Current Projects chat and miscellany

Yep, based in Edinburgh! Being able to sod off to the mountains at a moment's notice is probably the best thing about living here I reckon.

24.7mm

That looks like the diameter difference. The change in BB height will be half that.

The difference between a 700c wheel with a 38mm tyre and a 26" with 2.25 is 24.7mm.

Does that mean a 2.5cm lowering in BB when chucked on a bike?

Diameter of a 700c wheel with a 38mm tyre: 698.00mm;
Diameter of a 26" wheel with a 2.25" tyre: 673.30mm.

So the bb drop is (698.00-673.30)/2 = 12.35mm.

[Source]

Diameter of a 700c wheel with a 38mm tyre: 711.00mm

That seems like a lot, I'd have guessed at more like 698mm. I've got some 38s waiting to go on, maybe I should do that and get my tape measure out :)

[Source]

You've pulled the OD from the 635 rim table, scroll down to 622 and it agrees with me.

You've pulled the OD from the 635 rim table, scroll down to 622 and it agrees with me.

Yep, you're right. Had a brain fart and looked under 28". Thanks for the correction. Edited my original response.

The Donohue got some new pedals, courtesy of @robinmarine which I'm taking as an excuse to post a terrible phone photo here. Still needs a silver seat post and some mudguards fitting for winter. Might try and get a riser set up as well. If anyone has a nice skinny 1" ahead stem around 90-110mm send me a message!

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673.30

While we're being pedantic, quoting an overall diameter denominated in hundredths of a mm is pretty meaningless. Even if the tyre is exactly 2¼" wide, the overall diameter depends a great deal on exactly which tyre and what rim it's on. Oh, and your source is fundamentally flawed because it simply adds twice the tyre section to the bead seat diameter and that's not how clinchers work. You quickly learn how much of problem this is if you use this method to set up your medium gear bike, because you will over run the roll out test if you set it to a theoretical 72" exactly.

68cm seattube to top haha 61 tt. No clue how it ended up with bottle cages

@Tijs @BlackMath gold star for both of you.

Won’t be keeping it, will be going to someone the right size in a couple of weeks

Glad they went on such a nice bike! Orlowski forks?

While I'm here

Trying to attach rotor 3D 30mm cranks to BSA frame using BSA 30 BB

Needing to use a heck of a lot of pre-load bolt thread- is this usual?

Internet seems to suggest no additional spacers required with a BSA bottom bracket

Any help appreciated, here's a photo of the current situation

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It's not really clear in this picture, but if I remember correctly these BB cups need pretty think dust caps on the outside (both NDS and DS). Are these on here?

I have the dust caps but in the manual it said they were to be used on BB30 bottombracket frames to make up for the shorter BB width

Ah yes t'was.

if you want rid of the rx100 shifters and chainset, let me know- i'd love to have a full matching group for my CAAD2, I got mine with a mix of rx100 and sora with a random triple chainset

This is great. You have too many envy inducing bikes.

How terrible is this? (Alan CX, 2 small cracks in the bb lug) Not mine, but thinking about getting it

Are Alans valued because they're old and unique?
Because the construction method just seems like a bad idea, given the glues of the day, et cetera.

Rychtarski! Columbus Max and very nice to ride. They've got a really nice subtle sparkle which my awful phone camera can't seem to capture.

the construction method just seems like a bad idea, given the glues of the day

It was a bad idea in retrospect, but it wasn't completely stupid. The lessons learned gave us the bikes we have now.

Does anyone have a pair of silver full width 25.4 clamp on-one fleegle bars in their parts bin spare?

They're only £8 on PX. Apologies if you already knew that.

Like this one!

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