Down Tube Shifters - Surly Cross Check

[Hey_Presta]

Hi,
I’d like to fit down tube shifters to my Cross Check. I have a pair of 10-speed Dura Ace shifters which look the part. The downside is that the radius on the mount is for a skinnier tube than I have so it’ll not seat fully. I haven’t installed them as they are brand new and I think that they may damage the paint which will look a mess if (when) I change the build...
Has anyone got any experience of these shifters?
Are there any other type which uses the flats on the bosses the prevent them from spinning rather than mount with radius?
Thanks in advance, any help much appreciated...

[slowster]

You need to buy two of these:

https://www.sjscycles.co.uk/gear-spares/shimano-sl6028-lever-boss-cover-for-alloy-frames/

Shimano down tube levers come with either the curved boss lever covers for narrow frame tubes, or the above flat boss lever covers for oversized tubing and those early aluminium fames, like Cannondale, whose lever bosses had a large flat surround.

Usually the levers sold by most retailers come with the curved boss lever covers, but not many retailers make it clear which version the pack contains. Bike Components offer both versions of most of the various Shimano down tube levers and make it clear that they are flat (described as for 'aluminium frames') or curved (described as for 'steel frames').

As far as I am aware, the covers are the same whether they are for Dura Ace levers or the R400 8 speed levers.

[Hey_Presta]

Brilliant, thanks very much!

[Hey_Presta]

I’ve had a thought...
Maybe I could change the radius on the mounts by wrapping the down tube with emery cloth and then use it as a “former” to rub the mounts on..? I’d have to make sure they’re orientated correctly which may not be easy...
Worth a try?
Cheers

[Brucey]

yes that'll work....

….but.... the bezels are chrome plated die castings. IME once the chrome plate layer is breached, corrosion soon follows, and the bezels soon look really tatty.

Best to get bezels you don't need to modify.

cheers

[nsew]

Odd. A paint thickness thing? I don’t think Surly have increased the down tube diameter. Here’s a Cross Check with the curved boss covers and the paint does appear to have squished a bit. Looking at the size of the gap in photo I’d be inclined to go ahead with what you’ve got as the flats certainly aren’t going to be flush.

[Mick F]

Try them on a Moulton.

Ad hoc designed bosses to fit into the front rack mounts.
Yes, I could buy the flat covers, but it's all a Heath Robinson thing anyway on a Moulton, and they work brilliantly.

[nsew]

Update. I have an oversized 31mm down tube on one bike and the curved boss cover sits as yours does on the boss (with the gap) but doesn’t penetrate the paintwork when tightened up with a d/t lever. The reason being the cover can’t move any further in as the square boss section doesn’t allow it. So you’re good with what you’ve got.

[Hey_Presta]

Thanks everyone, I’m very grateful for all your help
Cheers

[reohn2]

yes that'll work....

….but.... the bezels are chrome plated die castings. IME once the chrome plate layer is breached, corrosion soon follows, and the bezels soon look really tatty.

Best to get bezels you don't need to modify.

cheers

I have to file the curved bezels to fit my Kelly Take Off's(wasn't aware there were flat bezels),they've never deteriorated in all 15+ years I've been been using them

[Brucey]

I guess you may not have sweated copiously over them....?

cheers

[reohn2]

I guess you may not have sweated copiously over them....?

cheers

That's a point though even if they were mounted on the D/T,me being a lazy beggar of a cyclist I try to avoid sweating profusely enough to reach the D/T at all costs

[Hey_Presta]

I fitted the shifters today but they started to squish the paint so I took them off. With nothing to lose, I had a go at filing one of them. This option looks promising as I reckon I’ve taken enough off one side without breaking through into the alloy...
Time will tell
Cheers