A few newb questions

[sswats]

Just was wondering a few totally random things.

1- Should the front gears be set at the highest possible or lowest, or it doesn't matter. assuming same ratio.
For example if set the front gear set to 3 back gears set to 4. Or front gear set to 2 and rear gear set to 8 and assuming that was the same ratio is there a difference in how easy it is to push the bike forward

Hope i've made that clear. I always assumed it was the same but thought i'd ask.

2- I've just started commuting 8 miles to work. I'm doing it in about 45 minutes on a mountain bike with slicks in London roads. how fast can you guys do 8 miles with same setup.

3-how useful are the pollution filters.

4-I bought a cheap argos helmet for £8.99, what advantages in terms of safety would getting a more expensive one be? or is it just a comfort difference?

5-any recomendations for a pump that i can use at home to get to 80 psi without resulting in RSI, but can also be carried about. for about £20.

I appreciate the help.

 

[punkypossum]

Top Peak morph .... they are £30 quid tho...

 

[Sittingduck]

Mini pump = Topeak MasterBlaster 15 quid
Track pump = Topeak Joe Blow Sport II 30 quid

Not sure on the other queries apart from the 8 miles / minutes one...
I do a 6 miler home and it takes me 25 mins give or take - I reckon about 32 mins for 8 miles but that's on a hybrid or a road bike. Wouldn't worry about your speed commuting in London, too many other factors to consider.

Cheers & Welcome
SD

 

[jimboalee]

1. If you find you have two combinations of ring/sprocket that give the same gear length or development, use the one which engages the most teeth on the sprocket.
The pull on the chain will be the same, so more teeth meshes will reduce the pressure on each individual tooth.

2. Don't worry about how long it takes, as long as you get there alive.

3. Polution filters with Activated Charcoal will filter out Nitric Oxide and Nitrogen Dioxide - The worst of the motorcar exhaust gases.

4. Not much.

5. Zefal hpr Graph, £18, Hawk Cycles outlets.

 

[Crackle]

1- Should the front gears be set at the highest possible or lowest, or it doesn't matter. assuming same ratio.
For example if set the front gear set to 3 back gears set to 4. Or front gear set to 2 and rear gear set to 8 and assuming that was the same ratio is there a difference in how easy it is to push the bike forward

You generally match your gears to the terrain i.e. Big chainring front, small cog rear would probably do you for downhill or with the wind behind you and then you'd use larger cogs at the back to make it easier as the terrain got harder until eventually you'd use a smaller chainring at the front.

It's probably more important to keep an even rhythm on the pedals (called cadence) than it is to try and stay at the same speed. As you've noted there's a lot of overlap in the gears, you may well find that different ring combinations feel the same. As Lee pointed out, try to keep your chainline straight i.e. don't use the largest front chainring with the two largest cogs at the rear or the small with the two smallest at the rear.

Nice article on it here

 

[Arch]

Pollution masks - I've never use one, but it's worth remembering that you're still probably breathing better air than that circulating inside cars and so on.... And I'd have thought they could get a bit hot...

plus one for a morph pump.

 

[palinurus]

2. How long your journey takes will be mostly dictated by junctions and lights.

 

[BIGSESAL]

+ 1 for a topeak. They attach to the frame and some ever have a pressure gauge.