E-bike without rear disc mount

[Smurf2]

Sorry, I just want to get the point.

Is that in package same size of calipers and two same size adapters?

If yes, that means that every manufacturer of bikes made rear IS mount 2 cm lower than front?

If yes, to resolve this, we can ignore 140/160 adapter which come in package and need to buy 2 bigger and different adapters for 180 discs?

Amazon

EDIT:
Also found at home used front wheel with disc mount.

For front 180 need this?

For rear 180 need this?

 

[Smurf2]

I was just happy because I found Shimano caliper TX805 for good price on AliExpress, then figure out that have only one piston

Who knows which Shimano mechanical caliper is cheapest (with two pistons)?

How are Zoom DB680? They works with Shimano pads (but need modify pad).

EDIT:
Found BB7 on Aliexpress, 2 calipers for 58€. But they are 1 piston too.

So, how is stoping power on 1 piston? In this case better looks shimano 1 piston than Avid.

 

[nicobie]

People here seem to like the Avid BB7. I know that I do.

 

[amberwolf]

BB7 on Aliexpress is almost certainly a fake or clone, not the real thing. I would not buy them there. The super-cheap price alone is a giveaway that it's not the real thing. (you might find a sale for a single caliper for that price...but not a pair).

This one is real

https://www.amazon.com/gp/product/B00553YPEY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

as it's what I'm using.

A single BB7 with 200mm rotor on my 26" wheel with a CST City tire on the front of the heavy heavy-cargo trike SB Cruiser gives so much stopping power I can easily skid the wheel from 20MPH, so more than I can use.

I expect on a regular bicycle with normal front wheel traction and no super-heavy backend, I could probably flip the bike or do a stoppie with it (but I can't ride regular bikes anymore, so I can't test this theory).

 

[Smurf2]

on the front of the heavy heavy-cargo trike SB Cruiser gives so much stopping power I can easily skid the wheel from 20MPH, so more than I can use.

Didn't know that.

Also I read that 1 piston can bend a rotor, and you must return it back.

140$ is a really big investment, especially for old bike.

 

[Chalo]

Also I read that 1 piston can bend a rotor, and you must return it back.

You heard wrong. Bicycle rotors are designed to flex, and if adjusted correctly you're looking at less than 0.5mm it needs to flex anyway. I would disregard technical advice from whoever told you that.

 

[99t4]

140$ is a really big investment, especially for old bike.

The age of the bike is not relevant. But spending $140 on a low quality bike, as yours is, , that may or may not appreciably improve braking performance, might be seen as foolish.

 

[Smurf2]

Found old wheel with rotor at home. After I watched many tutorials, it seems that is single wall rim. Label says 26x1.5. (My outer tires are 26x1.9).

The spokes are very tight and strong. But as you can see, they go out, over the border rim.

Few of them goes over nuts, but they can be removed with sander disc.

I have that plastic (or whatever it is) from other dual wall rim (in good condition). Can add some electric tape too. But will be that enough to prevent damage the inner tube?

 

[99t4]

Here is the helpful information for you:

Wheelbuilding

A tutorial on how to choose parts for, build and true a spoked bicycle wheel

www.sheldonbrown.com

Pay extra attention where he talks about correct rim tape width:
"The rim tape must be just wide enough to fit the bottom of the rim. Too narrow, and it doesn't cover what it needs to. Too wide, and it rides up on a bead seat of the rim as shown in the photo below, preventing the tire from seating correctly. The tire will sit too far out where it rides on the rim tape, and too far in at another place. It will give a bumpy ride, and there is a risk of a blowout."

 

[lnanek]

Never seen spokes that stick out that far, maybe all my rims are double walled.

That said, I never reuse rim tape. I always put a thick new layer on of this:

Amazon.com

Has definitely saved some old used rims where the spokes would pop any tube I put in them until I started doing that.

 

[amberwolf]

I don't much like the plastic "rim tapes" but if yours is intact, slighly flexible/stretchy and not fragile from age, it doesn't hurt to keep using it. My Grin GMAC wheel came with one installed, and I left it in place when using it for the SB Cruiser wheel testing recently, without issue for the few dozen miles I used it before swapping the wheel back out.

However, if it doesn't fit down into the nipple area between the bead seats, and stay down there, it may "move" as you inflate the tube and allow the tube to contact the nipples.

I prefer actual sticky rim tape, or other tough tape like Gaffer's tape or Gorilla Tape. (I haven't found a good duck or duct tape for this; too thin).

I use two layers of Gorilla Tape on my SB Cruiser's wide-rimmed rear wheels, though those are doublewall so I'm just covering the holes that access the nipples--the actual nipples are recessed so no risk of getting thru the tape.

Been years since I used a singlewall rim (except for one of the four on my big cargo/dogfood/piano trailer, which has four layers of gorilla tape over them *and* a (probably too wide) rubber rim strip; I think it's an Araya rim and has a hub that looks almost exactly like the ones on yours, except not disc-compatible).

 

[Chalo]

Single walled rims are very forgiving with regard to rim strips. The customary kind is a rubber band that covers the spoke nipples and that's it. There are no sharp edges as in a double walled rim. Electrical tape will do (though it leaves nasty mastic on the rim and tube), pretty much whatever covers the spoke ends.

 

[calab]

It cant be as bad as goo, lots and lots of goo in the tire then it hits the rim, and spokes and hands..... just a goo'ey mess, EEEeeeewwww

 

[Smurf2]

Single walled rims are very forgiving with regard to rim strips. The customary kind is a rubber band that covers the spoke nipples and that's it. There are no sharp edges as in a double walled rim. Electrical tape will do (though it leaves nasty mastic on the rim and tube), pretty much whatever covers the spoke ends.

Thanks guys.
But is my spokes stick out too much? Is that normal?
I can buy new tape, but not sure how that be. I think bumps and jumps will be present.

I can buy a new spokes, maybe with different heads (or use from other DW rim), and instal this axle hub on double wall rim, which I have, but that is too much work and take long time (for me at first time).

 

[Chalo]

But is my spokes stick out too much? Is that normal?
I can buy new tape, but not sure how that be. I think bumps and jumps will be present.

It looks normal. Get a rubber band rim strip at your local bike shop.

 

[Smurf2]

It looks normal. Get a rubber band rim strip at your local bike shop.

Grat!!!
I mesured inner wall is about 12mm only. So, the best track will be 14-16mm?
Look please my local shops, is there any good of these? Or you can try it in search bar of shop.

---

• 18mm, Basic

TRAKA KOTAČA 26”-28” 18MM - Cijena - Akcija - Rog Joma - Bicikli - Oprema - Kotači - Dijelovi - Rog Joma - Bicikli

TRAKA KOTAČA 26”-28” 18MM

www.rog-joma.hr

• 26x20mm

Traka kotača 26" HERMANS HPM 20mm

Traka kotača 26" HERMANS HPM 20mm

peloton.hr

• 15mm

TRAKA KOTAČA 24/26/28" X 15MM - MTB shop

mtb-shop.hr

• 20mm

TRAKA KOTAČA GIANT 26X20MM 870204

Par traka kotača. Značajke Kotač: 26" Širina: 20 mm

keindl-sport.hr

• 15mm -poliamid

https://ciklo-centar.hr/artikl/schwalbe-high-pressure-15mm-samoljepiva-traka-za-obruc/

• 16mm

https://ciklo-centar.hr/artikl/m-wave-rt-hp-glue-16mm-traka-za-obruc-kotaca-bicikla-2-kom-par/

 

[Chalo]

Use the 20mm strip.

 

[Smurf2]

Use the 20mm strip.

Ok. I bought some gummy sfrip 20mm. On valve, I turn the "smooth" side down to the rim, and "rough" side up, which side will be contact with inner tube (some video tells that is the right way), good?

Strip is not sticky, and I hope that will not move on pressure.
Do you want me to set electrical tape under that strip?

 

[99t4]

I would trim the width at the wide part around the valve hole so it does not extend over the tire bead seating area.

 

[Chalo]

It only has to cover the nipples. That's all.

The tire gets lifted up against the bead hook when it's inflated, so what's going on below that doesn't really matter.

 

[Smurf2]

Here I am!
I waited a package with Zoom mechanical brakes and 2x 180mm discs with separate IS mount adapter (clamp).



Rear wheel:
1) Disc touching fork:
As you can see (picture 1), maybe will work with smaller disc, but with 180 mm disc touching fork.
How I solved: I saw that my rear fork are so elastic, so I spread them and insert 3.8mm washer. Now gap is bigger, but is it allowed to spread fork like that, is there possibility that fork broken when driving because that (little) pressure?

2) Gap between Inner/Outer clamp face:
As you see (picture 2), when you put screw and screw to faces, because big gap, outer (silver) plate will bend.
How I solve it: I put left 1 nut, and right 1 nut+2 washers (read comment of other user which did same).

3) Adapter Size wrong: I got
F-180 R160, for front, and
F203 R180 for rear disc, right?

But, F203 R180 for rear side is too big. Don't know why, maybe is just rear mount bigger. So, I can use only F-180 R160 adapter for rear (which no sense).
Which is also big, and disc fit only 70-80% on brake pads (picture 3). It seems need lower adapter, do I need some 140 Like (160/140) or drive like that?

Front wheel:
Better to not talking, before I buy other rim

 

[lnanek]

Too bad that adapter plate has a round axle hole. Would have made a good torque arm too otherwise.

I run into similar issues with disk brake adapters too. Often have to swap, flip, add spacers and longer bolts, or order different looking ones. There's some good past threads on making them that explain all the standards weirdness.

 

[99t4]

How I solved: I saw that my rear fork are so elastic, so I spread them and insert 3.8mm washer. Now gap is bigger, but is it allowed to spread fork like that, is there possibility that fork broken when driving because that (little) pressure?

Spreading an aluminum rear triangle is not as safe as for steel. But 3.8mm should be OK.

Bicycle Frame/Hub Spacing

A bicycle frame and fork should match the wheels that are to be used in it. Older bicycles used narrower spacing, but older frames can often be spread out to match more modern wheels.

www.sheldonbrown.com

 

[Smurf2]

I finished rear disc brake. Need just fine adjustment.
As you can see, I had too much tension on disc and need create gap between lower adapter screw and upper adapter.

So I placed 4 washers, which were necessary to make sure that create some space between pads and disc for later adjustment.

(I know that I must lose adapter/caliper screw at the top, but not helped).

But, now screw is too short and not safe, so I will buy about 5mm longer screw, then will be fine.

Brake pads not sit on whole disc:
If you return to my previous post at 3), I order adapter +0 or 160/140 (current installed is 180/160, and that is too high).
Maybe that will be too small, but I will easily rise it.

 

[Chalo]

I had a custom frame made once, with 5mm thick, heavily windowed, laser cut dropouts. The rear disc brake bent the dropouts and made it impossible to keep the brake from rubbing for any significant amount of time. That's what I'm guessing may happen with your very thin disc tab.

I had to get the dropouts replaced with thicker ones made of stronger material to solve the problem.