Convert to SS

[brockers]

You guys use big gears! I'm presently on 42x16 which is ok around the lumpy part of SE London where I lurk. It's also the 'magic gear' for my old Peugeot frame, i.e., there's no chain slack and I don't need a half link. But if I go further out into Kent, I find the North Downs impossible in this high a gear, and I find I need 42x18. And I'm somebody who would be considered a climber !

 

[Ibbots]

The skid patches calculator on 3narf's link is really interesting - I see I have managed to achieve about the worst combination. Not sure about the gear calculator though, results seem a little high but I can't see that they state tyre size. Assuming this works...I downloaded the attached spreadsheet from somewhere, find it useful - especially as you can enter tyre size rather than overall wheel diameter.

 

[Bikenut63]

Here is the linkhttp://www.statebicycle.com/default.asp
I love the bikes and really want one , it's just the postage 

 

[Ibbots]

Bugger View attachment GearTable.xls

 

[brockers]

Bugger[attachment=3886:GearTable.xls]

I can't quite see how they're calculating them, but the values are coming out about 20% too low.

 

[Ibbots]

I can't quite see how they're calculating them, but the values are coming out about 20% too low.

20% margin of error would mean I'm pushing 84" up the hill home - hooray. In the version I saved I set it up for a 23 tyre. Click on the 27" tab which might give you figures you expected to see or scroll up the first tab and mess with the tyre size?

 

[brockers]

Even a cursory glance shows it's all to cock. For instance a 30T chainwheel with a 30T sprocket on a 27'' wheel should read 27. This table gives 23. My winter gear of 42x18 on 700c wheels is usually 63 inches. This spreadsheet gives 50.

 

[wheres_my_beard]

http://software.bareknucklebrigade.com/


Use this.

 

[Ibbots]

Even a cursory glance shows it's all to cock. For instance a 30T chainwheel with a 30T sprocket on a 27'' wheel should read 27. This table gives 23. My winter gear of 42x18 on 700c wheels is usually 63 inches. This spreadsheet gives 50.

Clearly that's wrong and I thought at first perhaps you had clicked on one of the other tabs but can't find a match for the figures you quote. Not sure what's going on because on my version I get the figures you are expecting on the 27" tab and slightly lower on the Custom tab because of the tyre size I have put in. Even when I download it from here the figures are right.

If it's still all wrong on the 27" tab I can only think something weird happened with the download but can't imagine what. Bin it if it's cocked, there's plenty of others knocking about.