Building a front wheel from scratch QR or Thru axle for Max disc strength 200 mm rotors

[MarkJohnston]

I am wondering if it's better to use a Thru axle hub and fork for use with 200 mm rotors because I've read and seen for myself that disc brakes pull the wheel to one side, I'd like to avoid that if at all possible.

But I also notice the thru axle hubs are not cheap, however I could pick up a shimano QR hub for $30... not bad. I really need to do this because my current front hub could seize up any day and throw me off at 40 mph. It's a junk old hub.

I am hoping this is the cheaper and better route to build my own wheels using a decent hub, spokes, etc. This is just the front wheel for my ebike. I definitly want to fix the wheel pulling to one side issue

 

[E-HP]

If it's pulling to one side, I'd invest in a better fork first.

 

[Chalo]

I really need to do this because my current front hub could seize up any day and throw me off at 40 mph. It's a junk old hub.

Hubs don't do that. The bearings can self-destruct in various ways, and even cause a (relative) lot of drag if they are horribly overtightened or rusted solid. But they won't suddenly arrest your bike's movement. (Like, say, a failed disc brake rotor might.).

Using a through-axle fork and hub would put a higher floor on how crappy the components could be, at least for the moment. One day we might get garbage stamped steel through-axle components on department store bikes, but not quite yet.

 

[PaPaSteve]

Sounds like the first step towards "peace of mind" is to disassemble, inspect and service the current front hub.
Changing from an older tech standard to a modern standard often involves more then anticipated ... changing to 20mm axle requires a different fork ... is that new fork compatible with the frame ?
Seldom does a hand built wheel cost less than a "off the shelf" production build.
For used parts ... have you ever shopped the Pinkbike site ?

 

[richj8990]

I am wondering if it's better to use a Thru axle hub and fork for use with 200 mm rotors because I've read and seen for myself that disc brakes pull the wheel to one side, I'd like to avoid that if at all possible.

But I also notice the thru axle hubs are not cheap, however I could pick up a shimano QR hub for $30... not bad. I really need to do this because my current front hub could seize up any day and throw me off at 40 mph. It's a junk old hub.

I am hoping this is the cheaper and better route to build my own wheels using a decent hub, spokes, etc. This is just the front wheel for my ebike. I definitly want to fix the wheel pulling to one side issue

They have 2.4mm thick 180mm rotors; that's going to have (I'm guessing) about the same stopping power as standard 1.9mm thick 203mm rotors. I have them on the front and rear of one bike and stopping power is excellent. Fresh pads are going to rub against the rotor on one side, just keep that in mind. 1/2 worn pads should clear with no problem.

So you don't have to really do anything but buy the 180mm rotor(s). Tektro sells them, Google Tektro 180mm rotors and make sure they are the thicker type, then buy.



On a slightly different topic: it is true that many 'say' a front QR fork will brake dive more (to the front, not really to the side) than a thru-axle fork. Personally, I don't see that happening with a brand-name QR fork, only with cheaper coil QR forks. With air forks (QR or thru-), you can simply pump more air into the fork to eliminate the brake dive --- if the ride gets a bit too harsh, you then open up the compression dial to the left / counterclockwise. You can't really do the same with a coil fork. The coil fork preload does 'something' but compared with air it's a joke.

You can actually stay QR and get a decent fork if you want to: Manitou Markhor, around $250 USD. I have the thru-axle version called the Machete and it works pretty good (again as long as the air is 60+ PSI). 50 psi and the fork is going to dive, even with a 155 lb rider. Also keep in mind the Markhor / Machete are 32mm stanchions (the two smooth parts towards the top that go up and down). For an e-bike (mid- or rear hub), it may be preferable to get a 34mm fork. Make 100% sure it's an air fork, and it has standard 15x100mm spacing for the front wheel. Do not buy an off-brand Chinese fork; you can do that with a lot of components but not the fork! The wheels are not that expensive, you can often find them for $120-150 now because that 100mm standard is now 110mm.

 

[scianiac]

They have 2.4mm thick 180mm rotors; that's going to have (I'm guessing) about the same stopping power as standard 1.9mm thick 203mm rotors.

I fail to see how the rotor thickness has any effect at all on the stopping power. It helps with heat buildup which is important and they're less likely to get bent but braking power will be less than a larger 200 or 220mm rotor.

 

[Chalo]

I fail to see how the rotor thickness has any effect at all on the stopping power. It helps with heat buildup which is important and they're less likely to get bent but braking power will be less than a larger 200 or 220mm rotor.

True, but a cooler rotor means better braking when stuff gets serious. Up to that point, it really doesn't matter.

I've sometimes wondered why we don't see cuprous alloy rotors. There are some that have excellent abrasion resistance, excellent thermal conductivity, good and predictable friction qualities, superb volumetric heat capacity, and more than adequate tensile strength for this job. And their density is almost the same as stainless steel. Ampco bronze alloys come to mind.

 

[MarkJohnston]

I fail to see how the rotor thickness has any effect at all on the stopping power. It helps with heat buildup which is important and they're less likely to get bent but braking power will be less than a larger 200 or 220mm rotor.

The bike issue is my rotors are getting cooked after 2 years of use.they've been used pretty hard. Maybe 10k miles on the rotors?

The hope tech V4 brakes I have said they could handle 2.4mm rotors. But they sure aren't cheap, and if they get bent should they get bent (not sure if they bend easy ) It'll be super annoying. And also the fork might not be able to handle it either. It's steel but also cast chinesium.

 

[MarkJohnston]

Sounds like the first step towards "peace of mind" is to disassemble, inspect and service the current front hub.
Changing from an older tech standard to a modern standard often involves more then anticipated ... changing to 20mm axle requires a different fork ... is that new fork compatible with the frame ?
Seldom does a hand built wheel cost less than a "off the shelf" production build.
For used parts ... have you ever shopped the Pinkbike site ?

One step ahead of you. Done. And that's where I got worried, because inside the actual hub races were a little bit worn. I read somewhere that it could seize, sending you flying over.

Yes yes, I've done all that. I am working with a junk fork and a bad geometric bike design. Pink bike is ok.... I can buy a new fork for as much as they want to sell their stuff.

 

[PaPaSteve]

One step ahead of you. Done. And that's where I got worried, because inside the actual hub races were a little bit worn. I read somewhere that it could seize, sending you flying over.

Yes yes, I've done all that. I am working with a junk fork and a bad geometric bike design. Pink bike is ok.... I can buy a new fork for as much as they want to sell their stuff.

If the wear groove in the race is smooth it could be OK to run for a while.
To reduce the possibility of a bearing breakage, change up the quality of the bearings.
Material type makes a difference.
Roundness tolerance make a difference.
Examples :

440C Stainless

Ceramic

As kids playing with Stingrays, as a way to improve speed we would upgrade the carbon steel bearings to Campagnolo.

 

[richj8990]

I fail to see how the rotor thickness has any effect at all on the stopping power. It helps with heat buildup which is important and they're less likely to get bent but braking power will be less than a larger 200 or 220mm rotor.

Try a thicker rotor, squeeze the brake levers, and you will see the difference in stopping power. BTW Tektro says the are 2.3mm, I measured 2.4.

2-piston calipers with 2.4mm wide rotors stop significantly faster than 4-piston calipers with 1.9mm wide rotors (same 180mm rotor diameter for both). I can really feel the difference.

Think about it this way: if a 1.9mm rotor has fresh brake pads, your hydraulic brake lever travel is say 20% until it the pads hit the rotors. For hard braking you maybe use 50% of the brake lever travel. For worn pads that are 3/4 done, the lever travel pads to rotors may be 40% and the hard braking 80% of the lever's travel. Now switch to 2.4mm wide rotors. Fresh pads = brake lever travel is only like 5-10% travel before it immediately has the pads hit the rotor. Then 20% the braking is pretty good, 30% it's very good, 40% is so solid you can't even squeeze the lever any more than that. The stopping power is multiplied because the brake lever travel starts having the pads bite into the thicker rotors much sooner. There is more hydraulic leverage on the rotor earlier with a thicker rotor. Then it becomes how hard to you want to pull the levers to slow down fast. If you squeezed the levers that hard with a 1.9mm rotor, you'd start overheating the thinner rotor after a while along with brake fade. That will simply not happen with 2.4mm; yes they will get hot and yes they can turn black but they will do the job down steep long hills. They don't cause lever fade. I've taken them down 20% fire roads several hundred feet on a 55 lb bike, braking all the way, no letup, and the brakes did not fade. No joke. And even if the lever did fade, you have far more lever travel left to still use with a thicker rotor.

The only reason I don't switch everything over to 2.4mm rotors is that they rub against fresh pads and slow the bike down. I consider them so good that they are the equivalent to 203mm or 6-piston rotors. They are an entire step up for braking. For an e-bike, pad rub is not as much as an issue as for a human-powered bike. Every e-biker that needs more braking should seriously look into 2.4 mm rotors. Especially if they can't fit a 203mm rotor on their fork or rear frame (they do have 2.4 x 203mm rotors too).

 

[scianiac]

You are totally correct about heat buildup and that is important but I don't think you fully understand how hydraulic brakes work. A full pull of the lever does not move the pistons their full stroke, only a small portion of it and when the lever is released it does not pull the pistons all the way back in, only slightly. And over time as the pad wears the fluid in between the lever piston and caliper is topped up from the reservoir in the lever keeping the stroke consistent (the exception is levers with bite point adjusts). So yes if you just swap in thicker rotors and don't reset the caliber pistons it will feel different but that will go away as the pad wear back to where the system is designed. It would be easier to just take the wheel out and bump the pads out just slightly to manually adjust the bite point or just buy brakes with bite point adjust or other systems designed to improve this.

Now are thicker rotors better, yeah for the heat reasons, could some rotors have different designs that improve braking performance, probably. I would assume a thicker rotor allows for a better balance of cooling to rotor area. And if you can't fit larger rotors and have brake issues then it's probably a good idea and cheaper than all new brakes. But if you can fit larger rotors that's probably a better solution as they also have much better cooling and additional leverage so additional braking force. That and of course correct lever setup and correct pad selection. Pad selection is probably just as important or more important than rotor cooling if you are really getting those brakes hot, those nice grippy organic pads won't be so happy when they get that hot while some sintered pads will take it.

True, but a cooler rotor means better braking when stuff gets serious. Up to that point, it really doesn't matter.

I've sometimes wondered why we don't see cuprous alloy rotors. There are some that have excellent abrasion resistance, excellent thermal conductivity, good and predictable friction qualities, superb volumetric heat capacity, and more than adequate tensile strength for this job. And their density is almost the same as stainless steel. Ampco bronze alloys come to mind.

You aren't wrong, and maybe I'm being pedantic.

But you know I never thought about that but you're totally right why hasn't anybody tried cuprous alloys for brake rotors, seems way easier than stainless aluminum welded "icetech" rotors and the downsides of maybe they wear out slightly quicker seem pretty negligible considering the possible applications.

 

[MarkJohnston]

Hubs don't do that. The bearings can self-destruct in various ways, and even cause a (relative) lot of drag if they are horribly overtightened or rusted solid. But they won't suddenly arrest your bike's movement. (Like, say, a failed disc brake rotor might.).

Using a through-axle fork and hub would put a higher floor on how crappy the components could be, at least for the moment. One day we might get garbage stamped steel through-axle components on department store bikes, but not quite yet.

My current rotors are so thin you can shave hair with them. They are burned and scorched. Definitely need to be replaced ASAP. I guess this is what you mean by "failed disc brake rotor", what could happen.

I want to buy 200mm rotors right now, even though the manufacturer said 180 mm is MAX for this fork. I don't event think this fork can handle 180mm, I think that was a lie. But even still it has not snapped or cracked all these years later...

I think as long as I go easy on the brakes, i.e. no emergency stops I can get away with using those huge rotors for a while. I definitley want to buy a judy or manitou fork, adjustable TRAVEL is a MUST MUST have. Considering the engineers only designed this BD.com bike for 60 or more probably 50mm of travel. 100 mm would be too much, 80mm is pushing it. I need that feature.

The other issue is I have a fender and light up front, super annoying these newer forks don't have bolt eyelets or holes, but I suppose that nothing hose clamps and zip ties can't solve!

I want to build a new front hub. I want to buy a through axle hub, and use sapim spokes, and a nice wide wim with a centerlock rotors attachement.

Buying this new fork will probably get my handlebars up so my shoulders don't ache all the time,I'll leave the steerer nice and long, the only issue is, they might get TOO high, but I think it will be ok.

 

[Chalo]

Tall handlebars will sit you upright without horking up the bike's geometry and introducing fit problems.

 

[MarkJohnston]

Tall handlebars will sit you upright without horking up the bike's geometry and introducing fit problems.

I need a new fork anyway. Wow this whole new set up will cost $500 most likley. The good thing is that all these parts can be cannibalized and used with a new steel frame when I decide to change frames. I think any steel frame will do, I just want steel. Aluminum is a head ache to think about all the time.

I am guessing the 1.5T fork is much more durable, but I can get away with using a 1 1/8 fork in a straight headset, or vice versa with a taper and an $20 adapter. I always future proof whenever I spend this much to justify it. I am also looking for a motorcycle right now, so perhaps this project might get put on hold for a while. I might just buy the cheapest 180 mm rotor I can get right now, and call it good for the present.

 

[MarkJohnston]

Anybody every heard of RST CAPA? Is this a quality fork brand?

RST Capa-ML Suspension 1in 26in Threadless | eBay

FORK RST 26 CAPA-ML 1in TDLS BK DISC/VBasic replacement cross country suspension fork. 80mm Travel. Coil spring / mechanical lock-out. Alloy lower legs and crown. Steel steerer tube. Oversized 28.6mm stanchion tubes. 2050g. Item Specifications: Material, Alloy, Size, 26`, Color, Black, Brake...

www.ebay.com

 

[Chalo]

It's a budget fork. Capa indicates it's a "premium" version, and many forks branded RST Capa have some sort of following.

For what it's worth, you probably won't find a better 1 inch fork anywhere.

 

[MarkJohnston]

You guys dont get it I dont think. What I am trying to tell you guys is that the wheel is getting pulled towards the disc. Eveverytime it does this its damaging the bearing races on the hub. I think I need a whole new wheel, and fork. I just checked the rotor and the forces of pulling the wheel put bent the rotor. Didn't know it could get bent so easy

 

[99t4]

What I am trying to tell you guys is that the wheel is getting pulled towards the disc. Eveverytime it does this its damaging the bearing races on the hub.

Could be you have it backward. Already loose bearings will for sure cause the wheel to get yanked way over when applying the brake. Simply cleaning/regreasing/resetting bearing play totally solved this problem for me.

 

[MarkJohnston]

Could be you have it backward. Already loose bearings will for sure cause the wheel to get yanked way over when applying the brake. Simply cleaning/regreasing/resetting bearing play totally solved this problem for me.

Ha. I already did that job. You make it seem so simple but getting the perfect adjustment on a cheap hub is very difficult. I spent hours in a stupid $20 wheel. I'm done with this wheel. I know how to build a wheel now. Send me a link to a good strong hub. That would help.

 

[calab]

Send me a link to a good strong hub.

Why?
Its been posted countless times.

Anybody every heard of RST CAPA? Is this a quality fork brand?

Its a pogo stick, better then a rigid. If you want better squish at more affordable price point, buying a good used fork that is rebuildable is an option and again its been asked which ones many a time.

brakes

Failed brakes sucks, the bb5's and entry Tektro disk brakes require a lot of attention, adjustments. Its better to use the regen or electrical braking feature to save on pads. A good brake is the Avid BB7's which is cable actuacted, its more affordable then the hydraulic brake you get hosed on. 203's up front, more mass, better cooling and readily purchased anywhere. I got mixed up on the post mount when purchasing adapters for the 203 rotor. The only new fangled tech I got is the fancy tapered headset, so buying a newer fork is made easy but for a decent fork, not much under 300, maybe if your lucky find a good deal for 250 somewhere.

If you want the suspension reaction time to the terrain your riding.

Pogo sticks dont react to quickly to the terrain

 

[99t4]

Send me a link to a good strong hub. That would help.

Thru-axle? What size? I would trust Chalo's recommendation more than mine.

 

[MarkJohnston]

The regen is dumb because it causes constant drag. Anybody know which seller on alibaba sells decent v brake pads? I know someone answered that on here but I can't find it. Best bet is to buy them in bulk and "GIT GOOD" at changing brakes. I'm already kind of a master at those kinds of brakes. I also have access to an ebike stand so that is nice, very nice. I can out my bike up in the stand fully dressed and loaded with cargo and everything...( could the seat post snap though?) Pictures coming.soon

 

[nicobie]

The regen is dumb because it causes constant drag.

?? I think you have it mixed up because that is not true.

 

[MarkJohnston]

Wound up getting these

Jagwire Mountain Sport V-Brake Pads Threaded Post Box of 25 Pairs Yell

Mountain Sport brake pads feature a tried and true all-weather compound and come in a variety of colors and attachment styles. Threaded attachment with orbital hardware to help toe pads Durable all-weather compound Low profile design with an offset post Box includes 25 pairs of pads

365cycles.com

I had a discount to so I got even more off. That's about $3 a pair of pads and these pads last a very long time. Pretty decent stopping power too. The Ali baba ones were the same price same amount ( shipping) and I heard those can delaminate. That's a no go. I expect the box of jags to last for three years.

Yeah i can only ever seem to.get my wheels so.true. I have todo a quick retrue every couple of weeks. I just leave the wheel in, way too much of a pain to take it out.

I dont recommend the kool stops. They wear super super fast. And they are expensive ASF. Not sure why chalo recommends them because they suck. Ebikes requires brake pads to be durable.l above all else.