Which will improve my time most?

Langman

I have got back into cycling this year after 15 years and built a TT bike and got up to an okay pace.

I am going to buy other bits and pieces and wondered which would be the best investment in terms of knocking time off a TT. I currently run a 53 chainring and find that I am spinning it quite a bit so a bigger chainring might be good but everybody is telling me that you have to be a monster to turn a 55. Anyway I am looking at buying one of the following over the next moth or so, which is best and can anyone recommend a product;

- Skin suit
- Ceramic bottom bracket
- 54/55chaing ring
-Aero hemet

Could anybody give an indication of how much they could save in a 10mTT.

Thank you.

redddraggon

What sort of times are you putting out now?

BTW what cassette ratios do you have?

Langman

23.52 last week and cassette is 25/12

Thanks

redddraggon

Skinsuit/Aerohelmet/Cassette with taller gearing?

A Coach?

A Powermeter?

Escargot

Not an expert but from a physics perspective your body accounts for about 70% of the drag so if you can reduce this in any way it would improve your times more than a BB (probably the worst thing to buy IMHO).

How this measures up to the benefits of a larger chainwheel I'm not sure.

dennisn

Langman wrote:

I have got back into cycling this year after 15 years and built a TT bike and got up to an okay pace.

I am going to buy other bits and pieces and wondered which would be the best investment in terms of knocking time off a TT. I currently run a 53 chainring and find that I am spinning it quite a bit so a bigger chainring might be good but everybody is telling me that you have to be a monster to turn a 55. Anyway I am looking at buying one of the following over the next moth or so, which is best and can anyone recommend a product;

- Skin suit
- Ceramic bottom bracket
- 54/55chaing ring
-Aero hemet

Could anybody give an indication of how much they could save in a 10mTT.

Thank you.

My vote goes to stronger legs.

Langman

Thanks for the feedback so far.

When you say taller gearing what do you mean?

redddraggon

Langman wrote:

Thanks for the feedback so far.

When you say taller gearing what do you mean?

11-21 or 11-23 cassette rather than the 12-25 - You are saying the 53t is too small, but I don't think it is

Langman

OK - but would it not be easier to put on a 54t?

By the way my course is a bit bumpy so going down the hills I am just spinning.

dennisn

Langman wrote:

Thanks for the feedback so far.

When you say taller gearing what do you mean?

I seriously doubt that you need a bigger chain ring than a 53 if you've got a 12 on the rear.
If you can SPIN a 53-12 you're a better man than all of us. This is a really big(tall) gear and
spinning it(except on downhills) is not gonna happen for you. I'm thinking your "spinning"
is definitely not "spinning". Grinding maybe, but spinning, no.........

redddraggon

53 -> 54 is a change of roughly 1.9% - is it really worth it?

Langman

so would a 11-21 would make more difference than a 54?

Slow Downcp

11-23 cassette as already said would be my route - if I could spin a 53/12! What cadence do you class as spinning?

Of the others, and assuming you have a decent position (Flat back etc), I'd say helmet first, then skinsuit. BB may make 1 second difference. If your position isn't good though an aero helmet will slow you down as it will act like an airbrake if your head is looking down.

Escargot

Should be a better bet as you'll see a 9% increase in gearing.

Even if you went to a 55 you'd only see a 3.7% increase and the larger ring would add more mass and be less stiff (relatively small tho) so the smaller cassette makes more sense.

dennisn

I'm going to assume you're talking 10 mile time trial at 23:52. This is over 25 MPH average speed and you've been training for less than a year??????

Bhima

Langman -

53/11 is a bigger gear than 57/12.

In fact, if you got a 58t chainring and stuck to the 12, you'd only go about 0.3% quicker than the 53/11.

See here: http://www.sheldonbrown.com/gears/

Langman

At some points on the course I am spinning i.e no resistance against my legs. I don't know the cadence. But always wish I had more gears!!

So it sounds like a skinsuit is best idea, what sort of time savings do they bring?

Bhima

Langman wrote:

At some points on the course I am spinning i.e no resistance against my legs.

This is good. Learn to hold this for long periods and you'll keep your legs fresh. You'll get out of breath quicker though.

Langman

dennisn wrote:

I'm going to assume you're talking 10 mile time trial at 23:52. This is over 25 MPH average speed and you've been training for less than a year??????

I started cycling in April , but did quite a bit when I was younger. I am pleased with my progress and wish I'd kept it up now. Back in April I did a 10m tt on my own i.e not an event, and it took 45mins! but it was on a heavy mountain bike that someone gave me!!

chriskempton

You're going very well on your comeback!

You'd definitely get some benefit from the sknsuit, and the helmet. It's difficult to say which you'd get more from, but probably the helmet - should be worth 10-15 seconds. The gain you'd get from the skinsuit depends on how aero your current kit is.

If you need bigger gears - like some others have said, you'd probably be better getting a new cassette rather than changing chainrings. Go for an 11-23 and you'll have a significantly bigger top gear (that's good for 38mph if you're spinning at 100rpm). If you can manage with an 11-21, all the better, as you'd have even smaller jumps in your gears.

Ceramic BB bearings would give you nothing measurable from what I've read.

Like slowdown says, you've not mentioned your position - getting this right (if you haven't already) might be worth as much as everything else put together.

PS a small easy win is some lycra aero overshoes. They're cheap and will get a few more seconds in a 10.

Chip \'oyler

Do you have a deep section front wheel and a rear disc?

If not these would bring big time gains

cougie

I think you need to learn to spin a gear properly - is this a proper certified tt course you are recording your times on ? Sounds like its got a pretty decent hill on it if you are spinning out on a 53-12 ?

Langman

Thanks for all the feedback just what I needed - much appreciated.

I have carbon wheels I think they are 40mm. No rear disc.

The hills on the course are quite good going down them I do around 36mph there are 2 of them the second of which is about 0.8 miles long.

I don't know if its a certified course but it is one a club use in summer.

Anonymous

I spin out at over 40mph on a 53-12.

And I'm rubbish!

You need to spin better

cougie

36mph - thats good going. I've done 56 though on my 52*12 - and was only just spinning out towards the end.

a_n_t

36 mph on 53:12 is only 106 rpm, hardly spinning out!

Langman

I neglected to say that for some reason the chain will not shift into the 12 so I am spinning in the one above.

holybinch

if the chain is not shifting to the smallest cog, it can be a few things:
1/ the limit screw
2/ the cable housing preventing the cable from getting loose
3/ derailleur hanger bent

Maybe the best investment would be a good service?