TiHabanero

Just rode a new frame and have found that I pushed the envelope too far with the head tube angle. Thinking about how to change the head angle I came up with removing the down tube, bending the head tube/top tube to get to the desired head angle (needs to move about 3 degrees) to steepen the angle. Any thoughts or is it replacement of the top tube/head tube/down tube and rebuild the front triangle?

Canaboo

How is it joined?

Andrew R Stewart 

3 degrees of bending? That's a lot IMO. Better to remove the HT and see if the existing TT and DT can be remitered for the new head angle. Andy

guy153

I agree with Andy Stewart better to remove the HT altogether. But why not instead make a new fork for it? Give the fork enough offset to get your trail back where you want it. Then the existing fork can be re-used on another project.

dsaul

What kind of frame and what is the current head angle? I doubt you could have gotten it that wrong.

TiHabanero

Here is what happened. I designed the frame around a 60mm fork rake, then changed my mind on the fork as I wanted the bike to look more modern, but the frame was already built by that time. Decided to install a 45mm rake fork and try it anyway. It is ridable, but rides like a chopper, lots of rise and fall with the front end, and it is a handful in high winds. The frame is lugged and figured redoing the whole front end of the bike would be best, but figured if there was a short cut, someone here will know.

dsaul

What is the purpose of the bike? Road, gravel, touring? My bikes vary in trail from about 60mm on the road bike to 75mm on the gravel bike and 90mm on the MTB. The longer trail bikes are not so easy to ride with no hands, but winds don't seem to be a problem. The only time I have problems with cross winds is with a deep section front wheel.

It just seems like a radical approach to re-build the front triangle, when riding the bike a few more times might allow you to become accustomed to the way it rides.

Trakhak

That's a sensible suggestion. I bent the (steel) fork on a 1986 Cannondale in 1990, left it unused for 20 years with a vague plan of replacing the fork, and then started commuting on it. Took a few rides to get used to the handling, but I've since ridden it for a good proportion of my annual mileage.

mikeread

Would a straight blade fork with 60mm rake look modern?

unterhausen

have you put your proposed numbers into a trail/flop calculator? 45mm rake fork is going to need a steep hta to get it to reasonable flop. What is the current HTA and proposed HTA?

Seems like it's time for a new frame, chalk this one up to experience. But if you really want to do this, replace the TT/HT/DT.

TiHabanero

I find my trail preference is between 71-73 mm. I have considered a straight blade fork with 60mm taken but need to draw it to get an idea of how it will look. As it is, I will give the thing another ride and see how it goes.

Cynikal 

A 7 degree fork crown with a 390-400 ac would get you really close to 60 mm.

Nessism

I agree with Andy too. Shouldn't be too hard. Don't think I'd work too hard saving the lugs though, although that's possible.

base2 

Rodriguez had someone contract build them bunches of 55mm rake forks (1&⅛) for their disc braked bikes. You might give them a call. Maybe they have one on the shelf.

Rodbikes.com

55mm is not 60mm, but it'd get you closer than you are. They are aluminum, smooth, disc. Nothing retro or lugged about 'em.

They also do custom to whatever your specs are.

Mine is 55mm rake for a 26 inch (559) wheel for a 69 degree head tube angle. ~55 to 62mm of trail depending on tire.

TiHabanero

I believe I will try to save the head tube as it is special to me. Last of the 531 tubes my brother gave me, and replace the lugs and TT/DT. Winter project.

TiHabanero

dsaul, I have been riding the bike with the inappropriate fork and am becoming accustomed to the low speed weirdness. I will say once I am up around 17+ mph, the thing settles down and is very comfortable to ride. Does not like to deviate from a straight line so a little extra effort on the bars is required for cornering. Oddly, this does not bother me at all. Only the low speed instability is bothersome, but I bet that can be overcome in time.

The OS down tube seems to make a difference in the responsiveness to heavy input such as climbing and sprinting. At 40mph on a downhill the bike was very stable, but as mentioned before, it did not like to deviate from a straight line without some heavy handedness. Again, I can deal with that. Thinking that using the wrong fork is livable. Thanks, dsaul!