Fit question, frame size/reach...etc

[Bwana]

Asking the fit/geometry gurus.

My Giant Defy has a 54.5 ETT and I use a 110mm stem. My Landshark has a 53.5 ETT, not sure on stem length but the reach is almost exactly the same, just a heck of a lot more drop than my Giant even with the stem slammed. Both fit pretty well, as far as I can tell. Multiple 60+ mile rides on each with no issues.

Here's the Defy's geometry, I have a medium:
http://i.imgur.com/hKKa31Tl.jpg
Landshark:
ETT 53.5 cm
ST c-c 52 cm
HTA 74˚
STA 74˚

Looking at a frame that has a 55.7 TT. Do you guys think I'd be ok on this frame with a 100mm stem or is the sizing too far off?

http://i.imgur.com/rgdHSVul.jpg

[ColonelJLloyd]

Try to calculate the reach and stack of your current frames. http://www.bikegeo.net/

[stien]

Well I'd be concerned personally about the super short HT on the new bike. Lots of drop with a longer TT might make it out of reach for you, especially if you're on a shorter stem on the original bike.

[Bwana]

I guess I should mention my saddle height is right around 69cm. Shorter legs, longer arms, I guess.

I'm running about 8cm of drop on the Landshark.

[stien]

I guess I should mention my saddle height is right around 69cm. Shorter legs, longer arms, I guess.

That's my saddle height as well, at 5'9" I'm using 120-140mm stems. I would consider the bike you linked a bit too low in the front for me, especially if the 121mm includes a headset.

[Bwana]

That's my saddle height as well, at 5'9" I'm using 120-140mm stems. I would consider the bike you linked a bit too low in the front for me, especially if the 121mm includes a headset.

Kind of what I was thinking, but I'm terrible with comparing geometry. There's no leeway on that either, the steerer is already cut/slammed on the IF (crown jewel on ebay).

Maybe if no one bids on it I'll throw a last minute bid and see if I can get it to work. :o

Thanks for the help.

[carpediemracing]

Fitting via internet is of course difficult if not impossible.

The red flag for me is the 12 cm head tube of the proposed frame. It's 4 cm shorter than your Giant Defy.

If you can drop your bars that much then that's one thing. If that's the case you may want to revisit your current bikes' fits.

The other red flag is the shorter stem. Having ridden the same bike with different stems (9-12 cm stems) I much prefer having a bit more weight over the front wheel. The longer stem does that, it slows down steering a bit, and makes the bike more stable at speeds over, say, 18-20 mph.

If you can stay with your current stem, that's about the shortest I feel comfortable with in terms of handling.

If you do both the stem and the shorter headtube then you're seriously changing your position. It may not be doable.

A note also. Don't use different reach bars to try and get stem length within the right parameters. It's not the actual saddle-bar reach that I am referring to, it's the position of your hands relative to the front hub and steerer tube. I find both height and reach (of hands relative to front hub and steerer tube) make a huge difference. I spent a frustrating year trying to dial in my bike with compact bars (shorter reach, shorter drop). I got the same reach but still had handling issues. I finally sprung for a custom stem to get the same drop as before and the bike was immediately perfect. Lesson learned.

[Joachim]

If your Defy fits really well then the Ebay bike would be too large of a difference to make work. Life is too short to ride a bike that doesn't fits.

[Bwana]

Just the info/experience I was hoping to get by posting this. Thanks everyone.

The Defy is endurance geo and I have the stem slammed, I would go lower for every day riding if the HT would let me (I don't do much more than 2 hour rides usually). When I did RAGBRAI I had a couple spacers on and it worked well for the longer days. With the stem slammed I'm only around 2-3cm drop.
On the Landshark I'm running 7 or 8cm of drop.

I believe my wife is getting my a Retul fitting for Christmas, so I should probably just wait for that before doing anything. Last fit I had was probably 8 years ago and there were definitely no computers involved, and hardly any actual measuring :eek:.

[ColonelJLloyd]

The red flag for me is the 12 cm head tube of the proposed frame. It's 4 cm shorter than your Giant Defy.

Head tube length alone does not tell you how high the stack will be. Fork length and BB drop are also relevant. Really best to compare stack and reach among frames.

[Bwana]

Head tube length alone does not tell you how high the stack will be. Fork length and BB drop are also relevant. Really best to compare stack and reach among frames.

Sitting at my desk at work and with no concrete numbers on the Defy or Landshark, the IF is fairly similar to the Landshark according to the calculator you posted. But again, most of the numbers I put in are straight up guesses, so who knows.:bike:

[sandyrs]

Just in general ETT is not a reliable number to go off of. As mentioned above, stack and reach are.

[John H.]

If you normally ride with 2-3cm of bar drop- the 11.5cm drop that this new bike provides will feel like a lot of drop.
Remember- no good deal is a good deal if the fit is off-

Just the info/experience I was hoping to get by posting this. Thanks everyone.

The Defy is endurance geo and I have the stem slammed, I would go lower for every day riding if the HT would let me (I don't do much more than 2 hour rides usually). When I did RAGBRAI I had a couple spacers on and it worked well for the longer days. With the stem slammed I'm only around 2-3cm drop.
On the Landshark I'm running 7 or 8cm of drop.

I believe my wife is getting my a Retul fitting for Christmas, so I should probably just wait for that before doing anything. Last fit I had was probably 8 years ago and there were definitely no computers involved, and hardly any actual measuring :eek:.

[Mark McM]

As the other have said, there's too much information missing to do a true comparison between the geometries of this frame and your current frame(s). It would be best if the stack and reach numbers of each frame was available, but there are too many missing dimensions to be able to accurately calculate them.

However, a few things stand out from the diagram of the new frame. Firstly, the diagram appears to be more like it was from a bike fitting (i.e. how it fits a particular individual) than it does a frame geometry spec. The second is that the frame seems to be unusually low and long - that 121 mm head tube (plus a fork that is on the short end of normal road forks) makes for an unusually aggressive (and low) position. From this I think we can guess that it is a custom frame, built for someone with very specific fit needs.

Based on your description of how your current frames fit, it appears that you fit well on standard geometry frames. I'm not sure I'd take a leap to see if you can also fit on frame with a geometry that is highly customized to one particular rider.

[Stevemikesteve]

Try to calculate the reach and stack of your current frames. http://www.bikegeo.net/

Input my info for fields 1 to 12. Anyone ever use this and know how to get it to spit out the stack and reach numbers? Can't figure it

[12snap]

Input my info for fields 1 to 12. Anyone ever use this and know how to get it to spit out the stack and reach numbers? Can't figure it

You just need to type the appropriate values in the fields and it will calculate the stack and reach for you. In the snip below I filled in the values in the green bike column.

1697931776

[Bwana]

This is the frame in question, if anyone was interested.

http://www.ebay.com/itm/222337459254

[Mikej]

74 degree hta - vs 72.5 is going to make a pretty good difference in the geo -

[drewellison]

Stack and reach are easy to calculate if you have the frame/fork. If not built, put a set of wheels on it. Then ...
1. roll rear wheel against a wall. Make sure frame is vertical and square to wall.
2. measure from wall to center of bb.
3. measure from wall to top-center of head tube.
4. calculate difference = reach.
5. measure from floor to center of bb.
6. measure from floor to top-center of head tube.
7. calculate difference = stack.

Of course, these assume you have a flat and level floor and a flat & perpendicular wall. If you're not sure about these, then turn bike around and do the same with the front wheel against the wall. Then average the two if the measurements are different.