- Oct 28, 2017
The gear ratio changes whenever you change the number of teeth. In your case, since we're talking about the front chainring:So I got into cycling recently and bought a purefix Juliet on eBay for 90 quid a few months ago. Friend put it together and I've cycled maybe 10 times on it.
Basically both pedals fell off in the space of two days because of the crank thread. I got the left crank replaced for a tenner but the crank set looks like it'll cost 100 at a shop to do.
I'm curious if anyone knows of the cheapest place to buy parts in the UK.
And the bike came with a 44T 165mm set. Would it matter much if the teeth amount were different?
More teeth: harder to start, more difficult up hills, but more speed (Fire Stingray)
Less teeth: easier to start, easier up hills, less top speed (Golden Fox)
What is the rear teeth count? According to the manufacturer's website, it's 16t freewheel / 15t fixed cog.
Let's say it's the 16 in that case, you have a 2.75 gear ratio. With this you can do the following speeds:
Cadence / Speed
10.8 [email protected] rpm
12.9 [email protected] rpm
15.1 mph]@70 rpm
17.2 [email protected] rpm
19.4 [email protected] rpm
21.5 [email protected] rpm
23.7 [email protected] rpm
25.8 [email protected] rpm
28 [email protected] rpm
So that gives you an idea of what your current ratio can do and if you wish to change things up, it all depends on your geographical location and you own abilities/needs/wants.
As for replacing the cranks, most crank arms will allow you to take the chainring off in order to replace them. So all you really need is a new crankarm. They're not terribly expensive and not difficult to change as long as you have the right tools.
But you can't put just any crank arm because on a single speed/fixed gear, it's very important that the chainline be straight. You need to see what size your bottom bracket is first and buy a crank arm that conforms to that sized bracket, otherwise you have to replace the crank arms AND the bottom bracket.
If you're unsure, just let the shop take care of all those issues. Or find a bike co-op that can help you.