<![CDATA[Urgent: Front wheel bearing size problems!]]>Wondered if anyone can kindly help..

Having a nightmare with wheel bearings in my 2005 dt125 supermoto.

Took the old wheel bearings out and threw them away and now the caliper side bearing I’m having a howler trying to get one to fit..

The hub seems to be 40mm ID and my spindle appears to be 15mm

Yet everywhere I’ve read online says my bearing should have a 17mm internal diameter, the speedo drive side I’ve got a 15mm is bearing, my sleeve is a 15mm ID and I can’t seem to find any bearing which is 40mm x 15mm to fit on the caliper side.

If I remember correctly (take this with a pinch of salt) that bearing I took out seemed wider than a normal bearing too.

Any help would be massively appreciated as I’m desperate to get it on the road and this is the only thing holding me back😆

Cheers guys!

]]>https://dt125r.co.uk/topic/3523/urgent-front-wheel-bearing-size-problemsRSS for NodeMon, 17 Aug 2026 10:48:07 GMTTue, 10 Mar 2026 13:36:51 GMT60<![CDATA[Reply to Urgent: Front wheel bearing size problems! on Thu, 12 Mar 2026 08:13:20 GMT]]>Well it looks like I have found the issue...

somewhere along the line someone has pikey bodged the front axle and spacers...

What should have had the sleeve spacer which has the 1mm wall which slides in to the 17mm ID bearing was clearly lost and someone had inserted a 40mm x 15mm bearing and used a spacer from an older DT in place of the correct one.. The joys of owning an unknown modified bike!

So I am now getting a spacer machined up and I should be good to go! 😁 It has only been holding me up since before christmas.. so now I can get the wheels fitted, get the bike back to mine and do the final few bits before MOT.. starting to get excited now😁

Picture of the spacer that I should have had below:
spacer.jpg

Versus the spacer that someone had installed and was somehow using..
shaft.jpg

]]>https://dt125r.co.uk/post/33190https://dt125r.co.uk/post/33190Thu, 12 Mar 2026 08:13:20 GMT<![CDATA[Reply to Urgent: Front wheel bearing size problems! on Wed, 11 Mar 2026 15:04:00 GMT]]>Well it's possible yours is a hybrid system. So it's actually DTR forks with DTR hubs laced onto excel rims.

Again, it's an old bike so it's possible it's been modified.

]]>https://dt125r.co.uk/post/33188https://dt125r.co.uk/post/33188Wed, 11 Mar 2026 15:04:00 GMT<![CDATA[Reply to Urgent: Front wheel bearing size problems! on Wed, 11 Mar 2026 12:52:26 GMT]]>yeah I believe they are definitely off a DTX. Interstingly enough I have just been reading that the supermoto have a 17mm front axle... and mine is definitely 15mm..

My brain is starting to scramble over this! Im wondering how on earth it worked before (really kicking myself for not photographing the bearings before taking them out)

]]>https://dt125r.co.uk/post/33187https://dt125r.co.uk/post/33187Wed, 11 Mar 2026 12:52:26 GMT<![CDATA[Reply to Urgent: Front wheel bearing size problems! on Wed, 11 Mar 2026 11:53:14 GMT]]>And they're definitely off a DTX and not the Saxxes from the WRX? https://www.fowlersparts.co.uk/parts/view/93306-20348

Dimensions: 17mm (Internal Diameter) x 40mm (Outside Diameter) x 12mm (Width).

https://simplybearings.co.uk/shop/p5076/SKF-6203-Open-Deep-Groove-Ball-Bearing-17x40x12mm/product_info.html

]]>https://dt125r.co.uk/post/33185https://dt125r.co.uk/post/33185Wed, 11 Mar 2026 11:53:14 GMT<![CDATA[Reply to Urgent: Front wheel bearing size problems! on Tue, 10 Mar 2026 15:15:15 GMT]]>IMG_8875.jpeg

]]>https://dt125r.co.uk/post/33183https://dt125r.co.uk/post/33183Tue, 10 Mar 2026 15:15:15 GMT<![CDATA[Reply to Urgent: Front wheel bearing size problems! on Tue, 10 Mar 2026 15:03:37 GMT]]>shaft.jpg

]]>https://dt125r.co.uk/post/33182https://dt125r.co.uk/post/33182Tue, 10 Mar 2026 15:03:37 GMT<![CDATA[Reply to Urgent: Front wheel bearing size problems! on Tue, 10 Mar 2026 15:01:28 GMT]]>shaft.jpg

]]>https://dt125r.co.uk/post/33181https://dt125r.co.uk/post/33181Tue, 10 Mar 2026 15:01:28 GMT<![CDATA[Reply to Urgent: Front wheel bearing size problems! on Tue, 10 Mar 2026 14:55:44 GMT]]>Hi Calum,

Thanks for the reply, I tried the 35mm bearing but it rattles in the hub.. its 5mm too small on the OD as the hub opening is 40mm ID, this is where im becoming a bit stumped...

]]>https://dt125r.co.uk/post/33180https://dt125r.co.uk/post/33180Tue, 10 Mar 2026 14:55:44 GMT<![CDATA[Reply to Urgent: Front wheel bearing size problems! on Tue, 10 Mar 2026 14:42:00 GMT]]>The bearing can still be purchased new from Yamaha: https://www.fowlersparts.co.uk/parts/view/9330620226

Part Number: 9330620226

Dimensions: 15mm (internal diameter) x 35mm (external diameter) x 11mm (width).

]]>https://dt125r.co.uk/post/33178https://dt125r.co.uk/post/33178Tue, 10 Mar 2026 14:42:00 GMT