John Tolhurst
Zen MBB Master
It's a road bike Jim, but not as we
know it.
The Cruzbike Silvio
If there's a road bike rider out there that says he or she never gets a twinge in the neck or back or feels a little saddle sore then he or she is either telling fibs or is under the age of 20. Hardened roadies (they have to be) will tell us that it's all about proper bike fit. This is true to a point, but their point is minimizing discomfort, not eliminating it. If road bikes were truly comfortable there wouldn't be a queue at the massage tables after long rides. Yes, I know massage is partly about recovery, but what's with all the groaning and stretching?
If you're a roadie riding in pain or a roadie that wants to ride faster in comfort, you can start thinking about Cruzbikes because Australian ingenuity has provided the solution with a road bike that is aerodynamically faster than a standard road bike; but with comfort. You can ride this bike as far as you like and still father children the next day...or even the same day if you have the energy...which is highly likely.
At first glance the Silvio looks like a road bike. Twin 700 wheels, SIS shifters, pretty standard wheelbase, racing tyres. It's fairly obvious that something strange is going on though because the chain wheels are hung out the front. If you look closely you'll see a high pressure shock
absorber in the fork tube and look even more closely and you'll notice carbon fibre beams here and there. Under the lightweight seat there's a titanium spring to absorb road shock. This is a true road bike with suspension front and back, but it's hard to see because it's cleverly engineered into the design.
I'm going to digress a little here. The story of why I happen to be extensively road testing the Silvio is long and boring. It's enough to say that I lusted after this design when it was first released, but already owned a couple of recumbents. At the time I wanted a faster recumbent than the P-38, but I don't have the resources to keep buying and selling bikes on the odd chance that one may be faster. I've bought a few and been badly disappointed. The Silvio caught my eye because it's designed from the ground up to be an alternative to a standard diamond frame (DF) road bike. The MBBFWD, or moving bottom bracket front wheel drive design eliminates most of the problems that recumbents have. These are the problems that owners and manufacturers either don't know about or don't want to know about.
The Silvio eliminates basic problems in recumbent design
The first problem with recumbents and one that roadies notice first, is that too many are poor climbers. Recumbent owners can be a bit obsessive about their speed down hill or on the flat, but put to the test, the majority will get dropped by any half way decent diamond frame road bike on a decent climb - something with a gradient in excess of 6%.
The Silvio is one of the very few recumbent designs that climbs to the ability of the rider. The technical reasons are the triangulated chain stays, the lack of any idlers and the stiff fairly upright seat. There is no power sucking flex in the Silvio design. The Silvio rates among the top climbing recumbents.
The second problem with many recumbents is non standard wheel sizes. Most have different front and rear wheel sizes. That means you carry two tube sizes and can't borrow one off the guy next to you if you get more than one puncture.
Many recumbents have small driven wheels. This means that standard bike gearing is too low and you either need massive chainwheels with all the attendant problems of derailleur cage limits or you have to fit a geared hub and lose 2-4% in transmission losses (which is added to the 1% or so sucked up by the power idler and sometimes another few percent by a soft mesh seat.)
On most recumbents a change in rider means a change in chain length and crank tube extension. This can't be done instantly and requires tools or quicklinks in the chain. The Silvio design adjusts to different height riders quickly and the only tool required is an Allen key to slacken and tighten the pivot points in the front frame.
Rear wheel drive recumbents require about three standard lengths of chain. At todays retail prices for good chains that can be $300.
The Silvio has none of these problems. The rider sits at a similar head height to a DF, using bog standard bike gearing into bog standard 700c wheels. Although not as aero as some radical recumbent designs the Silvio still has an advantage over DF riders 'on the hoods.' By my calculation it will take a mini paceline of at least three drafting road bike riders to neutralize the Silvio advantage... and of course a Silvio can draft too....!
To quote Kim Tolhurst ,(Geelong Advertiser 2010) http://www.cruzbiking.com.au/GT275
"The FWD retains the triangular drivehouse but doesn't have the very long chain to the back that recumbents do, and that vision, while slightly lower, is still at a height where people expect to see a cyclist amongst traffic. Plus the head is balanced in almost the same posture as driving a car. It's totally natural way to see the road ahead and allow you to comfortably and safely talk to a fellow cyclist."
There are no perfect bikes, so what are the disadvantages of the MBBFWD? The most talked about and probably least important is the learning curve. Since Cruzbike have posted instructional videos on their web site, anyone can learn to ride these designs in a few minutes. My first experience with MBB a few years back was without tuition and I found it frustrating. Recently I was shown how to ride the Silvio and got on it and rode off immediately.
Riding a MBB design is different. It's no good pretending it isn't - but you forget the unconventional transmission during a short ride.
The Silvio as I rode it weighed around 12 kg. This is slightly lighter than my P-38 but obviously heavier than the latest featherweight DFs. I don't know how lightly the bike can be built up but an educated guess is a little under 11 kg. That would require extensive study at the Weight Weeny web site and some spare dollars.
The Silvio eliminates medical problems caused by road bikes.
ED or erectile dysfunction is common in cyclists and more common in amateur and overweight cylists. There are numerous studies and articles discussing ED.
Neck and back pain are common in cyclists in spite of the common statement that it's all due to poor bike fit. It's still common! The Silvio doesn't cause ED, neck or back pain.
So what's the Silvio like to ride?
Fast and comfortable.
It's fast because it's aerodynamic and it's transmission is the same as a standard road bike. .
It's comfortable because of the very elegant engineering.
The rear horizontal stays are carbon fibre beams which flex to absorb road shock. The design eliminates sideways flex while allowing the rear wheel to ride over bumps. Under the top seat mount is a strong titanium plate spring. This isolates the rider from the rear triangle movement. At the front, the carbon fibre beams are repeated and the front fork is a mono shock. This is unique and very effective. You won't get numb hands or wrists, even on the roughest chipseal. There will be no saddle pain 'cos there's no saddle!
The swiveling front end is disconcerting to start with because the chainwheels want to swing around make love to your leg when you get off, but you quickly learn to stand behind the handlebars and keep the steering under control.
The Silvio is easier to mount and dismount than any other bike I've owned or ridden. You can pretty much walk forward over the seat and sit down. For older riders with possible hip problems it's just one more advantage.
Conclusion
I love this bike for the elegant frame design, the sophisticated suspension and the efficiency. Unlike a DF or conventional RWD recumbent the design gives some upper body exercise. The Silvio is a true alternative to diamond frame road bikes.
(Disclaimer - I have no connection with Cruzbike in any way. I am not employed by them and have not received payment for this review.)
