Ohlins Front & Rear for Rockster

[Hottech]

I was buying a slightly used very low mileage pair of Ohlins for a Rockster BM 3500 Front manufacturer date 3-12-10 & BM 3490 Rear manufacturer date 3-12-11 but found out it would cost me too much to convert them to my Roadster. I am willing to pass them on for what I would have paid for delivery. $900 for the pair and $45 priority insured shipping. Call me if interested 980-253-5904. Mitch

[riceburner]

Why would they need to be converted? My Rockster is running fine on an R-R rear - is the front massively different? (it shouldn't be).


$900 is a bit too much for me though.

[Hottech]

Ohlins said the Rockster rear was taller than the Roadster and would need a new shock body and shims but that the Rockster front was shorter and may rub on the roadster. They gave me an estimate to convert but suggested to sell the Rockster Ohlins and use the money to buy Roadster Ohlins. $900 for the Rockster Ohlins was the original price of just one. I thought that was a good deal to get two for the price of one but not when I have to pay for the conversion. By the way I am running a Roadster and trying to put Rockster's on it not the other way around.

[grwrockster]

Riceburner had to explain it to me a long while ago that he ran an R shock in his Rockster as they are more common to find used. I think RB said (no doubt he'll pop back at some point and confirm) that the (rear) R shock is 5mm or something similar shorter, but of course this is increased over the shaft length to be more like 20mm drop overall. Which can't be good for the steering/handling I'd have thought. I was told that this can be corrected by using the (shorter) R1150GS Torque arm rather than by modifying anything else to get the ride-height back to normal.

So - using the reverse idea - you could use a slightly longer rear torque arm to enable you to use the rear Ohlins (I don't have a clue if any other BMW boxer models use a longer rear brake torque arm that the 'R' does, but somebody else on here might) maybe?

I've seen some aftermarket adjustable torque arms advertised (they have a threaded rod so you can vary the length, which in turn alters the ride-height), or it wouldn't be too difficult to make/get made a longer arm?.

The front shock? Is it shorter for sure (I have no idea)? If it is, and its only a few mm shorter than the 'R' then I suppose it might cause a fouling problem as there is a swing-arm on the front as well (which I presume must increase the effect of the shorter shock in the same [but opposite effect] manner that the rear does). It shouldn't be too hard to check out though - take some stock ride measurements, then swap the f shock & see?

If the front of the bike was dropped a bit though, the geometry would change and it should quicken up the steering a bit (might be a good thing?), and you would lose a touch of ground clearance - so if you're the type to touch down the cylinder heads it'd be something to watch out for.

I'm not saying you'd want to actually do any of this or even if its worth the hassle - but I thought it worth suggesting as it might mean you get to use the shocks?

When the damping goes fishing on my Rockster, there are UK workshops that reckon they can rebuild to better than stock (and a lot cheaper than any replacements), so I'm hoping I can go down that route myself.

[riceburner]

GWR - where do you know that can rebuild a Showa shock? I showed my Rockster shocks to my closest suspension expert and he said it wasn't rebuildable. (so I threw it away).


You're right about the Roadster rear shock being only a tiny bit shorter than the Rockster rear shock. I've got the GS Paralever arm on my bike so it's back to (almost) the standard ride height for a Rockster (shorter shock, and shorter arm combines to give roughly the same ride-height).

I very much doubt that the front shock is going to be more than 5 - 10mm different in length. That WILL give a larger difference in ride-height at the front, but again, I doubt it will be enough to cause any interference. One way to check would be to remove the front shock (bike on centre-stand and braced, naturally!) and see just what happens when the front swing-arm is lifted - see where any interference happens and what might hit what. Again, I seriously doubt you're going to get any interference before the Roadster shock is fully compressed. (find out what that length is and ensure you push the swinging arm up beyond that height).

It'd take an hour to find out if your very expensive shocks aren't going to fit - an hour that will save you $900....


I'd also go so far as to suggest that unless your name is Casey Stoner or Randy Mamola, the ride-height difference due to the shorter shocks is not going to be a major issue in general usage... I ride fast on the roads, and corner quickly - I've NEVER touched the cylinder heads down. (Nor my knee fwiw, unless closely followed by arm, shoulder etc.... )

[grwrockster]

RB - regarding the shock rebuilding. It was an article which I made sure I hung onto which gave the details of the engineering firm specialising in shock rebuilding. I can't say 100% as I'll have to dig it out, but I think it was Ride Mag. One of the journos was running a 100K miles R1100RS as a project and they were chronicling the whole thing - finding what was worn on it after being bought with 90k miles, where and how to fix it up etc.

One months feature was the rear shock. The firm he took it to not only stripped and repaired the damper and put decent oil into it, bled and set-up the adjuster properly, but they even changed the spring for one more suited to him. Better than original was the claim made for the result. I'm guessing as a journo writing a feature they probably pulled all the stops out for him to showcase what they could do, but interesting nonetheless.

Esp after I learned that Rockster shocks were not that common used in the UK, and as the model isn't a very popular one here, I guessed that aftermarket choice wouldn't be extensive either. Which could cause me problems with sourcing shocks - a problem that can only get worse as the model gets older and more obscure. Hence my tucking away of the magazine in the hope I can refurbish mine when the time comes.

I'll try to get my enfeebled brain to remember to dig the article out and then post the details. As I recall, the firm would be nearer to you than me as well

[grwrockster]

I ride fast on the roads, and corner quickly - I've NEVER touched the cylinder heads down. (Nor my knee fwiw, unless closely followed by arm, shoulder etc.... )

+1 on that RB. I've touched a cylinder head down once, but it was immediately followed by the bar-end when I tucked the front on a nicely polished (worn) downhill Italian Alpine 180 bend . (When not falling off), Rockster ground clearance has never been an issue regardless of the pace or road type on the roads. I've clanged the mainstand down quite a few times (usually a small depression mid-corner when cranked over at pace loading the springs a bit more) and touched (literally touched, not scraped hard) the pegs a couple of times, nothing more. (FYI - When a mate was having a go on my bike in the Austrian Alps with me tailing him on his VFR800, I did notice that, when he was cranking spiritedly into tight uphill hairpins there wasn't much left at all between the Rocker cover and the road surface)

I did spend a while learning to do the whole knee-down bit years and years ago (just as a personal challenge to see if I could). I've short legs and if you're not on a full-on sports bike I found that it required an unnatural exaggerated riding stance to drag my knee (bikes I did this on were not typical choices, just available, like old Yam FZ750, early Yam Fazer 1000, Honda X11 and my trusty Yam XJR1300).

My own experience was that I was actually faster and in better control forgetting the whole 'knee-down' exercise and just ride the bike. It was fun to learn to do, but after that the only use (if that's the right word) would have been as a bit of a pose to show off - which would get old pretty quickly - I abandoned the practice shortly after learning how to do it. I only mentioned it because it seems a few guys DO touch down the heads (whether only on track or not I have no idea) and a shorter front shock would reduce clearance a bit.

[riceburner]

I'll try to get my enfeebled brain to remember to dig the article out and then post the details. As I recall, the firm would be nearer to you than me as well

Cheers mate!

[grwrockster]

RB,

I dug out that article and suspension repair people mentioned who rebuild BMW shocks.

The company is MCT Suspension in Stowmarket, north of Ipswich. http://www.mctsuspension.com Tel: 01449 777161

FYI - The article was in the April 2011 edition of Ride Magazine.

(My apologies to the original poster for hijacking your thread about your Ohlins.I hope you don't mind, & you've got somewhere with your own suspension dilemma!)

[riceburner]

Ah right - I figured it might be them. Highly recommended by a lot of friends of mine on the other forum.

Now - I just need to find a Rockster rear shock... last one I heard about was over £200 from Sherlocks!! That's nearly new price!

[grwrockster]

Now - I just need to find a Rockster rear shock... last one I heard about was over £200 from Sherlocks!! That's nearly new price!

I can't imagine it costing less than that sort of money for a shock rebuild though RB. Mind you, if the article is anything to go by, they reckoned that the damper unit of the shock is pretty hard-wearing as is the spring, but that most OE shockers have rubbish oil in them and the process gets far too much air contamination or something. Anyway, the original oil turns into nastiness and breaks down and that's why we get we get the underdamped pogo-stick effect. If that's true then maybe a couple of hundred on a pro rebuild with proper oil is money better spent than on a s/h or a new shock?

Sounds like maybe what you need is a cheap but tired Rockster rear shock, and then get it refurbished? Mind you, as you have the 'R' shock and a GS arm, isn't it just as good to simply perk up the shock you have when it starts to get all boingy?

At 33k miles (so far) my rear shock still seems to be ok -it still has damping anyway. I can't say that I've every rated the ride quality as fantastic, but it's not bad either. But it's only a matter of time before surgery will be necessary.

TBH - I've never even thought about enquiring as to the cost of a new shock - I just assumed it'd be something close to the National Debt of Mexico (or Greece, Italy or Spain)

Have you a figure on just how much a new one is from BMW?

[riceburner]

Now - I just need to find a Rockster rear shock... last one I heard about was over £200 from Sherlocks!! That's nearly new price!

I can't imagine it costing less than that sort of money for a shock rebuild though RB. Mind you, if the article is anything to go by, they reckoned that the damper unit of the shock is pretty hard-wearing as is the spring, but that most OE shockers have rubbish oil in them and the process gets far too much air contamination or something. Anyway, the original oil turns into nastiness and breaks down and that's why we get we get the underdamped pogo-stick effect. If that's true then maybe a couple of hundred on a pro rebuild with proper oil is money better spent than on a s/h or a new shock?

If I had a proper shock on the bike I'd agree. I used to ride the bike with a Rockster shock AND the GS paralever - handling was noticeably better (and ground-clearance). I want to get back to that.

Sounds like maybe what you need is a cheap but tired Rockster rear shock, and then get it refurbished?

Yup - but at £200+ a throw, ADDED to the refurb cost a new shock starts to look appealing.

Mind you, as you have the 'R' shock and a GS arm, isn't it just as good to simply perk up the shock you have when it starts to get all boingy?

see above - I want the improved handling back. Bike feels like it's dragging it's arse all the time at the moment.

At 33k miles (so far) my rear shock still seems to be ok -it still has damping anyway. I can't say that I've every rated the ride quality as fantastic, but it's not bad either. But it's only a matter of time before surgery will be necessary.

TBH - I've never even thought about enquiring as to the cost of a new shock - I just assumed it'd be something close to the National Debt of Mexico (or Greece, Italy or Spain)

Have you a figure on just how much a new one is from BMW?

Not yet - but I'll mostly likely be visiting Vines tomorrow (they've an open day on) so will make enquiries.

[grwrockster]

If I had a proper shock on the bike I'd agree. I used to ride the bike with a Rockster shock AND the GS paralever - handling was noticeably better (and ground-clearance). I want to get back to that.

Just a thought (Rockster Used shocks obviously being in short supply in the UK), but is there scope for you to get an even shorter (or adjustable) torque arm than the GS one, to get the effect you had with Rock Shock & GS Arm, but with 'R' shock & customer arm?

I wouldn't mind it if my Rockster turned-in and changed direction a bit faster (the GS handlebars I've got on help leverage of course, but the geometry change would be nice). Trouble is I've got quite short legs, so to lift the bum up would make things a bit more tricky come foot-down time. I do run the higher seat, but wouldn't want to run the low seat as that gives you a more cramped-leg riding position. So I think I'll have to keep mine as it is.

Maybe an 'R' front shock (if it truly is a bit shorter) instead of the Rockster one would be the way to go to get faster steering for those of us slightly more vertically challenged than you RB?

[riceburner]

If I had a proper shock on the bike I'd agree. I used to ride the bike with a Rockster shock AND the GS paralever - handling was noticeably better (and ground-clearance). I want to get back to that.

Just a thought (Rockster Used shocks obviously being in short supply in the UK), but is there scope for you to get an even shorter (or adjustable) torque arm than the GS one, to get the effect you had with Rock Shock & GS Arm, but with 'R' shock & customer arm?

I wouldn't mind it if my Rockster turned-in and changed direction a bit faster (the GS handlebars I've got on help leverage of course, but the geometry change would be nice). Trouble is I've got quite short legs, so to lift the bum up would make things a bit more tricky come foot-down time. I do run the higher seat, but wouldn't want to run the low seat as that gives you a more cramped-leg riding position. So I think I'll have to keep mine as it is.

Maybe an 'R' front shock (if it truly is a bit shorter) instead of the Rockster one would be the way to go to get faster steering for those of us slightly more vertically challenged than you RB?

I'm hardly tall...

Afaik i'm currently using the shortest available Paralever arm as it is (it's a R1100GS length arm, custom made for a mate of mine in aluminium). I "could" put a R1150GS shock in I suppose, but tbh, I think that would a) be just as expensive, and b) rather over the top! (literally!).

I also don't really have the cash to be buying yet more stuff - all I'm trying to do at the present is replace a shock that's on it's last legs at the expense of some other part of life that needs money spending on it...

[riceburner]

Got the new (well, used) shock from motorworks, after checking the extortionate price BMW wanted. Over £500!

Mind you the trip to Vines wasn't all wasted. In addition to some new gloves, I confirmed the Rocksters status as a Parts-Bin-Special! The Rockster shocks (both of em) were original fitment to the 2002 R850R Classic!

[grwrockster]

Got the new (well, used) shock from motorworks, after checking the extortionate price BMW wanted. Over £500!

Mind you the trip to Vines wasn't all wasted. In addition to some new gloves, I confirmed the Rocksters status as a Parts-Bin-Special! The Rockster shocks (both of em) were original fitment to the 2002 R850R Classic!

Is the 'Classic' different to any old R850R? - Spoked wheels and chrome or something like the R1200R Classic thing is now maybe?
Interesting though! Pity that the R850R Classic is probably even rarer than the Rockster - means that finding used shocks isn't any easier than before. I'll have to hope my 'rebuild' plan holds water when the time comes (34k miles up now - I'm sure I recall you saying that your original lost it's damping at 45k miles or so).

Lets face it - no-one is goping to fork out over £500 for a new one from BMW if there is any other option!

[riceburner]

Got the new (well, used) shock from motorworks, after checking the extortionate price BMW wanted. Over £500!

Mind you the trip to Vines wasn't all wasted. In addition to some new gloves, I confirmed the Rocksters status as a Parts-Bin-Special! The Rockster shocks (both of em) were original fitment to the 2002 R850R Classic!

Is the 'Classic' different to any old R850R? - Spoked wheels and chrome or something like the R1200R Classic thing is now maybe?

Not sure to be honest - but something like that yeah.

Interesting though! Pity that the R850R Classic is probably even rarer than the Rockster - means that finding used shocks isn't any easier than before. I'll have to hope my 'rebuild' plan holds water when the time comes (34k miles up now - I'm sure I recall you saying that your original lost it's damping at 45k miles or so).

Lets face it - no-one is goping to fork out over £500 for a new one from BMW if there is any other option!

exactly.