Yet Another Cycling Forum

General Category => The Knowledge => Topic started by: eckagain on 17 November, 2019, 05:31:35 pm

Title: Oversize clamp for downtube gear levers?
Post by: eckagain on 17 November, 2019, 05:31:35 pm

Does such a thing exist?  ???
I'm thinking of converting my 1996 Marin Bear Valley from flat to drop bars. I don't fancy bar end shifters or Ergo / STIs.
Problem is that the downtube doesn't have bosses, only cable stops (very high up. close to the head tube)  and, more importantly, the downtube itself is oversize, about 34mm diameter, so a normal downtube clamp won't work.
I've plenty of spare, assorted levers, so just need the clamp.
I've tried the usual suspects, SJSC, Spa and Velo Orange.
Any ideas? Thanks.

Title: Re: Oversize clamp for downtube gear levers?
Post by: IanDG on 17 November, 2019, 08:23:27 pm

Problem Solvers do a 31.8 clamp, probably need to use an American supplier and at $40 it's not cheap.

https://problemsolversbike.com/products/shifters-derailleurs/downtube_shifter_mount_-_31244

Title: Re: Oversize clamp for downtube gear levers?
Post by: Paul H on 17 November, 2019, 08:36:06 pm

There's plenty of options to mount bottle cages without the braze on thanks to bikepacking fashion, you might find one suitable, though you'd need one for each lever.
Here's a selection
 https://bikepacking.com/index/add-cage-mounts-bike/
The DMR Hinged clamp looks the most robust.

Title: Re: Oversize clamp for downtube gear levers?
Post by: mzjo on 17 November, 2019, 08:42:18 pm

SJSC do Problem Solvers kit IIRC so if they haven't got it they might still be able to get it, if it exists. Have you asked or just looked at the website?

Looking at that Problem Savers clamp my first reaction was "3D printer" but it would likely end up very fugly and mahoosive if it was going to be strong enough (although would solve any problems of non-round tubes).

Title: Re: Oversize clamp for downtube gear levers?
Post by: JohnL on 17 November, 2019, 09:38:43 pm

What about stem mounted?

Title: Re: Oversize clamp for downtube gear levers?
Post by: mzjo on 17 November, 2019, 09:51:02 pm

Quote from: JohnL on 17 November, 2019, 09:38:43 pm

What about stem mounted?

But use modern levers! The levers on old stem mounts (friction ones) don't pull enough cable for more than 6 cogs and sometimes it is difficult to stop the lever banging on the top tube in bottom gear. DAHIKT

Title: Re: Oversize clamp for downtube gear levers?
Post by: Brucey on 17 November, 2019, 11:00:01 pm

https://www.sjscycles.co.uk/gear-spares/origin8-down-tube-shift-adapter-286318mm/ (https://www.sjscycles.co.uk/gear-spares/origin8-down-tube-shift-adapter-286318mm/)

or better ( I think)

https://www.sjscycles.co.uk/gear-spares/kelly-take-off-gear-lever-adaptors-per-pair/ (https://www.sjscycles.co.uk/gear-spares/kelly-take-off-gear-lever-adaptors-per-pair/)

cheers

Title: Re: Oversize clamp for downtube gear levers?
Post by: Torslanda on 04 December, 2019, 06:39:15 pm

Crossbar mounted? Provided it's 28.6mm.

Or am I talking thru it again...?