. Downhill, Freeride, and DJ moved to short 40-50mm-ish reach stems a while back; now even Enduro and some All Mountain bikes are going that way.


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## Walt (Jan 23, 2004)

OP specifically said they have tried adjusting with stem length and been unhappy.

FWIW, I'm 5'10" or 5'11" and have a saddle height at around 820mm from BB center. It appears to me that OP is ~100mm higher than that, which is pretty far into weirdly long leg territory assuming a 6'6" rider. I actually recently did a 920mm saddle height bike and we resorted to using a 150mm 29er fork, uncut steerer, 130x10 stem, AND a 75mm riser bar to get the saddle height up high enough.

So there are some real freaky shapes of person out there who really can't just swap out a stem and fit.

-Walt



cmc4130 said:


> So, exactly how high do you run your seat (measuring from center of bottom bracket up to top of seat surface) ?
> 
> I have my seat at 29.5" (749.3mm) from center of bb to top of seat. About 34.5" inseam and 6'1".
> 
> ...


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## HelmutHerr (Oct 5, 2012)

*Now with pictures!*

Thanks for all the great feedback.

To clarify, I'm 194cm/6'4" tall, and have a 98cm/38.5in cycling inseam. So, over half of me is leg.

To answer the setup questions, here's an annotated pic of the Rawland Drakkar I use most days. It's the most comfortable setup I've ever had, but it still feels too long, in the way I described above.









You can see I've got the saddle way up high, and bars to match. But here's the weirdest thing: I had a go on a colleague's 56cm Kona Dew Drop last week, with the seatpost all the way out and a huge drop to the bars, but even perched like an ogre on a tricycle, my weight distribution felt much better. A little too far forward, like I was plunging into the bars, but so much more control and it seemed like less neck strain, even though I had to pull my head way up to see the road.

That's why everything leads me toward front centre as the crucial equation. Clearly my legs are crazy long, but I also need about a 58cm top tube - obviously not standard geometry.



Eric Malcolm said:


> This is a difficult topic to cover as it is ethical to detail a build with a builder and Walt is following that line.
> ...
> When finished, and standing up from our seats, one person would rise very little, and I would keep rising to my full height. Strange feeling that. This workmate had short legs and a long back, either that or his legs forgot to grow.
> ...
> ...


Thanks for all the geo tips. I've noticed hip angle plays a lot into it.

I've got a friend who's two inches shorter than me standing up, and an inch taller sitting down. Leg length counts.

Dictating geometry to a frame builder is the last thing I want to do. I just want to be able to speak the same language!


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## TrailMaker (Sep 16, 2007)

WARNING!!!

I am NOT a Geo master by any stretch of ANYONE'S imagination, so this is just corned beef hash here; I might add from a total MTB rider perspective. I am a stretched out kind of guy like you. Not quite the same, but close enough that I feel your pain. I am a bit more "in proprtion" at 6'5" with a 37" inseam and a 38" sleeve. The main problem for me has always been _endohysteria_; like I am perched miles above and right over the front axle with the bars in my lap, just waiting to hit the slightest pebble and go for another Superman. The high center of gravity coupled with the short front center (for my height) was just unnerving. Stand and peddle? Impossible!!

My previous Santa Cruz Heckler in XL is 28" in FC, and is a veritable launching pad. My current XL Niner RIP9 is the first bike that I feel comfortable on. It does not have that long an FC at 28.25", but at least the big hoops have me feeling like I am a bit more in it than on it. The (fat)bikes I have built for myself were based on a 29.3" FC. The wheelbases run 45, 46.25, and 47 respectively. The difference is fairly dramatic. Now I know what an average person feels like on an average bike. I can do what I want or need to do on my fatties at any moment and have NEVER gone ass-over on one of them.

I use uncut steerers with riser bars and 6-10* stems and manage to get bar and seat height about level. Even with all of that, my bikes do not have any semblance of the bizzar appearance of that FrankenSurly you posted.

I personally think Eric is on to something for you. I would seriously investigate ST angle as a way to compensate for your legs-longer-than-torso build. Longish FC to counter you seat height, with a steeper ST angle putting you a bit more forward toward the bars. I'm not saying it would definitely work, but it is something I'd be surprised to see in a standard frame.


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## HelmutHerr (Oct 5, 2012)

That makes a lot of sense. The two bikes I've posted have ST angles of 73 and 72.5, and on both of them I'm pushing the saddle all the way forward trying to get that feeling of being properly over the front end of the bike. It's exacerbated by the 200mm cranks on the Rawland.

On significantly shorter top tubes I get that exact "endohysteria", because the front wheel is right underneath me.

So if I understand correctly, you and Eric are suggesting that instead of shortening the front centre, geo might be improved by steepening the ST angle, which would bring me further toward the front of the bike without being too far over the front wheel. Is that right?


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## Walt (Jan 23, 2004)

Are you going for a mountain bike? Or a touring bike sort of setup? You can get used to lots of different bike "feels" but you can't keep a super short front center and high COG setup like you've described from being an endo-machine no matter what. 

If you want to ride relatively non-technical stuff, what you are describing might work. If I were designing you a mountain bike for serious trail riding, though, I'd have you on about the shortest stem I could find you and a long toptube/pretty slack front end with the longest offset fork I could find as well. IMO you'd get used to such a setup quickly and then if/when you went back to that crazy short front center, you'd be terrified. You need longer chainstays too, of course.

But it's all about enjoying the ride, not what someone else tells you is right. If you like what you've got, have someone duplicate that position with longer head/seat tubes. Boom. Done.

-Walt


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## HelmutHerr (Oct 5, 2012)

In theory the Rawland is still my ideal: road geometry with offroad and touring capability, but if I go ahead with a custom frame I'll probably exploit the options of a cherry-picked tubeset and lean more toward cyclocross, like a scaled-up Surly Crosscheck.

I'll leave the thread there. Thanks everyone for the input. I've learned enough to probably have a frame planning discussion with a builder that doesn't mystify _me _and frustrate _them_.

:thumbsup:


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## Eric Malcolm (Dec 18, 2011)

Helmut

Walt raises a good point in end use. The pictures you have posted suggest a pavement/gravel mix. If you are inclined to this mix, I will give you some further insight, but if you are more into the MTB, the specific need is balance, and Walt has better insight than me. 

I was also going to ask you about the crank length of the Rawland, so that is clear at 200mm. I have a question, as, I have an actual inseam of 917mm (36") and have wondered about proportional length cranks. I use 180mm presently. When I go back to 170mm, I find that I can't develop the same Torque, it is difficult to settle into a steady cadence and just seems 'un-natural', though I can spin quicker on 170's.

To answer the question of the steeper ST angle, yes you conclude correctly. My own bike is like a sort of Ducati Mulitstrada, I use it for road, Gravel and light MTB use, but, it is front end weighted and hard to lift the front end when riding. It suits my purposes, it offers excellent secure front end 'bite', though I don't feel as if I'll I go over the H/bars. It is not hilly where I live. If you're into technical MTB riding, then you need balance, so, which compromise are we directed to?

I will point out an interesting observation from looking at Manufacturers specs for the more road orientated bikes, if you look at the small sizing, say 50cm, you will note that they are often steep ST and slack HT angled, and have been for decades. They operate with short TT's to fit the smaller riders among us, so it is not a new design theory, just not applied to tall people....

Hear from you soon.

Eric

ops, I see that you have already posted and answered my post in part, thanks.


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## HelmutHerr (Oct 5, 2012)

Look like the season has been extended.

Yes, roads and gravel are really what I ride on. I like light singletrack when I find it, but I wouldn't plan a frame around it. Bikes like the Crosscheck, Kona Rove, Soma Wolverine and obviously Drakkar appeal to me most - that line between rigid mountain and cyclocross - but their geo just doesn't fit me on board, particularly with the BB heights and long cranks.

In that regard, I'm very reluctant to give up the cranks. Going back to 175mm would be frustrating. I'm not a performance rider and can't comment on that aspect, but for comfort and the sense of leverage they're amazing. The Drakkar has a BB height of 310mm and heaps of clearance. Haven't had pedal strike yet. But the lower that goes the more careful I'll have to be.


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## Eric Malcolm (Dec 18, 2011)

I will collate some info and come back in a couple of days.

Eric


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## dr.welby (Jan 6, 2004)

You have the 'T-Rex' build which can be tough to fit. Stock frames that fit your legs end up being too long. If you try to get a shorter top tube by sizing the frame down then the bars are too low and you usually run out of spacers before you get the bars high enough. One often gives up before coming up with a good solution. Fitting one T-rex I had to take a spare steerer tube and clamp it to the top of the fork with an extra stem to get the adjustable fitting stem high enough to actually get a position to work from. The frame for that person will be the equivalent of a 60cm road frame with a 54 top tube.

Moving the seat forwards can sometimes be a solution. Usually you want the fore-aft position of the seat to provide good balance for your torso and arms. You'll see it described as that you when pedalling up a slight grade with a light effort, you can take your hands off the bars and float them without feeling like you're going to topple forwards. For T-rex folks your upper body is smaller than other people your height so you might not need to sit as far back on the bike to still get some balance.

In the photo of your Rawland it looks like the saddle is positioned with the nose down. This could indicate that your pelvis is being rotated forwards by too much reach to the bars. Moving the seat forwards, assuming you still have good balance, would help the reach and let you roll your hips more level. It might also help to do some hamstring stretching.


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## HelmutHerr (Oct 5, 2012)

dr.welby said:


> You have the 'T-Rex' build which can be tough to fit. Stock frames that fit your legs end up being too long. If you try to get a shorter top tube by sizing the frame down then the bars are too low and you usually run out of spacers before you get the bars high enough. One often gives up before coming up with a good solution.


For reals. If I hadn't had done so much cycling when I was younger and really missed it, I would have given up a long time ago. Bloody-mindedness FTW.



dr.welby said:


> Moving the seat forwards can sometimes be a solution...
> 
> ...In the photo of your Rawland it looks like the saddle is positioned with the nose down. This could indicate that your pelvis is being rotated forwards by too much reach to the bars. Moving the seat forwards, assuming you still have good balance, would help the reach and let you roll your hips more level. It might also help to do some hamstring stretching.


I've pushed the saddle forward to shorten the cockpit, but then the nose hurts my perineum, so I rotate it forward and get hand/arm pain because it's pitched too far down. All of these factors are what leads me to a custom frame and this thread!

Also, stretching has helped a _lot_. Doesn't make things perfect, but I was literally getting injured by riding a bike previously.


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## Eric Malcolm (Dec 18, 2011)

*Number 1, making the cockpit roomy*

A couple of small matters first. Buy a saddle like the ISM Adamo Breakaway and your perineum problems will be gone forever. Second, if you are able to ride your friends bike with a lower H/bar height and find it comfortable, there would appear to be some room to move. Just a thought, generally as tall person's, we spend our lives walking and living looking downwards, it could be therapeutic to get on a bike and have the opportunity to relax and re-train the neck muscles to flex the opposite way....

Anyway, back to looking at this situation in a holistic context. I am going to give inspiration and weird actual results from my own experiences building my own bikes.

Finding room for the legs on a short TT:
















The Blue bars are the originals that evolved from my Mule, but emphasis here is on how much space has become free for one's knees, the freedom to not hit one's knees against the H/Bar. Side benefits are better leverage, blood flow at the wrist and reduced numbing of the hands - particularly, fingers. You can follow this theme without the aero extensions. I see you have on the Rawlands, some form of bar that follows this thinking.









This view will be how you see bikes, scary low TT, a place to attach your hands and open ENDO feeling fear. (I put that there for perspective to those that need to know this).

To conclude, You can jump out of the saddle freely and power along.

More to Come...

Eric


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## Eric Malcolm (Dec 18, 2011)

*Number 2, Geo and fit*

Looking at Chainstay lengths, I see that the Rawlands is spec'ed at 450mm, the Surly at 425mm. The rear of the saddle on the Surly is directly above the rear axle. To compare with the 2 bikes below, if you raise the saddles up by approx. 75mm, which would be about where your saddle will fit, the rear of the saddle on both these would remain inside the rear axle. The Orange bike has a 405mm CS, the other @ 385mm. How does this work? Apart from the CS length, these bikes are identical at the contact points. The seat angle is 75*.









The EFT on both bikes is 600mm, this bike has the Adamo saddle, so I sit forward of where the white patch shows. You could fit this Cockpit no problems as the saddle has placed you forward a little more to reduce the reach by 50mm. The HT angle on both bikes is 71.5*, with Trail @ 70mm. Very stable on the gravel. Oh, and you would not endo, I have tried - OK?

I could easily set you up on this lay-out adding height to the seat tube, 40mm to the HT and you will notice from this angle how far forward the H/bar stem projects. Attaching the stems to the head stock means a change to a steeper angle to raise the hand contact a further 40mm.









I added this side view to show how you can hide the steep ST angle. A wee bend makes all the difference to 'appearing" normal.

More on Style in another post.

Of the 2 bikes that you ride, I note a wide variance of Trail. You prefer the Rawlands at 72.5* and 58mm Trail. The Surly is at 72* and has 67mm.

If you build a crank length corrected bike with the Rawlands geo, I would find this to be a very nervous bike (on gravel especially) with your high CoG. Without understanding your preference here, I would opt for a long CS, steep ST angle, slack HT, and you will gain Front Centre that will be modern and pleasant.

With some riders, steering a bike is like turning a steering wheel, turn and as the bike begins to lean, you lean with it. For others, they drop the elbow slightly as the bikes leans over, the steering follows the body movement. Which do you prefer? Low Trail figures follow the steer type, high figures - the leaner type of rider. A longer FC will give better Stability.

OK, Moving on....

Eric


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## Eric Malcolm (Dec 18, 2011)

*Number 3, Style*

Now, I do not expect that you will want to follow my style (well maybe), but there is something about how tall bikes look that really grates me.

In the real world we have these images of the Beautiful bike advertised, you know, the Road bike, 56cm ST x 56cm TT, always look drop dead gorgeous. Wish I could have a bike that looked like that. Bleep bleep legs. Proportions that just kill style. I'm left with a bike that looks tall - because it is. The perfect Square box with wheels at each end. I have to settle for a vertically placed rectangle with wheels at each end. Well no, I object.

So, I design with cunning. I do low profile. I give the impression of normality, but stand beside the steed, and the saddle towers. Can't steal this one - Ha.









This view of the overlay. They are the same, but look completely different.









Here, separated, the orange bike appears longer, lower. By comparison, the metal bike seems to look shorter, yet taller.

Trailmaker, has on another thread, placed an overlay of #3 over his Kroozer. Similar visual deception is employed. Trailmaker has already contributed to this thread, but go and have a look at his work. He is tall and we share the battle to defeat poor style.

So, you have some more knowledge. The thing for you to do, is evaluate, accumulate, and evaluate some more. I think you are working towards your goal, and have most of this sussed out now. Obviously, if you get stylish, it will push the price up, but find a builder that will work with you, make him your friend. You know, a good relationship.









I put this one here for you shorter people, just to show I'm not Biased.....

Eric


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## TrailMaker (Sep 16, 2007)

Sharing the Battle to Defeat Poor Style;

I like that! 

The M-Bike (the steel one, folks) is just flat out COOL.


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## unterhausen (Sep 28, 2008)

funny thing is I was given an old univega road frame with 65cm seat tube and 56 cm top tube. I have tried giving it away, no takers


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## Walt (Jan 23, 2004)

That would fit me, but I need another frame kicking around like I need a hole in the head.

-Walt


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## m-gineering (Feb 5, 2012)

HelmutHerr said:


> Yeah, I'm second-guessing too much, but a custom frame isn't something I invest in every week, and the CAD schematic that came back from the last builder consult was monstrous.
> 
> But I guess that if I'm a weird shape, my bike should be too!


to me it looks like your problem is that you're all legs and not much else. If you ride a standard frame your seatpost is way back over the rearwheel, as will be your CG. There won't be much pressure on the frontwheel, unless you go to a short front center too. It won't be a unicycle, but close. With your proportions forget common wisdom about what constitutes proper chainstay lenght, scale up and go long.

Marten


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## Walt (Jan 23, 2004)

Yes, that's a great point. I'd put you on 500+mm (yes, that's right) chainstays.

-Walt


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## ACMtb (Mar 22, 2015)

Hello Helmut Not sure where you are up to with the fitment of your bike I thought I might add that there is a guy in Sydney who is a bike fitment guru and all round fitness fanatic I don't have any of his details His name is Steve Hog Good Luck


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## HelmutHerr (Oct 5, 2012)

Didn't mean to wait so long to reply, but that's a lot of great stuff from Eric and I haven't had time to post.

Those bar setups are amazing! The backward drops are something I'd like to try in future, but so far I haven't had too much trouble with hitting knees. The tri bar is a lot like the Jones bar I'm using currently, which has been very good to me.

As far as cool goes, it looks like the choices are cool-by-stealth or bawls-out freak machine. I'm not really opposed to either.



m-gineering said:


> With your proportions forget common wisdom about what constitutes proper chainstay lenght, scale up and go long.





Walt said:


> Yes, that's a great point. I'd put you on 500+mm (yes, that's right) chainstays.


Ah! I was wondering about that. The Rawland feels light on the front, which is presumably because of the long front centre, but I also wondered if I'm getting the effect of short chainstays because I'm jacked up way over the rear wheel and effectively reducing the CS in terms of handling.



ACMtb said:


> there is a guy in Sydney who is a bike fitment guru and all round fitness fanatic I don't have any of his details His name is Steve Hog Good Luck


He's got a good reputation, but I'm in Victoria. My regular physio has done amazing stuff with my previously bad hip and also does bike fittings, so I'm booked in with him next month and we'll nail the geometry down for the build.


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## Eric Malcolm (Dec 18, 2011)

Hey Helmut

Good to hear from you. Great that you already have the Jones bar. 

The ease of being able to lift the front wheel is due to where your centre of gravity is. I would conclude that on both bikes, your CoG is above the BB instead of being forward of the BB. This being due to sitting directly above the rear axle. A long FC places the front wheel further forward putting weight out front more, so this is not the reason. The cause is due to your rear-ward ride position. 

Don't be frightened to set yourself up more forward, you will place your weight better between the wheels, you will need to bend forward a bit more, but if you rotate at the hip correctly, you will only place a small amount of extra weight onto your arms and shoulders with only a small amount of neck bend.

Eric


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## Eric Malcolm (Dec 18, 2011)

An area I did not cover, but occurred to me today, is the use of clever design around the fork. To reduce the overall length of the whole steering/head tube, we have the 29'r to thank. Suspension corrected forks extend the axle to crown somewhat. If using Disc brakes, a 100mm suspension corrected fork will have a rather large space between tyre and bottom of the crown. This picture shows what you can do to 'hide' the gap. This would be easily done with a unicrown fork blade and a plate brace. Subtle, but effective, it allows for 30-40mm of reduced HT length, along with a tall stack height headset... The angle that the DT comes off the BB will be steeper angled, and require a longer DT, but here's the thing, you can now get DT's in 35 and 38mm Dia that are 750mm long (up from 670mm) to take up the variation. There are more options available to both builder and owner today, than say, even 3 years ago.

Eric


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