Ritte Bosberg Seat Topper

Discuss light weight issues concerning road bikes & parts.
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gmitt98
Posts: 57
Joined: Thu Apr 05, 2012 6:49 pm

by gmitt98

Hi Guys,

I'm putting the final touches on my new Ritte Bosberg build, going for the lightest build I can afford. I've got a new carbon-railed Specialized Romin to top it off, which means that the OEM mast topper won't work (and it's a bit of a porker, anyways). However, the mast seems ever so slightly oversized, enough so that a Woodman 34.9 topper was uncomfortably snug. Has anyone upgraded a Bosberg mast topper before, and if so, what fit? Or is my frame just wonkish? I will sand off the clear coat from the inserted section if I really need to, but I would rather not. And if I have to use the OEM topper, then I'll need a different saddle - which would make me sad.

Galen

gospastic
Posts: 266
Joined: Tue Jun 08, 2010 4:58 am
Location: Chicago

by gospastic

I use the stock topper and my carbon railed Selle Italia SLR works just fine.

I've used a Ritchey topper temporarily and it fit a lot tighter than the stock one.

by Weenie


Valbrona
Posts: 1482
Joined: Fri Oct 28, 2011 3:25 am
Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

You need to measure the OD of the seat tube and get a topper that fits.

gmitt98
Posts: 57
Joined: Thu Apr 05, 2012 6:49 pm

by gmitt98

I did measure the OD - it's supposed to be 34.9 but it's 35.1-ish. I think it's a paint/clearcoat thickness issue. I guess I was wondering if there was a topper out there that was machined with wider tolerances that people had experience fitting.

gospastic - what shape are the Selle Italia rails? The Romin has ovalized rails and says specifically to not use it with side-clamp seatposts, which makes me nervous about trying to put it on the Ritte OEM topper.

gospastic
Posts: 266
Joined: Tue Jun 08, 2010 4:58 am
Location: Chicago

by gospastic

The rails are oval, 7x10. I haven't had any issues, but my topper doesn't clamp from the side. Did they change the design?

gmitt98
Posts: 57
Joined: Thu Apr 05, 2012 6:49 pm

by gmitt98

Yeah, mine has a Ritchey 1-bolt style clamp.

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lancejohnson
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by lancejohnson

Even though you call it 'uncomfortably snug', I would just use a 34.9 topper on it. There should be about .1mm of slip and if you take some fine grit sand paper and just remove a bit of clear coat from the top of the mast in very small increments and refit the head, that would be better than having a 'loose' head that has to be excessively compressed to get proper clamping on the mast.
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Valbrona
Posts: 1482
Joined: Fri Oct 28, 2011 3:25 am
Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

Look at the Ritchey websiteb bottom RH corner of this page http://www.ritcheylogic.com/dyn_category.php?k=98376 and you will find replacement clamp sets to take oval saddle rails, if that helps.

thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

ive had ritchey seat masts be an excruciatingly tight fit on some of the Wilier CentoUno SL they came with. sanded the seat tube. wilier said after to sand the topper, but since the frame was the one out of spec, i disagreed. ive seen some not reduced enough, the topper eventually cracks. so be careful.

gmitt98
Posts: 57
Joined: Thu Apr 05, 2012 6:49 pm

by gmitt98

Thanks guys! I'll sand the new topper a little bit and see if I can make it fit. I'm not worried about cracking the topper as much as I am cracking my frame by over-compressing it. The new saddle & mast should knock off ~120g over the stock topper & steel-railed SMP on there right now, so it's a worthwhile endeavor.

gospastic
Posts: 266
Joined: Tue Jun 08, 2010 4:58 am
Location: Chicago

by gospastic

How much does your topper weigh? I've considered going to something lighter but honestly haven't found it worth it since the stock one is color matched and isn't that terribly heavy.

KWalker
Posts: 5827
Joined: Mon Dec 28, 2009 8:30 pm
Location: Bay Area

by KWalker

gmitt98 wrote:I did measure the OD - it's supposed to be 34.9 but it's 35.1-ish. I think it's a paint/clearcoat thickness issue. I guess I was wondering if there was a topper out there that was machined with wider tolerances that people had experience fitting.

gospastic - what shape are the Selle Italia rails? The Romin has ovalized rails and says specifically to not use it with side-clamp seatposts, which makes me nervous about trying to put it on the Ritte OEM topper.

You can use it with them just fine. I'm convinced the only reason Speci has this is because they don't make a side load clamp for these rails.
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by Weenie


gmitt98
Posts: 57
Joined: Thu Apr 05, 2012 6:49 pm

by gmitt98

I think the topper is ~150g (I would have to go double check)

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