The bombproof frame arrives…

January 30th, 2007 by Tim Grahl

We have received the Surly Instigator which will be the frame used for our Blue Collar Bombproof Bike. This was originally spec’d for the project as it’s known for it’s burliness and the ability to take a beating. So a big thanks to the guys at Surly Bikes for stepping up and sponsoring the build by providing the frame.

Here she is in all her glory…

Surly Instigator Frame

And here’s the specs from the Surly site:

Tubing: 100% Surly 4130 CroMoly steel. Main triangle double-butted. TIG-welded

Rear dropouts: Proprietary Surly 4130, 135mm spaced

Brake compatibility: International Standard disc or cantilever rim-type

Braze-ons: Removable cantilever bosses, dual water-bottle mounts, downtube shift cable routing, guides for hydraulic hose or solid housing, ICGS chainguide mount

Seatpost diameter: 29.4mm

Seatpost clamp diameter: 31.8mm (1-1/4″), Surly Constrictor included

Headset: 1-1/8″ threadless

Front derailleur size: 31.8mm (1-1/4″) bottom-pull

Bottom bracket shell: 73mm wide, threaded English 1.37 x 24t

Tire clearance: 26 x 2.7″

Chainring clearance: 48t max

Fork Compatibility: Geometry is designed around a 100mm–130mm suspension fork. Using shorter or longer forks will compromise intended ride characteristics, i.e. less BB clearance, faster or slower handling, etc. Most of you will choose a suspension fork, so we don’t include a fork with this frame, but we do make a rigid fork for the Instigator

Color: Red Rocket

Weight: 18″ (which is used for this project) = 6.61 lbs. (3.0 kg)

28 Responses to “The bombproof frame arrives…”

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1 nathan on Jan 30th, 2007 at 2:15 pm

reminds me of a steelhead. seems to me like surly might do well to make this frame with track fork end dropouts (which hanger, ala the steelehead) instead of the vertical ones.

i’m anxious to know whether you’ve took any suggestions to heart for the build
2 SlowerThenSnot on Jan 31st, 2007 at 2:48 am

I like red! can’t wait to see how it lasts… If you ever loan it out for some other opoins i’d be happy to flog it on some CO single track =)
3 MIchael on Jan 31st, 2007 at 12:31 pm

I followed the last thread and am still unsure of what the objective is here… from what G-Ted said, it’s to prove that the industry isn’t building bikes that last? To formulate some sort of cost: durability: weight ratio and show that what consumers buy isn’t as good as it could be?

A Surly frame is hardly “affordable” when compared to the $50 Nashbar offerings, the constant $150 Fetish/eBay options and all the others out there. What’s retail, like $550?

And I’d like to resurrect the 7spd argument here… 7 and 8 speed cogs are the same width. 7-speed parts will be no more durable than 8. There’s no sense in spec’ing 7-speed as parts are tougher to find and they offer minimal upgrade potential.

If there’s room for argument, it’s in either the 9 versus 8 or in the wheel dish department.

9 versus 8: 9 speed chains are .8mm thinner than 8 speed. This .8mm allows 9 cogs to be used where 8 were previously used. It’s like the airlines using small seats to pack in more people.

Wheel Dish: 7 speed offers an advantage regarding wheel durability. Since 7 and 8 speed cassettes use the same cog width, a wider cassette body is required for the 8. A wider cassette body means more dish on the wheel, which can translate to a weaker wheel.

I’d argue that the use of better materials and the professional craftsmanship that will come with a slightly more expensive 8-speed wheel will offset any sacrifice in durability you’ve accepted by going to an 8-speed. That is, buy a 7-speed wheel and it’s cheap–But it’s made of cheap materials and it wasn’t built with as much care so it won’t last as long.

So don’t waste your time pursuing 7-speed. And it’s silly to have started with this boat anchor of a frame. Unless you’re hucking staircases, that 1×1 or a Nashbar frame would’ve been your better true Blue Collar build.
4 nathan on Jan 31st, 2007 at 1:18 pm

7 speed has 5mm center to center spacing, vs 8 speed’s 4.8mm
http://www.sheldonbrown.com/cribsheet-spacing.html
and hence is more forgiving of the indexing system coming out of adjustment.

i agree with your affordability conclusions. this will not be the most affordable bike, but that’s not the objective — as near as i can tell.

i think 7 speed hub bodies have approximately the same width as 8/9 speed hub bodies and therefore offer no dishing advantage. i think this because 7 speed hubs are narrower end to end than 8/9 speed hubs. aren’t all 7 speed hubs spaced for 130 mm dropouts?

i think the best idea is to use a 7 speed cassette with a spacer on an 8/9 wheel. it’s commonly available and it offers advantages of both worlds.
5 MIchael on Jan 31st, 2007 at 1:38 pm

I didn’t realize the .2mm difference due to manufacturers claiming interchangeability with chains between 7 and 8 speed systems. Are they more sensitive to adjustment? in my experience, maybe. By the 1/16 twist of a barrel, perhaps. Not nearly as dramatic as the difference between 8 and 9 (7-8 is .2mm, whereas 8 to 9 is .34mm, nearly twice).

But come on man, if you’re gonna site Sheldon’s site, please understand the terminology you’re throwing around…look up the terms dish and cassette body, and understand that mtn. hub spacing is 135mm, not 130mm (road).

When you use a 7 speed cassette on an 8-speed body, you’re forced to use a spacer, which negates any wheel strength benefit you may have achieved by opting for the 7 speed system.
6 nathan on Jan 31st, 2007 at 2:37 pm

i do understand my terminology. 7 speed mtb hub spacing is 130 mm. you’re looking at the 7/8/9 speed spacing. i don’t think they make 7 speed dedicated hubs for 135mm dropouts, but i don’t really know.

and slight bends in your derailleur hanger will compound the spacing sensitivity. i think this is a pretty big deal, because slight bends are very common and it seems equally common to have a 9 speed bike shifting well on one side of a cassette but skipping at the other side.
7 MIchael on Jan 31st, 2007 at 2:59 pm

7 speed 130? No. Not always.
I built bikes in the 7-speed era, and they didn’t have 130mm rear spacing. Maybe I came in on it late, maybe the 1984 stumpjumper was 130, but back when i started in a shop, it was 7 speed and 135mm.

Yes, slight bends in your hanger compound the sensitivity. That’s irrelevant to the 7-8-9 speed argument. That’s specific to any geared bike, which just points to the fact that if you want a bike you don’t have to work on much, go get a rigid singlespeed.
8 nathan on Jan 31st, 2007 at 3:21 pm

i don’t think bends in the hanger are irrelevant, because 7 speed would be more tolerant, which is the point. singlespeed is more reliable but i don’t think it’s within the scope of the project. i’m not sure why i think that though maybe it’s because singlespeed is less beginner friendly, or maybe it’s because the project is aiming higher. the original vision (i.e. the first posted build kit) is multi-speed. it seems to be a given part of the spec.
9 MIchael on Jan 31st, 2007 at 3:25 pm

I think a bend in a hanger is irrelevant when talking about 7 and 8 speed. The difference is .2mm. It’s just not going to matter… if you’re having to tune the derailleur, you’re going to have to do it with either setup.

I guess this all brings me back to the original point: what IS the point of this project?

Right now it seems like an exercise in educating people new to riding on why products have developed in the way they have…
10 nathan on Jan 31st, 2007 at 4:18 pm

i can’t offer an objective reason why the difference is considerable (or not considerable), but i think that it is. so i’ll start pulling stuff out of my ass

let’s say 0.2mm * 7 speeds = 1.4mm further that your derailleur can be out of whack before causing shifting problems. if it needs to be within about a 3mm window to begin with (which is what i’m estimating) i guess that’s 50% more you can bend your derailleur before it will mis-shift.

i guess the reason for this is that the on-center spacing is larger while the window of good chainlines per gear remains the same.
11 nathan on Jan 31st, 2007 at 4:20 pm

i had that last part backwards i think. not that it makes much sense either way.
12 MIchael on Jan 31st, 2007 at 4:21 pm

While I disagree that singlespeeds are not viable for the entry-level rider (insert quote from numerous girlfriends over the years, “I just don’t want to think about shifting! It’s confusing), I can see giving that one to you.

But if you’re going to follow that mentality, then I don’t see how this build can include a rigid fork. Arguing for gears because they make it easier is the same reason you can’t spec a rigid fork.

But given the objective of the project, spec’ing a rigid fork is probably the only way that the price will be anywhere on the lower side of $1000. But that price has just eroded the entire point of building an entry level bombproof bike. But that idea got lost when a $500 frame was chosen.
13 MIchael on Jan 31st, 2007 at 4:26 pm

yeah, that math doesn’t make any sense.
14 MIchael on Jan 31st, 2007 at 4:37 pm

And the project still doesn’t make much sense…pseudoscience at its best…

“We can build and test a bike that will be more durable than your normal entry level bike and will better serve the industry.”

To what “normal entry level” bike are we comparing this to?
Are they supposed to cost the same amount?
How are you measuring durability?
Has anyone participating in the test had any prior experience with 7-speed?

It seems the primary focus of this project is harking back to the day when 7-speed was the answer to everyone’s problems. If that’s really what you want to get at, why not just take 2 bikes, exactly the same, off the shelf.

keep Bike #1 as 9-speed.
retrofit Bike #2 with 7-speed.

Compare, contrast. Keep it as scientific as possible…
15 nathan on Jan 31st, 2007 at 8:02 pm

confusing math notwithstanding, wider spacing, more tolerant. this project, while it will not bring world peace, will advance the understanding of what a more durable entry level bike could be. there’s a spectrum of mountain bike accessibility, from full rigid singlespeed to full suspension geared, this project just aims at one point along that spectrum. to comdemn it as pseudoscience is to misunderstand the goal. even if this bike were built with a $1000 ti frame it would still make the case that an entry level bike can be more durable than what is otherwise available — because it’s easy to see that an affordable frame could be substituted. the aim here isn’t to engage in laboratory testing, correct me if i’m wrong but it seems that the goal is to spec a sturdy design and see how it goes.
16 jason on Feb 1st, 2007 at 9:32 am

MIchael,

Don’t try to understand it as it doesn’t make sense to me either. Just appreciate it as another bike.
17 miketually on Feb 1st, 2007 at 10:51 am

You could also argue that the cost of certain components would come down if it was proved that there was a market for it.
18 Tim Grahl on Feb 1st, 2007 at 11:28 am

Hey Michael, Nathan and everyone that commented on the original post… I appreciate ya’ll weighing in on this project.

As blogging goes we have the opportunity to post stuff as we’re forming it behind the scenes which means it’s not always in the clearest form at first. We’ll be standing by most of our original specs and ideas, but we’re working on explaining our goals and choices a little better.

That said, we’re not jumping into the fray just yet on SS vs. geared, Instigator vs $50 frame, 7spd vs 8spd vs 9spd, etc etc. We’ve decided to touch on each of these topics on their own and will in the very near future give a more clear reasoning behind each of our choices.

So just around the corner look for a more clear mission statement for the project and then an opportunity to discuss each of the choices we’ve made.

We’re excited about this project and the discussion it’s causing and will cause. Our goal for this project and everything we do is to show people options and make sure everyone gets to make informed choices.
19 nathan on Feb 1st, 2007 at 4:35 pm

so ted, let me ask you this…

i have a square taper crankarm (indeed, non drive side) that has become self loosening. do you have any advice for fixing the problem? i’m thinking disassembly, degreasing, and careful reassembly may help. though i’m worried that once the galling has begun it is irreversible though, is this so?
20 Peter K on Feb 2nd, 2007 at 3:16 am

It looks like the project is trying to buck as many current trends as it can, and so it’s trying to be anti-trendy at any cost. Thus, instead of 9spd vs single speed (which is a growing trend), dig 7spd out of the box. Granted, with this logic I feel like my old set of 27 inch/6spd wheels would trump, so thank goodness for a little bias for practicality.

I like the idea of going against the current trends- I’m appalled at the scant choices for a decent, new square taper bb for under $50. My current set of Sugino Impel cranks are still in decent shape, why do I have to start weighing the choice between a new GXP crankset and a Phil Wood bb? Maybe even an ISIS drive set on closeout? Why isn’t ISIS good enough, now? Many of the current trends seem to focus more on bling than on staying affordable/practical to maintain.

I have a preference for xc bikes, so one trend I dislike is all these entry level bikes with huge amounts of front suspension travel and super-slack geometry. I understand the pogo-stick fun factor- but for most of us, zipping around on errands and most trails probably won’t need the boat-like suspension float (bobbing) most of the time. So if this were my project, I would’ve looked for a more traditional xc frame. However, the Surley frame is very non-trendy looking, and has a rigid fork. Plus, it’s steel!
21 nathan on Feb 2nd, 2007 at 8:08 am

i think isis is good enough now, in what way is it not good enough? the reason dura-bike chose square taper was it’s purported extra longevity.
22 Guitar Ted on Feb 3rd, 2007 at 1:44 pm

Hey all:

Thanks for weighing in. I haven’t been over here for a bit, but Tim gave me the heads up, and what he said here in the comments that we are going to do will help clear up alot of the misconceptions here.

A lot of effort has gone into the commentary on the 7-8-9 speed thing. I would like to say that I have worked on, and ridden all of this and I have some opinions on why the current systems are failing the “ordinary” mountain biker. We’ll get into that later.

Basically, the idea behind this project is to point out how this failure to serve the needs of average trail riders is fixable. For example, as Michael alluded to, 9 speeds are being crammed into the same spacing as seven speeds used to be. Less material on cogs, since they are thinner, means they wear out faster, along with the chains, and chainrings. This isn’t good for the sport. It’s discouraging, and it’s starting to rub folks the wrong way. I see it at the “street level” every day.

We could have used a “cheap” frame set, but we know that the Surly instigator is a tough, do all frame that we can utilize in many different roles to help us in this endeavor. As some of you have caught on, it’s not about making the strongest, cheapest bike we can. It’s about making a reliable, lower maintenance mountain bike that you can just grab on a whim and ride the crap out of for a long time.

Single speed? Yes, that would be a logical conclusion if we don’t take into account that we are trying to appeal to a wider sector of people here, and quite frankly, it avoids wrestling with the “real” problem, which is higher tech for the sake of racing. Not that there is anything wrong with being a racer, but the technology used for racing isn’t fitting the needs of “everday” riders, in our opinion.

Thanks again for all of your interest. We will be dissecting the project as it goes along, so make sure you stop by and check it out from time to time. Hopefully things will start to take shape in a little clearer fashion from here on out.
23 nathan on Feb 6th, 2007 at 1:02 pm

well ted, what’s the poop? am i square taper out of luck? here’s my question:

so ted, let me ask you this…

i have a square taper crankarm (indeed, the non drive side) that has become self loosening. do you have any advice for fixing the problem? i’m thinking disassembly, degreasing, and careful reassembly may help. though i’m worried that once the galling has begun it is irreversible though, is this so?
24 Guitar Ted on Feb 7th, 2007 at 8:09 am

nathan: The bad news is once you tweak a square taper interface, even just a little bit, the crank arm is junk- no good. It’s best to start with a new left arm, and torque it to 25-30 ft./lbs or to the crank arm manufacturers spec. Make sure to double check the torque setting after a few rides.
25 nathan on Feb 7th, 2007 at 8:12 am

drat, that was a nice arm too, one of the old race face cnc’d yellow turbine jobs.
26 jgsatl on Feb 10th, 2007 at 9:55 pm

i love my instigator frame. i’m using it in a x-country setup at the moment. it’s heavy…but seems very tough and doesn’t kill my back the way an aluminum frame does.

i like the frame for it’s relative compactness (i run a setback post and just ordered a long stem) and ability to take a wide range of fork lengths. it’s designed around a 100-130 fork i think…but i’ve read of folks running an 80 on it and up to a 150 with no harsh effects.

the downside is that the somewhat oddly shaped frame can draw a little attention on the trail. i’m old, fat and slow….attention is the last thing i need (unless i’m laying in a ravine or something!!).
27 jgsatl on Feb 10th, 2007 at 10:20 pm

oh….and for cheap, reliable components….i went with a set of $89 32h sun rhynolites on xt hubs that came with skewers and disc adaptors. a great deal, imo…as they’ve held up nicely. i also have had great luck with the $85 set of fsa megaexo cranks. the rest of the bike is a hodgepodge of things i already had, except for the longer stem i have on order and marzocchi fork i got for christmas. front der is an lx and rear is an x9 mated to x9 shifters. headset is a cane creek s3….which has the terrific design of the s6 but with chromoly bearings instead of aluminum, from what i understand.
28 Kevin on Apr 19th, 2007 at 2:04 pm

BTW…I recently saw my first SURLY bike and was transformed to some sort of mutant, mountain bike alien! I dunno…coulda been the big, fat tires and all of the stuff I’ve only heard about…like whispers of demon riders and stuffff!

The bombproof frame arrives…

28 Responses to “The bombproof frame arrives…”

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