Any question answered...

Garmin make a specific strap for swimming, which is wider than normal ones and is designed to stay in place whilst you are in the water- intimating that non-swimming-specific straps will end up as a loose waistband. It’s also designed so that it transmits your HR at the end of your session as Bluetooth, ANT+ and I suspect many other RF transmissions don’t make it through water. Wrist based HR within the watch that is gathering the data strikes me as a better approach, but I have to say I personally would go for the super nerdy option: HUD goggles that monitor your HR.

https://www.formswim.com/pages/polar

Well I obviously want those now.

Wrist based HR within the watch that is gathering the data strikes me as a better approach

While browsing today I almost pulled the trigger on a Garmin option. Then I remembered they're essentially wrist-mounted bricks at the moment.

is there something about the geometry of the Surly which makes the front wheel less inclined to track back into a straight line after receiving a shock?

The steering geometry of the crosscheck could hardly be more conventional, so the problem is not likely to be found there.

I tried a super cheap one (sub £10) out of morbid curiosity*, and even though they “work” (as in they have a nice colour screen and can show your heart rate), the software is so poor that they’re not much more than Xmas cracker toys. IIRC you could log a workout but it wouldn’t activate the HR monitor during it...

I’d avoid anything you don’t have a personal recommendation that it actually works.

(* I already have an Apple Watch)

Yeah, that's my concern with the many 30-40 quid options.

What surface?

Tarmac. Chipseal type thing.

As it's a long frame, the surly has a shorter stem than my other bikes. Maybe there is a weight distribution thing that is making a difference.

Have both offs happened when you're tired?

I mean, the second one sounds like it might be. 3 hour ride? (anything over an hour for me is long, so I might be skewed there)
Maybe your weight wasn't on the front so much? Hit a lump, boom off.
First one, maybe similar?

I think it's more about inattention than tiredness, but yeah; I guess the two things can be related.

I'm probably just trying to rationalise my own stupidity, but the impression I have is that on other bikes, I can have a wobbly moment and recover it, whereas this one seems to be less forgiving.

Which is the opposite of what is expect from the slacker angles on the Surly.

Definitely. Recommend this dude’s video: https://m.youtube.com/watch?v=OyE67jKp1To

Been feeling a bit to much weight on my hands on the bike recently. If I move the saddle back about a cm or so, is that enough to make a difference?

Definitely. Recommend this dude’s video: https://m.youtube.com/watch?v=OyE67jKp1To

Are these listings legit?

https://www.ebay.co.uk/itm/223146680854

Certainly possible that they are.

eBay and PayPal will have your back if they are not.

Obvs. the stuff isn't going to arrive tomorrow, and you might get import duty, admin and VAT on it.

Given it's the basic Deore kit, you might find equivalent kit for similar prices (after import and VAT are paid for) on CRC or German websites

Are these listings legit?

Why does it matter? You can get the same parts from ze Germans for less
Ebay RD-M5100+SL-M5100+CS-M5100/11-51 = £123.98, same items from /www.bike-discount.de £121.80 with quicker delivery and VAT already paid

Thanks!

Double thanks!

Geometry question:

I have rectangular mouthed bag 510 x 250mm, into which I want to sew a drawstring top, this would close up to be a rectangle fitting the top.

When open it is in effect an extension upwards of the existing bag.

Maximum length of material needed is therefore 280mm (which is half 0f 560 - the long side of the triangle). This will be too much material elsewhere - coming in from the midpoint of the long side to the middle is only 125.

Presumably, the change from longest to smallest is a straight line (blue)? If it is a curve (orange), what kind of curve??

Diagram attached will make all clear.

1 Attachment

What's your vision for how the centre hole will look when closed? If you're happy with a slot, a top 125mm will do.

If you want an infinitely small hole (let's ignore the practicalities of the material, the corners need to be the length of half the diagonal, which you can get by pythagoras - square root of (a squared plus b squared)

And that also gives you the shape of the curve, where a is the distance from the centre of the edge you're drawing and b is half the length of the other side.

ETA: Curve of the long side https://www.desmos.com/calculator/fkuqjnmsqd

a circle would be preferable to a slot

so i could do say, 10 pythagorus calculations and join up the points. is there a better way? like a 4 circles one from each corner all intersecting the middle?

doublepost

from looking at that graph, i can get away with shallow, straight lines i think.

Was gonna suggest looking up climbing chalk bag schematics online, unless you’re interested in the actual calculations.

While browsing today I almost pulled the trigger on a Garmin option. Then I remembered they're essentially wrist-mounted bricks at the moment.

They're back, and they were never really bricks. Anything recent can have the files taken off it via USB, which is what I do anyway to upload to Strava. I've used my Garmin (Forerunner 945) for the last 4 days with no problems, it just didn't sync to the phone or website, but I could still use it perfectly fine for recording activities and then uploading those to Strava.

For swimming you either need a strap, but you'll need a swim specific one as a normal HR strap (like the waterproof HRM-Tri) just gets pulled down each time you push off from the wall.

Or you need an optical HR that is rated for swimming (the Garmin wrist based ones on the back of the watch aren't). If you're wearing something on the top (i.e. a skin or a wetsuit) then an HRM-Tri should work fine without any slipping.

I've never had a problem with the Garmin HRM-Swim strap slipping down but it's still not 100% comfy.

None of the straps can talk to the watch during the swim because the signal can't get through water to the watch. The Garmin HRM-Tri and HRM-Swim are designed to store the HR data and then have it downloaded from the watch as you end the swim.

I don't think there are any 3rd party straps that can record data AND integrate with Garmin so you can download the stuff to the watch at the end of the activity.

To avoid the strap I moved to using a Polar OH1+ mounted on the goggle strap and reading HR from my temple. That's much easier although the downsides are:-
a) it sometimes gets flipped over and you don't notice = no HR
b) it doesn't integrate directly with Garmin, so you have to end up downloading the FIT file from the Garmin and then HR file from the Polar App (after syncing both) and then finding a way to combine them (which isn't simple).

You can use the OH1+ when running too although, again, it's not as good as a proper HR strap.

[EDIT] If you just want HR info from a swim, and no info such as lengths/distance/pace/etc then a Polar OH1+ on the goggle strap would be the simplest. You'd only have to get the data from the Polar app/website after syncing and then you could upload that anywhere.

If you want swim info (like this: https://connect.garmin.com/modern/activity/4067649025
) then you'll need a better watch and probably the HRM-Swim strap. I've got a Garmin 935 (no strap) you could have for £250...

Where can I source this dropout?

On a Chinacarbon frame so a bit of a mystery...

Workswell 162

2 Attachments

Have you tried the Facebook pages Shenzhen Workswell Bikes Co. Ltd?
It says any - Please contact Chris sales05@workswellbikes.com if you have any inquiry or questions.

I would say you have more chance there than here.