So todays question was "I just bought a Supercross ENVY BLK, but I don't know what parts to use to build it."
And we thought this was an easy question, and then we thought about it, with todays new Tapered Headsets, Different BB types, Different Dropout types etc... that it may be a bit confussing and is only going to get more confusing. Hopefully this little guide will help answer everyones questions and make it easier for you to do your builds.
Please note that this article is for the Supercross ENVY BLK, Pro size and larger frames. Meaning that it is for the Pro, Pro Plus, Pro XL and Pro XXL. We will do another article for the smaller ENVY BLK's in the future. Also please note that as we are mentioning the ENVY BLK specifically, this all transfers over to the ENVY v5 Pro size and Larger frames as well.
Where to start, how about the headtube and the headset.
1. The Supercross Envy BLK uses an Integrated Tapered Headtube. This is one of the easiest headsets to install. There are great headset out there in this type from Speedline, Cane Creek and others. If you want the Technical specs it is a S.H.I.S 42/28.6 Top and a 52/40 Bottom.
The top bearing just sets into the frame, always apply a thin layer of grease inside the headtube where the bearing will sit. The Bottom bearing takes a slight press fit. Again be sure to grease the frame or the bearing before inserting it into the frame to insure proper seating and eliminate any creaking. The angular contact bearings have bearing seats that are a 45 degree angle to make sure that they fit into the headtubes bearing seats, and a nice layer of grease gives a perfect cushion and allows them to easily move into the proper position.
When installing the fork race, if you buy the Speedline Sealed Bearing Headset it comes with two bottom fork races. One that fits the Supercross SLT Carbon Tapered Forks and also one that fits all 1 1/8" BMX Pro Forks. So you can use a Supercross Pro LT Fork, an Answer Dagger, or any 1 1/8" fork. By having both races included with the headset it makes the Tapered Headtube extremely versatile as you can start with a std. 1 1/8" fork and when you are ready you can move up to the performance advantage fo the 1.5 tapered headtube. But with the Supercross Tapered headtube, regardless of which fork you are running you still get the benefit of the larger, smoother 1.5" bearing on the bottom which helps stiffen up the front end of your bike to enhance stability in the gate and through turns.
Both of the headset races are alloy and are split so you don't have to have a press to press on the bottom race. Again make sure it is well greased when you install it and that the bearing side is also greased to maximize the ease of settling as the headset is tightened. Once you slide the fork with the bottom race and bearing installed up the headtube and through the top bearing, you will slide down the top split compression ring. This is also a good piece to have a little bit of grease on all contact areas where it comes into contact with the headset bearing. After the top split compression race goes on there is a thin washer that separates the race and the aluminum top cap with dust seal. This is important , as the washer eases the movement of the compression race against the top cap as it is being installed. Once you have the top cap in place you can install your headset spacers if needed and your stem. If you are using the Supercross SLT Carbon Steertube fork on your Envy BLK build it is recommended to put some carbon prep on the steertube before you install the stem and tighten the pinch bolts of your stem with a torque wrench to 6nM.
Next up we have the bottom bracket. There is alot of confusion in the BB world now, way more than in the headset arena. We at Supercross are continuing our support of the good old European Threaded 68mm shell. A lot of people question this position, but lets expalin why. On the Bottom Bracket, you have a lot of stress , torque and constant movement. People have been complaining for years on the BB30 about the creaking and constant feeling of being loose. PF30 is a little better, but not much as it is still a press fit function. BB86, BB92, they are all the same type of interface with a press in bearing. The Threaded Euro BB ensures a positive fit with the BB cups to the frame as they are threaded in, they lock down. it makes installation very easy.
Less movement, less flex, less creaking. The conventional Threaded Euro BB also allows you the option of many types of cranks and spindles unlike some of the other BB styles. You can use a 19mm spindle for Profiles, a 24mm spindle fro Shimano DXR's, and a 30mm Spindle in the Speedline Carbon cranks. All work with your ENVY BLK with no modifications or funky adapters.
And installation is a snap, grease up your cups, thread them in and away you go. It doesn't get much simplier than that.
Part of what makes it so easy is that your BB shell is pre faced and there is no warpage due to heat treating, since it is not a welded frame structure like an Aluminum or Cro-moly frame, there is no heat warpage. Our 1 pc BB shell is custom made spcifically for our ENVY BLK and is optimized to let the carbon bite in and keep it secure. And with it's CNC machining you can thread the cups in by hand and only need your BB tool to give it a final lock down. As with all contact points, be sure to grease the threads on the cups before you thread them in. Also make sure you pay attention to the Crank MFG's recomendations on spacing and any washers.
Our ENVY BLK frames as with most BMX frames use a 68mm shell spacing. This is important to know so you can ensure you get the proper spacing for your bearings and spindle type.
Next we move to the seating area, this is the simpliest part of the Supercross ENVY BLK, it uses a std. 1 1/4" ( 31.9mm ) clamp and a very common 27.2 post. No strange sizes, no aero posts, etc... all stock off the shelf items so there is a wide arange of options for you. Pivotal, no problem, railed, east, carbon posts, you got it, One piece combo seats like the Speedline and Tangent ones, easy. Common sizing to make it easy.
So with that done we move on to the rear dropouts. It seems many people are scared of the carbon dropouts. And there is no need to, they are strong. We do have titanium scuff plates on the inner and outer surface of the dropouts jsut to prevent you from digging the axle nuts into the carbon, if you somehow lose one of the titanium scuff plates, which we never thought could happen, but we have heard of it happening, just be sure to use a flat washer on the inside and outside of your dropout to spread the stress and to keep anything from digging into the carbon.
People also wonder about the size, it is a 15mm dropout to optimize the ride handling of the frame. If you are building a performance race bike, the 15mm axles are the way to go as it offers a stiffer rearend and transfers power better. And while there are a ton of great 15mm hubs on the market, the Supercross Quick Twitch, the ONYX, Profile, Stealth amongst others, some peopel are still wanting to use the 10mm rear axles. When Jeremy Rommel rode for us, he accidently ran the 10mm rear axle on his carbon fro about 6 months with no adapters, we don't recommend doing that, but it can be done and has happened with no damage being done to the frame. If you would like to do it properly we do have the 10mm - 15mm adapters that you can get to install any 10mm hub on to your ENVY BLK, but we do strongly recomend tha tyou use the 15mm axles for the most benefits.
We also recommend that you run chain tensioners on your Supercross ENVY BLK. we didn't go the built in route as some frames do as when we did FEA testing of our frame, one of the weakest points is the inner area of the dropout where the seat stay and chainstay join, so it didn't make sense to us to put a hole there for a chain tensioner. And there are plenty of great chain tensioners on the market. We do recomend the single bolt type that pushes the block into the dropout center as the 2 bolt ones that have individual allen bolts top and bottom seem to be problematic with the 15mm dropout slots.
Well that's it, now hopefully your questions have been answered on how to build your Supercross Envy BLK. When you build yours up be sure to share your photos with us so we can post it up on our gallery of readers rides.