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Novatec and Kinetix 74mm front hub dimensions for Dahon and others
I made drawings for the Novatec A215SB and A211SB, and the Dahon / Kinetix OEM front hub for 74mm dropout width. They were cheap, so I decide to order all 3 of them to compare. I'll probably use the A215SB for the larger number of spokes and larger ball bearings.
Hubs The A215SB is heaviest at 112g and largest, because it offers 28, 24, and 20 holes, and uses large 6000 RS cartridge bearings. One problem I have is that one bearing sits +0.15mm outside the surface of the hub body, while the other bearing sits -0.15mm inside the surface. The A211SB is lighter at 70g and only offers 20 holes, and uses smaller 699 2RS bearings, common on their other 100mm hubs. But the bearings were a little bit crunchy, maybe there's some particles stuck in the tracks. The bearings are flush with the surface of the hub. It runs on a 9mm axle, that steps down to 8.9mm starting from 1.5mm away from the bearings. You could modify this for a narrower fork that is limited to 9mm axles, but the small 1.5mm wide shoulder with the 0.1mm step may cause problems for your replacement "precision" washers if you drill the bore hole to 8.9mm. You'd have to either make a counterbore into your washers, shave the shoulder of the axle, or accept a loose 0.1mm tolerance. It may then be easier to modify the A215SB instead. The Dahon Kinetix OEM original hub is the lightest at 53g. It uses R4 2RS bearings that are difficult to find in some countries because they're imperial inch size. They're also very small. The axle doesn't pass through the bearings, instead the end caps are pressed in (probably steel core). But with a 6.35mm inner diameter of the bearings and 5mm skewer running inside, you've got less than 0.5-0.6mm thickness of material that's transferring all that load from your fork. I'm surprised that the caps don't sheer off. I won't be using these Dahon OEM hubs anymore. I'll use this as a dropout spacer when I disassemble the bike and pack it into a suitcase. End caps The Novatec ends caps are not really precise. The silver serrated part isn't sitting exactly flush against the black main part. On the A215SB there is about a 0.05mm gap on some areas for a total variation of dropout width of 0.1mm. But it's better than the caps on the A211SB which has a gap almost completely all the way around the silver serrated part, with variations in dropout width of up to 0.2mm. I don't have a photo of this gap. A questionable design is the large gap between the end caps and the hub body. I think they could have made a better design for the caps to reduce dust and water splash. The gap is wider on the A211SB than the A215SB. The gap is around 0.5mm on the A215SB. Spoke holes The spoke holes on all 3 hubs are not drilled precisely centered to the axle. They're off by around +/- 0.2 to 0.3mm. So spokes on one side may be up to 0.6mm deeper into the nipples than the spokes on the other side of the wheel. Bearings 6000 RS= 26 x 10 x 8mm with 4.762mm balls x 7 balls (not available everywhere) (same ball size as 3/16" loose balls for Shimano front hubs) 699 2RS= 20 x 9 x 6mm with 3.175mm balls x 8 balls R4 2RS= 1/4 x 5/8 x 0.196" (6.35 x 15.875 x 4.978mm) with 2.38mm diameter balls x 8 balls (very difficult to find) https://www.astbearings.com/catalog....ct&id=6000-2RS https://www.astbearings.com/catalog....ct&id=699H-2RS https://www.astbearings.com/catalog....duct&id=R4-2RS https://cimg0.ibsrv.net/gimg/bikefor...ee70c02bba.gif https://cimg8.ibsrv.net/gimg/bikefor...d9b1882eef.gif https://cimg9.ibsrv.net/gimg/bikefor...cba7584ca3.gif https://cimg6.ibsrv.net/gimg/bikefor...6f81d3c317.jpg https://cimg5.ibsrv.net/gimg/bikefor...c3a0d90273.jpg https://cimg7.ibsrv.net/gimg/bikefor...65b1c7e578.jpg https://cimg3.ibsrv.net/gimg/bikefor...73da7b66dd.jpg https://cimg4.ibsrv.net/gimg/bikefor...3a12074578.jpg |
It’s a shame there are no 32h 74mm hubs that I can find available in something like Novatec’s A215SB quality. The lowest end hubs that I use if I build new wheels for my bikes are Novatec chosen from their range with the biggest bearings, and I’m soon going to free up some CR18 rims when I get some wider tubeless compatible rims for my BF. The OE hubs and rims on my Speed D7 Dahon are pretty rubbishy. It’s a trade off though. The Dahon is the right size to be allowed on buses here in Melbourne, so I take it for multimodal trips where it may be interfered with. I therefore don’t want to put big dollars into the bike, but want it to be reliable for me at 225lb and roll nicely. And what is a reasonably priced screw on rear hub in what seems to be about 112mm? Do people just spin up or cut down shorter spacers for old 120mm hubs? I’d not do that to one of my Royce hubs, but it might be a good approach with a cheaper one.
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Originally Posted by tomtomtom123
(Post 21098664)
The Dahon Kinetix OEM original hub is the lightest at 53g. It uses R4 2RS bearings that are difficult to find in some countries because they're imperial inch size. They're also very small.
R4 2RS= 1/4 x 5/8 x 0.196" (6.35 x 15.875 x 4.978mm) with 2.38mm diameter balls x 8 balls (very difficult to find) Here are some images of the R4 bearings from a Dahon "Neutron" hub (made by American Classic) which I serviced at a bit under 2,000 miles. These were in all-weather service in Chicago. Replacement was pretty simple, but I was a little disappointed to get so few miles out of the hub. I weigh around 200 pounds, which might have had an influence...(!) I've since been using a dynohub ("Joule III", made by Shutter Precision) and have over 6,000 miles on it with no problems. https://cimg5.ibsrv.net/gimg/bikefor...6736759793.jpg One of the replacement bearings https://cimg6.ibsrv.net/gimg/bikefor...d65abba1b6.jpg After the autopsy https://cimg7.ibsrv.net/gimg/bikefor...7aeb4d04d8.jpg Squeaky worn bearings minus the seals |
After searching around for a while for another hub with 32 or 36 holes, I think I've identified the hub that BikeFriday uses. It's probably the Chosen T4B.
Chosen Co., Ltd:::HUBS?Disc brake?wheel set https://cimg2.ibsrv.net/gimg/bikefor...2201109056.jpg What you see in the photo is the 74mm hub, but with extended axle and end caps for 100 or 110mm (for some odd reason). Here is another photo from a Japanese auction listing. There seems to be several of these in Japan, but under rebranded names: https://aucview.aucfan.com/yahoo/k165761390/ https://cimg0.ibsrv.net/gimg/bikefor...b6d4bc8baf.jpg https://cimg2.ibsrv.net/gimg/bikefor...8cefeffa00.jpg Here is the image from the BikeFriday site: https://store.bikefriday.com/product_info.php?cPath=26&products_id=12802 https://cimg7.ibsrv.net/gimg/bikefor...261d043d95.jpg Here is a photo from a Thai wheelbuilder's facebook post with the same hub. Although the Chosen website writes up to 28 holes, this one in the photo below has 32 holes: Facebook Post
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Facebook Post " class="fb-xfbml-parse-ignore">Facebook Post https://cimg2.ibsrv.net/gimg/bikefor...8dc5c5c245.jpg I suspect it's the same hub sold by Ginkgo in Germany. They sell them in 20, 24, 28, 32 holes depending on the color. https://www.ginkgo-veloteile.de/gink...mm-111-gr.html https://www.ginkgo-veloteile.de/gink...1-gr-oxid.html https://cimg3.ibsrv.net/gimg/bikefor...78cec18823.jpg The Novatec hubs that I opened up seem to have axle shoulders that are a bit too long, so there is a gap in between the bearings and the inner wall of the hub, so There's a risk that the bearings could slip around inside if the force of the hold from the interference fit of the bore hole is overcome by lateral force. Also, at least one of the bearings will stick out a little bit from the outer surface of the hub. I made another post about it here: https://www.bikeforums.net/bicycle-m...l#post21079632 https://cimg4.ibsrv.net/gimg/bikefor...3d5acea266.jpg I've already spent money and effort making pressing and extractor tools for the 6000 bearings, replacement Enduro bearings, and also the DIN 988 19x26mm shims to fill in the gap. So I don't really want to buy another hub. But I couldn't find wider rims with 28 holes that matches the Novatec hub that I have. I want between 20-25mm inner widths. 19 is acceptable but is the minimum for the Big Ben Plus 55mm (2.15") tires. But the wider rims usually only come in 36 holes, and more rarely in 32 holes. I think the 20/28 holes that Dahon buys are custom volume orders. Which is why I was looking at the Chosen T4B hub. For 36 holes, CH White and Sons has a built wheel with Quando loose ball hub with 36 holes. The site says it's assembled by Roland Werke. Someone on the Geman folding bike forum wrote that he got the hub by calling them. I emailed them asking if there were any hubs left over that are available for purchase, but there was no response. I can't speak German so I didn't bother calling. I also emailed KTGroup, which is the owner of the Quando / Quanta brand, but no response either. https://foldingbike.biz/Stronger-Fro...6-Spoke-Silver However, it looks like the KT-A8QF. Although it says 28 holes, but it's got a 40mm PCD diameter, so it should be able to handle 36 holes: KT :: FOLDING BIKE :: KT-A8QF https://cimg4.ibsrv.net/gimg/bikefor...fff033c729.jpg KTGroup also makes the Quanta KT-A8BF. At first I thought it was the hub that BikeFriday uses, but I noticed that the lip of the shaft, and the endcaps are slightly different. KT :: FOLDING BIKE :: KT-A8BF http://www.ktgroup.net/Archive/_eng/...1505200067.jpg These were the rims that I found that are available in Europe that might fit for me. I wanted the Mach1 Kargo, but it only comes in 36 holes. https://www.bikeforums.net/bicycle-m...l#post21106421 https://cimg2.ibsrv.net/gimg/bikefor...362aa165df.jpg Ginkgo has what I think are Kinlin rims that are 26mm internal width, in both 32 and 36 holes. I might decide to go with these. But 26 is a bit too wide. https://www.ginkgo-veloteile.de/gink...ake-417gr.html Along my search, I also came across Bitex hubs, A702SB. They look very similar, but the profile is a little bit different. And the spoke holes are very far from the edge of the flange. BITEX It also looks very similar to what CNC Shop in Germany is selling: https://www.cnc-bike.de/product_info...ducts_id=15685 All of these rim and hub manufacturers are currently at EuroBike this week. I was thinking of going there to ask all these questions about availability of parts, but it's not economical to pay the airfare, or the tens of hours to get there and back, just for wheels. |
"But I couldn't find wider rims with 28 holes that matches the Novatec hub that I have. I want between 20-25mm inner widths. 19 is acceptable but is the minimum for the Big Ben Plus 55mm (2.15") tires. But the wider rims usually only come in 36 holes, and more rarely in 32 holes."
I went through the same search, needed a 28H wider rim for Big Bens and for a 28-hole S-A X-RF8(W) IGH on my Downtube 8FH. Alienation Malice TCS rims are 23mm internal. |
I found a drawing for it (edit: these are not available in 28H locally)
https://cdn.shopify.com/s/files/1/01...1c_600x450.jpg Looks very shallow. The modernbike site says 16mm tall, but that's only at the very center. I noticed that the wide rims labeled as "cargo" are taller, while the other rims labeled "bmx" are very short. Is that because the bmx rims are supposed to flex to absorb jumps? For something like loaded touring, I think taller profile with less flex reduces loss of rolling efficiency. There is a local bmx shop that sells a 28H Rhyno Lite. It has a profile of 27 outside, 23 inside, and 16 tall. It's very similar to the Alienation rim. But I think I prefer something taller for more rigidity. I read on the Remerx website, that 0.3mm of worn material is the maximum allowed before you must change their rims, or a minimum of 1.1mm remaining thickness on the sidewall. The YAK19 was already only 1.3mm thick. So thin. |
I measured the Chosen T4B hub. The machining and finishing looks better than the Novatec hubs. The end cap design is also much better, as the bearings sit 1mm inside the hub body, and the end cap also sits about 0.5mm inside, with a 0.2mm gap all the way around, so less dust and water exposure to the bearings. The serrated surface is also machined directly into the end cap, unlike the Novatec end caps which have a separate piece that is poorly pressed or glued on unevenly.
I haven't removed the bearings, so I don't know if the axle shoulder width matches the hub body. The bearings are 6000 LLU from TPI, which are full contact seals. If feels like there is a little bit of friction from the seals. I might replace the bearings with another with LLB seals, since I'll be removing the original bearings in the future anyway to take a look inside. Weight is 111g. Also, someone from Chosen told me that this shop in Europe stocks 32 and 36 hole hubs but in 76mm width. http://www.tretroller.de/roller.htm https://cimg1.ibsrv.net/gimg/bikefor...b9b045d046.jpg https://cimg9.ibsrv.net/gimg/bikefor...dbd8c819fb.jpg https://cimg9.ibsrv.net/gimg/bikefor...ba3a08374e.jpg https://cimg0.ibsrv.net/gimg/bikefor...a07de6b5d7.jpg |
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