Road Cycling - Correct Frame Fitting

Has anyone used the www.wobblenaught.com bicycle fitting routine? Is so, what did you think? Worth the effort? Thanks.

Never heard of it, but will go check it out. The frame fit method I use is saddle height minus 18cm. For me that is 78cm - 18cm = 60cm frame.

Originally posted by cycletourist
Never heard of it, but will go check it out. The frame fit method I use is saddle height minus 18cm. For me that is 78cm - 18cm = 60cm frame. C-C,C-T or, C to top of extended seattube and how about toptube length?

Hi Pokey,

That varies from brand to brand. Bottom bracket drop is also a factor. Measured C-C I usually ride a 60cm but with some brands I can ride a 59 or 61. I don't worry much about top tube length- I can adjust that by changing stems.

No matter what fitting system is used you will still need a test ride to verify that you have the right size.

Originally posted by cycletourist
Hi I don't worry much about top tube length- I can adjust that by changing stems.
I worry alot about TT length. Maybe more than 'nominal' frame size.Changing stem lengths only works within certain limits. Any fit system only gets one in the ballpark. Some people get away with them for ordering online and get lucky.Others aren't so lucky. Lots of test riding is the only way to get it right.

You should both check out wobblenaught. It takes in ALL the measurements, like any good fit should.

Originally posted by ParamountScapin
You should both check out wobblenaught. It takes in ALL the measurements, like any good fit should. So do many others. And it is still NO GUARANTEE!!!I have even heard of people getting bad results on a Serotta fit cycle,because the guy doing the fitting was incompetent.Buy if it you want and skip the test ride if you feel lucky.

Originally posted by pokey
I worry alot about TT length. Maybe more than 'nominal' frame size.Changing stem lengths only works within certain limits. Any fit system only gets one in the ballpark. Some people get away with them for ordering online and get lucky.Others aren't so lucky. Lots of test riding is the only way to get it right.

I have to agree with pokey here (did I just type that? :eek: )
I first had a 58 cm bike with a 58 cm TT, and after ridings many different bikes (friends and test riding at an LBS) I found that no matter how I adjusted my seat and stem, I could not get my reach (to the hoods) to feel just right, however after riding a 56cm (c-t) frame everything seemed to just click, and with some more research I got my seat and stem adjusted correctly on a new frame 56cm (c-t), 56 TT.

http://www.wrenchscience.com/

I did not initially use wrenchscience for fitting, but I did find that it came closest to the size of what I thought was most comfortable.

There are lots of good online sources for bike fit info... but nothing can match an experienced cyclist working with you. The trick is finding the right guy to do the fit. It has to be someone knowledgeable, but also willing to listen to your requirements, instead of trying to force you to the fit that's right for him.
One local shop doesn't have a Fit Kit or Serotta fit cycle... the guy just works with you trying different frames, stems, etc. You just make an appointment (so there will be sufficient staff and the guy won't have to run off and deal with other customers), and he spends an hour or so getting things dialed in. I forget the cost... I think it was around $50.00. Money well spent.

I'm with the esteemed Pokster, recipient of the grouch of the year award, on top tube length. It's an important component of frame fit, and a lot harder to adjust than pedal-to-saddle height.

I have even heard of people getting bad results on a Serotta fit cycle,because the guy doing the fitting was incompetent.

Count me in that group. I could have flushed the $60 down the toilet and gotten more satisfaction.

When it comes to good bike fitting information, the best money I have ever spent is $15 a year for the Rivendell Reader.

http://www.rivendellbicycles.com

Originally posted by cycletourist


When it comes to good bike fitting information, the best money I have ever spent is $15 a year for the Rivendell Reader.

http://www.rivendellbicycles.com Grants Ideas work for some,not all.Deal me out.

I have found that Wrenchscience bike fitting tool gets to within a cm either way of the ideal set-op.
Another good fitting tool is
<http://www.bioracer.com>

I do find however that the toptube measurement they provide is rather long for my level of flexibility (which is actually above average)
Over all these tools provide a better basis for grass roots bike fitting than thesimple 4 fingers nder the crotch technique

Unless you are going to race or ride a lot of centurys or metrics,whatever,just get as close as you can and be comfy.You can go crazy doing a cm here,a cm there,it can get nutsand $$$$$$$$$$$$$$$$$$$$$$$$$$$.

Deal me in for many MANY test rides. Being in this sport for many years, I fit myself with some occasional feedback from my LBS. I tested Wrenchscience and it sux (the fit webpage). I ride 56 or 57. If I listened to Wrenchscience I would be riding 52 or 53....just my opinion but I think there is a wee bit of difference between the 2?

If I were getting measurements off of a website, I would take them with a HUGE grain of salt.

Although I agree that you should take any internet fit system with a grain of salt, the wrenchscience got pretty close to my setup.

I believe fit is something that is developed over time on the bike. If you only ride 30 miles a week, fit is not as crucial as you probably won't notice any problems with something that is "close enough".

As for someone spending a great deal of time on the bike, the fit becomes much more crucial. That goes for everything- shoes, cleats, clothes, bike, saddle, etc.
1cm off and I, personally, notice a big difference. Fit is a BIG deal to me and I try to maintain the measurements I like for any bike I get. These were developed over time on the bike as well as being fit several times and alot of experimentation.

Get in the ballpark, do your best to get good advice, research it well and then just ride and your body will tell you the rest. If you are not planning on living on your bike, don't worry as much and get it so you feel comfortable.

I ride 56 or 57. If I listened to Wrenchscience I would be riding 52 or 53....just my opinion but I think there is a wee bit of difference between the 2?

If I were getting measurements off of a website, I would take them with a HUGE grain of salt.

TLN-That represents a huge discrepancy, and is worth looking into-what is the measurement that you entered into the the frame measuement section on www.Wrenchscience.com?
This is supposed to be the measurement from the top edge of a thick book underneath the crotch ( with the same pressure as a saddle), with the side edge to the wall- to the floor. If they are out by the amount you say on the frame size results, we can fault the site, otherwise it may be unfair to simply say the site "sucks," and if that is the case you are not doing the person asking for advice a favour.

In a practical sense those who suggest that trying various bikes is the best approach to fit overlook the fact that novice riders will usually find a an ideal riding position strange at first. We naturally gravitate to using the muscles we normally use in everyday activity, which may not include any cycling. The first site the person referred to recommended using the fit results over one month before changing it. This cannot usually be done prior to purchase.
Also, novices will not usually have the inclination to ask the LBS to loan them bikes for extensive try outs.
Bike stores themselves in smaller areas especially are more geared to letting the cyclist, "take it around the block", which would tell them nothing.
Relying on the human element in the salesperson you stumble into is a hit-and-miss affair. He or she could be Lance's coach, or some guy who quite The Burger Ranch yesterday.
I personally would use a combination of info. from varios Fit sites and other methods, and walk into the best LBS that I could find, ask to get fitted by a mechanic or salesperson with some history with bikes, and then discuss the figures that I came up with and how they differ from his results. He or she may have good reasons why you should veer off of a Fit's site recommendation based on how you intend to use the bike, and your flexibility etc., but he will likely respect you more once he finds you have done some homework.
Your money is only your own 'till you give it to someone else. Doesn't hurt to have sticky fingers.

TLN,

I have had the same experience as you. Most of the fit systems I have tried, including Wrench Science, Fit Kit, and Serotta, put me on a frame size that is too small.

TLN,

I have had the same experience as you. Most of the fit systems I have tried, including Wrench Science, Fit Kit, and Serotta, put me on a frame size that is too small.

Cycletourist:

I must be missing something here, or we are dealing with a situation where you two for one reason or another prefer
larger size frames that would normally be suggested either by a simple stand-over assessment or a mathematical model. Maybe if you could give us your measurement as stated above and what Wrechscience says should be your frame size, we could see what you mean when you say they are recommending frames that are too small. I am not sure whether the other body measurements have an effect on the one referring to frame size, but I doubt it. TLN says that Wrenchscience is off by somewhere between 3 and 5 cm. on this very important measurement, and I find this hard to believe. If you state that modified inseam measurement and it becomes obvious that the suggested frame size is way out of wack, lets get back to them and tell them so.

I'm171cm (5'8") with annseam of 81.5cm (32.08in) FTC and 61.5 if measured the other way but I digress................
I always rode a 56cm and felt fine on it. then I wanted a new training bike and thought i'd try out Wrenchscience.
It told me a 53cm C2T (51C2C) would be ideal. I did'nt believe it at first but then i bought a 53cm frame and hey presto, it fit like a glove. I could'nt believe i had beenr iding a bike so much bigger and longer. Now I'm way more relaxed and I can feel I more powerful ,especially on the climbs. Wrenchscience works. If only it were more detailed to give me a seat tube angle as well.

It won't be to everyones taste but it is designed to give you the smaleest possible frame that you willbe comfortable on

My reach has decreased from around 70cm to 64 and that bike wnats to go like a rocket.

Well here is my measurements:

Height: 68in

Sternum notch: 58in

Inseam length: 32in

Arm length: 21in

Shoulder width: 21in

Flexibility: 6

Weight: 190 lbs

Foot size: 42 UK

The result was 53cm cen to cen.....

I have no idea whats going on. I havent changed at all since previous to my last fitting. Last fitting was 2 months ago and the one before that was 4 years ago... 2 different guys from 2 different shops with both the same outcome.... I should be riding 58cm road and 56cm cyclo-x. Unless there is something that I and both other guys dont know, I think there might be a flaw in there system. I have ridden a 60cm once (my friends road) to see if I liked the way the frame handled but obviously was too large a frame. Then I tried another friends road to see if I like that one, which was a 53/54cm and that just didnt feel good.

Must be a great deal of "personal preference" going on here. I am 5'9" with a 31" inseam and ride a 53.5 cm seat tube, c-to-c by 55 toptube, c-to-c frameset and it fits me just fine. I rode a 55 x 56 cm for about a month before deciding it was too large. Last article I read about proper fit stated that proper fit for 99% of riders was plus or minus 2-3 cm due to all the adjustments available on a bike (seat height, stem length, etc.). But someone an inch shorter than me on a 58cm framset must be very stretched out or have very long arms/torso. The 53cm he mentioned seems just about right.

My inseam is similar to yours TLN and I'm riding a 53 CtoT!
You're a lot heavier though at 190Lbs but flexibility is similar at 6.
All you r dimentions are similar to mine so perhaps you should try a smaller frame.
You won;t really know if it'll fit you till you try. May just be the best thing since sliced bread

6Foot with a 33 inch inseam at 190 lbs.My bike is 59cm so they are all different.

But someone an inch shorter than me on a 58cm framset must be very stretched out or have very long arms/torso

TLn-With respect to the above quote the meaurements indicate that your torso is not disproportianally long. When you "feel" a frame is too short it must refer to either total reach or to saddle ht., of which seat tube is one variable. I am the same ht. as you, but with a short 30 inch inseam. I ride a 52 cc. .Wrenchscience says I should ride a 50cc. I modified total reach radically to get close to what they recommend, and my riding immediately improved. If I did attempt this reach on a 50, however, I would definately be looking at a custom-made bike. Wrenchscience as previously noted may opt to the smallest frame possible, maybe because smaller tubes flex less, but I don't know.

The mystery is though how two fitters independantly could arrive at a 58 inch road frame set for someone with your measurements? If I were you, I would measure total reach on my 58, and compare that to Wrenchscience and to the borrowed bike that felt too small, maybe that the crux of the problem.

Well you have a good point there. I will have to check it out the next time I test ride some frames. Thanks for your input. I like to think that you can always learn something about something.

I agree with ParamountScapin. For someone that is 5'8", a 58cm frame sounds all wrong. I cannot picture how this would be correct unless you are riding a 80cm stem or something really odd like that.
Also, your measurements sound a bit funny. I have a friend with 32" inseam (he rides a 58cm) but he is close to 5'11"-6'. Even then, he looks long-legged. Your proportions may require an unusual frame fit or something the internet programs don't account for.
Sounds like your leg length calls for a 58cm and your overall height calls for a 53cm. That means you have a short torso. It's more like a women's proportion.
Also, could it be that you mis-measured somewhere along the line? I don't want to get into too much internet-diagnosis as this is woefully inaccurate but I have to admit an interesting thread!

Sorry, I had a typo....my height isnt 5'8" its 5'-10"...70 inches.
They typo wasnt in wrenchscience though.

Even so the wrenchscience frame size sounds right.
Remember that you should rather size a bike according to your top tube length requirement. Wrenchscience gives my ideal reach at 64cm so i look for a frame with either a 53 or 54cm top tube and fit a 100mm stem to the 54cm top tube or a 110mm stem to the 53cm top tube to give me 64. It feels very comfortable indeed.

I think RacerX and TimB pretty well nailed this one for you TLN.

I plugged in your measurements and your overall reach is 63.69,
which seems to make sense with proportianate legs to torso and
not very long arms. My reach is 66.23 although I am (at 5'8) two inches shorter than you, to account for my short legs and long torso/longer arms. Your saddle ht. is 71.77 which is 41/2 cm. higher than my 67.28, which should account for your inseam being longer by 2 cm. You really should not have any fit problems, at least compared to me. Why don't you try to lower your saddle on your present bike to 71.77 and give it a few weeks to grow on you.
As well TimB's comments on top tube are well said. I am pretty sure that the reason I ended up with a 53 cc top tube had more to do with what was hanging on the wall, rather than what the Fit Kit at the store said back then. I can make do by going to a 120 mm stem, but anything beyond that is looked upon with scepticism due to how it changes weight distribution over the front wheel.They should have suggested a custom job, but realistically they were unlikely to do so if it means turning a sale away. This is why self-accessed Internet fit systems are a real help before going to the store in the first place.

If overall reach is 63.7 than there is no way a 58cm bike would be comfortable. That would be a 5cm stem!
If someone said they were about 5'10", 32" inseam than off the top of my head, I would guess a 55cm frame (55cm tt).

As for stems, I use a 120mm and I know guys that use 130 and 140cm. There are no safety or handling issues. It slows steering down but it's not unsafe.

Originally posted by RacerX
If overall reach is 63.7 than there is no way a 58cm bike would be comfortable.

I have been on my 58cm for several hours at a time and had no discomfort at all. But I will dropping my saddle down and see what that does. Ill let you know in a couple of weeks of how it feels.

Maybe it's just the way you feel comfortable. What size stem do you run?
Also, I noticed that having the seat too high up is common with recreational cyclists. They have a lower cadence and I guess the rocking hips doesn't bother them, but it isn't ideal that's for sure.
Not that you have that problem because it maybe that a 58 is ok for you. A little experimentation is a good thing, tell us how it goes.

so what are the reasonable comfortable limits plus or minus with frame fit?

What is going on with all these zombie threads? If you have a separate issue, then start a new thread.

What is going on with all these zombie threads? If you have a separate issue, then start a new thread.

It all appears to tie in with bike fit from my perspective

It all appears to tie in with bike fit from my perspective

Start a new thread and drop this one. People are going to read the 1st page and then get to your post, which I can't really make any sense of and then stop reading. Begin something new and be very clear with what you are trying to say.