WTB Paul Racer Braze On

[steve...@gmail.com]

Desperately seeking the discontinued braze on version for a conversion of a Riv Rambouillet. I'm having a framebuilder make me a fork and "all" the other centerpull options require wacky posts (ie rene herse)

Thank you!

[JohnS]

Hello Steve,

I'm no expert, but I think you have it backwards, the Paul center pulls use cantilever posts whereas RH, Diacomp and Mafac use center pull posts. Per the Cycle Toussaint web site (need to scroll to the bottom).

https://www.cyclestoussaint.com/collections/frames/products/velo-routier-2-0-650b-low-trail-frame-with-braze-ons

Good luck,

John

[JohnS]

Correction: RH has unique posts. Weinmann are on the list of std posts.

[Alex Wetmore]

There aren't really standard centerpull brake posts.  Diacompe ones aren't even consistent, the Diacompe GC brakes use shorter posts than the DC750s for instance.

Most or all are 8mm in diameter, but the length and the shape of the base is not always consistent.  Brazed on centerpull brakes are great, but in my mind when you pick a brake you are making a lifetime choice for the bike.

Alex

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Subject: [650B] Re: WTB Paul Racer Braze On

 

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[Hahn Rossman]

Also to add to Alex's comment:

The weinmann/dia compe brakes use the same boss as mafac, but they use the same spacing for all the brakes.Mafac uses a different spacing for the raid versus the racer or competition. 

The RH bosses are functionally interchangeable with the dia-compe clones of the original mafac boss.

The problem with the Paul brake is using "non-wacky" bosses, which are bulkier than all the other ones. This doesn't matter for cantilever or v brakes, but for centerpulls the pivot is where you need clearance for the fender or bigger tire.

Your builder should be happy to use the RH bosses, which are even premitered! They are more expensive than cantilever bosses, but time is money!

Hahn Rossman

To view this discussion on the web visit https://groups.google.com/d/msgid/650b/CO1PR01MB6679C47D262FA7B8F36E4CFAD5BF9%40CO1PR01MB6679.prod.exchangelabs.com.

[ericni...@gmail.com]

All braze-on Paul brakes mount on the same standard canti post, just in different locations.  A framebuilder can shorten them and leave off the spring perch to get a cleaner look.  

However, one does not need to use a canti post at all!  Paul brakes contain their own strong steel pivot, so they don't need to rest on a canti post.  They only need a flat surface next to an M6 threaded boss. Here is an example:

These bosses were made from 1/2" steel rod, center-drilled, tapped, and coped. I rode this fork for many years, including multiple brevet series and PBP.  Worked great. 

Eric in NH

[JohnS]

Thank you Eric for sharing the image of your fork and brake bosses. Its a good looking functional and minimalist solution.

JohnS

[Squire Black]

Mafac RAID centerpulls fit the Rene Herse posts.  Indeed, the Rene Herse centerpulls are nothing more than more nicely finished (and more expensive) RAIDs.

[Benz Ouyang]

On Friday, October 22, 2021 at 5:35:20 AM UTC-7 ericni...@gmail.com wrote:

All braze-on Paul brakes mount on the same standard canti post, just in different locations.  A framebuilder can shorten them and leave off the spring perch to get a cleaner look.  

However, one does not need to use a canti post at all!  Paul brakes contain their own strong steel pivot, so they don't need to rest on a canti post.  They only need a flat surface next to an M6 threaded boss. Here is an example:

These bosses were made from 1/2" steel rod, center-drilled, tapped, and coped. I rode this fork for many years, including multiple brevet series and PBP.  Worked great. 

Did you use the pivots specifically designed for their center-mount conversion kit, with the inner diameter sized for M6 bolts? I ask because the braze-on pivots need to accommodate the canti braze-ons, and thus have thinner walls. In addition, the surface on the braze-on pivots that would contact your prepared flats is quite small/sharp, instead of a flat mating surface like that of the center-mount pivots.

[ericni...@gmail.com]

Yes, these bosses were paired with center-mount brake pivots.

Eric in NH

[steve...@gmail.com]

Thank you all for the great info. My gmail wasn't alerting me to the convo thread and forgot to check. A member had a pair of the Pauls, so I'm going with those. Very interested in the DIY post build Eric. 

Since this is a conversion of a Rambouillet that fits me, I'm just going to go with the Paul's for now. If I ever commission a custom frame, I'd be dreamy to spec the Rene Herse stuff.