Monday, 31 August 2015

ElliptiGO Disc Brake conversion + Dynamo Hub

The ElliptiGO is a great machine which is extremely well-built and has served me well for 4.5 years and counting. The only modifications I've done to my 8S in that time is to convert the rear geared hub to an 11 speed and upgrade the chain ring to a 54 tooth. However I've since replaced this with the original chain ring (53 tooth) as the replacement lasted less than 12 months before identifying 4 broken teeth just 2 weeks ago. Last year I also upgraded the standard brake calipers (front and back) from the factory Avids to Shimano XT’s.

But anyone that read my report of the Pendle 600 ride will know that my rim brakes didn't survive that test. This wasn't really down to the quality or inadequacy of rim brakes under 99% of conditions you will find, but it’s not every day that you find yourself descending 30% gradients for hours on end. This one experience left me asking what the available alternatives were. Disc brakes and the proven benefits that come with them was the obvious answer. Hugely enhanced stopping power and no fade.

Enter stage left – Mr Andrew Nuttall (ElliptiGO Preston team) who has quietly gone about converting his own ElliptiGO with a front disc conversion. I watched on with much interest and Andy kept me fully informed as to its success. In short – it worked brilliantly. I was sold on being Andy’s first test subject.

Andy Nuttall - ElliptiGO Preston - Paris Brest Paris
What follows is a pictorial of the full conversion. Because the conversion requires a new wheel build I also took the opportunity to upgrade the hub to a dynamo hub which generates power for a dynamo specific LED headlight as well as charging mobile phones and GPS devices. This is also covered below as well as a full costed list of the parts and components used in the conversion.

I welcome any questions and will answer them if I can.

The Parts

  • New standard ElliptiGO fork (pre modification)
  • Velocity Aeroheat 20" Rim (1.5 32H)
  • Shutter Precision (SP) Dynamo Hub PD-8 (6V 3W output)
  • Standard Shimano skewer 
Velocity Aeroheat rim - stunning!

Rim spec - 20 x 1.5  32 Hole
Shimano twin-piston hydraulic brake lever & caliper
Shimano disc brake pads
Extended 1700mm brake hose to reach ElliptiGO handlebar

Fork modification

The fork modification is the major element of the whole project because without it there is simply no way to attach the disc brake calliper to the fork. The work on the fork was undertaken by Steve Goff Cycles & Frames. and designed with the requirements from Andrew Nuttall. Steve is a master craftsman with 30 years of experience so there is no better person to tackle this unique ElliptiGO project. The project required Steve to manufacture a bespoke bracket for the Shimano disc brake caliper that was then brazed onto the steel chro-moly fork. Steve also removed the existing stays for the rim brake calipers as they were redundant. This provides a very ascetically pleasing clear finish to the top of the fork. Steve also brazed on eyelets to thread the wiring for the dynamo hub, as well as a c-clip holder for the hydraulic hose. The results are below.

New caliper bracket brazed onto the ElliptiGO fork
Caliper bracket, dynamo wiring eyelets, and C-clip holder all brazed on
Dynamo eyelets up close (Shimano brake lever in shot)

C-clip holder for hydraulic brake hose
First test assembly - It all fits!
Sprayed up fork - courtesy of Andy Nuttall Custom Paints Ltd! :-)
Perfection - A thing of beauty and skill
Andy Custom Paints - fork prepared for the ElliptiGO Swoosh!
Andy Custom Paints - keep the masking tape industry afloat 
ElliptiGO swoosh added
Final Swoosh. Great job Andy Nuttall!
The Assembly

SP Dynamo hub PD-8 and brake disc
SP Dynamo Hub PD-8 in-situ - a fantastic bit of kit!
Dynamo and disc in-situ 1
Dynamo and disc in-situ 2
Dynamo and disc in-situ 3

Shimano hydraulic brake lever in-situ

32 spoke wheel built and assembled - I opted for semi-wave brake disc

Assembled built wheel with Shimano caliper attached  
Bracket and caliper up close
Final assembly on the ElliptiGO - incs Schwalbe Durano Plus 1.1 tyre
Alans BMX who calculated the length and supplied FREE spokes!!! Thanks guys :-)

Dynamo headlamp + generator hub

I did a lot research on dynamo hubs and headlamps. There is a lot of choice out there so it was important to get the right set up for the ElliptiGO and at the right price. A great resource to read up on headlamp and dynamo technology is PeterWhiteCycles.

There is also a very good article from CTC comparing the Top 5 dynamo hubs here. This article includes the SP dynamo hub PD-8 that I purchased. A key factor in my decision was the average speed that I would be riding my ElliptiGO. Dynamo hubs produce different output (Watts) at different speeds. Paris Brest Paris was a major factor here and I knew that we would be looking to ride no faster than 15-18kph. And the ElliptiGO is inherently a lot slower than a standard bike. And remember that you will also only being using the light at night when you are unlikely to be riding that fast anyway.

SP Dynamo Hub PD-8
The graph below is really helpful to understand the output of different dynamo hubs. It includes the most popular dynamo generator hubs on the market. The market leader is the SON Delux which retails at £180. However compare the Watts generated at 15kph and you can see that there is no difference between the SON and the SP Dynamo which is half the price. So for my needs the SP was perfect.

Output (W) for different hub generators
You also often hear people asking whether a dynamo significantly adds to the effort required to pedal along at a given speed (known as 'generator drag'). In the old days this was certainly true but the new breed of hubs are so good that you would be very hard pressed to even tell they are on. The chart below illustrates this by expressing the extra effort required to ride (with the hub switched off and on) in ascent (ft) per mile.

Dynamo hub generator efficiency
The SP dynamo that I purchased equates to an extra 4.5 feet of ascent per mile in effort. The CTC article linked (from which these graphs were published) go into more detail if you are interested.

When it comes to headlamps there is a lot of choice. After much research I opted for the Busch & Müller IQ2 Luxos U headlamp which received rave reviews, with many folk on the Audax UK facebook group singing its praises. One of the key factors when deciding on the lamp is whether you want just a standard light, or some of the extra bells and whistles that come with others. The Luxos U is a very clever bit of kit and incorporates a cache battery which is charged by the dynamo hub. So as well as using the battery to power the light it can also be used to charge other devices. This is what sold it for me allowing me to keep my mobile phone charged throughout Paris Brest Paris, and it worked perfectly. 

I shot the video below on my first night test ride. It compares the Luxos U headlight versus my existing battery powered Hope Vision 1 lamp.

Video of my test ride demonstrating the B&M Luxos U headlight in action

Pictures below.

Busch & Müller IQ2 Luxos U LED headlamp
Busch & Müller IQ2 Luxos U headlamp - provides a car headlamp shaped beam
Busch & Müller Luxos U headlamp affixed to ElliptiGO fork fixing point
Busch & Müller Luxos U - perfect fixing point for the lamp
Really nifty remote button to control the Luxos U lamp 

Very handy for charging mobile phones, GPS devices and bluetooth speakers! :-)
Remote button affixed to ElliptiGO stem
(Button couldn't mount on the handlebar as it came with a short cable - I didn't realise they do it in 3 lengths!)
Final Set-up :-)
At night after my first successful test ride

Final full set-up for Paris Brest Paris
Headlamp & dynamo doing its job brilliantly on Paris Brest Paris 2015

So how did the SP hub, B&M Luxos and disc brake perform on PBP?

In a word - brilliantly! I'll start with the hub and light set-up. In the day I was able to charge my Garmin etrex30 from the dynamo and also keep my mobile phone topped up. At night the dynamo was still capable of powering the Garmin whilst simultaneously powering the B&M Luxos headlamp. The illumination on the road ahead was absolutely superb with both a long and very wide beam (much like a car headlight pattern). Night riding was a real pleasure to the point where I was actually looking forward to using the light. At one point I rode along fellow ElliptiGOer Bill who also has exactly the same B&M Luxos light, but with the SON Delux hub. The SON costs twice as much as the SP hub but there was no discernible different in the light output at all. Result! I would definitely recommend a dynamo light set up to anyone that wants better light output, no hassle from batteries and the ability to power other devices. Note however that not all light have a cache battery with this capability.

Now on to the Shimano hydraulic disc brake and I also can not fault it. I'm glad I made the modification purely because it is a bit different to the standard set up. PBP certainly wasn't a flat course and so it allowed me to test the brake on all gradients. I had complete confidence in it and the key difference from a rim brake is that it doesn't fade under braking. The bite is instantly there and squeeze just a little harder and the ElliptiGO was coming to a complete halt in seconds. So a BIG thumbs up! The only consideration to take into account is that a hydraulic brake is not as easy to service as a rim brake, but on the other hand it should require less servicing. The pads pop out and can be replaced in seconds. It was only the initial sponginess of the brake that gave me doubt, but after a re-bleed from Grant (qualified bike mechanic) it was sorted. I just need to learn to do this myself.

Cost breakdown suppliers

My huge thanks to Andy Nuttall for making this project possible. Thanks mate! 

Note: Please contact Andy for advice if you are thinking about this upgrade due to the Safety implications of such a modification. Andy can provide full details of the design if anyone else would like to do the modification themselves. 

Thanks also to Broadgate Cycles, Steve Goff Frames, and Alans BMX.

Fork Disc Brake conversion

£47 - Velocity Aeroheat rim - Ordered from Bricklane Bikes, London
£80 - Standard ElliptiGO fork - ElliptiGO Preston, UK
£10 - Shimano skewer SJS Cycles, UK
£45 - Shimano twin-piston hydraulic caliper and brake lever kit - Broadgate Cycles, UK
£7 - Shimano Mount Adaptor Rear Post to IS - Broadgate Cycles
£20 - Hydraulic hose 1700mm - Broadgate Cycles
£10 - Hydraulic oil and bleed kit - Broadgate Cycles
£13 – Shimano Wavy 160mm Disc - Broadgate Cycles
£20 - Wheel build - Broadgate Cycles
£145 - labour on fork conversion - Steve Goff Frames & Cycles, UK
FREE - Spokes - Alans BMX, UK

Dynamo hub + light

£95 - SP Dynamo hub PD-8 (32H) - SJS Cycles, UK
£85 - Busch & Müller Luxos U - Rose Bikes, Germany

1 comment:

  1. Hey! great article. very helpful. The information is very well written and very well explained. Thank you for sharing. carbon fiber bicycle rims