www.recumbents.com - 63T on a NoCom
www.recumbents.com
www.recumbents.com
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
 Password:
Save Password
 All Forums
 www.recumbents.com
 Technical / Bike Building
 63T on a NoCom		  New Topic  Reply to Topic
 Printer Friendly
Next Page
Author Previous Topic Topic Next Topic
Page: of 2

AA
human power expert

USA
2373 Posts
Posted - 04/26/2012 :  08:53:43  Show Profile  Reply with Quote
Instead of mashing large gears in years past I have set the bike up with large cassette cogs and big chainring. Bigger cogs are better for chain line efficiency. The current gearing with 63T chainring and 14/28 cassette is about the same as a 50T chainring with an 11/23 cassette

Currently have a 14, 15, 16, 17, 18, 19, 20, 22, 25, 28 cassette. Next ride I'll try a 15, 16, 17, 18, 19, 20, 21, 23, 25, 28. Small gear inch jumps which will be good tfor time trialing.
Much easier to spin small gears than mash big ones and the speeds are higher with the weenie gears.

Speedbiker
human power supergeek

USA
1995 Posts
Posted - 04/26/2012 :  11:49:22  Show Profile  Reply with Quote
Smart and fast!
Go to Top of Page

airxxxwolf
New Member

USA
96 Posts
Posted - 04/26/2012 :  18:43:11  Show Profile  Reply with Quote
Alan,
It seems we are thinking the same way.....I also have a 63-T chainring on my NoCom and modified my 11-28 cassette. I had also planned on making my 63-T ring more aero by enclosing it in with a carbon disc the same way you did. Did you try the alternative regulation point on your Rotor cranks that I told you about?

Don Smith
BBM Racing Components
bbmracing@yahoo.com
Go to Top of Page

AA
human power expert

USA
2373 Posts
Posted - 04/26/2012 :  18:48:04  Show Profile  Reply with Quote
The 15t cassette cog did not work. With a large cog the chain makes contact with the bottom of the rear stay. The 14t cog was doing the same but not as loud. I thought it was the thickness of the Miche cog creating the sound but its chain deflection on the frame with large cogs.

Not willing to grind any carbon off the rear stay for chain clearance. I'll try 56T 13t cog next ride. Darn!
Go to Top of Page

Dreamer
recumbent guru

USA
541 Posts
Posted - 04/26/2012 :  18:55:48  Show Profile  Reply with Quote
72 with a 16-38 cassette
Go to Top of Page

airxxxwolf
New Member

USA
96 Posts
Posted - 04/26/2012 :  19:08:11  Show Profile  Reply with Quote
I`m running a 63-50-36 triple with a 12-28 9-speed

Don Smith
BBM Racing Components
bbmracing@yahoo.com
Go to Top of Page

AA
human power expert

USA
2373 Posts
Posted - 04/26/2012 :  21:38:52  Show Profile  Reply with Quote
Don,
I have tried several different regulation points and 155's and 65's. Currently with 165's and slightly different regulation than your photo. Just a mater of dialing in what works for my legs.

At this time I'm going with easy to turn over gearing to keep my pedal stroke smooth. Goal is to go fast and avoid injuries.


quote:
Originally posted by airxxxwolf

Alan,
It seems we are thinking the same way.....I also have a 63-T chainring on my NoCom and modified my 11-28 cassette. I had also planned on making my 63-T ring more aero by enclosing it in with a carbon disc the same way you did. Did you try the alternative regulation point on your Rotor cranks that I told you about?

Don Smith
BBM Racing Components
bbmracing@yahoo.com
Go to Top of Page

mhelander
recumbent enthusiast

Finland
257 Posts
Posted - 04/27/2012 :  03:32:44  Show Profile  Reply with Quote
As I still have 50/34 chainrings with 11-23 10-speed cassette in my lowracer, my butt feeling is that because of riding now in open roads which enable higher speeds, I'm using more 50t and typically gears 3-6 (19,17,16,15) when speed is between 30-40 kph. Lowracer feels faster, ie less resistance, when using big chainring and bigger cogs, that is, 15t or bigger.

My HRM, speed in flats and average leg speeds are confirming this. Then there's psychological factor of pushing early uphills with bigger gear to maintain momentum. Rolling hills legs will get immediate gain in average speed. Steeper hills will force to drop from 50-19 to 34-13.

I'm following my Edge's data very carefully to learn new tricks in improving uphill and flats performance...

Cheers,
-Mika

MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
Go to Top of Page

alevand
human power supergeek

USA
1646 Posts
Posted - 04/27/2012 :  05:02:11  Show Profile  Visit alevand's Homepage  Reply with Quote
Higher chain tension also improves efficiency.

C:
Tony Levand
Go to Top of Page

mhelander
recumbent enthusiast

Finland
257 Posts
Posted - 04/27/2012 :  05:24:15  Show Profile  Reply with Quote
quote:
Originally posted by alevand

Higher chain tension also improves efficiency.


Yes up to a practical point, then higher tension turns to added frictions.

That's why I have compact double road gearing but are using middle-cage X.9 RD's in both of my bikes. Plenty of leverage and spring to keep chain where it belongs, even in rougher roads and conditions.

Cheers,
-Mika

MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
Go to Top of Page

Zyzio
recumbent enthusiast

USA
120 Posts
Posted - 04/27/2012 :  10:25:06  Show Profile  Reply with Quote
The big ring also reduces the torque on the frame, so there is less flex and more power makes it to the rear wheel. There is probably some aero benefit as well, not to mention a nice, smooth feel as you pedal.

Alan, you'll probably find out that your NoCom will feel much better with the tail fairing, since that will reduce the effect of the extra surface area that the large ring adds at the very front of the bike. The fairing should make it more neutral in side-winds.

PeterB
Go to Top of Page

AA
human power expert

USA
2373 Posts
Posted - 04/27/2012 :  10:51:12  Show Profile  Reply with Quote
Peter,
No odd handling with the large ring and wind. I'd luv to keep the 63T on but I'd have to use a 13t cog for frame clearance. Too large of a gear to turn over non faired but that may not be an issue with the TF

Need to setup the TF for quick install and removal. At present there are too many bolts required for easy installation. Front end has to be patched as the previous owner cut huge chain clearance holes. Its a lot of work.

quote:
Originally posted by Zyzio

The big ring also reduces the torque on the frame, so there is less flex and more power makes it to the rear wheel. There is probably some aero benefit as well, not to mention a nice, smooth feel as you pedal.

Alan, you'll probably find out that your NoCom will feel much better with the tail fairing, since that will reduce the effect of the extra surface area that the large ring adds at the very front of the bike. The fairing should make it more neutral in side-winds.

PeterB
Go to Top of Page

Speedbiker
human power supergeek

USA
1995 Posts
Posted - 04/27/2012 :  14:53:58  Show Profile  Reply with Quote
Allan, grind that carbon for clearance. Be a man! Ha ha ha.
Go to Top of Page

tom porter
recumbent enthusiast

154 Posts
Posted - 04/28/2012 :  07:59:47  Show Profile  Reply with Quote
Have you given any thought to a larger diameter pulley to lower the chain line to clear stay.

O---o
Go to Top of Page

alevand
human power supergeek

USA
1646 Posts
Posted - 04/28/2012 :  08:28:39  Show Profile  Visit alevand's Homepage  Reply with Quote
Maybe you could modify the super tight dropout for a little clearance, and a a slight spacer. Or what about the super 11 speed cog.




C:
Tony Levand
Edited by - alevand on 04/28/2012 08:43:52
Go to Top of Page

AA
human power expert

USA
2373 Posts
Posted - 04/28/2012 :  11:31:15  Show Profile  Reply with Quote
Tom & Tony,
If I go lower with the idler it will bottom out on the street. I was advised to use a washer to space the dropout away from the cog. Not sure if a washer will provide enough clearance. 11, 12 & 13 t cogs no problem. 14 and 15t raise the chain up to high. I'll try a washer next.
Go to Top of Page

airxxxwolf
New Member

USA
96 Posts
Posted - 04/28/2012 :  17:59:46  Show Profile  Reply with Quote
Alan,
I know you have already redone your rear dropouts a couple times, but if you really want that 14-T cog in the first position, you could make another set of rear dropouts that will raise the frame enough to clear the chain on the 14-T cog.....looking at the photo of the drive side I think you could make the dropouts in a way that would not only give you the clearance you want, but also decrease the gap between the tire and the rear splitter plate.

Don Smith
BBM Racing Components
bbmracing@yahoo.com
Go to Top of Page

AA
human power expert

USA
2373 Posts
Posted - 04/29/2012 :  09:13:13  Show Profile  Reply with Quote
Dan,
I used a metal rasp to file down the edge of the frame touching the chain. Very minimal amount and should be OK. If not I'll add some carbon fiber to the other side of the rear stay to compensate.

I was not willing to redo the dropouts. Space between tire and rear brake bridge is less than 1/8". Not easy to move the rear wheel any closer. After reading your post I am now considering filling the gap with foam.
Edited by - AA on 04/29/2012 09:14:34
Go to Top of Page

AA
human power expert

USA
2373 Posts
Posted - 04/30/2012 :  12:37:19  Show Profile  Reply with Quote
After I removed some carbon fiber off the edge of the rear stay for chain clearance I decided to lay down some layers on the inside to compensate for monkey grinding. The layers were pressed into the frame with foam, wood block and clamps. I'll continue heating the area for another hour.

This will make my rear stay modification quite strong. The beauty of carbon fiber wonderbikes is they can easily be changed. Chop it up at night, lay down some carbon fiber in the AM and ride it by afternoon.
Edited by - AA on 04/30/2012 12:41:28
Go to Top of Page

WanaB
Starting Member

USA
4 Posts
Posted - 05/02/2012 :  20:02:54  Show Profile  Reply with Quote



C:
Tony Levand
[/quote]

Backwards pedaling would really straighten that chain.
Go to Top of Page

sean costin
human power supergeek

Lesotho
1918 Posts
Posted - 05/02/2012 :  20:15:45  Show Profile  Reply with Quote
Nice,
Where is the fairing?
Go to Top of Page

AA
human power expert

USA
2373 Posts
Posted - 05/02/2012 :  20:40:00  Show Profile  Reply with Quote
Sean,
I will start working on the TF installation next week. I had to get the bike dialed in first.

Everything worked perfectly on todays ride. What I saw on the speedo I have not seen for 4 years. Having an excellent time with this bike and looking forward to Sunday.

quote:
Originally posted by sean costin

Nice,
Where is the fairing?
Go to Top of Page

warren
human power expert

4229 Posts
Posted - 05/03/2012 :  09:10:40  Show Profile  Visit warren's Homepage  Reply with Quote
Alan was cranking on our ride last night! It's good to see him get his mojo back.
Go to Top of Page

Speedbiker
human power supergeek

USA
1995 Posts
Posted - 05/03/2012 :  10:30:56  Show Profile  Reply with Quote
Does he even have to pedal that NoCom?
Go to Top of Page

tom porter
recumbent enthusiast

154 Posts
Posted - 05/07/2012 :  17:13:39  Show Profile  Reply with Quote
Hi Alan,
How did you avoid the rain at the Single Bong? I see by the results you aren't in your best shape yet. Did everything work alright?

O---o
Go to Top of Page

AA
human power expert

USA
2373 Posts
Posted - 05/07/2012 :  18:53:03  Show Profile  Reply with Quote
Tom,
I shoveled and wheel barreled over 6000 lbs of gravel on Saturday. I still have not fully recovered.

But that's life and I'll be at the next Bong time trial. Doubt i will be doing any heavy lifting the day before.



quote:
Originally posted by tom porter

Hi Alan,
How did you avoid the rain at the Single Bong? I see by the results you aren't in your best shape yet. Did everything work alright?

O---o
Go to Top of Page
Page: of 2 Previous Topic Topic Next Topic  
Next Page
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
www.recumbents.com © 2009 www.recumbents.com Go To Top Of Page
Snitz Forums 2000