Frame Sizing a Road Bike for injured rider

whv

I have broken 45 bones in my body. I have an enormous amount of metal and foreign bodies in my body. I have broken pelvis in 3 places, back in 2 places and severe neck injuries. I think I have overcome most of the crooked pelvis and broken back, but the neck just does not like being on a big long bike. Sooo I want to "build" a new bike and am trying to come up with my geometry. I believe I am classically a sz 56. I am currently on an huge Pinarello FP5 that I cannot figure out what its actual size is but it is too big and I am sick of the too big even though I am in love with the bike. I am 6' 0" tall. My correct saddle height from BB to top of saddle is 90cm. My current too big bike right now has a 57ish top tube, 120mm stem, 61cm seat tube, reach 41cm (BB vertical line to HT center). I am thinking of getting an Aethos frame in either 56 or 54. I am leaning toward a 54 and then just getting a longer stem if I need the length. Both sizes recommend a 100mm stem. Any opinions on frame size with my height and neck issues? If I got a 54 are there any problems with me being 6' and wearing a sz 11 shoe? Thanks!

whyamihere

This is impossible to answer as nobody but you knows the extent of any limitations associated with the injuries. You need to at least test ride the bikes. This would probably be one of the few times I'd recommend a professional bike fit as long as you can find someone who specialises in fitting after injuries.

veronese68

I second the above, at the very least you'd have to try the bike in a 54. But a proper fit taking into account the injuries would be best.

How long is it since the injuries? Are you likely to improve in terms of flexibility? If things are likely to change you will probably want a bike that you can adapt to suit as flexibility improves.

Webboo2

You state your correct saddle height is 90cm from bottom bracket to the top of the saddle. I guess this would only be correct if you always use the same size cranks.

focuszing723

A cheaper alternative would be new forks so you can space the stem (bound to be cut) until it's comfortable. Also get a short stem. Back/Neck higher and less stretched.

Wheelspinner

https://forum.bikeradar.com/discussion/comment/21089393#Comment_21089393

I’m the same height at 6’0, or 184 cm, yet my BB to saddle top is 76.2. I’d consider myself fairly standard proportions in torso to leg length etc, so someone who has nearly 6 INCHES higher saddle than me sounds unlikely to find an off the shelf frame to suit. Unless you have really really long arms.

I ride both a 54 and a 56 frame, both of which have relatively tall HT (therefore stack) than most, and on both of them I stick to stems less than 100. One is an old Cervelo RS, the other is a custom build Seven. Nothing else fits, as the saddle to bar drop gets too great for a bad neck (I fractured my neck years ago).

whv

Lower back and pelvis are stable. Neck is very painful. I can not find a bike fitter in my area that I trust, so I thought I would start a discussion here to atleast get more info on what others have done. Since most pro riders from what I have read on the "errornet" ride frame sizes 1 to 2 times smaller than what they would classically be sized at and then keep the reach with a much longer stem I was thinking that maybe that is what I would do but probably not need the longer stem, but be able to go longer if need be. So, I guess I wanted to know what the downside to riding a frame sized down is if any?

First.Aspect

Are you sure that you will be able to use any form of road bike comfortably? It's not just the riding in a straight line neck position you need to think about, it is the checking behind you motion. Do you have enough flexibility in your torso to compensate?

The issue you may have with a particularly small frame is that the stack will also be smaller, which will possibly necessitate a stem with a positive angle, as well as a longer stem. The positive angle will also add a few mm to the required stem length. There is only so much you can do with spacers before it would be beyond what is safe for the steer tube - the more spacers you have, the more the torque around the top of the headset.

There are some drop bars you can get with a small rise, which can help.

Very hard to say how extreme we are talking here, but those are the issues in broad brush. There is nothing per se to stop a 6 ft rider using a 54. I'm 5 10 and something in the 54-55 range is fine for me. I used to ride a 56 when I was 25, and I've rented a 53 on holiday and it has been fine with a longer stem. (I am talking effective tt here and normal 73deg or so angles - I am old school when it comes to frame sizing).

Budget permitting, I wonder if you would be better off with an eBay bike (rim braked bikes are cheap as chips these days - I got a 7.2 kg Ribble with 11 sp Campag chorus as a parts bike for £500 for example only last month), plus an adjustable angle stem. You could at least experiment and get close before you take things further.

Long term I could see potentially you ending up with an endurance type frame - although the stack height differences aren't huge in a lot of cases - or alternatively a custom frame.

veronese68

To try and gauge where you want to be, what about trying one of those angle adjustable stems on your current, too long, bike? They are pretty cheap and by bringing the bars up you are also bringing them back making the bike appear shorter.

Wheelspinner

Just for shits and giggles I have set my custom geometry size 54 ish frame up with a BB to saddle top as per the OP dimension of 90 cm.

Does anyone think that’s a reasonable option for someone with a bad neck?

Either the OP has a typo somewhere or can’t use a tape measure.

Wheelspinner

And this is what it looks like with saddle height set for a 6’0” tall normal proportion bloke also with a bad neck.

whv

90cm from the top of pedal to the top of saddle. Inseam is 86.5cm/34". Using the 1.09 technique my saddle height should be from top of pedal to top of saddle 93.74cm. My bikes are between 87.5-90.5cm depending on the bike. Using the Lemond 0.833 method from BB center to top of saddle I would be a 76cm and they are between 71-73cm.

The Pinarello is currently 90.5cm (1.09 method) and 73cm (Lemond 0.883 method)

veronese68

Ok, from BB to saddle would usually mean from centre of BB, not from pedal, hence the comment someone made about crank length.

First.Aspect

https://forum.bikeradar.com/discussion/comment/21090180#Comment_21090180

That's a lovely frame, but needs a different crank. The Shimano cranks are gopping at the best of times, but polished Al against brushed Ti is a "no" from me. Saddles and bar tape should be black as well. On any bike.

Also, why do you have such a long seat post?

First.Aspect

https://forum.bikeradar.com/discussion/comment/21090211#Comment_21090211

It was a desperately helpful comment that really moved things forward for the OP.

Wheelspinner

https://forum.bikeradar.com/discussion/comment/21090205#Comment_21090205

Ah, this makes a bit more sense. Top of pedal to top of saddle is not an ideal method IMO as there is no allowance for variation in stack height of your shoes and cleat system. Even a few mm will be noticeable. It’s also dependent on where you have the cleats positioned on your shoe (forward/aft etc).

There are some good videos on YouTube about setting all those things from Neil Stanbury, bike fitter here in Oz. Think he comes up on Road Cycling Academy channel

Wheelspinner

https://forum.bikeradar.com/discussion/comment/21090213#Comment_21090213

I’ve had a few cranks on it, but these were the only 50/34 I had in the parts bin. Saddles get swapped around a bit and I don’t have that one in black.

I may do new bar tape soon. I’ve been through a couple of handlebar trials and the white was all I had left. I’m still not entirely happy with the bars and may change again.

The pic with the saddle way up had very little post left in the frame, no way you’d ride it like that 😁

First.Aspect

Those carbon/Ti Sevens are on my list of classic bikes I'd have to try hard to resist on eBay. There was a high end bike shop* I used to go in in the late 90s that had some of them and they were just stunning close up.

Merlin Cyrene is another. I've only ever seen the Extralite (same shop) but that was again a work of art.

Bikes are so fugly now in comparison.

*a proper bike shop that opened onto the warehouse of his own brand frames ready to be built up, not an espresso and designer chairs bike shop

Wheelspinner

https://forum.bikeradar.com/discussion/comment/21090241#Comment_21090241

The workmanship on the Seven is exquisite. I bought this one some years ago, and although I rarely ride out on the road these days, I can’t imagine selling it. I see Campag have released a new rim brake groupset…. Tempting.

whv

I guess back to my question what are the down sides of a smaller frame size if I can just raise the saddle and change to a longer stem. Stretching a bike seems to not affect handling nearly as much as shortening a bike. By the way my saddle height currently is perfect. It is the reach that is killing my neck. Grateful for everyone's time! Thank you!

slowmart

https://forum.bikeradar.com/discussion/comment/21090495#Comment_21090495

Simply the geometry of a small frame and long stem means your weight distribution is different in that there is a lot more weight thrown forward with the associated extra stress on your lower back, core, neck and hands

theres a reason why pros ride like this, but one reason isn’t for comfort.

spend for a bike fit and sort the issue properly

First.Aspect

Answered in full above.

Size of frame isn't an issue if you are only going down one size, and the effects on handling etc will be fairly subtle and something you would get used to. It is not clear that this will be the solution you need though, because the stack will be lower. This may, or may not, be within range for you to achieve a more comfortable position.

On reflection the suggestion of trying different stems on your existing bike is very sensible, because you can use a shorter stem, flip it or try an adjustable stem to find out if it makes a difference to your comfort.

I disagree that a bike fit is the next step. A bike fitter will give you a more upright position if you tell them you need a more upright position, but you will learn very little about how your neck will feel after a couple of hours on a bike.

Achieving a comfortable fit for a lot of people used to involve getting the right size of frame then making small adjustments and seeing how it felt. The bike fit industry tells us that bike fitters are biomechanics whisperers with the magic ability to remove discomfort. They aren't. Nor are they orthopedic specialists or physios and their understanding of what causes you discomfort will be based only on what you tell them, plus experience. Your injuries will be unique, so I am not sure that will be enough.

What they might be able to do, if you can tell a fitter what you find comfortable and what you don't, is position you on a bike in such a way as to mitigate those handling issues and possibly to mitigate any knock on effects of what might be considered extreme changes in bar position.

But you will want a bike fit to be tweaking what nearly works, not making big changes in the hope that it will - in my opinion (based on getting a post severe ankle injury bike fit that was worse than useless, for broadly these reasons).