INTO THE RIDE #10
A High Performance Rocket
The Rocket. What a great SWB. You can buy one for 10 Bens, and have one of the best values on the market. In stock form it is a fine bike, inherently light and a blast to ride. So what could be better? Well after the fun we had souping up the V-Rex, we just had to have another project.
The approach would be close to the V-Rex, shave some weight, and add hot wheels. The only problem is the rear wheel; there are a limited number of choices. A quick call to Velocity and our good friend Mike was busy fabricating a matching rear to front
Thracian. The rear wheel arrives seemingly moments after the phone is hung up, good service Mike! With a set of Schwalbe Stelvios we are on the way!
The first step was to modify the handlebars. As you may recall in Into the Ride # 7 we created a new riser from the existing by knocking off the cable stops, and shortening it at the bottom 2.5″. Do the same for the Rocket, but test fit first before cutting, your bar height may vary. Cutting 2.5″ off the bottom of the riser places the center of the B-37 bar at 19″ off the top of the frame, use this for reference.
I prefer this bar set up over the in the chest position, and find I do not miss the flip-it at all. I suppose this is because there is just enough room between bar and seat for me to mount. This could be tight for some, if such is the case use the flip-it, and still modify the riser.
As mentioned the B-37 bar is used again, this bar geometry is finding popular appeal, and is the best bet if you are wanting a bar change and are not sure which.
Be sure to get the threadless fork tight against the headset, you will not have the star plug and cap to take up any play. Lightly tighten the clamp in place over the fork stem and tap in down against the headset. This essentially does what the cap and star nut do, by using clamp friction and a mallet.
Refer to Into the Ride Article #7 for more details on modifying and adapting the shortened riser.
To further spice it up we install the new 20″ aluminum fork. This reduces the weight by a ¼ pound! The net result will be about a full pound lighter, but the reduction in weight is only part of the fun.
With bar and fork complete and the wheels installed it a short work to set up the cables. Discard the short lengths of housing from the first most forward stop and set up all four cables with continuous housing. If you are careful you can recycle the cables and only need housing. Use the neoprene wrap to contain the cables.
Check the brakes, they will need adjusting against the rims, since the Velocity wheels are about .40″ less in overall diameter.
I am running the Shimano Ultegra 12-25T cassette; no change to chain length was needed, darn! Less chain equals more speed. It seems to shift fine with the Rockets stock 7.0 Scram. Maybe I will go all out to see how light I can get a Rocket with carbon seat and lighter components, but for now it will be fun to see how these changes affect performance.
Riding the souped up Rocket was sheer fun. The acceleration and climb are improved, and holding a little higher cruise speed was easy. The coolest thing was we did not lose the neat handling of the Rocket. It is still the sweet ride, but the bars seem for me to make it even sweeter.
I love compact nature of this SWB. This is of course a direct result of the 20×20 wheel combo. Rockets have had an impressive speed record, you may know of or heard of riders who have turned in good speeds on rides up against much higher cost, or extreme for speed bikes. Part of why this occurs is simple; if the bike is a good fit you ride it better. The other part is despite the science of rolling friction saying bigger is better; the 20″ wheel is not that inefficient. Take that same wheel and pump up the pressure, cut the weight, improve the bearings, and decease the profile, and you have an even more effective wheel. In fact if strict science would be applied, and you measured an optimized 20″ wheel against the not so optimized (fatter tire) 26″ you may find it very close in rolling friction. One other factor comes into play, whatever makes a 26″ wheel better rim, hub, and tires wise, will also make the 20″ wheel better by an increasing factor, since the wheel will always be inherently lighter. Less turning mass equals less required energy.
What is the point to increasing a bike’s performance? Is not the stock out the box average bent indeed a great steed as is? Sure, but there is great fun in expanding performance, I guess just for the sake of seeing how far we can go. So despite the critics I will continue to quest for more zoom factor, more lightness, more trick components, and not even wavier on the point if it all makes sense or not. It’s just plain, clean fun, folks! Ride safe and see you next month.