aspiringcyclist wrote:So are you confirming that I could use a road bike or folding bike on the Lea tow path?
Yes – any bike would be suitable. That section of the Lea is very pleasant to ride with no barriers, if I remember correctly. I would certainly use it, but would be prepared to share the path with dog walkers, joggers and other cyclists, so I would factor in extra time.
Bike type: I agree with Tonyf33 – think carefully before splashing out as second hand will get you much more bike for your money. It will also have the advantage of looking less attractive to thieves who very often target universities. If you're planning to carry anything I would definitely look for a bike that has a rack, or fittings for one, as a rucksack on your back will be uncomfortable. Mudguards are a must – tow paths throw up even more dirt than the roads.
Folding bikes are a very practical choice for commuting – as mentioned, they can be kept indoors and taken on public transport if there's ever a problem. The down side is that they are less comfortable over longer distances and more expensive, although Bromptons do hold their value when sold on. Also, I think only Bromptons are allowed on the tube now as they fold the smallest. I would try a few out before deciding whether to invest in one.
Locks: Definitely invest in two – look for gold standard and buy the best you can afford. D locks are one of the strongest. You could also consider security skewers for the wheels and seatpost. Ensure the frame is locked to an immovable object and both wheels are secured. It's also advisable to lock the saddle, or even carry the seatpost with you, to avoid a very uncomfortable ride home
Spares & accessories: 2x sets of lights front & rear, 2x inner tubes, puncture repair kit, tyre levers, 1x track pump for home use, 1x good hand pump such as this one: http://www.topeak.com/products/Pumps/RoadMorphG
Practice changing an inner tube at home so you're already prepared if you get a puncture on the road – the odds are it will be cold, wet and dark
aspiringcyclist wrote:Do you think that my aversion to the main roads is justified because it seems that they are the only viable route when I can't use the tow path.
It's entirely down to what you are comfortable with and you should not feel pressurised to tackle anything that appears intimidating. Confidence comes with experience so once you are used to city cycling you might find you prefer faster and more direct routes via the roads. The TFL cycle maps are free to order and are very useful in working out quieter routes into London. Try out your route on a weekend in advance so you're not under pressure on the day. Some councils offer free one to one cycle training – I did this a while ago and can recommend it. There may be others at your uni who are already commuting from your area and willing to buddy up – having someone with you is always a big help.
Most of all, have fun finding your bike and cycling. Good luck