Brakes. Can stop, do wanna: Fitting Tektro 926AL mini V's.

General CX/MTB
1

I used to have Shorty Ultimates on my S&S CX bike, but for travelling this is a pain, as I would have to release the spring tension to pack the bike, and reset it on arrival, which needs a 15mm spanner, a 4.x allen key (because the bolts aren’t quite 4mm), and time to balance the spring tension left to right.

Given I have 6600 Ultegra, which pulls less cable than 6700, or SRAM, the shorter the arm, the better for modulation and pad->rim clearance. The shortest arms on the market to my knowledge are the 80mm Tektro 926AL BMX mini v’s. Any shorter and the noodle will start fouling on tyres >28mm. As a bonus, they’re hella cheap at $10 each end. Add an adjustable noodle and some good pads and the price doubles, but still a bargain compared to TRP CX8.4’s, which are too long anyway.

How to fit Tektro 926 AL 80mm mini v brakes to an Alpha Q CX20 fork:

Turns out the shortest arm mini v’s (Tektro 926AL, 80mm) have the pad slot quite far back, which wouldn’t be an issue if my fork (Alpha Q CX20) didn’t have so much carbon around the studs. If TRP made a CX8 model I’d have bought that, but no such luck.


Brake arm on left of photo can’t retract any further, as arm fouls on fork.

So I filed the brake pad slot away until the arm nearly cleared my fork, added a 1mm washer underneath the canti stud and finally the arms didn’t foul the fork.

[i]Brake arms before & after filing.

[/i]
Washer added under canti stud, arm filed to clear fork blade

But then I had to trim the brake pad washers down because they hit too. Then I chose between four different kids of brake cartridge to minimise the distance between pad face and back side and maximise the amount the arm can retract so I can get my wheel out without deflating the tyre.

Kool Stop V brake pad retracts much further than “CX” pad.

Then, just when I thought I was done, I discovered that the bushings were proud of the canti stud, so when you tighten the bolt, the arm binds. So I lapped those back too with some #600 silicon carbide paper and a very flat surface (aka glass louver panel).

Bushing sits proud of stud


Lapping bushing down & keeping it parallel.


Bushing is just below stud, no more binding.

Now I can finally cable the damn things up and use them.

Complete photoset:
Fitting Tektro 926 AL Mini V Brakes to Alpha Q CX20 carbon fork - a set on Flickr

If you want ballin’ buy TRP CX8.4s, don’t bother with CX9s. 84/90mm arms. (ebay/JensonUSA/etc)

If you ball even harder, buy Paul Minimotos (83mm arms, Aspire Velotech / local Paul dealers)

If you don’t ball at all, buy Tektro RX5/BX3V (ebay/JensonUSA/etc) BX3V are the cheapest and nastiest.

If you absolutely must maximise your rim clearance, buy Tektro 926 (ebay/JensonUSA/etc)

If you don’t want Tektro, Sinz and some other BMX companies make mini vees, and Campy did some 85mm arm ones for a while.

Edit: Shimano are now making Sora/Tiagra/105 level mini v brakes for 2013. 90mm arms though.
BR-R573 - 105 V-Brake
BR-R463 - Tiagra V-Brake
BR-R353 - Sora V-Brake

105:

Tiagra:

If you’re not using flatbar levers, you absolutely must buy an ‘adjustable noodle’ for each brake.

Also, I’m just going to leave this note that I sent to a very handsome gent earlier this week here for you all:

Levers

As far as I can remember, cable pull (The more cable you pull the less leverage you have) from least (needing shorter mini v arms) to most (working with longer arms) is something like:

Shimano aero non integrated // Shimano 8/9/OG10 Campy 8/9/10 Tektro R200/Cane Creek // Shimano current10 SRAM // Linear pull MTB levers Drop bar linear pull levers

Don’t know about Campy 11, but based on how chorus 11 is working with my shimano touring cantis in my shimergo setup I’m assuming similar pull ratio to Campy 8/9/10.

Unsure where the RL340 sit, probably similar to R200, or TRP RRL, (which IMHO are much much better from an ergo point of view, and everyone who’s used them loves them). I wouldn’t bother with RL340s generally.

Edit: Lever mechanical advantages: New Shimano: 1.4:1, older Shimano, SRAM, and Campy are 1.3:1

Brakes:

Ok, so for mini v’s you have 3 choices: 80/83-85/90mm arms:

80 to my knowledge are only available in 926 BMX model, shortest arm, leads to the most rim clearance and and “lowest” power, but let’s be honest, if I can do stoppies while I’m seated, it’s hardly low power. Being the shortest, tyre clearance might be an issue at the noodle, but my setup will take a 32-35mm tyre easy, and the noodle’s above the fork crown. They’re hella cheap, and the QA/QC isn’t stellar, if you buy them, you’re best off buying 3-4, as you might need to mix & match if you get a dud part. The spring tension is quite light, the lever feel nears hydros on my 6600 ultegra setup! Significant for chunky carbon forks: The pad slot is really close to the stud base, I had to file it down a lot.

83-85 are available in a few BMX brands (Sinz etc), Tektro do a couple of 85mm (RX5 BX3V), TRP do the 8.4, Campy did an 85mm one once and there’s the Paul Mini Moto (83mm). The RX5 & BX3V are cheap and nice, and with a pad upgrade are near perfect, at ~5x the price of the tektros, the TRP is balleur with Ti hardware (but weighs the same…) and significantly: the brake pad mount is further forward from the canti stud, which helps with pad->fork clearance when getting the wheel out, less of an issue with steel frames/forks. Mini Motos are hella nice, but price is out of control, even compared to TRP, at ~10x the cost of the tektros, and the visual asymmetry of the arms kills it for me. Plus they’re a little more fiddly to setup adjust, with external springs.

90 (TRP CX9 / Tektro RX6 / 2013 Shimano mini Vs) are a waste of time. Whilst they’re aimed at longer cable pull levers (new Shimano), why bother, as the rim clearance will be better with 85s and the power is still phenomenal, and 85s will clear a ~40mm tyre. They do have the highest leverage of all the brakes. Paired with linear pull levers (designed for ~100/110mm arms) they’d probably give good power and rim clearance.

Making it all work

For your pompino, if you have SRAM SS levers, which don’t have a return spring, I’d go RX5 / BX3V, or TRP CX8.4 if you want to ball hard. If you get the cheaper brakes, grab a set of Kool Stop Cross cartridges (don’t order the smooth stud ones by accident) or MTB cartridges and fill with your pad of choice (KS Salmon). Keep in mind that cartridge / pad shape will affect how far the arms can retract. I went through 6 different pads/carts until I found the slimmest one to maximise opening for wheel removal.

If you want different levers, skip the RL340, I don’t think they’re much chop, either go straight to TRP RRL or I can hook you up with a set of the good old Tektro R200s.

If you are going to a flat bar, you can also just use regular MTB v brakes with linear pull levers, and you can get linear pull drop levers too (Tektro RL520).

The other option is an MTB v brake and a travel agent with caliper/canti pull levers, but it’s a kludge that you don’t have to do.

2

this is the worst thing i have ever seen.

3

No it’s not.

4

ftfy
(+ pics because I can’t believe you said that to a vegan)

5

Hmmm, I hope this doesn’t happen when I try the Mini-v’s I got.

Though on a quick side-by-side mock up the 85mm arms look ok on a easton cx90 fork with a ‘42c’ tyre that actually measures 38ish.

6

RX5s (85mm) have their pad slot further away from the base of the stud than the 926 do. Plus your fork will be different to mine, and likely doesn’t have as much crabon fribe around the stud area.

I think I can clear 35mm tyres with these arms, 32 if the tread is particularly tall. Also depends on where the studs are in relation to the axle, and if the pads end up high or low in the slot. Higher gives you more rim clearance as it has to trace a longer arc to the rim, but cuts down on your vertical clearance to the noodle.

You can also file away the base of the noodle anchor to gain another mm or two.

7

Derp, realised that most of the photos were set to private…

8

Appreciate you taking the time and effort to share the knowledge Blakey. Although my next cx bike will have disc brakes mind.

9

I’m sitting here, literally on the edge of my seat, waiting for Horatio’s thread discussing his new CX bike.

10

Don’t worry I’ll be sitting on the fence for a while. Shimano hydro brifters would be nice.

11


New bars, wheels, tyres, brakes by ah_blake, on Flickr

Hell yeah. Can do seated stoppies now.


80mm Tektro 926 mini v on Alpha Q CX20 fork by ah_blake, on Flickr

12

I love that bike, who else sells those mini’s other than Jenson?

Is there an alternative to the Tekro?

13

TRP which is Tektro’s fancy brand do them too, but they are ~$100 a pair
TRP

14

I got my 926s from somewhere other than jenson (but probably still in the states).
When i bought them i think the 926 may have been the only 80mm mini V available, the TRP’s are 90mm or 84mm.
shorter arms equals more pad clearance (different levers might work better with different length Vs you’ll have to do some research)
The 926s seem to work fine for me (with koolstop cross cartridge pads and tektro R200 levers) though it should be noted i haven’t ridden in super sticky mud conditions so i can’t comment on potential gumming up of the brakes with mud

15

If you want ballin’ buy TRP CX8.4s, don’t bother with CX9s. 84/90mm arms. (ebay/JensonUSA/etc)

If you ball even harder, buy Paul Minimotos (83mm arms, Aspire Velotech / local Paul dealers)

If you don’t ball at all, buy Tektro RX5/BX3V (ebay/JensonUSA/etc)

If you absolutely must maximise your rim clearance, buy Tektro 926 (ebay/JensonUSA/etc)

If you don’t want Tektro, Sinz and some other BMX companies make mini vees, and Campy did some 85mm arm ones for a while.

If you’re not using flatbar levers, you absolutely must buy an ‘adjustable noodle’ for each brake.

Also, I’m just going to leave this note that I sent to a very handsome gent earlier this week here for you all:

Levers

As far as I can remember, cable pull (The more cable you pull the less leverage you have) from least (needing shorter mini v arms) to most (working with longer arms) is something like:

Shimano aero non integrated // Shimano 8/9/OG10 Campy 8/9/10 Tektro R200/Cane Creek // Shimano current10 SRAM // Linear pull MTB levers Drop bar linear pull levers

Don’t know about Campy 11, but based on how chorus 11 is working with my shimano touring cantis in my shimergo setup I’m assuming similar pull ratio to Campy 8/9/10.

Unsure where the RL340 sit, probably similar to R200, or TRP RRL, (which IMHO are much much better from an ergo point of view, and everyone who’s used them loves them). I wouldn’t bother with RL340s generally.

Brakes:

Ok, so for mini v’s you have 3 choices: 80/83-85/90mm arms:

80 to my knowledge are only available in 926 BMX model, shortest arm, leads to the most rim clearance and and “lowest” power, but let’s be honest, if I can do stoppies while I’m seated, it’s hardly low power. Being the shortest, tyre clearance might be an issue at the noodle, but my setup will take a 32-35mm tyre easy, and the noodle’s above the fork crown. They’re hella cheap, and the QA/QC isn’t stellar, if you buy them, you’re best off buying 3-4, as you might need to mix & match if you get a dud part. The spring tension is quite light, the lever feel nears hydros on my 6600 ultegra setup! Significant for chunky carbon forks: The pad slot is really close to the stud base, I had to file it down a lot.

83-85 are available in a few BMX brands (Sinz etc), Tektro do a couple of 85mm (RX5 BX3V), TRP do the 8.4, Campy did an 85mm one once and there’s the Paul Mini Moto (83mm). The RX5 & BX3V are cheap and nice, and with a pad upgrade are near perfect, at ~5x the price of the tektros, the TRP is balleur with Ti hardware (but weighs the same…) and significantly: the brake pad mount is further forward from the canti stud, which helps with pad->fork clearance when getting the wheel out, less of an issue with steel frames/forks. Mini Motos are hella nice, but price is out of control, even compared to TRP, at ~10x the cost of the tektros, and the visual asymmetry of the arms kills it for me. Plus they’re a little more fiddly to setup adjust, with external springs.

90 (TRP CX9 / Tektro RX6) are a waste of time. Whilst they’re aimed at longer cable pull levers (SRAM/new Shimano), why bother, as the rim clearance will be better with 85s and the power is still phenomenal, and 85s will clear a ~40mm tyre. They do have the highest leverage of all the brakes. Paired with linear pull levers (designed for ~100/110mm arms) they’d probably give good power and rim clearance.

Making it all work

For your pompino, if you have SRAM SS levers, which don’t have a return spring, I’d go RX5 / BX3V, or TRP CX8.4 if you want to ball hard. If you get the cheaper brakes, grab a set of Kool Stop Cross cartridges (don’t order the smooth stud ones by accident) or MTB cartridges and fill with your pad of choice (KS Salmon). Keep in mind that cartridge / pad shape will affect how far the arms can retract. I went through 6 different pads/carts until I found the slimmest one to maximise opening for wheel removal.

If you want different levers, skip the RL340, I don’t think they’re much chop, either go straight to TRP RRL or I can hook you up with a set of the good old Tektro R200s.

If you are going to a flat bar, you can also just use regular MTB v brakes with linear pull levers, and you can get linear pull drop levers too (Tektro RL520).

The other option is an MTB v brake and a travel agent with caliper/canti pull levers, but it’s a kludge that you don’t have to do.

16

wow, that was an essay on Mini-V’s!

Kudos.

17

See folks this is why you should always ask Blakey before buying ANYTHING :stuck_out_tongue:

further to this I have the koolstop cross cartridge pads on my pompino (with 926). the pad retention screws hit the fork blades reducing clearance for wheel removal. I can get a set of narrow cheap v’s with 35s in but that’s probably the limit.

18

I’m kinda in love with the visual asymmetry. Haven’t raced with them yet, but just riding on the road, and in the bunch, they feel not much less powerful than the long reach Shimano dual pivots on my road bike (BR600??).

Minimotos on a CAADX

19

In the ask Blakey category: Would you agree that the RX5 would probably clear a Schwalbe Kojak 35 with SKS fender? Or should i get RX6 just in case?

Will be using Avid MTB flat bar levers.

EDIT: and do i want “836.12 EN standard pads” or “720.12 adjustable cartridge pads” ?

20

Fukka RX6. Overly long arms reduce rim clearance.

I ran 85mm RX5s with 30-something tyres plus fenders plus a mini front rack on my old cross check, worked fine, noodle sat on the top of the fender. Kojak 35s measure closer to 32, so you should be aok. It will depend on your canti stud positioning though, this can affect clearance by ~+/-5mm.

Look at the photos of my 926ALs, those are 80mm arms and they clear the brake bridge / fork crown.

You want the 720.12 pads, the 836.12 are disposable turds. The 720.12 are a cartridge with a turd compound, but at least you can replace the insert with something good (KS salmon etc)

Edit: Wait, MTB flat bar levers? Did you edit that in? Just buy MTB V brakes then. You have no need for mini Vs. The RX6/MTB lever combo will give you plenty good braking with better rim clearance though.