Quick general question about installation…

The shim is a customised USE type with a large flange probably 4-5 mm that will protrude above the seat tube.

There are two options, to install the clamp first and then shim on top so that the clamp operates on the tube completely and the shim flange protrudes above the clamp, or install the shim first and install the clamp on top which will mean a large part of what the clamp is operating on is shim and not tube.

I’m not sure whether I think this matters or not – either way, the shim is acting on the seat post to transfer the clamping force, so is it really a problem having some of the force directly on the shim? It looks better that way…

You just drop the shim into the seat tube, the flange (ffnar) sits on the seat tube and drop the post in. Tighten as usual.

I don’t see how you can install it a second way? Are you talking about having the clamp right at the top of the tube so it covers the flange as well?

I test fitted earlier and both methods fit. Obviously 5mm of shiny sticking out over the clamp against a black post looks crap.

I was just wondering if the lack of frame contact for the clamp was an issue though- the Thomson seat clamp I’m using is really about 75% on the shim flange and 25% on the seat tube. I’m not sure if this makes a difference or not, hence the question. I wouldn’t normally choose to run a shim, this frame needs one though.

Don’t install it before the seat post clamp.

I see disadvantages to both approaches.

I’m thinking that priorities are efficient clamping and minimal chance of frame damage.

Is the clamp more effective directly on the seat tube and fully engaged with it?

Why design such a pointless extra area of metal into the thing? I can’t see the very large flange providing any benefit…

The clamp should be in full contact with the seat tube, for max clamp force. There is no disadvantage to this, bar aesthetics.

The only way to avoid that Is the correct size of post.

Correct post size is impossible in this case (very long story) and this particular bike always needs a shim due to a remanufacturing mishap. I accidentally destroyed the previous neater shim (with barely there lip) a few weeks ago when I forgot I’d bonded it in a couple of years ago and gave it a good tug.

Pooh. Oh well, maybe I’ll look as getting the top of shim being black with some spray or something. I can understand a lip to stop the thing falling in, but something the height of a Bic biro is excessive!

I’m struggling to visualise your options (and your shim) – got any pics ?

Me too , really need pictures . Why was the shim customized ?

I’ve never seen a 5mm flange on a seatpost shim.

Clamp round the frame/seat tube.

You have now…

Yup, USE have that big lip. Not sonething you notice once fitted though IMO.

Shim is customised for two main reasons – width and length.

The refinisher at the end of the remanufacture process unexpectedly used an acid dip to remove remaining paint, which affected (melted) a designed in shim at the top of the tube as the guy wasn’t expecting it not to be all steel. This left a step in the tube about 90mm deep (shorter than a USE shim) and an odd diameter that needed normalising to 31.6.

Thus, the manufacturer supplied USE shims with 10mm off the bottom and a bit cut out down the length to get the odd diameter. Frames were sold as seconds with oddities declared. The original shim was neater, must have had most of the flange machines off too but iirc was a sod to fit. The replacement fits better but is more visible.

Sorry,
Pure curiosity but what frame is it?

Just bolt it on as usual, clamp on, shim in, post in, do up. If you cover the flange with the clamp then you won’t be attached to the seat tube properly.

I’ve used use shims before and you don’t even notice the flange when assembled.

Instal the clamp before the shim so the clamp has more contact with the frame. Then either spray the shim black so it matches or file down the flange. I have a use one and the flange is only about 2mm tall. All it does is stop it falling into the frame when the clamp is open so filing it down will have no impact on it’s efficiency.

Sharpie on the top of the shim.

oh, yeah then – definitely need the clamp around the seat-tube and so below the lip of the shim and do whatever you like with the protruding bit of it as long as you leave a small lip (of any colour you can paint it)

Bit too much to sharpie in, there’s almost as much exposed shiny alu as a seat clamp which looks a bit daft between a black clamp and black post hence I was wondering if hiding it under the clamp was a problem. I can see the argument for not, I’d be clamping the shim and post together and nipping the edge of the seat tube, which in retrospect is a dumb idea. 🙂

I reckon I’ll spray it black and forget about it again for the next four years…

Frame is one of the first batch of Soul275’s which had quite a saga. They weren’t right when they landed apparently and so had some welding done (additional gussets HT:DT for sure, not clear what else) and then went for powder coating. Easily recognisable; matt blue and matt orange powder. They ended up being sold cheap because some people whined that the decals weren’t under clearcoat…

Wow, some people are that fussy about looks?

I know! 8) So far as I was concerned I got an awesome deal on a frame.

Strange I’d have no issue with the decals sitting on top of powder but silver between two black areas puts my teeth on edge!

I have a black stem, black top cap, two black spacers and TWO SILVER ONES.

I honestly couldn’t cope with that. Unless it’s a deliberate accent I like my finishing kit the same colour.

I’m fine with mixing tyres and stuff though which I know some people freak about!

Can’t mix tyres unless they are a designed combo.