Fork was on backwards anyway...Frustruck said:Someone's bought that Nigel Dean frame that Bonjers refers to in post #11. I wonder who... (not me, too small, don't need but at £75 + postage it was a good deal)
Chuffy said:Remind me to come back to this thread when it moves onto gearing and sprocket choice.![]()
Uncle Phil said:Well, just because your fixie only has one gear, that doesn't mean you don't have to choose what gear ratio it is.
In fact, it's much more important than on a multi-geared bike, because you can't just change up or down a gear or two as the terrain changes. Your single gear has to be a compromise that allows you to ride all the terrain you're likely to encounter, up hills and down.
If you lived in a totally flat place and were super-fit, you could have quite a high hear (90-odd inches) and be spinning along in it at 30 mph all the time.
In Sheffield, and being merely human, you'll need a rather lower gear - you'll want to be able to climb some hills with it. (60", perhaps?) You certainly don't want to be seen walking your fixie up a hill!
And worse, you have to bear in mind that you can't stop pedalling coming down hills either. So if you choose, say, a 50" gear to get you up the hills, you'll be "spinning out" coming down them - that's to say you'll be riding slowly down with the brake(s) on so that your legs can keep up with the pedals.
So choice of gear is really quite critical, and probably the single point on which you should seek the most advice, preferably from those who know the terrain you'll be riding on this bike and are experienced riding it on a fixed gear.
Joe24 said:Gearing is hard. Need to work out the GI, which i let someone else do. Which i think, you divide the chain-ring tooth number by the sproket, then times by 27 or something. I have 65GI. Thats good for me, and i like hills. I was out on it today on the club ride, faster then most on the hills and into headwinds i found i was able to keep my speed higher. 2 hills, one long with a headwind i felt like chucking up by the time i got to the top but carried on. The last one i do was slowish but it will get easier. If your going to do hills, go for mid 60GI was the advice i was given.
Only problem though, was when there was a tailwind and the group was doing 27mph i was spinning like mad. Ended up turning off with another guy, he was really struggling on his geared, and i just wanted to stop spinning so fast.
The Mavric CXP33 or whatever, the rim suggested is whati have on the back of my fixed. Pretty deep really, nice looking aswell. Dont do your bike in all one colour though Bonj, or it will look bad IMO.
Uncle Phil said:Gear inches: number of teeth on chainring divided by number of teeth on sprocket. Then multiply the answer by 27 (if you're using a 27" or 700 wheel).
Somewhere between 65 and 70 inches seems to be right for most folk.
My fixie's only ever used on the flat, but carries a load sometimes, and I'm not fast anyway, so I have 69" (46 by 18).