I am a newbie, but I have been lurking for a while. Therefore, I anticipate being flamed for asking a fit question. None-the-less here it goes…
I am going to purchase a tri-specific bike but would like to be armed with knowledge prior to arriving at the bike shop. I’d like to know which manufacturer’s frame are most likely to fit me best. It is after all difficult to know if someone is trying to actually help you find what is best for you or if they are simply giving you what helps their bottom line. This also helps dramatically when choosing a bikeshop considering they usually don’t carry every manufacturer and will usually try to put the customers on a bike that they sell.
So for the fit experts out there here is the information that I have. I currently ride a Specialized Roubaix and I love it. I am 5’8.5"(174cm) and have been professionally fit on the bike. My seat height on my Roubaix is 71.5 cm. It is my understanding that from this information that certain assumptions can be made to guestimate the best fit for me.
This is what I can gather making some of the assumptions from the fit articles and the information I have. I should have a cockpit length of 71.5cm and a saddle to armrest drop of ~9.5cm. It also sounds like the total height of spacers plus headset plus stem is going to be ~7-8cm and the height of the armrest is going to be ~3-4cm. So the armrest should be ~10-12cm above the top of the headtube(Correct?).
How do I translate this into stack and reach components? How long is the typical aerobar with extensions?
Ok so flame away (by the way my seat is probably too high:))
You say that you were professionally fit on your road bike.
did they do a good job? do you trust them? and do they also do a lot of tri-bikes?
if so, ask them, not a bunch of strangers on the internet.
You say that you were professionally fit on your road bike.
did they do a good job? do you trust them? and do they also do a lot of tri-bikes?
if so, ask them, not a bunch of strangers on the internet.
I got fit in Santa Monica and now live in Denver. Additionally, as is stated again and again most shops have experience with road bikes not tri bikes.
With resources such as this community and some of the fit experts here I am more comfortable with their knowledge than with many local shops. To paraphrase Slowman “I can fit a person on a bike remotely better than 9 out of 10 shops can in person.”
I can accept and reject the information here without making the investment of a trip to 4 or 5 shops and hours of time. If 5 people without financial incentive tell me the same thing that is more likely to be true than one person telling me that same thing in an effort to make money. Is it possible that I could get bad advice? Sure. I’m not blind to that fact.
My analogy would be this: after a day of research about a particular electronics purchase I am more likely to know about that product than an employee at Best Buy. I am more likely to make a good purchase than I would have been without researching it and listening to a potential uninformed or misinformed shop employee.
Tom demerly at michigan bike sport sells all types check out his web site.
I’d like to buy from a well respected shop such as his but I’d like to know what I am doing (at least a little) first.
My buddy was in a situtation like you and Tom himself helped him. He had Kevin measure himself and with these he was able to suggest the best frame to fit his body but he didnt push anyone frame set. The only one him didn’t have info on was specialized. He will let you make the final decision without any pressure
If you live in Denver then you are really lucky. Boulder is arguably the tri capital of the world. Give Ryan at Colorado Multisport a call. They take Bike fitting very seriously and will give you a list of all of the bikes you would fit best on even if they don’t sell that bike. If you choose to buy a bike from them then the cost of your fitting will be applied to your purchase. If you decide to go elsewhere you will at least know that you are getting the right bike.
I forget his name buy the guy who started the Retul (dynamic motion capture fit system) is based in the Denver area. He can do the same thing for you.
I know that doesn’t exactly answer the question you asked. I have asked the same question and frankly you aren’t likely to get the answer you are looking for here. The problem with trying to use the remote tri bike fit system you referenced is that it assumes you are at a certain effective seat angle. If you decide that you will ride at that seat angle even if it means an adaptation period for you where you are not completely comfortable then you can most likely ride any of the bikes designed to be ridden steep. But without seeing a goo fitter and getting your stack and reach I don’t think that you are going to be able to answer your question definitively. If you do then let me know because we have similar measurements and I’d like to know as well.
What bikes do you think you are most interested in?
OK. So I was fitted on a tri bike. My seat height is 72cm riding at 78 degrees. My drop is 8cm and seat tip with an ISM to handlebar is 51.
So based on this and some trigonometry:
BB to a level line with the saddle height is 66.75 cm.
So is my ideal stack = 66.75cm - 8cm - 4cm (Stem) - 1cm (headset) - 4cm (height of arm rest off basebar) = 49.75cm
And is my reach = 51 cm - 10cm (Length of proposed stem) = 41 cm
Cervelo P3C 54CM Stack = 49.8 (Delta 2mm) and Reach = 41.9 (Delta 9mm) cm seems close
Cervelo P2C 54CM Stack = 51.2 (Delta 2mm) and Reach = 41.8 (Delta 8mm)CM also seems close
Felt 54CM Stack = 51 cm (Delta 0mm) and Reach = 41.5 (Delta 5mm) is even closer
Argon E-112 M Stack = 51.5 (Delta 5mm) cm and Reach = 41.9 (Delta 5mm) is not bad
Transition Medium Stack = 51.6 (Delta 6mm) Reach = 39.5 cm (Delta -5mm)
The higher stack frames appear better suited for the majority of Bars/Extensions and the shorter reach is probably better given that a 105 stem is better and easier to find than a 95mm.
Holy cow I just realized my reach measurement is not very useful. I actually need the distance between my seat post and handlebars and then need to subtract 26.9 cm.