Proprietary Geometry: A Redux Apr 13, 2010

The last time I brought up the notion of a Proprietary Geometry, there were only a few trick bikes available. In the past few months since that post, it seems like every company is putting out a 700c trick bike. Most of which do not release the geometry, for good reason. What is it that makes these bikes all different? Is there a deciding factor that seems to work for one bike and not another?

There’s more below…

When I first saw the Volume Thrasher, I was pretty impressed. It’s not easy to nail down the market demand on a new bike, especially with the “twenty six fixed” riders all wanting to clear a 2.5″ tire on their smaller wheels. Volume has learned a great deal from their sponsored riders during the time they developed the Thrasher. Puckett, Congo and Mosher all had a say in the bike’s design. Through PR&D, they’ve nailed down the geometry, specs and a release date (slated for May, 2010) for the frame.

I’m still stoked on the bike but one thing caught my eye; the angles. Now, assuming the Thrasher was designed around a fork with a specific axle-to-crown length, its angles are identical to the Milwaukee Bruiser‘s with a 74.5° head tube angle and a 74° seat tube angle.

Here’s the specs off the Volume Fixed site:


Is this the magic ratio between track and bmx? Fixed and free? Personally, I love it and I’ll be interested to hear what new owners of the Thrasher have to say once they get theirs in the mail. Now, I am in no way trying be a bully here and call Volume out. I’m simply making an observation and stating the same thing I said last time;

In the end, special details like curved tubes, gussets, cleaves, clamps, track-end and fork tapers will mark the individuality of each of the frames. Much like modern-day BMXs. Who would have thought, two years ago, that we would be engaging in such a discussion?

Not me, that’s for sure…

What do you guys think? Volume, if you’re reading this, feel free to comment as well. I want to open up a discussion here. Was the frameset designed together, or is the fork going to affect the angles? What led you to looking at these angles and experimenting with them? Hopefully we’ll hear some responses. There’s a thread going on over at Trick Track, so head over and read up on the discussion there.

Proprietary Geometry?
Volume Thrasher Prototype Forks
Volume Bikes Thrasher Build

  • Curtisss

    its not like all track bikes have different Geo (there’s a standard). i wouldn’t worry. volume didn’t steal the bruiser specs.

  • prolly

    I didn’t say they stole the geometry!

  • lucca

    yah track bikes pretty much all have stander square geo, and bm are all pretty much the same except for tt angle and the rear triangle
    you got it right the first time so just relax

  • aj

    i agree, i’ve road eric’s thrasher a bit and it feels pretty different from the brusier. I would have more to say but thats a long post to read for a lazy person such as myself.

  • duker

    i don’t know. i see “track” bikes with road geometry. (Lynskey is making a Ti one) I started out with a conversion. Wheel clearance is a newer issue – fork rake and trail, HT and ST angle can all have an effect. I rode some trick bikes that weren’t that fun to maneuver. Wheel base is different sometimes. Prolly, i think you (any rider) have to decide whether your trick bike is just that or more. Do you see a lot of people on bikes you might say were too small for other types of riding?

    So here’s something I wonder about how to balance: short chain stays for tighter wheel base and turning with enough trail in the front end to corner well while allowing bar spins with 700 x 32ish. Again, i’m thinking of building the ONE. A fixie for all seasons.

    There may not be a standard as Curtiss said. I read the article in urban velo by Don Walker who shows at least three trad track geos depending on the race type. Seems to know.

  • Craig

    I’ve always been a little confused – is a larger (74, 75) head tube angle more or less vertical? Since I’ve seen this referred to as a “steeper” head tube, it makes sense, but still…

  • duker

    Just checked the fu manchu’s rake (32mm), plugged it into a trail calculator with the 74.5 HT angle and got around 63 mm trail which is good i think if the axle to crown doesn’t change it much. I should ask a friend who has one what he thinks. He’ll probably just say “sweet”. The crimp in the seat tube only bugs a little. more affordable than a curved tube(?)

  • prolly


    they’re making a Thrasher fork (which is what I linked) specific to the bike…

  • Brian

    We really considered what our riders wanted and based it off a lot of BMX frames HT angles of 74.5º. I think it’s just coincidence that the 2 frames share those 2 angles. We did take inspiration from a number of different bikes. We’ve been in the frame business a long time and even the Bruiser shares the some similarities that we’ve done in the past.
    Better second guess using a Mid BB, Sanko tubing, integrated HT and… or I’ll call you out Prolly! Wink

  • SkidMark

    How am I supposed to know whether I will like the way a bike handles without knowing the geometry?

    I wouldn’t even consider purchasing a frame without knowing HT and ST angles, top tube length, chainstay length, and bottom bracket height. I wouldn’t purchase a fork without knowing its offset, and if I was retrofitting it to a frame I already have, its crown height.

  • Drew

    It’s no surprise that geometries will overlap.
    If anybody read the cog interview they would know that we took our geo from bmx; it’s no secret. There wasn’t one 700c frame we looked at; the Bruiser is readjusted bmx geo for 700c (simplistically speaking). It just so happens that bmx geo is quite close to traditional track geo with slacker st angles.
    FTR I never looked at one bmx frame specifically. I was more concerned with the ht/st angles in general and as you can imagine there were plenty of sites that delved into the evolution/theory of bmx geometry over the last 30 years.

  • duker

    Kudos to Volume in general for innovating. There’s so much about these bikes that make em a new breed. The thrasher fork may have a similar rake/offset, so I think the magic bullet as far as geom. was the longer top tube. Seems that’s how they preserved handling and reduced toe overlap for spins. My only gripe will be fork availability. As you said it was designed around the fork and the fu manchu was hard to get last year.

  • prolly


    BMW beat everyone to the Mid-BB game over a year ago. That’s just a given at this point with everyone running BMX systems.

  • ken

    So the longer top tube is a new innovation? Leader says they invented the long top tube. Third paragraph…

  • prolly

    I remember that. LuLz.

  • jase

    Anyone else wanna call bullshit on Volume? I rode the first Thrasher prototype and there is no fucking way the head tube was that steep. If I recall the owner said it was around a 72. Just look at that photo above. The two bikes have way different head tubes.

    Thrashers gone through a ton of reworkings since that photo then. The bike was super super long and rode like riding lawnmower. I think they just smartened up and looked at the Bruiser. There. Someone had to say it. You guys beat around the bush too much.

    I wish I still had my bruiser. I had to sell it to pay rent.

  • duker

    I don’t think anyone owns geometries. Rear suspension linkages MAYBE. Cutting material longer or setting a different angle shouldn’t be looked at as “inventing” just part of creative development of different use bikes. It’s not like trick 700s final geometries or BMX current ones for that matter differ that much. They just have to do the job. Longer top tubes come from cross country mtn bikes.

  • lucca

    to end this
    everyone will always try and reinvent the bicycle but it alwasy comes back to the same geomotry. Track is always square road is always a bit streached out mountian is all the same, all bikes are the same. FGFS will always come back to this comon geo, no one did anything that innovative to begin with they just opened their eyes and started desiging stuff with their heads and not their ass

  • prolly

    Track bikes are not all square. Road bikes aren’t all stretched out and MTBs are certainly not all similar.

  • duker

    Prolly: I second that. but do you think you should be able to own a configuration? you hinted with that i think. For that matter, should the butthole surfers sue beck? (Loser beat via Pepper, the real question).

  • Jussi

    As already pointed out, there’s not much point in trying to argue that one specific frame “owns” some specific geometry and that all others are just copying it.

    John we all know you were involved in the design process of the Bruiser, and that you feel all defensive about it since some Chinese guys copied so quickly. However, trying to present it as The First Truly Innovative Tricktrack Frame doesn’t really make much sense. There was always the BMW Gangsta, all the bmx bikes of the past etc. etc.

  • prolly

    Jussi, I never said anything to those sorts in this post. Leave your preconceptions at the door man.

    Duker, I also never said that. I presented the case in this entry the same as the last. I am in no way claiming to “own” anything.