Front gearing

craven2354

Well-Known Member
I currently have a 50t and a smaller one I couldn't find the size and am wondering how hard is it to fit a bigger sprocket so I can go faster?
 

ianrauk

Tattooed Beat Messiah
You probably have a compact chainset with 50/34.
Best thing would be to buy a normal racing set up is 52/39 as if you put a 52 on your existing set up the jump up and down to/from a 34 would be too much. You would also have to buy a new chain to for the extra length.
 

HovR

Über Member
Location
Plymouth
Assuming the rings are removable (on some they're riveted rather than bolted), it's as easy as buying a new ring with the correct BCD (bolt circle diameter), undoing 5 bolts, remove old ring, fit new ring, do bolts back up. In addition to this, your front derailleur may need moving up a small amount.

However, most common ring sizes only go up to 52 or 53, so you may not find much of an increase. How many teeth does the smallest sprocket have on the rear? It may be easier to gain a higher gear ratio there.

Edit: Cross posted with Ian. I didn't consider the gap between the two rings that Ian did, so that's also something to keep in mind.
 

Nebulous

Veteran
Location
Aberdeen
Not really that hard depending on your set-up, but it won't necessarily make you faster!

I had a 50/36 Tiagra chainset and managed to get a 105 52/39 in a sale. I tend to be a bit of a grinder and find it hard to crank quickly when tucked down, I've been trying to do some TTs. I swopped it over about a week ago, and so far so good- but you still need to plf, as the saying goes.
 
OP
craven2354

craven2354

Well-Known Member
How much difference are we talking between a 50 and 52? Is it worth the change? Also thanks for speedy replys
 
OK, well, I max out at 24 on a 38 tooth ring, on a 50 it would be more like 30/32, so it sounds like a faster cadence would help you out there. As a very rough guide, a 50 to 52 change for the same cadence would give a few extra miles an hour, you'd obtain a much bigger difference by increasing your cadence.
 
OP
craven2354

craven2354

Well-Known Member
Looks like I need to just get fitter ;) cheers anyways guys
 
Looks like I need to just get fitter ;) cheers anyways guys
Yes and no. Sounds like your pretty strong already and churning a big gear for your speed, which is pretty good but if you can churn it faster then even better.

Take an imaginary top gear of 50 front, 12 rear. If you peddle at 80rpm you'll do 26mph, if you peddle at 90rpm you'll do 29mph and a 100, 33mph. If you changed your 50 for a 52 and peddled at 80rpm still, you'd do 27mph a opposed to 26mph.

Everyone has a natural cadence they feel comfortable at, so while improving it is good and desirable, once at that point you can look at your gears again. Whilst trying to improve your cadence a cadence computer can be pretty useful.
 
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