Nexus 8 & Alfine 8 Compatibility

[saudidave]

I accquired a new (14miles only) Raleigh Centros ebike at a bargain price a couple of months ago but I can't live with the Roller braked Nexus 8 it's fitted with. I like IGH Hubs and I've had Nexus 8 for several years now but the Coaster brake has to go & I won't be persuaded otherwise. I've considered trying to disable it but I would be concerned about reliability so I decided to purchase a new hub and have my LBS rebuild the existing wheel with it in.
There is a problem in that Nexus 8 hubs, 36 hole disc brake version, black, are unobtainable at the moment and I can't get hold of one until late October. Alfine 8, black, are rare but can be sourced. The O.L.D. is the same and the gear range is identical albeit I know the Alfine has some different internal parts. Would I be able to substitute one for the other and if so would I be able to use the drive cog, Gates belt, and Revoshift from my existing bike?

Any information or advice would be much appreciated.

[a.twiddler]

Doesn't the roller brake just slide into some splines on the hub and can therefore be removed easily? You might need to fit a dust seal and a spacer to the hub but looking at my Dawes Low Rider which has a Nexus 7 with roller brake it seems straightforward enough. The roller brakes are one of the things I like about this bike.

There seems to be some confusion in your post as to whether it is a roller brake or a coaster brake that you have. I believe that the coaster brake is integral with the hub so that would be a different situation.

Does your frame have fittings for a disc brake caliper? It might be more straightforward otherwise to fit a rear rim brake.

Sheldon Brown could give the solution as the website has a mass of information on IGH hubs.

[saudidave]

It’s a coaster and integral to the hub. I’ve never used it as it’s useless as a brake. As I stated I want to replace the hub, not remove the coaster brake as Googling the process reveals issues afterwards and I’d rather just be done with and replace it.

The bike has a rear disc brake as well so I’m not sure what Raleigh were thinking when they specced the bike.

[Sum]

The Alfine 8 (A8) hub comes in slightly different flavours and some use of the same bits as some of the Nexus 8 (N8) hubs. One thing to watch out for is the shifting - the 7000/7001 series A8s shift the opposite way to the 500/501 series A8s and they use different cassette joints. For example, if your Nexus uses the CJ-8S20 cassette joint, then this will work with either a 500 or 501 A8, but I'm not sure if it will work with a 7000/7001 A8 (which itself is meant to use the CJ-S7000).

I've linked to Sheldon's website which gives the different type of hubs and which cassette joints they use. There a few coaster brake versions - do you know which one it is? It should be written on the hub.

[saudidave]

Thanks for the reply, it's much appreciated, however....

First off there a lots of cassette joints that have the reference CSJ820. They then have a sub reference that is specific to the particular hub/sproket or Gates belt combination and Nexus ones are not a straight swop with Alfine, they have different CSJ820 sub part nrs. For instance a cassette joint for an Alfine 8 with a Gates belt drive is a CSJ YZR98040 & that for a Nexus 8, Gates belt drive is CSJ 820 YZ3E98030. The Gates Belt Drive versions are offset so that the gear cable clears the Gates cog which is wider than a chain sprocket one which in turn will have a different sub reference to CSJ 820. Additionally Raleigh, being specification wombats have fitted my Gates Belt drive bike with a standard Nexus Cassette joint for sprockets that has the gear cable runnung so close to the Gates cog that it's frightening. I have now sourced the correct Gates drive one for a Nexus 8 Disc brake hub from Germany and that willl clear the cog when I eventually get the new Nexus 8 IGH

I came up with the bright idea of fitting an Alfine 8 hub as the Nexus 8 Disc brake one is currently not available in the UK. The Afine 8, 36 hole, Black is available from one source (Bikester) however the cassette joint I require to be able to fit the Gates drive cog and belt that is on my bike isn't available anywhere, so in the interests of sanity I've instructed my LBS to order a Nexus 8 Disc brake only version for delivery in October and they can rebuild the wheel with that and fit the Gates Belt specific cassette joint CSJ YZ3E98030 that I have accquired from Germany at great expense. (£29.00)

It's all quite bewildering & I've coped with the useless coaster brake for two months now so I'm sure I can hang on for another three.............

[Sum]

Here's a compatiblity chart for the Shimano IGH. There's only two types of CJ-8S20 cassette joint:
Y74Y98130 - CJ-8S20 Cassette joint
Y73E98030 - CJ-8S20BD Cassette Joint for Belt drive system.

I got the Y-part numbers from item 38 on this EV:https://si.shimano.com/en/ev/SG-C6001-8CD-4130.

Of the various Alfine 8 types, the Gates technical bulletin regarding the belt-drive compatible cassette joints mentioned only the SG-S7000-8, and not the SG-S7001-8 or SG-S501/S500 Alfine 8s. I assume the SG-S501/S500 Alfine 8 were omitted because they had both been discontinued and replaced by the SG-S7000-8 at the time. I'm not sure why the tech bulletin omits SG-S7001-8 as it had superceded the SG-S7000-8 when the bulletin was updated. In any case, as mentioned previously, the SG-S7000/S7001-8 Alfine 8 shift the opposite way to the SG-S500/S501 Alfine 8 and also Nexus 8, and they use different cassette joints.

The SG-S500/S501 (and SG-S7000-8) are not listed on that compatiblity chart unfortunately, I guess because they are now discontinued, but I think the CJ-8S20BD will work with one of the older SG-S500/S501 Alfine 8s, since they use the equivalent non-belt drive CJ-8S20 Cassette joint, same as the Nexus 8.

However this is probably not much help; brand new SG-S500/S501 are getting a bit rare. There's been a few used on eBay, and I've been buying the odd one here and there for spare parts, but the condition of these can be hit and miss, which is reflected in their price. If you're lucky enough to come across a SG-S500/S501 in good condition, then I'd suggest taking a closer look at it, but otherwise your current plan to replace with another Nexus 8 is the right choice.

Edited for clarity.

[saudidave]

Many thanks for the comprehensive reply.

This is all beyond confusing and more than a little dissapointing. It would appear that for the moment I am stuck with my current set up. I am really pleased with the bike apart from the coaster brake but it would appear that the Nexus 8, 36 hole disc brake version isn't available anywhere on planet earth. Try as I might I can't come to terms with the coaster brake, depite now having covered 700+ miles on the bike. I either sell the bike and replace it with a new one, which I'm now seriously considering or I wait and hope that Shimano get their act together.

The only other alternative is to disable the coaster brake in the one I have. I'm not sure I have the skills to do that personally and my L.B.S. aren't prepared to attempt it. There is also the danger that if I attempt it and get it wrong, I can't get a replacement and thus the bike is effectively trashed. Sell and replace the bike is definitely starting to look the best option

[saudidave]

Finally I've done a 180° here at a total cost of £188.97 and if it all goes horribly wrong, I can sell the gear on ebay at a loss that I can afford and thus live with.

This morning I ordered from Bikester:

Shimano Alfine SG-S7001-8 Gear Hub 8-speed Disc Center-Lock black (Design 36H); £149.99 no shipping fee
Shimano Alfine SL-S7000 Rapidfire Plus Gear Lever 8-speed Right black ; £25.99 no shipping fee

And from the "Woolly Hat Shop" on ebay (they sell bike bits!):

What was described as "CJ-S700 Nexus cassette joint unit for belt drive" however the part reference CJ-S7000 YZR98030 is actually an Alfine 8 Cassette joint; price £12.99 incl postage.

The only other bits I can think I may need are different anti turn washers and they are freely available. I would prefer to keep the Nexus Revoshift and the gear ratios of the Nexus 8 and Alfine 8 are identical, but there is confusion as to which way they pull so I'll wait and see on that aspect.

I'll post again with the conclusion when the parts have been delivered and are hopefully fitted and working. If all goes to plan it will also be interesting to see if the Alfine is any better in any way than the Nexus

[Sum]

Goodo. Glad you're making progress.

For (my) piece of mind I'd suggest double-checking that you haven't misread the part reference for the "CJ-S700 Nexus cassette joint unit for belt drive". The CJ-S700 is what the CJ for the Alfine 11 is called, and it has the part ref: Y72A98030 - CJ-S700 Cassette Joint Unit for Belt drive system. Those part numbers looks almost identical except for the 2A and ZR and it's easy to mistake one for the other.

[saudidave]

Goodo. Glad you're making progress.

For (my) piece of mind I'd suggest double-checking that you haven't misread the part reference for the "CJ-S700 Nexus cassette joint unit for belt drive". The CJ-S700 is what the CJ for the Alfine 11 is called, and it has the part ref: Y72A98030 - CJ-S700 Cassette Joint Unit for Belt drive system. Those part numbers looks almost identical except for the 2A and ZR and it's easy to mistake one for the other.

You are correct, I've ordered the wrong cassette joint! The question is can I get the correct one in the UK? I'll search today and if I can't I'll cancel the hub and shifter purchase.

[Sum]

I had a quick look last night and found this CJ from the Holland Bike Shop: https://hollandbikeshop.com/en-gb/bicyc ... ck-644696/
The listing is a bit confusing since it says "S700 8S" (which may be a typo) in a couple of places but also says "For belt drive Switching unit, CJ-S7000 Shimano Code: Y7ZR98030" which is the thing you want. The photo also shows "CJ-S7000-8BD" stamped on the arm of the CJ which is encouraging. If you was going to get it then I'd suggest emailing the shop and checking, however the shipping costs to the UK (15 euro) is expensive, so perhaps check elsewhere first.

Did you see much difference between the non-belt drive and belt drive versions (CJ-8S20 and CJ-8S20BD) of the cassette joint for your Nexus 8? If the difference is simply the arm has been bent slightly to one side, then I'd suggest getting a CJ-S7000-8, and altering it yourself just enough to clear the belt. Just don't try bending it when it is in place on the IGH, as the fixing ring is likely to get damaged. You already got the CJ-8S20BD to give you and idea of how much tweaking is need. The Woolly Hat Shop sells the CJ-S7000-8 so maybe you can ask them to swap.

I'm sorry this has turned out to be so much hassle. I was cringing a little when I was typing my previous post, asking you to check the part numbers. I didn't want to add to your problems!

[saudidave]

I had a quick look last night and found this CJ from the Holland Bike Shop: https://hollandbikeshop.com/en-gb/bicyc ... ck-644696/
The listing is a bit confusing since it says "S700 8S" (which may be a typo) in a couple of places but also says "For belt drive Switching unit, CJ-S7000 Shimano Code: Y7ZR98030" which is the thing you want. The photo also shows "CJ-S7000-8BD" stamped on the arm of the CJ which is encouraging. If you was going to get it then I'd suggest emailing the shop and checking, however the shipping costs to the UK (15 euro) is expensive, so perhaps check elsewhere first.

Did you see much difference between the non-belt drive and belt drive versions (CJ-8S20 and CJ-8S20BD) of the cassette joint for your Nexus 8? If the difference is simply the arm has been bent slightly to one side, then I'd suggest getting a CJ-S7000-8, and altering it yourself just enough to clear the belt. Just don't try bending it when it is in place on the IGH, as the fixing ring is likely to get damaged. You already got the CJ-8S20BD to give you and idea of how much tweaking is need. The Woolly Hat Shop sells the CJ-S7000-8 so maybe you can ask them to swap.

I'm sorry this has turned out to be so much hassle. I was cringing a little when I was typing my previous post, asking you to check the part numbers. I didn't want to add to your problems!

I found the same part myself at holland bikeshop this morning and I've ordered it. I've also cancelled the order with the Woolly hat shop so all is well. The Nexus Belt drive cassette has an offset around 5mm, but I reckon 2 or 3mm is all that is required to clear the Gates Belt Drive.

I only found one other correct unit, at Bikeinn who I think are in Spain. Their web site greyed out the product with a message that they were not able to deliver it to the UK due to instructions from Shimano!

Many thanks for your help with this, it is much appreciated.

[saudidave]

The CJ-S70008BD arrived today and it is totallly wrong. It's quite a bit longer than the Nexus one and the diameter of the section where the metal casing at the end of the cable fits in is semi circular and 10mm diameter as opposed to as 3/4 of a circle and 6.5-7.00mm on my bike. There is no way it is compatible!

Ther Shimano 8 hub and shifter is being delivered by courier today and I think I'll just return everythung. It's all too much of a saga.

[PH]

There is a problem in that Nexus 8 hubs, 36 hole disc brake version, black, are unobtainable at the moment

I have one of those that is now spare, SG-C6001-8D, bought April last year from Starbike, I got it as a spare when I thought an Alfine might be on the way out, but that survived and I no longer have it. Still in the box it arrived in,
Just the bare bones hub, no fitting kit or shifter, cost me £126, can't see them for under £160 now so I'm hoping to get my money back, I'll cover postage.
let me know if you're interested, I'll stick it in an advert with some other surplus if you're not.

[Sum]

The CJ-S70008BD arrived today and it is totallly wrong. It's quite a bit longer than the Nexus one and the diameter of the section where the metal casing at the end of the cable fits in is semi circular and 10mm diameter as opposed to as 3/4 of a circle and 6.5-7.00mm on my bike. There is no way it is compatible!

Ther Shimano 8 hub and shifter is being delivered by courier today and I think I'll just return everythung. It's all too much of a saga.

The CJ-S7000-8 is different to the Nexus CJ-S820, and it has its own fitments (e.g. item 12 on the EV below). You can't reuse the ones that are used with the CJ-S820. Let's wait until everything arrives and then see what you've got and haven't got before making a decision.
https://si.shimano.com/en/pdfs/ev/SL-S7 ... -3722D.pdf