Knee to handlebars reach

Timmyboy

I think I've made some enquiries here before in regard to frame sizes.

Anyway I've been looking at bikes over the past few days and just wanted to put some information out there in case it might be of use to anyone.

I'm 6' tall, or 183cm in new money with a 34.5" inside leg (not sure what that is in cm).

So I went to the bicycle shop to investigate stock and see if they would have sizes to suit me available. I was looking at KTM bicycles.
They had 55cm and 57cm in stock but not the 59cm that I thought would be my best fit. I sat on the 57cm and we were able to adjust the seat height to suit my height with still plenty of seat post within the frame.

It fit OK but I was uncertain. I'm a believer in geometry.

Anyhow I looked also at Trek and at Giant and took a spin on a Giant L SCR (something like a Defy I think) and that felt Ok if a little big and more pacy that racy!

So back to the shop and looked at the KTM again. The shop lads seemed to be thinking that the 57cm (in stock) was the size for me. I wasn't so sure.

Anyhow, the big chooser for me was that I already have a 60cm (old style szie measurements centre to top of seat tube) frame. And then I decided to go for the 59cm KTM because I WAS ABLE TO BANG MY KNEES OF THE HANDLEBARS EASILY on the smaller size frame (i.e. the 57cm).

So that's how I ultimately chose the frame size. I strongly hope and believe that this is the correct size for me and that I won't be limited by it.

I also used the Canyon PPS system which indicated an equivalent Canynon Aluminium would be size 60cm which worked out close enough in other dimensions to the KTM at 59cm.

But it's the knees that count.

Smaller sizes, yes but as a bigger rider I've felt from experience that having a too long stem (anything over 12.5cm is in my view too long) is looking for trouble and twitchiness in response from the frame on decents and heavy braking.

Just my thoughts.

Don't be convinced until your knees have checked the situation.

Lumen

Smaller sizes generally descend better. One mans "twitchy" is another's "responsive".

Banging your knees off the bars is a bit wierd. I'm about the same size as you and didn't get close to banging my knees off a 54.

Are you sure your saddle height is correct?

Timmyboy

Lumen wrote: »

Smaller sizes generally descend better. One mans "twitchy" is another's "responsive".

Banging your knees off the bars is a bit wierd. I'm about the same size as you and didn't get close to banging my knees off a 54.

Are you sure your saddle height is correct?

Maybe I should have explained better.
Sitting on the saddle there was no real problem.
Saddle had been ajusted to near the correct height by raising the seatpost and by adjusting the clamps so that it held the saddle a little rearward ( I felt that this rearwardness was not to my liking which I remember now but not mentioned in the first posting).

Anway, when standing off the pedals, and with me in a leaning forward, sprint/agressive climbing position, then my knees would be able to comfortably reach to the horizonal straight part of the drop handlebars.
I'd had this issue on my previous bike which had originally a 10cm stem and which I resolved by fitting a longer stem). The 57cm KTM had an 11cm stem.

By moving to the 59cm KTM frame size, I expect to gain another 10mm or so in Top Tube and likely another 10mm in stem length and likely another 2.5mm in crank length overall more or less stretching the knee reach by about 17mm or so which I hope and believe should make the 59cm KTM just the right size for me.

I really do hope so because I ordered it today. A Strada 2000 with full 105 groupset.

Timmyboy

Lumen wrote: »

One mans "twitchy" is another's "responsive".

Mmmm....That gives me an idea for a thread. It would be the fastest descent thread of certain hill roads or such. Anyway it's going off topic. Still it has me thinking.

Lumen

Well, most of the 57 KTMs have a 561mm top tube, which is about average for a 6fter.

I wouldn't worry about long stems though. I have 120mm and 130mm stems on my bikes and the handling is very stable.

100mm stems are for little people. There's a rule about that.

edit: I'm not saying the bike won't fit you.

mo_bhicycle

You should have started this thread before ordering the bike!
I'm about 2 inches taller than you and cycle a 58cm, definitely wouldn't want anything bigger.

Is it your knees hitting the handlebar or your thigh (i.e. just above your knee)?

Timmyboy

mo_bhicycle wrote: »

You should have started this thread before ordering the bike!
I'm about 2 inches taller than you and cycle a 58cm, definitely wouldn't want anything bigger.

Is it your knees hitting the handlebar or your thigh (i.e. just above your knee)?

The part hitting the handlebar would be the end of the main bone of the upper leg just near the point where the main upper frontal leg muscle is beginning to take form. So about 10 to 15mm or so back from the farthest point of reach of the knee towards an imaginary handlebar situated at greatest distance from the pedal position that would put it closest to the imginary handlebar at that point.

In relation to what you say about 58cm or others have said about sizes, I think the nominal "size" of the bike is irrelevant without referring to top tube length.

It seems that different manufactures may all list the same size say "58cm" but this gives frames with widely different reaches. The "58cm" is nominal I believe.

As an example to this, in advance of ordering I did some research.

1. KTM, Strada 2000, nominal size 59cm, has effective top tube length of 572mm
2. KTM, Strada 2000, nominal size 56cm, has effective top tube length of 561mm
3. Giant, TCR 1, nominal size M/L, has effective top tube length of 570mm
4. Gian, TCR 1, nominal size L, has effective top tube length of 585mm
5. Trek, 2.3, nominal size 58cm, has effective top tube length of 573mm
6. Current bike, Raleigh Dynatech, nominal size 60cm has effective top tube length of 570mm


I do note that obviously you would be looking a specific breed of bike here when doing comparisons. Essentially I was comparing racing frames made of aluminium.

In the end I choose on the 59cm which, although it sounds like a larger frame, is comparable to the 58cm treks in top tube reach. I had fitted on the 58cm trek in another shop a few months back and it seems to be just about right. Then I believe and hope that with only 1mm in top tube length difference that the KTM would also be just right at the 59cm size.


Still. THE BASICS REMAIN THE SAME. Do a climb and see IF YOU ARE HITTING YOUR KNEES ON THE HANDLEBAR WHEN OUT OF THE SADDLE PUSHING HARD, IF SO YOU MAY NEED A LARGER SIZE.

I was unwilling to accept the idea that I could fit a longer stem.
Why do that when the next size up will give the requirment without extra cost (Right now I'm not in the race at all cost mode but more in a conservative mode about finance - and I also think that a sprinter gets a lot of strenght from the hands so I don't think that longer stems are the way to go as they may introudce more flex up front
(I'm still a little worried about it all though.)

Timmyboy

Lumen wrote: »

Well <SNIP> a 561mm top tube, which is about average for a 6fter.

I disagree with this.

Most italian frames appear to have shorter top tubes.
But most other frames have tubes for those of 6foot length specified by their manufacturers at the 570mm mark or so.

As reference see the mini-table that I produced in the posting above.

For my 6' height, Giant recommends the M/L or L. (I'd have chosen the M/L in this case but in another shop about 6 months ago the owner told me that I woudl have needed the L. I disagreed with him and we had a rather major falling out about it!:cool:)

KTM recommends the 59cm frame size for my height.

The Canyon PPS system calculator recommends their 60cm frame size for my height.

Common to all of these is the closeness or slightly above 570mm top tube effective dimension.

C3PO

I really think you should give this some more thought before taking delivery of your bike! I would be reasonably sure that a 59cm bike will be too big for you. I'm an inch smaller than you and was tossing up between a KTM 55 and 57 - I actually ended up buying a 54cm Pinarello!

mo_bhicycle

Timmyboy wrote: »

The part hitting the handlebar would be the end of the main bone of the upper leg just near the point where the main upper frontal leg muscle is beginning to take form. So about 10 to 15mm or so back from the farthest point of reach of the knee towards an imaginary handlebar situated at greatest distance from the pedal position that would put it closest to the imginary handlebar at that point.

I can if I try hit that same part of my leg off my handlebars ... but in reality this never actually happens when cycling.

I'm not sure what the point of your original post is. Was it just a braindump about your experiences buying your new bike? If so then I well wear and I wish you many happy miles on it.
If you are looking for peoples opinion about your purchase, then based on the details you have provided I think you bought one size too big.

Timmyboy

mo_bhicycle wrote: »

If you are looking for peoples opinion about your purchase, then based on the details you have provided I think you bought one size too big.

I guess I'm looking for two things based on my purchase.

1. Comments on top tube being the most relevant measure (per style of bike) rather than "nominal size" (as typically related to seat tube length).

2. Fact based responses based on personal experiences based on actual relevant geometries and personal dimensions and comments in regard to manufacturer's recommended frame sizes.
For example, I'm after choosing the 59cm KTM nominal frame size, I expect it to have 57Xmm top tube with 12cm stem and I'll adjust the saddle front or rear to suit final reach.

They guys in the shop definitely were thinking that the 57cm nominal frame size was good for me but I felt while sitting that it was a touch (not much mind) small and also based on me easily able to belt my knee of the handlbars (about 20mm or so) I felt the next size up was for me.

T

mo_bhicycle

6'2", 570 TT, 12cm stem

You've ordered the bike so this conversation is pretty much academic anyway. If you're comfortable on it and happy with it then forget about it and enjoy the bike.

Timmyboy

Thanks for the help guys!


Anyhow I went back home (to parents) to where my original 60cm frame sized bike is kept. Went for a cycle.
I felt stretched on that bike. It has a 57cm top tube and 13cm stem (old style one piece designed to be horizontal also).

Anyhow, to cut a long story short, after a lot of consideration and feelings, I decided that the 59cm bike was just a little too big for me and I would be better off with the smaller sized bike, the 57cm. Contacted my dealer and asked him if it would be OK to suspend the order of the 59cm KTM Strada 2000 and instead get a 57cm size. He didn't have 57cm Strada 2000 in stock but did have the Strada 3000 so since this is probably my last new bicycle purchase for a while (the last would have been roughly year 1994 (actually I forgot that BMX that I bought in 2005 (oh I actually also forgot the second hand Mongoose Hilltopper that I bought in 2001).....));).....

I decided the budget was to be blow and got the 3000.

Nice 57cm KTM Strada 3000 is now sitting in the (spare;)) bedroom.
Happy Days!:D

Thanks again folks.

dave2pvd

You did the right thing.

I am 6'1" and race 56 and 57cm frames. Stem length is dependent on top tube dim.

You are right about top tube length, or virtual top tube length, being most important when sizing a frame.

You are wrong about adjusting your saddle f/r to suit reach. The f/r saddle location is chosen to maximize power transfer to your bottom bracket spindle. Some use the Knee Over Pedal Spindle rule to do this; myself included. A good place to start for saddle height is 109% of inside leg measurement. The height is measured from the BB center to the top surface of the saddle, parallel to the seat tube.

For saddle height, here's a useful link. Bottom line, the rule of thumb is Inseam x 0.66.

Your inseam measurement is somewhat long. How did you measure it?

I am scratching my head as to why your upper leg was hitting the bars. Perhaps your climbing & sprinting postures are a bit off?

Timmyboy

@dave...

Thanks for the feedback dave, useful and appreciated.
I got the inseam measurement by standing in bare feet and then pushing a plank between my legs to the crotch bone. Then measuring from the top of the plan to the ground. Definitely on longer side of normal I believe.

This may also explain why I'm prone to banging the knees off the handlebars.

Although I don't think it's a cycling technique issue with climbing or sprinting it may be an artefact of the fact that I don't have a kneecap in one knee and it certainly has altered the behaviour of that leg (it doesn't enjoy cycling!:mad:).
I think that the legs (actually both of them but primarily the right) have adjusted to a more longer stroke and rotation, i.e. the sweeping of a bigger circle where as the knee angle is near its most acute (pedal near top) the greates stress is felt by the knee and in this stage both the hips and ankle are adjusting to tend to reduce this angle.
Then on the downstroke the ankle joint mainly is articulating again to the benefit of the leverage of the knee joint, i.e. by extending a more down toe point rather than a more relaxed down point than would be normal.
That said I guess that this would really only explain about an inch or so of extra pedal to handlebar distance.

I'll have to see how it works out on the road but I'm confident that it shouldn't be too much of an issue or that I can sort it by lengthing with a new stem or flipping the existing stem around.

Now to wait till the snow clears.....

dave2pvd

OK. So you are compensating by moving your hips forward. Gotcha.

Move your cleats as far back as they can go. There is a school of thought that supports this practice. I can't recall who - maybe it was Alan Lim - anyway, some Protour team expert suggested this idea. I have tried it, as have most of my race team. Just about everyone has persisted with it. I am convinced it adds power. For you it would also open up your knee angle.

Have you tried S&S*-type bars? Maybe the reach to the hoods would be less? Then you could use a longer stem?

*Short & Shallow

C3PO

dave2pvd wrote: »

You did the right thing.

A good place to start for saddle height is 109% of inside leg measurement. The height is measured from the BB center to the top surface of the saddle, parallel to the seat tube.

I don't think that could be right? 109% of inside leg measurement and then you'd have the length of the crank!

dave2pvd

RPL1 wrote: »

I don't think that could be right? 109% of inside leg measurement and then you'd have the length of the crank!

You're right! I should have said saddle to pedal spindle at its farthest position (almost 6 o'clock).