[Mad Cow Disease]

Hello, first post...but I've been lurking for the last few months.

I am having lower back pain/cramping about ~10 miles into a ride. My road bike is a GT Series 2.0. Now I do have a history of a lower back injury, which undoubtedly contributes, but I am concerned that my frame may be too small. It is a medium, with a seat tube height of 51 cm and top tube of 54.5. The issue is I'm about 6'-6'1", and almost everybody I've consulted is convinced the bike is too small for me - coach, friends, random posters on the Internet. But I have yet to get "professionally" fitted.

Stand-over height (for what it's worth) is about 1.5", and my inseam is almost exactly 32". Other general aspects of fit I've seen online seem to be in place. I'm now considering getting professionally fitted and/or converting the bike into a tri setup, but if the frame is too small I'm just throwing good money after bad. My questions are: what are the odds the pain is partly due to a too-small frame? Would a fitting help significantly or is this like trying to put a round peg into a square hole? Is there anything I'm missing?

At this point I'm thinking I will just fit it as a road bike before I throw the cash into a tri setup...thanks in advance.

 

[Zeet]

Hello, first post...but I've been lurking for the last few months.

I am having lower back pain/cramping about ~10 miles into a ride. My road bike is a GT Series 2.0. Now I do have a history of a lower back injury, which undoubtedly contributes, but I am concerned that my frame may be too small. It is a medium, with a seat tube height of 51 cm and top tube of 54.5. The issue is I'm about 6'-6'1", and almost everybody I've consulted is convinced the bike is too small for me - coach, friends, random posters on the Internet. But I have yet to get "professionally" fitted.

Stand-over height (for what it's worth) is about 1.5", and my inseam is almost exactly 32". Other general aspects of fit I've seen online seem to be in place. I'm now considering getting professionally fitted and/or converting the bike into a tri setup, but if the frame is too small I'm just throwing good money after bad. My questions are: what are the odds the pain is partly due to a too-small frame? Would a fitting help significantly or is this like trying to put a round peg into a square hole? Is there anything I'm missing?

At this point I'm thinking I will just fit it as a road bike before I throw the cash into a tri setup...thanks in advance.

First of all, before making any cash investments, I would simply take a few weekends out to visit several LBS. I would then set out to test ride all kinds of road bikes. I'd test them all! Endurance, tourers, and racers alike. I might even try a few hybrids. Just to get some idea as to what size bike would best fit me, and to determine the best geometry for my back. Being professionally fitted when you're already in pain, just might be counter-productive. IMO, It would be best to get fitted when you're not in pain, so that you could better assess the fit. Otherwise, you'll just be in preference of a position where you feel less pain.

 

[Mad Cow Disease]

First of all, before making any cash investments, I would simply take a few weekends out to visit several LBS. I would then set out to test ride all kinds of road bikes. I'd test them all! Endurance, tourers, and racers alike. I might even try a few hybrids. Just to get some idea as to what size bike would best fit me, and to determine the best geometry for my back. Being professionally fitted when you're already in pain, just might be counter-productive. IMO, It would be best to get fitted when you're not in pain, so that you could better assess the fit. Otherwise, you'll just be in preference of a position where you feel less pain.

Maybe what I intended didn't come across correctly. I am asymptomatic when NOT riding, so "determining the best geometry" is a bit more involved than just riding on a bike around a parking lot or bending myself into a certain position to see if it works. Everything is comfortable, it's only about 30 minutes into the ride that I feel tightness/strain in my back. I would not get fitted while symptomatic; I am extremely flexible, so I will really not know if the fit works until I go for my ride. Right now, for instance, my back is just slightly tight. No discomfort like when I'm in the saddle.

My concern is that if the frame size is too small, I am starting from a bad position. There's very little point in investing in an advanced fit and ultimately converting this road bike into a tri bike (and yet another fit).

 

[mikerp]

Based on your info you will need to spend a decent amount of time being fitted.
Find a shop with a fit system where you sit on an adjustable frame and ride. Explain the issue and pony up for the hours. Once they find a fit that works for you, you can look into duplicating it on a real frame.

Without knowing anything else about your fit and geometry, you may want to move your seat back some and take some load off your back (this could require a shorter stem). This would be the option I'd suggest if you can't afford the fit time.

How long have you been riding? The perfect setup isn't necessarily something everyone can step into and run with, sometimes you need to build yourself up to it (this takes time).

 

[Len J]

Hello, first post...but I've been lurking for the last few months.

I am having lower back pain/cramping about ~10 miles into a ride. My road bike is a GT Series 2.0. Now I do have a history of a lower back injury, which undoubtedly contributes, but I am concerned that my frame may be too small. It is a medium, with a seat tube height of 51 cm and top tube of 54.5. The issue is I'm about 6'-6'1", and almost everybody I've consulted is convinced the bike is too small for me - coach, friends, random posters on the Internet. But I have yet to get "professionally" fitted.

Stand-over height (for what it's worth) is about 1.5", and my inseam is almost exactly 32". Other general aspects of fit I've seen online seem to be in place. I'm now considering getting professionally fitted and/or converting the bike into a tri setup, but if the frame is too small I'm just throwing good money after bad. My questions are: what are the odds the pain is partly due to a too-small frame? Would a fitting help significantly or is this like trying to put a round peg into a square hole? Is there anything I'm missing?

At this point I'm thinking I will just fit it as a road bike before I throw the cash into a tri setup...thanks in advance.

I'm 6'0" and ride a 57.5 TT bike with 73 degree ST & HT's with a 120 stem. a 54.5 TT bike would be a terrible fit for me. That said. if you have extremely long legs and a short torso, it might be perfect for you. There are a number of fitting sites on line that have you take some very basic measurements and suggest the proper size of your bike. you might want to try those first. Len

 

[stevesbike]

the geometry spec that is likely at the root of your back issues is head tube length. According to GT, it's 140mm for your frame. To get the proper seat height, it may be creating too much drop (the height of bars relative to seat). It's possible to rig things up to make the frame better for you (spacers under stem, long, positive rise stem), but it's going to be suboptimal - the frame is definitely too small for you. A better starting point in that series would be the L or even XL depending on riding style.

It could work to convert the bike to a tri setup, but that also depends on what sort of tri - if you're planning on long courses, you're going to want something that is not too low. If short courses, it could work as an aggressive setup, but it's not really a good frame geometry-wise for a tri setup.

Start thinking about stack and reach for bike sizes - not perfect, but better than top tube lengths etc. slowtwitch is a good resource.

 

[Rickard Laufer]

Hello, first post...but I've been lurking for the last few months.

I am having lower back pain/cramping about ~10 miles into a ride. My road bike is a GT Series 2.0. Now I do have a history of a lower back injury, which undoubtedly contributes, but I am concerned that my frame may be too small. It is a medium, with a seat tube height of 51 cm and top tube of 54.5. The issue is I'm about 6'-6'1", and almost everybody I've consulted is convinced the bike is too small for me - coach, friends, random posters on the Internet. But I have yet to get "professionally" fitted.

Stand-over height (for what it's worth) is about 1.5", and my inseam is almost exactly 32". Other general aspects of fit I've seen online seem to be in place. I'm now considering getting professionally fitted and/or converting the bike into a tri setup, but if the frame is too small I'm just throwing good money after bad. My questions are: what are the odds the pain is partly due to a too-small frame? Would a fitting help significantly or is this like trying to put a round peg into a square hole? Is there anything I'm missing?

At this point I'm thinking I will just fit it as a road bike before I throw the cash into a tri setup...thanks in advance.

I am 5'11½ with a 33½ inseam and i ride size 54 Scott Foil (55cm TT/ Stack 54.9cm/ Reach 38.5cm) with either 90 or 100mm stem. I also use an offset seatpost. Most dealers and online bike size calculators suggest a 56 size frame with has 1cm more reach and stack is 56.5cm and TT of 56.5cm. I felt this size was to big, handlebar was way to high even with all spacers removed. 56 came original with offset seatpost, perhaps if i had tried the bike without offset seatpost, but still i felt handlebar should have been lowered 1cm or so.

Most recommend a size up if the back feels sore and if one wishes more aggressive position the size below. But if you look at your bikes stack and reach and go from here, perhaps you got a bit easier to find what you've been looking for!?

Well, it's just a thought:wink5: