New custom hard tail being built in Tustin

I went by over to Duty's house today to talk about a new frame. Here is what we came up with:

This will be a steel frame with a mix of double butted tubes. I think the down tube is 44 mm *edit: I think it is actually like 42. I was excited, and typing from memory**in diameter. Some of the tubes look as big as aluminum tubes. The front triangle tubes will all be round.

Hooded drop outs with replaceable hanger. I think they are made by paragon. I strongly believe integrated steel hangers, but this bike may have a really really hard life. Also, Denis says that these drop outs will help get the stays wide for tire clearance. They are 40 grams heavier than the second choice, and a higher grade of steel.

-Seat tube center to top 15" with a low top tube and gusset at seat tube.
-Top tube 21.75" actual so about 22.75" effective.
-Seat tube angle static 73.5 (around 74 sagged)
-Head tube length 115 mm
-BB drop is 38mm, which should lead to a static BB height of about 11.75" with 2.4 tires.
-Chain stay length 16.5" (Lee this is actual)
-Head angle static 65 degrees
-26 inch wheels front and rear.

ISCG tabs (or maybe ISCG 05)

We are going for clearance for a 2.5 rear tire with room to spare.

The bike is designed around a Pike with an axle to crown of 518mm and 140 mm of travel.

I am trying to basically create the hard tail version of my custom Ventana. I want a bike that will rip the DH, and still get into a position that I can climb in. I expect the complete bike to weigh about 28 lbs. Maybe some Super D

The new hardtail DH class at Fontana is part of the inspiration here.

I will try to update with pictures as this develops. The next step is a drawing.

For those that don't know, Duty is our local frame builder. This will be my third frame from him. He does frame repairs, and modifications. He does trials bikes, road bikes, XC, trail, 29 etc. He will replace tubes, add disc mounts, you name it. He mostly works on steel and ti, as he has no heat treat setup. He took me on some of my first mtb rides over 15 years ago, and helped me get going with the wrench. He is a seriously good guy. PM me for contact info for Duty.

 

Sounds like a lot of fun...can't wait to see pictures.

Cheers,
Andy

 

65 head angle hardtail... its a summer season (on one) on roids!

 

Wow thats a LOW bottom bracket.

 

I still have his business card in my glove box. Really nice guy. Cant wait to see the bike.

 

can I get one with a 1.5 HT, 64.5* HA, 12.25" BB, longer TT, and sized/strengthened for a boxxer?

sounds sweet though. I'm interested to see the finished product.

 

What's Duty's number? I need some work done on a steel frame. Your recommendation is strong.

 

so...pretty much a summer season that took a little to hard of a landing

 

PM sent.

He works from his home.

Shorter stays. I think it will be lighter, and have a cleaner look.

 

+1 for Denis. He did all the frame mods to my Schwinn cruiser and really great guy too.

 

I can't speak for Duty, but I would say that he could do that.

 

its gona be a fun bike thats for sure, youll have to take it to oaks, i love my hard tail at oaks, made it a new challenge

 

That is kind of the intent, except for the lighter weight.

 

d@mn, that build sounds like the sh!te, or should i say duty

post dem pics

 

loving the idea of the 65 degree HA and low BB, that is gonna be a fun ride.
good luck!

 

:-k

 

Really, that's not low for a hardtail. Actually, that's a common height for XC bikes (although those have a less fork travel than a 140 mm Pike)

So...you didn't mention headtube diameter? Are you going with a 1.5"? That would mate up nicely to the 44 mm DT. However, a 37 mm head tube (for normal 1-1/8" forks) may be an odd fit, unless he's going to build it like an old-school VDC with the head tube going through the DT (although the VDC had a head tube going through the TT and DT).

To get that fat of a tire in the back with the shortish chainstays (have you thought of going a tad shorter?), depending on the junction Duty is going with, you could also consider an 83 mm BB shell to get more clearance.

All in all, it looks like it's going to be a really hot bike! For those who are thinking about it, act fast, because Duty is a one-man shop and can only build so many at a time!

By the way, Denis Duty is really a stand-up guy and very good to work with. When I was thinking of having him build me a frame, I wasn't sure if i wanted to go with a 26er or 29er, he loaned me his personal 29er for a few weeks! While asking around, I heard of only good things about him, as well. :clap:

Here's an old VDC with some monster tubes:

 

Yeah, I think the 1 1/8 head tube is going to disappear in the down tube. As cool as that VCD looks, I don't think that is the way I will go. I will talk to Duty, maybe I will do 1.5. If it is going to add a lot of weight, or be difficult for him to source, I think I can be happy with 1 1/8.


We were back and fourth between 73 and 83 on the BB shell. We mocked up some tubes, and it looks like there will be plenty of tire clearance on the 73 shell. I think 16.5 is short enough for me this time.

 

A 1-1/8" DT will be fairly small (28.6 mm). You could easily go with a 35 mm (1-3/8") DT to go with a standard 1-1/8" head tube (the measurement is of the fork steer tube). A head tube for a 1-1/8" fork is 36-37 mm in diameter.

The Black Market Mob uses a 35 mm DT.

Also, you mentioned the seat tube at 73.5 degree pre sag and 74 degree with sag. Considering you're using a 140 mm fork, your sag is going to change the seat tube angle a bit more than half a degree. You may want to reconsider your seat tube angle (and if you do go slacker, you'll need to extend your TT).

 

if you can swing it, you may be able to do a tapered head tube too. bigger on the bottom to account for a larger diameter downtube, with lighter weight than a full 1.5 HT.

iunno how much extra area you'd have though, and I bet it would be a pain to miter the tubes, but it may be worth considering.