Who is making a frame with a 50cm Top Tube?

Hawker · #1 10-08-2013, 09:41 PM

I'm short with short arms and after trying a lot of bikes and owning more tha a few I know that my ideal TT length is 50cm. 51 is too long. Typically this is a 44-48cm frame size or an XS. However most men's frames even in these sizes will have a 51cm or longer TT. Shoot, most women's frames have at least a 51 top tube, but not all. I don't mind riding a women's frame but sometimes the colors are just too feminine.

So, any major carbon frame manufacturer come to mind with shorter top tubes?
And yes....I've shopped them all.

Thanks.

cmg · #2 10-08-2013, 10:28 PM

you might consider looking into a frame with a less than 74 seat tube angle. why? because it will place you further behind the BB. a bike with a 73.5 STA and 51 top tube will have a smaller reach than a frame with 74.5 sta and 51 top tube (which is common). the top tube on the 73.5 sta frame will be further behind the saddle, by about 1cm for example. the problem with a smaller than 51cm top tube will be that toe overlap is unavoidable. look at Jamis, Cervelo, early BH, BMC frames for less than 74 STA frames.

christian · #3 10-08-2013, 10:34 PM

With a 700c wheel, no one serious makes a 50cm tt bicycle, because you'd have to rake out the HTA and fork ridiculously and typically, they make silly steep seat tubes to take the tt measurement out of the stack.

Have you considered getting a bike with 26" wheels?

bicycletricycle · #4 10-08-2013, 10:36 PM

Yep, everyone hates on the mall wheels but they are good for short top tubes, a 700c bike with that short of top tube will have crazy seat tube and head tube angles.

ultraman6970 · #5 10-08-2013, 11:02 PM

+1 with christian... never seen a carbon frame as short as 51ish. That's the price for using oversize tubing too.

What about aluminum/carbon or steel/carbon??

If you want to go classic you might be able to find a nice steel frame with a 50 top tube if you dont mind overlapping.

Custom paint job in a girls frame??

carpediemracing · #6 10-08-2013, 11:38 PM

I think you should go custom.

Also I wouldn't worry about overlap, I'd just accept it. This really opens the door to having a nice handling bike.

There's a local former-pro woman racer who rode a frame with a 49 cm top tube. She had a (custom) GT-labeled frame, the ones made for the National Team. She didn't have just toe overlap, she had like pedal overlap.

Later she had some other frame. I don't know what the second one was because when she got on a team she'd outfit the bike with appropriate decals so she wouldn't have to use the team issued bike. I have no idea what the original brand was, if it was custom, etc.

kenmetzger · #7 10-09-2013, 10:54 AM

Jamis does make "femme" models with a 49.5 tt in a 44 size and a 50.5 tt in a 48 size.

http://www.myjamis.com/SSP%20Applica...&cat_grp=fem_2

christian · #8 10-09-2013, 11:07 AM

Quote:

Originally Posted by kenmetzger

Jamis does make "femme" models with a 49.5 tt in a 44 size and a 50.5 tt in a 48 size.

The STA in the 44 is 76d and the 48 is 75.5d. Reach will be the same as a normal bike with a 52cm ETT. This is the nonsense I was talking about.

false_Aest · #9 10-09-2013, 11:29 AM

Brah,

You might wanna reach out to someone like Eric @ Zimmerman Bicycle Works.

He's a shorter dude and has been building for shorter people lately. He understands our concerns pretty well + builds a bitchin bike.

No website. You'd do best to contact him via V-Salon.

Sensible pricing too.

David Kirk · #10 10-09-2013, 11:38 AM

I don't often need to build a bike with a 50 top tube but it happens now and again. It's no rocket surgery to get the numbers right but thought does need to be given to be sure the bike has proper balance with the wheels being in the right place...........this is of course no different than building a bike with a 56 top tube but since most builders don't build the smaller sizes as often as they do the sizes in the middle of the bell curve it can be more of a challenge.

Any way you cut it I think you'll be best off going with something built for you and there are a lot of builders out there building in all different materials and with different techniques so you should have no issue finding someone who does what you have in mind. I would just be sure the builder is comfortable building in this size range.

dave

nicrump · #11 10-09-2013, 01:39 PM

Yup, I've done it. 50cm TT on 700c wheels for a 4'9" local gal. It rides great.

ergott · #12 10-09-2013, 02:58 PM

Well there you go. You can't get a more authoritative confirmation that it can be done than that.

cmg · #13 10-09-2013, 03:58 PM

the difference between the jamis comp and comp femme is in the seat tube angle. 73 for the comp and 76-75.5 for the comp femme. i mention this because it does make a difference. the reach will be further on the comp femme. more of your weight will be over the front wheel.

Hawker · #14 10-09-2013, 08:36 PM

Thanks guys, lots of great information here that gives me some things to think through. I'm traveling right now and will post again once I decide the next step.
Most appreciated!

Steve

djg21 · #15 10-09-2013, 09:24 PM

I'm not a frame-builder, but I'd think a bike built around 650c wheels would make sense for a vertically challenged rider so a more "standard" geometry can be built around the smaller wheels. You can use a larger chainring to compensate for the smaller wheels to the extent necessary. I know one frame-builder who prefers to build small frames for 650c wheels, and always wondered why you don't see more of these.

On edit: Just came across this discussion of pros and cons of 650c wheels on small frames.

http://www.cervelo.com/en/engineerin...cyclists-.html