Road bike build, advice please on seat tube angle.

[Matuka]

So I have watched at least 3 youtube videos and am now convinced I can build up my own road bike as I'm basically an internet expert. Having looked at a number of frames I really like the look of some of the TT/tri bike frames and then I started wondering. Please correct me if I'm wrong but TT bikes tend to have a higher seat tube angle, upwards of 76 or 77 degrees and my understanding is that this gives you better drive on the flats. So is there any benefit for Frankensteining a TT frame with Road Bike components and in so doing winning the 947? I assume the higher seat tube angle might make climbing harder but since I push my bike uphill it wont really worry me. Excuse the joking this is actually a serious question and I would really appreciate any advice. I assume there will be several issues or else this would have been done before? 

[Butterbean]

Nah, loads of people have turned TT frames into road bikes, IIRC the main issue tends to be the saddle position over the pedals. The rest is a fairly simple swap of bars and shifters, and your choice of wheels.

[DieselnDust]

The steep seat tube angle works when you the bars very low as it allows your hips to drive the pedals over the top of the pedal stroke. The higher the bars go the less of an advantage that becomes. Mtbs with steep seat tubes have that feature to get the riders weight between the wheels better when the bike has a long front centre.

So yes you can repurpose a TT bike or you can get a bike with a seat tube angle of 74 degrees or steeper (my bike has a 75.8degreee seat tube angle).

 

However you may not like so why not first try reversing a seat post and seeing if the more over the pedals position works for you.

[Jewbacca]

So, my 2c...... Don't build a TT/tri bike into a road bike.

 

They are usually incredibly stiff and carry their weight awkwardly. On a road bike you want some compliance in the rear. A TT bike usually has  none.

 

I tried it, it was a massive fail. The bike rode really well, pedaled super well etc BUT they also tend to have a slacker head tube as they aren't really made to corner all that much, which makes the super stiff, uncomfortable rear end even less inviting when it handles like a drunk dog mowing the lawn.

 

So yes, in theory you can juice the numbers to make it work, but the reality is you will have an uncomfortable bike that handles badly.

 

Sorry if that's not what you want to hear...... Get a road bike. 

 

If you don't, I hope your experience is better than mine. If not, I told you so! 

[gummibear]

Your kidneys will never forgive you if you do it

[Riaan H]

I get why you would want to do it, I love the look of TT bikes myself, but as has been said before, it would most likely not ride the way you expect.

 

The seat tube angle and general geo is designed to open up the hips so you can run better off the bike, while being as aero as possible, once you put a different bar on it I reckon the whole thing will just be akward.

 

But, you may just prove us all wrong and actually like your Frankenbike

[Duane_Bosch]

I love the look of TT Frames myself

 

There's a lady I see from time to time (I think she's a Savage) who rides a Swift TT frame with normal drop bars etc.

 

But she looks AMAZING on the bike. Tall and skinny with a slammed front end. If I tried that I wouldn't be able to breath with my gut hitting my knees all the time and my back would demand a transplant to a less demanding person. 

[Matuka]

Thanks everyone for advise! I knew that if it would actually work everyone would be doing it.  I'll stick to a road frame methinks. 

[Matuka]

 (I think she's a Savage) 

Arent they all