A4 scale = 70%
|
|
A4 scale = 70% |
EGGring Ovals page 2
Every Oval EGGring is unique, custom-made to suit your cycle and your style of riding. The following notes will help you to complete the Order form which will provide us with all the details we need. Please contact us if you need further advice.
Ideally you should choose the same numbers of teeth as you would for round chainrings. However the smallest Oval that can will fit your cranks will be a few teeth larger than the smallest round chainring (see Minimum size). We will check your order carefully and let you know if there are likely to be any problems.
This specifies how oval a chainring is, as the following 38 tooth chainrings show:
 |
 |
 |
 |
| 0% ovality (round) | 10% ovality | 20% ovality | 30% ovality |
(note: if the round ring isn't round then your computer's screen resolution
is wrong - eg. don't use 1280 x 1024 with a traditional 'crt' monitor)
Round chainrings (0%) work well when you spin the pedals fast (a high 'cadence'), whereas large ovalities suit slow pedalling rates. So your smallest chainring, used for plodding up hills, should be more oval than the others. You can mix round and Oval on the same crank but, to maintain your rythmn after shifting gear, don't exceed a 15% difference between adjacent chainrings.
The table below gives various recommendations. Choose the ovalities which match your style of riding...
| type of cycling | outer chainring |
middle chainring |
inner chainring | |
|---|---|---|---|---|
| road racing | double chainset fixed-wheel |
0% 7% |
- - |
7% - |
| road touring | double chainset triple chainset hub gears |
20% 20% 10% |
- 30% - |
30% 40% - |
| off-road | racing touring trials |
0% 20% 30% |
7% 30% 45% |
14% 40% 70% |
| BMX | 10% | - | - | |
When you order an Oval, we ask you several questions about your cycle and riding style. Your answers will help us to get the orientation correct. (See Crank position / orientation for more information about this.)
Because Ovals must be mounted correctly, each one is permanently marked with the correct crank position for your setup. This won't necessarily be the same as that for a different cycle or another rider. In particular, Ovals are orientated differently on standard upright bikes, small-wheelers and recumbents.
The next page answers some common questions about Ovals. For more technical information, see our Oval Technical Notes.
| © Chris Bell, 2004 |
continued on the next page... |
| HIGHPATH ENGINEERING Cornant, Cribyn, Lampeter, Ceredigion, SA48 7QW, Wales, UK phone / fax: +44 (0)1570 470035 (UK office hours only) email: 
|
 |