Mechanics and Fixing Any Questions Answered

Stupid fat fingers on a smart phone…

You can assume a rechargeable is 3.7 V unless otherwise stated, so your light is likely 3.7 x 10.8 = 40 Wh. That would correlate with it containing three 18650 cells, which other big Exposures do.

So your light consumes 20W of power, or 20/460 = 4.3% of her eBike battery per hour of runtime.

Thank you!

Anyone know of someone who can weld 7005 aluminium? I have a genesis day 02 frame which is lovely aside from the sliiiight problem of a crack in the headtube coming up from the bottom cup about 1cm.

Obviously I’m not gonna ride it like that because as ugly as my face is, I’m attached to it and am quite keen on keeping my teeth as it took me a long time to grow them - but -

The internet tells me 7005 Alu (which this frame is) can be welded so… here I am asking for help

I’m in Kings Lynn / Norfolk if anyone magically knows someone nearish that can do the work

Patrick at Limit Fabs, conveniently in Norfolk.

TLDR: How do people with small hands work with STI levers? Might need new calipers to replace [edit: 4500] Tiagra, what's the most cost efficient?

Trying to kit out my girlfriend with a bike at the lowest cost possible (she mainly wants to get from point A to point B, I'm trying to help her do it a bit faster) and bought a pretty great bike off someone here. Only issue is that her hands are tiny, and she is having difficulties braking from the hoods. She can apply sufficient force from crosstops, also from drops, but she spends most of her time in the hoods and is feeling uncomfortable with not being able to brake efficiently from there in the event of emergencies.

Levers seem to be ST5600 3x10 flight decks, while callipers appear to be Tiagra [edit: 4500]. Levers are a bit stiff, but she can pull them all the same, just not exert sufficient force on them. Things I have tried so far:

1. Angle the hoods upwards to put the bottom parts of the lever closer to fingers
   
2. Swap out brake pads for the salmon jagwire ones decathlon sell
   
   

Things I am thinking of trying:

1. Clean wheel surface
   
2. Swap out callipers
   
3. Swap out rims
   
4. Swap out levers
   
5. Bail on the current setup and get a flat bar system/down tube/bar end shifters and single-speed brake levers
   
   

I'm not sure dirty wheel rims are an issue since I've not cleaned mine in a million years and they brake just fine, but at the same time I've tried her bike and I don't seem to be able to lock the wheel. Rims definitely have wear in them - could that be the issue?

Leaning towards swapping out the callipers since I've had 4600 before and their performance was not confidence-inspiring, so I'm wondering if they're the issue. If I do so, are there compatibility issues I should be concerned with, or can I just get any brake calliper (I'm thinking 5700 or 4700[edit: or Sram Apex/Rival]) and replace it?

Because of cost (and, if I'm being honest, the faff involved) I would probably want to avoid the last two if at all possible, not to mention I'm not entirely sure whether swapping out levers might actually make a difference if the callipers are the issue. At the same time, the shape of the 5600 levers are really not ergonomic for small hands..

Sadly it’s not been addressed by manufacturers until recently. Home fixes include:

Set up slack brakes so they engage closer to the bar where small hands grip harder (not ideal in emergencies).

Use hor glue or other material to create a stopper at the top inside of the brake lever, preventing it from travelling all the way out.

High quality pads and callipers. Don’t underestimate how poorly contaminated pads and rims can perform!

Angling hoods up or down, to suit.

Possible that there are reach adjustment shims out there somewhere, like these for the 5700

https://www.bike-components.de/en/Shimano/Reach-Adjustment-Block-for-ST-6700-ST-5700-p35236/

Compresionless housing for the cables might help as well, since it helps to transfer all the force applied at the lever to the caliper

Thanks a bunch! Any issue with using dish soap on rims? Also would I have any cable-pull issues with using any callipers with the 5600 levers? I've read somewhere that the 5600 levers (Super SLR, dating to 2005) have a longer mechanical advantage (3.5:1) than subsequent generations (3:1); would that create issues?

Trying to source a left crank arm for a customer with a Genesis with a fucked pedal thread.

It's a Samox TAF37 crankset - 170mm, which I'm finding difficult to source so looking for a generic replacement. Any ideas where to start, or suggestions for a replacement?

Day one?

There was a recall on them, check with the customer when it was purchased and if they are the first owner and have the receipt.

Think it's a flat bar Croix de Fer from last year, sadly

Dang.

Bob Elliot does left hand crank arms for not a lot of money.

Currently building a salsa fargo with a rohloff speed hub 14 and gates carbon belt drive.

I'm hoping to use a Shimano deore xt chainset to mount the front chainring but I am struggling to calculate the correct chainline.

Anyone got any advice.

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Dish soap is probably fine, just don’t leave residue. Give the pads a scrub too. If you have rubbing alcohol, give the surfaces a clean with a wetted wad of paper when you’re done.

Longer pull does play into it, yes.

Are the pads Shimano?

I had initially put in some black R55C4s but they seemed a bit too hard/slippy so swapped them for red Jagwires instead. Bike is pretty old so I'm hoping maybe a change of brake cables and housing might improve braking performance, but also worried that marginal gains aren't going to change things much..

Anyone know if small cogs work alright on Sturmey AW hubs? I'd like to build a wheel for my raleight Twenty with one and would need to use a cog around 12 or 13t. Some of the photos of them on ebay make it look like the chain might hit bits of the hub if a cog that small is used.

Sturmey Archer make a 13 tooth cog OEM so I guess that will fit?

If you use a Brompton hub (or just the driver) with Shimano splines you can use a 12t.

Aye I saw that, did wonder if they were for other hubs in the range but then there’s specifically ‘AW’ cogs in that size so should be alright I guess. They were pretty common fitment on Bromptons I think and would have needed small cogs for that.

“…the driver…” So that’s a separate piece? Hmmm…

for my raleight Twenty with one and would need to use a cog around 12 or 13t

Need? 48/14×4/3×20"=91" top gear, which seems like more than you'd ever need on a shopping bike. Also 68" direct and 51" low are more than I'd want.

Maybe I need to do my maths. It’s single speed just now and I think it’s on something like 48/14.

Edit: Realise that makes little sense but I'm feeling like it's currently a bit under geared so thinking I'd fit a smaller cog.

I'm feeling like it's currently a bit under geared

But it probably won't feel undergeared if you have the upshift option. Anyway, sprockets are cheap so get 13 and 14 and see how it goes.