NX250 AX1 spoke wheel conversion

Open for English requests from all countries!
Antworten
Benutzeravatar
scrambler
Site Admin
Beiträge: 3871
Registriert: Fr Sep 14, 2012 8:50 am

NX250 AX1 spoke wheel conversion

Beitrag von scrambler » Sa Sep 14, 2019 7:21 am

The AX1 has a cast rear wheel that lacks a cush drive. There are only little rubber bushes which can’t be replaced and thus were never available as spare parts. The rear wheel of my AX1 was ruined by the previous owner when trying to replace the bushes and a spare wheel was nowhere to find viewtopic.php?f=11&t=915

So I thought of using a NX650 rear wheel, which has a 220mm brake disc (same as AX1). However it turned out that the AX1 sprocket, lacking a cush drive, runs very closely (ca 10mm) to the swing arm.

Bild

The NX650 cush drive needs more space, that’s why the NX650 swing arm is wider than the AX1. One could grind the cush drive and abandon the circlip and the seal – but I don’t think that this is a permanent solution.

Bild

After some searching I found a rear wheel of a KTM 620/640 with cush drive - there are also some without the later. Those wheels can be recognized by the silver hub – older versions got red hubs. The ktm also got a 220mm brake disc and the distance brake disc-sprocket fits too.

Bild

The only downsize – KTM has a 20mm axle, AX1 17mm.

Bild

So you need three new spacer - I had them made in a metal shop, because I can’t do something like this myself.

Bild

Fits :)

Bild

The only downsize – there isn’t much space in the AX1 swing arm for a much larger tire size. A 4.00-18 won’t fit, a 3.50-18 is tight as well as a 110/80-18. A 17’’ or even 16’’ rim would fit better.

Bild

jonathan
Beiträge: 4
Registriert: Fr Sep 13, 2019 12:11 am

Re: NX250 AX1 spoke wheel conversion

Beitrag von jonathan » Do Sep 19, 2019 5:54 pm

Scrambler, you are a star for posting this up! :D Thankyou. I'm about to do a spoked conversion on my AX1 (as you know) but I'm looking to go with 17 Rear, 19 Front, to retain the original geometry as far as possible. I'm on the look out for a KTM 620 cush hub (not easy to come by here in the UK) and will use a new, undrilled rim (with spokes to suit). For the front wheel, I'm thinking to use an XL125R hub ('87/88) or XL 250/350 (similar vintage) plus matching rim. Whether the XL speedo drive/spacers/axle etc. are compatible with the AX1 remains to be seen. Plenty of options for rim widths in both diameters so the next job is to trawl through the online tyre catalogues and see what's readily available (preferably in matched pairs). In short, I'd like to set the bike up as close to stock as possible, in terms of handling characteristics, but with greater tyre choice. Seems like an involved and potentially expensive way to go about it, but needs must...finding a good set of those cast wheels is akin to finding the Ark of the covenant and probably as priceless :lol:

I'll post up my progress as and when. I suspect it will be slow going...pics soon!

jonathan
Beiträge: 4
Registriert: Fr Sep 13, 2019 12:11 am

Re: NX250 AX1 spoke wheel conversion

Beitrag von jonathan » Do Sep 19, 2019 7:31 pm

Quick question: do you happen to remember what year the KTM wheel was from? I had a look on the KTM parts fiche and they changed the hub configuration over the years...

Kurze Frage: Erinnerst du dich zufällig an das Jahr, in dem das KTM-Rad gebaut wurde? Ich habe mir das KTM-Teiledokument angesehen und im Laufe der Jahre die Nabenkonfiguration geändert ...

Benutzeravatar
scrambler
Site Admin
Beiträge: 3871
Registriert: Fr Sep 14, 2012 8:50 am

Re: NX250 AX1 spoke wheel conversion

Beitrag von scrambler » Sa Sep 21, 2019 7:30 am

jonathan hat geschrieben:
Do Sep 19, 2019 7:31 pm
Quick question: do you happen to remember what year the KTM wheel was from?
1996, but I'm not sure. I was told by someone who knows more about KTM than me that the rear wheels of 620/640 are the same and can be
distinguished from older wheels (red hubs) by the grey hubs.

Affordable rear KTM wheels are rare, even around here. If possible try to get a complete set with the cush drive and all spacer, that’s usually cheaper than buying it separately.

without the cush drive
https://www.ebay.de/itm/KTM-LC4-620-EGS ... GTR=1#shId

https://www.ebay.de/itm/KTM500-1992-REA ... SwJhtddpn3

That’s the cheapest complete set I can find at the moment
https://www.ebay.de/itm/Hinterrad-Brems ... GTR=1#shId

jonathan
Beiträge: 4
Registriert: Fr Sep 13, 2019 12:11 am

Re: NX250 AX1 spoke wheel conversion

Beitrag von jonathan » Sa Sep 21, 2019 10:17 am

Thanks for taking the time Scrambler. Much appreciated. I'm trawling the internet as we speak. I think all the cush hubs have been pilfered by EXC and DRZ owners :roll:

So the KTM 500 hub in the link is the same as the 620/640? Germany seems to be the best source, based on my search. UK sellers tend to omit the details :(

Benutzeravatar
scrambler
Site Admin
Beiträge: 3871
Registriert: Fr Sep 14, 2012 8:50 am

Re: NX250 AX1 spoke wheel conversion

Beitrag von scrambler » So Sep 22, 2019 7:58 am

jonathan hat geschrieben:
Sa Sep 21, 2019 10:17 am
So the KTM 500 hub in the link is the same as the 620/640? Germany seems to be the best source, based on my search.
I think so - there have been different engines with 500 and 400cc (LC4) in the same chassis as far as I know. I let you know if I can find something more affordable.

Antworten