PDA

View Full Version : HighRoller rear triangle



Kardolf
07-29-2011, 04:02 PM
I saw the question posted in one other spot, but didn't really see an answer to it. Since I just got my HighRoller project off the ground, I'm wondering if it's possible to use the rear triangle without the seat tube instead of using a front fork and then the uprights.

Is there a good reason NOT to do this?

Racer46
07-29-2011, 04:54 PM
I don't see why this wouldn't work unless the seat stays were too short to reach the seat back support.

Radical Brad
07-29-2011, 07:27 PM
This could probably be done, but you would have to deal with the fact that the joint at the original BB would be under a lot of stress (where it joins the main square boom), and my not hold up. The other issue would be the drive side of the chain coming from the underside of the dropouts. This may require a few washers to widen the stays.

I would imagine a decnt gusset at the BB to boom joint would help if using a full rear triangle.

Brad

Kardolf
07-30-2011, 12:29 AM
I was going to cut the BB out, along with the seat post, and "smash" (with some creative cutting and welding) the boom onto the cross piece that sits about 4 inches behind the BB. But, after looking at it again, looking at the plans, and mostly reading your comment about the chain routing, I think I will forego that idea, at least for my first bike. Maybe when I have some more experience under my belt.

Philv88
09-12-2011, 12:31 PM
I dont have my plans yet, but I hope to have them this week. But I was curious about using an existing rear triangle as well. What is the issue with the chain routing?

trikeman
09-12-2011, 01:37 PM
One issue with chain routing is that on a bike with a crank way out front, its tough to get the chain low enough to make sure it clears the rear chain stays. That is why those bikes have a big pulley under the seat and in Brad's design the reason that the dropouts are welded a couple of inches below the rear chain stay. The other issue is that every pulley adds some friction, but there are a lot of really fast low racers with multiple pulleys.