8/31/14 12:24 PM

OK, new bike new considerations.

I think I have the original wheels form my Roubaix sold already, so shopping for rims/hubs etc.

The thought occurred to me that being the SL4 will only fit about a 33 max, maybe a 650B wheelset for adventure type use. With a bigger tire no upset to the geometry. If the OD of a 42C 650 for example being close to a 700x28 etc.

No Google results specifically for a disc Roubaix I could source...

We have any 650B conversions here?

8/31/14 1:17 PM

nick Payne has Litespped I bieve. May be searchable. ?

8/31/14 1:24 PM

Yes, a recent thread I started has him chiming in.

Also the smaller diameter if you swap out to your 650 wheels for loose/dirt/gravel/adventure/woods will also have an effect on gearing in the desired direction for the purpose. Depending on how close the OD is of the tire sizes et al.

9/2/14 6:41 AM

My Litespeed with 650b wheels and 32mm GB Cypres tyres. I couldn't fit a larger tyre in the frame because of the way the Litespeed chainstays bow in between the BB and rear dropouts, but on a frame with sufficient room between the chainstays and fork blades (eg lots of older steel frames), there's plenty of room under the fork crown and rear brake bridge to fit a 38mm or even larger tyre.

Heaps of information about the subject here: http://www.bikeman.com/bikeman-blogs/650blog

9/2/14 7:00 AM

What brakes did you use to make them line up with the smaller diameter rims? The radial difference between 700c and 650B is 19 mm which is quite a lot.

I looked at the blogs you linked to and saw the one on the Surly Pacer conversion. I have that bike and it already requires "long reach" (47 - 57) caliper brakes with 700c wheels. The writer used Tektro 73 mm really looong reach brakes but didn't mention how well they work. I wonder if the extra length compromises braking.

9/2/14 2:58 PM

That bike has the Tektro R556 brakes with 73mm maximum reach. They work perfectly well - I really don't notice any difference in braking between those and the previous short reach Shimano brakes I had on the frame when using 700c wheels.

I think Tektro has updated the model since I bought those and now calls it an R559.

The other brake I have used on a conversion is the Paul Racer long reach centerpull - gives more clearance if you want to fit fenders - dual pivot brakes tend to squeeze the fender down on the tyre when they are applied - but the Paul brakes are a lot more expensive (like four times the price) and need cable hangers if the frame does not have the braze-ons.

Last edited by Nick Payne on 9/2/14 3:10 PM; edited 1 time in total

9/2/14 3:04 PM

FWIW, Not sure if a fair comparison. I have had both the Tektro R556 55-73mm and the Shimano 47-57mm BR-650s on the Bridgestone. The Shimanos to me have a lot more power, same Salmon Kool-Stops on both.

If it matters, the BR-650s finish and shape is more high line looking to me by a long shot. Cost way more too I think.

9/3/14 3:55 PM

The Rando I ride was designed for DiaCompe centerpulls , but with fairly wide rims. With the rims I use, the CP didn't clear the sidewalls in front, so it was change the frame, the rims, or the brakes.

I changed to a long-reach Tektro in front, and it's fine. True, it's not as nice feeling as a shorter Shimano brake, but a shorter brake won't work here. Apples &.Oranges.