Thumper Club Forum
Technical => Project Progress => Topic started by: mad99mike on November 05, 2020, 05:04:57 AM
-
hi yep i have one of these using a ft500 engine i realise this is similar to the xr500/xl500 which is a easy fit, has anybody got any knowledge of fitting a xbr500 in the cb250rs frame any info gladly received.
-
Morning Mike, yes myself and big bro (mainly big bro) put an XBR engine into an RS250 frame. Needs a whole load of work to do it though, so be warned. I did a fair bit of welding to brace the frame in certain areas. As I’m sure you’re aware the XBR is a cradle frame where as the RS uses the engine as a stressed member (ooo eerr vicar 😉). The project is still on going and will eventually be used as a trackday/hillclimber, it is being built simply for a spot of Tom foolery really and probably not as a road bike. I’ll ask Matt if he’d be so kind as to pop some photos up as I’m clueless in that department. Cheers.. Michael
-
Hi All, I am just beginning to build up what I hope will be a CB500RS.
If anyone has an XL/XR/FT 500 single engine they would like to move on please let me know.
Thanks Foxy
-
thanks moto63 would be interested to see some pics just thought it was aquick way to 44hp but sounds like a lot of work it was really because the xbr engine is in the shed the alternative was to put it into my norton featherbed but seen one and it looks a bit lost in there.
-
Evening Mike, my apologies mate but unfortunately I don’t have any photos of the bike in it’s semi built up stage to post at the moment. The bike is stripped down at present in a hundred pieces 😥 and as I say it’s an on going project so not to sure when I’ll get round to start on it again. All the best if you do decide to go for it 🤞👍
Cheers, Michael
-
Doesn't Rossco500 on here have one of these?
-
Sorry, not me who built the CB500RS. Think it may have been Steve who set up this forum. I have a vague recollection of reading a write up possibly on this forum years back or or in one of the bike magazines. Probably using the XL / FT motor.
Regards
Tony
-
Think it was tevie54 who built a cb500rs if my aching brain isn’t playing up to much. I don’t recall anyone on the TC site having built an XBR engined RS. Not 100% sure though.
-
Aye,
SteveH used an XL500 engine in a CB250RS donor bike, I believe. I seem to remember at least one picture and there was also at least one article published in a paper magazine that the Thumper Club used to publish in the early days. I'm not sure if there are any copies still about or what date that it might be, but suggest before 2005.
Regards, Bill
-
Hi Everyone
Yes I've still got mine, it's got a 1980 XL500 engine but you can use an XR or FT engine, these are the easiest to fit although it's not 'easy' there is a lot of fettling.
I have seen an XBR engine fitted to an RS but it's not an easy fit, the mounting points are all different and you have to find somewhere to put the oil tank as it's a dry sump engine. In my opinion it doesn't look right, the angle is all wrong but that's just me.
I've put a few videos on youtube over the years to show how I've done mine and it's in this months Practical Sportsbikes magazine.
If I can be of any help please feel free to ask any questions as I want more of these bikes to exist.
-
Hi Steve - picked up a copy of the magazine earlier this week. Your conversion looks great. Very subtle and a credit to you.
Regards
Tony
-
Yes going to buy a copy myself whenever I drop into Asda over the coming week. Look forward to looking at the pics and reading about it. 👍
Cheers, Michael
-
Yep, just read the article again. 1st time I read it I didn't know it was one of us responsible, but I might have guessed. Top class work ;D
-
Thanks, I'm currently building a longer box section swinging arm using one from a CBX 250, cutting and welding in strengthening gussets. Keeping distortion to a minimum is a challenge even with a jig.
-
Thanks, I'm currently building a longer box section swinging arm using one from a CBX 250, cutting and welding in strengthening gussets. Keeping distortion to a minimum is a challenge even with a jig.
I feel your pain tevie54, when I de seamed my XBR tracker tank with my gig I had to do it in very short opposing sections to stop distortion. Took me an age, worth it in the end. Stick at it, keep thinking of that feeling of satisfaction when it’s done... oh and don’t forget to pop a photo or two up.
-
TIG.... not gig 🤪
-
I'm not sure how to upload photos into the website
-
No nor me, I’m lucky, I simply email them to a very clever chappie called Matt (mathee) and he very kindly pops them up for me. Be good to see your project though.
Cheers, Michael I'm not sure how to upload photos into the website
-
I'm not sure how to upload photos into the website
- Type your message into the box
- When you post a message there is a section under the panel you type into named "Attachments and other options" press the '+' icon
- This will then display a section which is titled "Attach" with a "Choose File" button
- Press the button and select a picture
- If you want to add more picture select "(more attachments)"
- Press the "Post" button
- It may take a while to upload but after that the pictures should be visible
-
what a cracking view that is Steve, where was it taken?
Cheers, Michael
-
Its near Hay-Bluff in South Wales. We were lucky with the weather that day, misty when we turned up and cleared the higher we climbed.
Can you try the instruction for uploading, if they work ok I will create a Sticky Post.
-
Aye Steve,
Sometimes the problem is that the size of the image is restricted and if you have an image that is too large or you try to upload multiple images that have a total size greater than allowed they too will be rejected.
Software to alter the image size is available, but you have to know how to use it and then there is the Windows, Android and ?, operating system differences to further confuse.
I don't envy you posting the sticky, but good luck. Thank you for trying.
Good health, Bill
-
Has anyone fitted an oil cooler to one of these engines or are they necessary.
Steve
-
I just went to do a trial fitting of the new swinging arm and I noticed the tube that's welded to the frame and attaches to the footrest bracket has cracked and is allowing the footrest bracket to move around the swinging arm pivot. I've had this problem before and I think there's even been a post about it on the Thumperclub website so it looks like I'll be doing a bit of welding repair before I can get the swinging arm fitted.
It's ironic that just when I was thinking I've bitten off more than I can chew making a new swinging arm i discover a fault that would have gone undetected until I suddenly wouldn't have been able to select any gears and wonder why. Funnily enough that footrest had been buzzing a lot more lately and giving me a numb left foot. Fate eh?
-
Fate indeedy, least you’ve got it in hand before disaster struck 👍
-
Here's a photo of the trial fitting
-
Looking good, roll on next spring eh 👍
-
Just been reading the PSB article - Nice looking Bike!!
-
There's an XR500 engine on Ebay at the moment, it's going to be about £400 including postage from the 'states' but that's quite good.
-
I just went to do a trial fitting of the new swinging arm and I noticed the tube that's welded to the frame and attaches to the footrest bracket has cracked and is allowing the footrest bracket to move around the swinging arm pivot. I've had this problem before and I think there's even been a post about it on the Thumperclub website so it looks like I'll be doing a bit of welding repair before I can get the swinging arm fitted.
It's ironic that just when I was thinking I've bitten off more than I can chew making a new swinging arm i discover a fault that would have gone undetected until I suddenly wouldn't have been able to select any gears and wonder why. Funnily enough that footrest had been buzzing a lot more lately and giving me a numb left foot. Fate eh?
Yes I had this problem on my RS250 12 months ago -couldn't work out why the kickstart wouldn't return. Tried repeatedly tightening all surrounding bolts up and it transpired the frame weld inside the right footrest hanger mount had broken/corroded. The whole footrest hanger and rear brake pedal was pivotting round as there was insufficient bracing without the inner frame lug being secured so the right footrest was moving into contact with the kickstart-quite scary. I rode it slowly (very) to my mates at Solihull and he did a load of work including welding this part of the frame up for me. He said it had already been (badly) welded there before and on the opposite side too.
-
There's a breather hole in the frame downtube just behind the engine so I assume water must get in there and slowly corrode from the inside out. I managed to grind away the old weld and reweld the crack and then respray with satin black. I think I'll spray some chain lube through a long nozzle down those breather holes in the frame.
-
There's a breather hole in the frame downtube just behind the engine so I assume water must get in there and slowly corrode from the inside out. I managed to grind away the old weld and reweld the crack and then respray with satin black. I think I'll spray some chain lube through a long nozzle down those breather holes in the frame.
Yes that's pretty much what my mate did / said. Not sure whether the battery breather could affect it if poorly routed. Had a similar corrosion problem on my XBR500 but it was the swing arm itself which corroded on that. Luckily I had a spares bike which I raided for a replacement.