big ring is 50 small sprocket is 12

Brewer

Big ring has 50 teeth, small sprocket has 12 teeth. Is this why I spin out going downhill while everyone else is getting faster?

rc856

I take it you have a compact chainset mate? 34 on the inner ring? If your riding partners have a 52 or 53 for their big ring, they'll find downhills easier.
They may also have better leg speed??

pilot_pete

They may;

1. Just be stronger than you.
2. As RC856 says, may have a higher cadence.
3. They may have a bigger, bigger ring.
4. They may be heavier than you (it does make a difference downhill)
5. They may have smoother wheel bearings (i,e better quality) than your bike, which again makes a difference.
6. They may take a more aerodynamic stance in the drops than you.
7. They may have a more aggressive geometry which aids point 6.

You may spin out for a number of reasons, but chiefly if the hill is steep enough and you go fast enough you will spin out at some point. I have a compact and this frustrates the hell out of me! Having said that, I do seem to pull away from most of my riding buddies downhill due to a number of the reasons stated above. Even if we just roll I go faster than them downhill, mainly due to frame and wheels I think, but the odd pie or two seems to play a part as well!

PP

SBezza

I only have a compact on my road bike, and above a certain speed just freewheel, I still overtake those with standard chainrings. As above there are various reasons why they may be faster, it isn't just the gearing.

You should be able to get about 40+ mph with a 50/12 setup, at least I have had over 42 mph on my road bike, before I gave up pedalling and freewheeled.

Pross

At 40mph you would be doing about 122 rpm whilst someone riding on 53 x 12 would be doing 115 rpm so not really a massive difference. Just practice riding a low gear so that you get used to pedalling faster, a lot of people struggle to spin for any length of time (myself included). Too much is made of spinning out on compacts, it is more likely to be a combination of the factors in Pilot Pete's post than you being under-geared.

neeb

Ask your riding mates with standard chainsets to use their 53-13 gear (about the same as your 50-12) instead of 53-12 when descending and see if it makes any significant difference... probably it won't! On the off chance that it does, you could always get a cassette with an 11 tooth sprocket.

rick_chasey

sheffsimon

They have bigger b0llocks than you.

pneumatic

You pedal going downhill? :shock:

Blimey! That is when I take a breather and enjoy the rewards of climbing. 8)


There again, I don't (and couldn't) race.

what brakes

I have compact with a 12 rear sprocket. on the slight down hill i can push 40 odd mph. When i get to a big hill i just tuck in and overtake! its the corners and being tucked that will allow you to over take downhill oh and having the balls to push the limit of the bike.

Now and again i wish i had an 11 tooth at the rear but generally a compact 50x12 is more than enough! Staying with a compact also has the added benefit when your climbing! which i need.

jgsi

what brakes wrote:

I have compact with a 12 rear sprocket. on the slight down hill i can push 40 odd mph. When i get to a big hill i just tuck in and overtake! its the corners and being tucked that will allow you to over take downhill oh and having the balls to push the limit of the bike.

Now and again i wish i had an 11 tooth at the rear but generally a compact 50x12 is more than enough! Staying with a compact also has the added benefit when your climbing! which i need.

best last year was coming down the MA10 on Mallorca back to Pollenca, keeping up with a trio of maniacal Norwegians.

Brewer

Thank you for all the helpful comments. I'm still planning to spend money on a new group set, but in the mean time I will work on the suggestions (even the pie eating )
As for the testicular speculation, if mine were more magnificent in their girth and heft, I wouldn't be able to wear bib shorts. In fact I received compliments last summer from the staff at the baker's in Presteigne and that was after 80 miles.

paulnettles

Rick Chasey wrote:

You're supposed to descend in the drops, right? For max speed and aero advantage, I mean, elbows tucked in to minimise drag as much as poss... So, does the Rabobank guy know something we don't, or is descending crouched on the tops (with or without your elbows stuck out) just as effective?

Down the Road

He has almost the right idea. You should set your hands as narrow as possible and if you are keen enough sit on the top tube. with your chin on the top of your hands.

This minimises frontal area and therefore drag

springtide9

I have big ring 50 and small 11. When my legs spin out I personally think it's a warning not to go any faster. I think 40 mph is more than enough for me on 25mm width tyres LOL

And I always think.... whenever this is a downhill - it's usually followed by an up.

If the choice is between going 5% faster downhill for 5 mins or 5% faster going up for 20mins.. personally I think the 'up' option looks the preferable option.

Erudin

Gears: Double reduction gearing,
primary built by Cook Brothers,
70 / 13 teeth - 60 / 15 teeth,
covering 114,2 ft distance with one pedal system rotation
(fourfold of a normal 10-speed gearing).
166mph

Ron Stuart

Rick Chasey wrote:

The Phonak guy is sorted, letting the other guys in front go through all sorts of contortions while he is slipstreaming at a reasonable distance and relaxing for the next climb. Let the other Muppets ruin there sex lives eh

langster

Just drop in behind your mates and slipstream them down, this way you wont need to pedal and can use this time for recovery

Ron Stuart

langster wrote:

Just drop in behind your mates and slipstream them down, this way you wont need to pedal and can use this time for recovery

This season I am mainly crashing my specialized (CAVENDISH) :P