JohnJ80

Agree. Also, most fork manufacturers have a spec on the maximum spacers between the stem and top of the headset. I just went through this with Enve where on the fork I am using they specify a max of 40mm of spacers. Above that, while probably a remote chance, there is a danger of a broken steer tube with the obviously bad consequences that brings. Bottom line, you shouldn't really just start stacking spacers to get to a fit.

J.

mstateglfr 

True, yet that would require custom and I didnt want to go that route.
If a two frames are of different sizes, but the contact points are the same, are either really ill fitting?

The answer is no, even if aesthetically one looks better than the other. That's been the point.
Many frames dont look 'right' once they are fit to individually because many cyclists dont fit the arbitrary dimensions of a showroom bicycle.

mstateglfr 

Its 43mm of spacers under the stem in that pic. At the top end of things for sure.

It's a steel frame thread and many use steel forks. Stack away on a steel steerer. It's partly why people have 80mm of spacers on a surly last- because the frame stack height isnt high enough and a steel steerer can handle that much without concern.

sumgy

Why did you need to go custom?
Is that the biggest sized frame they make?
That is a lot of seatpost and I have seen frames structurally compromised through the leverage created by a long seatpost (not to mention the possibility of the post itself breaking.
As JohnJ80 mentioned, fork manufacturers also have rules around the number of spacers that can be used.

JohnJ80

Sure, they both "fit" but the performance won't be the same.

Just because the contact points are the same, that doesn't mean the the wheelbase, trail, and other specs of the two frames sizes are the same. If those are different, then the frames will have different handling. Sometimes the differences can be fairly dramatic if the frame geometries are not similar.

I just went through this with my wife's bike. Set the same contact points up on a larger frame so they two bikes were identical in fit but first frame was smaller than the other. But she now has a shorter stem, less spacers (now in spec), a longer wheelbase, longer chain stays, etc... She reports the bike is much easier and more comfortable to ride largely because it requires less input (the first bike is "twitchy" in comparison according to her). The bikes are largely the same frame geometry from the same frame manufacturer but two different sizes. I believe her because her average speed when we ride together just took a big jump up without her even knowing it. She's more confident on the bike because it's more stable in it's handing and she's able to ride faster much more easily. So, yes it does matter in performance and that is an example.

You can visualize this too - take two wildly different frames. It's very possible to get the three touch points in the same places over the different frames. Just because those are in the same place is no guarantee that they will handle the same. If that were the case, there would be no need for touring frames or racing frames or any of the different permutations available. You could just set the touchpoint to be consistent and ride away and it all would be the same. That's obviously not true, so yes, it does make a difference and yes they both "fit" but that's far from the end of the story.

J.

mstateglfr 

Fully agree with what you say.
In this instance, all geometry of the frame was taken into account compared to my prior gravel frame as well as my road bike frames.

sumgy

But all that tells us is that your prior frames may not have fit either.
What size is this frame and why would you have needed custom?

JohnJ80

So I'm curious now. Why did you select this frame size instead of a larger one? What characteristics where you looking for that a larger frame wouldn't accomplish?

mstateglfr 

I had planned to build the frame over this winter. It would have basically matched this frame I bought in terms of all important geometry except bottom bracket drop.

This is the biggest size and the largest stack height of quality frames at the price I wanted to pay. There are a few taller stack frames that i wasnt interested in due to a variety of reasons(weight, brand, paint, geometry, or features)

It is a lot of seatpost, but it's well less than max so I am not concerned.

And yes I'm aware of spacer limits for forks.

Appreciate all the concern, it's been long considered.

The point of posting the bike was because it applies to the comments since this thread has been resurrected. It isn't a bike with showroom floor geometry, yet it is a bike that will be comfortable and perform as intended for hours on end over rough terrain. That last part, to me, is what's most important.

mstateglfr 

Ha, this is getting funny. I have built a road frame, been fit on bikes, etc.
Had this been less of a sloping top tube, it would have less exposed seatpost and that suddenly wouldnt be a potential fitment issue.

I'm good, but thank you for the concern.

mstateglfr 

- It's at the largest size so an even larger frame wouldnt be possible.
- At this frame size, the stack and reach are comfortable for me with a proper amount of spacers.
- At this frame size, the other geometry met what I want- the seat tube angle, head tube angle, chainstay length, fork offset and trail, and bottom bracket drop were all what I want to have. So i ultimately know it will fit well for me.


This may open up more work cans, but the fullcourt press seems to be on already, so let's open another can- the bottom bracket height was the only concern for me since it's more than I'm used to on a gravel road bike. That affects the stack height relative to my old frame and its a minor 7mm difference in drop, but the feel would be slightly different as I would sit more in the bike than on it.
I'm not a princess and the bike isn't a mattress, so I haven't been able to feel any negative difference so far.

sumgy

I have also been professionally fit on road bikes.
The quality of those fits has ranged from absolutely woeful to fantastic.
And I don't think that the sloping top tube is the problem as it does not seem that great a slope based on the numbers.

Anyway, you seem happy with your bike so nothing anyone will say will change that.

bruce19

At 5.42 KG

Dirt Farmer

Just remember what Greg Lemond has said.... the amount of seat post visible should be almost equal to the length of your head tube, or as close as possible. Yours seems "in the ballpark" (maybe a tad too much post). As long as you're safely within the limit, I see nothing wrong.

sumgy

Given the 61cm frame has a 583mm seat tube, I would guess that the exposed post is somewhere near 30cm.
That quote from Greg Lemond is interesting, because in this case there is likely almost triple the amount of seatpost exposed vs inside the frame if using a 410mm post.

Edit
The HT is only 18cm, and there is much more than 18cm exposed seatpost IMO.

Dirt Farmer

Well, I did say "Maybe a tad too much post", to be diplomatic.

sumgy

Then again, I think the fit of that bike in Bruce19's video is awful too.

venturi95

The Breezer Venturi was a full on racing frameset. It featured a revolutionary Dropped top tube design (horizontal, not sloping). Mine had a 0.4 mm thick top tube in the thin center section, Tange Presitge tubing. If you are not an active racer the bike is not at all your best choice. I had a ton of seatpost out and a Mountain Bike stem to get the bars up high enough, yet the top tube length was perfect for me. It was one of the best bikes I have ever owned, it was eager to accelerate, floated over small bumps, and was very lightweight for its time.

jbchybridrider 

That's mostly remarkable for the sum of parts than the frame. If I bolted everything on that bike to my larger size 93 Olympia it would weigh a still amazing 5.7kg +or- a few grams.

dan911

Take a look at Marinoni for the top quality craftsmanship, the custom geometry and their unbeatable price .

Marinoni

bruce19

Back in the day I lusted for a Marinoni. They are beautiful.

mstateglfr 

I learned a new word! My day is complete, time to pack it up.

kansukee

As far as Il Massimo, I had a frame built a couple of years ago and while I was happy at the beginning, it ended up being a disappointment. The paint started bubbling a bit under the seatstays and by the time I got ride of it and replaced it with my current Cinelli SC, there was quite a bit of rust inside the BB. Stay away from them is my advice. I'm glad I got the Cinelli, they are in a different universe as far as quality and finish.

dan911

Ça me fait plaisir que tu ais appris quelques chose de nouveau aujourd'hui. L'anglais n'est pas la langue première de tout le monde. Certaines personnes, comme moi, font des efforts pour apprendre une deuxième langue, voir même une troisième mais il se peut que l'on fassent des erreurs de syntaxe en cours de route.

Bonne journée

bruce19

The stem has been changed but alas no white bar tape. It got boo'd out of the peleton. Guru was also a Montreal based builder. I feel quite lucky to have this bike.