Stuck at the end -L or Start -XL of bike size.

[Bikeman]

I would like to get a Trek FX1s. The sizes are Large 5'9" to 6'1" and XL 6'1" to 6'6". I am right in the middle at 6'1".

I can get the Large and have me be at the end of the size limit, or an XL and be at the front of the limit.

Trek is running low on these bikes and the local bike shops don't have one in store.

One thing is on my mind is, almost every single bike I've had in the last 35 years is either to small or way to small. Last bike I had to get a longer stem. I am so sick of smaller bikes.

On the other had, I've seen in the past where bikes where a small, a little bigger is medium, then a little bigger is Large, then the XL is a "Freak bike." It's way out of proportion to the other sizes.

Not looking for someone else to make up my mind (I hate when people do that) seeing if anyone had any incite or experience with this same problem.

No XL is available until September 10 if I want that one. I sat on a "similar" Trek bike that was a Large. It "fit" but as advertised, I was right at the limit of what fits. Wish I could sit on a FX1s XL and see what it's like but I can't.

Any experience with this size issue you could guide me on? Anyone have a rare FX1s XL?

Thank you,
ebm

 

[spokewrench]

I hear you. I've had to modify seat and handlebar positions of 3 e-bikes that were supposed to fit me. After the first one, I learned to study the geometry to see how much modification would be necessary. The other day I looked at a Specialized Como online. They asked my height and shin length, then recommended LG with a 30.94" saddle height. To the hundredth-inch: imagine that! But I need saddles at about 39", which I think is typical for size LG.

I've read about a rule of thumb many fitters use for saddle position. You raise the seat for good leg extension. You put a crank arm level and forward, sit in your normal position, and put your foot on the pedal in its normal position. If the forward end of your knee isn't over the spindle, the seat has to move forward or back. It works for me. All my bikes have come with posts too far forward, meaning wear and tear on knees, a rough ride on bumps, and poor control.

 

[Marcela]

I'm in the same boat. Height, shoes, waist, you name it, always right in the middle. I was thinking the other day, if I get another bike, I'll make sure not to go big. I have a couple cane creek suspension seat posts that I can't use, they articulate to the back and down and it is hard on my lower back. I think if I had a smaller bike I could use them and maybe not be as affected, re the back. But this is just speculation. And I have made small bikes bigger and big bikes smaller, I like the small bike bigger route.

 

[6zfshdb]

Most of my bikes over the years have been a size larger than I need, and all have worked out well. As I get older though, I find I need to use suspension seatposts. This means the seat tube height needs to allow enough clearance for the mechanisms on many of these quality suspension posts. Consequently, I've switched from a large frame size to a smaller one to gain more clearance. In some cases, this meant adding a stem riser to get the right handlebar height.

The mechanic at my local LBS says, you should be able to straddle the bike with the bar touching, but not bothering "the boys".

Of course this is just his opinion and my experience though, so YMMV.

 

[Stefan Mikes]

The issue occurs when a person of a specific body height has short legs but a long torso and arms. Or, the opposite.

 

[stompandgo]

I have a lot of experience fitting riders by eye, as well as beginner level experience with the Selle Italia IDMatch computerized fitting system. My comments will be based on this.

The problem with size charts is that they assume that everyone that's 6'1" is built the same way, but they're not. The way IDMatch works, is that it takes a couple dozen measurements of the parts of your body that matter to bike fits, then uses an AI model composed of fit data from thousands of riders to match you to the right size of the bike that you choose. All of that technology still does not get it perfect every time. We have to tweak by eye.

I recently bought a mid step e-bike without a fit beforehand. I used the size chart and the geometry chart to choose the frame size. I got it wrong. I got the standover right, as that's important to me as where I ride, I have to stop and start a lot. When I raced bikes, I always went a size smaller and used a longer stem, for performance purposes. Like you, I was in between two frame sizes for this e-bike, so I chose the smaller. I should have chosen the larger, but I would have lost the standover clearance.

Most bike shops will tell you that you can make a short bike longer, but you can't make a long bike shorter. There's some truth to that, but it's not absolute. You have options. You also have a cooperative LBS. That's very important when you are in this position (pun intended).

I would run the following by the LBS. Purchase the bike. Have them order an XL and an L. Try the XL first. Have them evaluate you on the XL, and determine whether it makes sense to take the L out of the box.

Good luck.

 

[stompandgo]

The issue occurs when a person of a specific body height has short legs but a long torso and arms.

That's me. Bike racer build.

 

[Stefan Mikes]

That's me. Bike racer build.

Same here. It forces me to select a size M frame (Standover Height) but install a long stem. For this reason I cannot buy any fancy (totally proprietary) e-bike (with a non-standard or integrated stem).

It was OK with my Vado SL. I might live with the size L (I've demo ridden it) but the size M with a longer Redshift stem slammed and inverted has worked for me. (Innerbarends have further improved my riding position).

I had a real headache with my Vado 5.0/6.0 rebuilt on the warranty. Whatever the Specialized Warsaw people had tried to do ended up in a size S frame as it was the only thing they could get in a proper colour. That ended up with a very long seat-post (they paid for that!). The geometry of the seat tube and the seat-post* had forced as tight a tolerance as only a person of my leg length could ride this e-bike! Moreover, I had to buy a very long Specialized stem and invert it to increase the reach. These are the pains of a wrong frame size!
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*) You cannot trim a Redshift ShockStop seat-post.