Bike fit question
 

Okay, I have a question for other shorter people about bike fit.

I am planning to get a new mountain bike (a Brodie Bruzza) and am 5'6" and female.

Okay, so I stand over this bike which is a 16" frame and there is about an inch clearance from the top of the bar to my crotch. Is that enough when you are mostly doing road cycling ?

The bike shop people say that frame is big enough but I am wondering if it really is ?

I have taken it out 4 times now and it feels comfortable but I just don't want a frame that is too small. They only have this size in the Bruzza because it is last years model and I am getting a deal on it.

So what size bikes do you all have ?Please give your height. Is one inch clearance enough ?

Justen

I'm 5'5" and ride a 17", but I have about 4-5 inches of clearance. Although you will do mostly road riding, the rule of thumb is 4-5 inches on a mt bike, 1-2 inches on a road. In case you might start playing in the dirt with the bike I'd go with a smaller frame. I had an 18.5 inch for a month, and trust me smaller is better when it comes to frame size.

-Middi-zon

Hi,
1)an inch is fine for riding on the road. It's cutting it pretty close for mountain bike riding.
2)There are bicycles with straight handlebars, that are designed to be ridden on the road. A nice example of the breed is the Bianchi Strada. Quick, pleasant.
3)What sort of riding do you plan on doing? Will you commute to work, charity rides?

Okay, sounds like it might actually be too big than too small. I actually plan to use it 85 % for road cycling/commuting and 15 % for off road stuff but I live in an area where there are lots of cool trails and pathways which can be pretty rough so I chose a mountain bike with what I believe is decent front suspension.

I was just wondering - you are 5'5 and yet have 4-5 inches on a 17" frame ?? I only have 1" clearance on a 16" frame and am 5'6.

Justen

Hey,

I've always heard an inch or two is good for road bike sizing. This is the amount of clearance I have on my road bike. I tend to like larger frames for some reason, and favor a slightly larger size, so I usually run a little less clearance than others who I mountain bike with. I tend to think 5 inches or so is excessive depending on what type of MTB'ing you are doing, though many people fit an MTB that way. The general guidelines above are correct from what I have heard. I'd say you are ok if you will be using the bike on the road for the most part. If you might decide to try the offroad route more often though, you should probably consider a slightly smaller frame.


-Moab


EDIT: Was typing this when Justen posted preiously.

Long legs? I don't know? I actually have my seatpost quite high. I know am 5'5" and ride 17", moab can vouch for me.

-Middi-zon

It depends on the frame design. Some bikes have a lower BB than others. Since the seat-tube is measured from center of BB to either center or top of top-tube, you can't always get an accurate comparison of standover between two different bikes from just the seat-tube length. Likewise, angles will also effect your numbers. Oh, also inseams vary from person to person too. :D

Just to double check, standover clearance is measured all the way up to the public bone.

A too-small frame can be a problem if you plan a lot of road riding, if it means you can't get your saddle back far enough, so be sure to check that. You'll end up either crammed into too small a cockpit and pushed too upright, or with your knees too far forward, or with a too long stem in an attempt to compensate, which will reward you with poor weight distribution on the bike.

A too-large frame is mostly a problem in sudden forward dismounts, and I wonder how often people actually end up jamming their top tubes unexpectedly into their sensitive areas, especially with clipless pedals.

Personally, I think any standover clearance is enough; on a MTB with a sloping top tube if you still have clearance standing all the way forward you should be fine.

RichC

For road riding you need enough clearance to stand over the bike. For off-roading you need to be able to move around a lot more and have some safety factor in case of sudden dismount.
The standard clearance is 1-3" for road, and 3-6" for off road.

Frame "size" is fairly meaningless term, since frames are measured so differently. The only measurement that counts is the one you do with a tape measure.
Given sufficient clearance, the most important dimension is the length of the frame. A larger frame will also be a longer one. If you have long legs and a shorter torso or arms, you may find that with adaquate standover, the bars are too far away for comfort. Find out what length you like from (correctly positioned) saddle to bars.
Different manufacturers have different recipies for frame geometry, so you can scour bike shops for one which combines your ideal height and length.
NB dont forget Khuons comment that bikes have different height bottom brackets. Many smaller sized bikes have higher ones which is simply wrong.
Also, check out the crank size to make sure you have at the most a 170mm crank, not a long 175mm one (which is for larger people).

Well, given that I do have a smaller/shorter torso, I probably wouldn't be able to go much beyond a 16 or 17" bike. However I still have very little clearance over the top bar when standing over it- maybe an inch or so. If I go for a smaller frame, it is too small for my road cycling which I will be using it for more frequently.

Justen

If the smaller size is correct for you in the top tube length, then it doesnt matter if the frame has lots of clearance; this is even considered a design feature of compact style road frames such as the Giant TCR. The modern style generally is for greater clearance.

Using smaller frames puts the head tube in a lower position, ideal for aerodynamic riding, but less suitable for general purpose use. The solutions would be to use a frame with a sloping top tube, an extended head tube(custom frame feature), or a stem with a lot of rise. Modern stems are available with plenty of rise, so its not such a problem as it used to be.

I was told by one bike shop staff that the bike I am currently riding is too small for me. It is a 16" frame. I would agree that for a road bike it might be a bit small. I don't really have any pain while cycling except for knee pain. It is hard to tell if that is because of my positioning on the bike or from the size of the bike.

Justen

Hi Justin,

MTB ... 85 % road vis-a-vis 15% off road:

If you purchased a smaller frame to accommodate the safety issue for off-road riding you might consider having two sets of seats and seatposts.

A standard post/saddle for off-road and a setback seatpost/saddle for the road riding .. it wouldn't be a big deal swapping them out depending on the ride. Also, bar ends positioned in a more forward position could help stretch you out for the road riding.

Hi Roaddog,

I really should have come up with a more creative user name than just using my boring old first name but oh well ! :-) Anyway...that's a good idea - two different seats and seat posts.

I guess I just don't want to be spending $1300 dollars on a bike that is not the right size. This is last years model that I am getting at somewhat of a discount and all they have is the 16" size. I thought this would be the right size so it didn't bother me at the time but I think I am going to go to a different store and try out a 17" Bruzza and see how it fits for me.

Justen

Good first name (and handle), next time I'll try to spell it properly.

Have fun .. ( :

No worries :-) I am a female and I think most people are more familiar with the more common spelling of the name for guys. How my parents came up with this name for me I don't know - but I like it more now than I used to !

Justen

Justen,

I really don't know alot about the whole MTB setup being
an avowed roadie, but would something like trek's
WS (women specifc), or Terry bikes offer a better fit?
It might be worth it to check these out at an LBS even
tho you may not want to purchase it, the fitting is
the thing.

Marty

Hi,

Thanks for the reply. I might try out the Trek's just for fit but I really do like the Brodie Bruzza. From what I have read here, Brodie bikes seem to have a pretty good reputation and the fit is not bad. I did not think there were women specific mountain bikes as they all seem pretty unisex. I would guess that the overall length of the bike might be different for women specific bikes though to address womens' tendency to have shorter torsos then men.


Justen

Hi Justen!

A friend of mine has a Trek WS and is absolutely thrilled with it, but other than that I can't tell you much about pricing or construction , although I would bet it runs much the same as their other lines. I have always been just fine with "men's" bikes due to the fact that I'm just shy of 6 foot and built like my father(thanks for the legs, daddy!) but I know from discussions with other women that getting fitted for a femme-specific bike can make all the difference in the world as far as comfort goes.
Your LBS should be able to help you out.