Another Converted Sherpa

[rualexander]

Looks fine to me.
With my Sherpa I didn't do anything until the chain started coming off and it was a good bit slacker than yours is by that time.

[geocycle]

Yes, I agree with rual, only worry if it falls off.  I wonder if a half link might help your chains last longer?

[phopwood]

Thanks both.  It is not ready for a half link just yet maybe in a few months. 

Peter.

[Danneaux]

Hi Peter!

Very nice-looking conversion! If you wish to consider it -- and the external-bearing bottom bracket required, with its own list of positives and negatives -- a Phil Wood "PhilCentric" bottom bracket will allow fine-tuning of chain tension without a chain tensioner or half-link.

Here is a customized Google search on the topic: http://tinyurl.com/l522qnd
Here is a link to the Phil page: https://www.philwood.com/products/bbpages/philcentric.php

Just another data point, another means for adjusting tension, but it won't provide much movement; Phi warn a half-link may still be required. Alternatively, swapping to a 1T larger 110BCD chainring would take up slack as well, but odd-numbered ones are tough to come by these days and the jump would be too large at this point.

Please don't file the dropouts. Very little travel would be gained at the expense of a great many problems. I agree with Rual and Geo' for what it's worth; run as-is for awhile longer if you wish to avoid using a tensioner.

Best,

Dan.

[phopwood]

Thanks Dan I had considered a eccentric BB conversion and the 3 mm of movement each way would give me enough movement to cover .75% stretch on a standard chain. 

Your idea of an extra tooth may be an option, I might consider that when the skipping starts to happen.  Then between the two chain rings I would get full life out of a chain and it only take a few minutes to change the chain ring.  1 tooth adds 6.6mm to the length of the required chain. 

All that said I can buy a new chain for a few pounds.

Don't worry I will not file the drop out honest gov.

Peter



Peter.

[macspud]

A post by il padrone on BNA - Australian Cycling Forums, covers safe amounts of chain slack with info from Thorn including measurements and diagram.

Second post down on following page:

http://www.bicycles.net.au/forums/viewtopic.php?f=2&t=37092&hilit=thorn+raven&start=75

Hopefully that will set your mind at rest.

[alfie1952]

Hi Peter ,

I had to come in to your post to see how your conversion worked out as I may attempt something along the same lines. The nice thing is you also have the flat bar rather than drops so it gives me an idea of how mine might look. I also had a look at Rualexanders  sherpa,and he also has done a tremendous job. Please bear in mind if I go ahead with the conversion, I may never be of your backs asking advice.

Regards, Alfie

[phopwood]

Alfie,

I am so please with it and the whole experience was a pleasure.  I have since replaced the bars with butterfly bars with the brakes on the vertical part I fine that position much more comfortable.

Please ask away.

Peter