Moving MTB parts to new frame

Gavin

My current 2004 Specialized Rockhopper frame is too large for me. It's 19" and I'm 5'8". Heartbreaking, but I want to get a bike that fits. I am thoroughly skint at the moment so would like to do this and break even if possible.

I was looking at buying a new cheap, but reliable, 16" frame from chainreactions http://www.chainreactioncycles.com/Models.aspx?ModelID=12529

and move everything from the Rockhopper over and then sell the Rockhopper frame. So here are my questions.

I think everything will go over except for the seatpost. However, I am a bit confused about the headset, I've never installed a new one, only re-greased bearings. Will this transfer over or do I have to get a new one?

Secondly, could I reasonably get 150 euro for a 2004 rockhopper frame, or is that just pie in the sky thinking ?

edit - crap. Just realised the clamp size on the rockhopper front mech is 34.9mm and on the frame I'm looking at it's 31.8mm. Possible to change the clamp size on the mech ?

I suppose an other option could be to sell the rockhopper completely and try to buy another bike second hand for the same amount. Anyone want to hazard a guess at what I'd get for it. I was thinking around 350 or so. Optimistic? Pessimistic ?

kenmc

in theory you should be able to move the headset over, but they're not really all that expensive - 7.99 sterling on CRC - and a bit awkward to get out without damaging it. Again in theory you need to have a headset press, to put it into the headtube, but you can get around this with a long threaded bar (hardware store) and some washers and bolts - pretty sure it's on youtube or instructables or something.edit here. recommend churchtown stores over by the braemor rooms for all the hardware

this should allow you to get the derailleur to fit

Gavin

kenmc wrote: »

in theory you should be able to move the headset over, but they're not really all that expensive - 7.99 sterling on CRC - and a bit awkward to get out without damaging it. Again in theory you need to have a headset press, to put it into the headtube, but you can get around this with a long threaded bar (hardware store) and some washers and bolts - pretty sure it's on youtube or instructables or something.

this should allow you to get the derailleur to fit

Ah ! good find, thanks for that !

doozerie

Verb wrote: »

I think everything will go over except for the seatpost. However, I am a bit confused about the headset, I've never installed a new one, only re-greased bearings. Will this transfer over or do I have to get a new one?

Without the proper tools to remove the headset, you'll need a hammer and something between it and the cups in the frame. You'd be using a hammer with the proper tool anyway, but the advantage of the tool for removing the cups is that it fits more snugly against the cups and therefore is less prone to slipping when you hit it and causing damage. The proper tool is basically just a cylindrical piece of metal pipe with a cap on one end and the other end splayed out to a larger diameter than the pipe itself.

The same applies to installing the cups into the new frame. The proper tool (threaded steel rod) makes it simple and safe, and even a homemade version should be able to do it well. Without either you have to resort to a hammer again, this time place the cup into the frame by hand as much as you can, put a piece of wood over it, and basically pummel the piece of wood and hope that the cup goes in evenly all round (if it tacks/tilts, things get messy).

I've used the "hammer only" approach and the correct tool approach, and there is a world of difference between the two. Both work, but particularly with an aluminium frame the "hammer only" approach is risky as one slip of the hammer or the makeshift tool could ruin the frame. Buying a new headset avoids the risk to your old frame, but you still have the risk to your new frame of fitting it if you go the "hammer only" route.

I presume that the head tube diameter on both frames is the same. There are at least two different diameters commonly used on road frames, but I think mountain bike frames are pretty consistent with they 1 1/8" diameter. Might be worth checking though.

I presume also that you will transfer the forks to the new frame, so you won't have to remove the race from the base of the fork column (another hammer job, and the correct tool in this case is just a piece of metal that is more conveniently shaped than some alternative you might have lying around such as a screw driver). If you buy a new headset that you may have to swap the old race on the forks for the race from the new headset. Have you checked that the forks will fit? Chances are the new frame is designed for suspension forks, but I'm not sure that all suspension forks are the same length/height so it would be worth verifying this.

The bottom bracket diameter is the same between the two frames, but the width can vary so that is something else to verify is common between the two of them. Also, bottom brackets come in either English or Italian thread so you may need to check whether they match - both frames were probably made in the same area of the world and so probably match, but it is just another thing worth checking (I have only hit this issue with road frames in the past, but that is because none of my mountain bike frames were made in Europe and it seems to be a Europe vs the rest of the world issue despite the names given to the different threads - I think the rest of the world settled on the "English" thread, but I don't recall for sure).

For the front derailleur, your current bike has a bottom-pull one. Some frames take top-pull. It's not clear from the photo of the new frame which one it takes but there is an eyelet on the frame high up at the rear of the seat tube and this is likely to be for the front gear cable. Unless there is a roller down low around which the gear cable wraps to feed back up to the front derailleur (a horrible option, in my experience), it is likely that the new frame takes a top-pull front mech.

The only other thing I would suggest thinking about is whether a 16" frame is the right size for you. Size measurements differ between manufacturers (sometimes dramatically), and personal taste plays a part too, but I am half an inch shorter than you and my mountain bike frame (a Kona) is 18".

doozerie

I've just read the reviews of the new frame on CRC and someone mentions in there that they got CRC to fit a new headset to it for a fiver. That is worth considering if you decide to buy a new headset from CRC from the outset. You would probably pay a lot more in a local bike shop for the labour involved.

penexpers

doozerie wrote: »

I've just read the reviews of the new frame on CRC and someone mentions in there that they got CRC to fit a new headset to it for a fiver. That is worth considering if you decide to buy a new headset from CRC from the outset. You would probably pay a lot more in a local bike shop for the labour involved.

I bought my headset in an LBS and it fitted and they cut the steerer for free.

doozerie

penexpers wrote: »

I bought my headset in an LBS and it fitted and they cut the steerer for free.

You did well there as there is a bit of donkey work involved if they have to cut the steerer too. Some bike shops have a minimum charge for any work on a bike - if you buy the part to be fitted from them then they might give you a discount on the labour, but I'm inclined to think that is rarer and rarer these days. Being on friendly terms with the bike shop staff can still count for a lot though.

Gavin

Cheers doozerie ! Thanks for the comprehensive reply.

I'll probably get the headset fitted by CRC alright if I go ahead. It seems to be the easiest option.

Re the frame sizing, my brother got a 17" BeOne recently and I found it far more comfortable than the rockhopper. Much lighter, easier to move around in. I'd read stuff from good aul Ned Overend recommending almost 4" of stand over on a bike. It was never really an issue until I started trying to cycle up steep slopes. Bailing out can be difficult when the top bar is forced into your crotch. That Brand-X frame has no slope on the top bar either so, I reckoned the 16" would be much better than 18".

Seeing as I'm crap at mtb I figure I won't really notice the difference between frame quality, if there is even much difference.

doozerie

Good luck with it. You may have thought of your cables already but they are one other area where you might have to spend some cash. If your existing gear and brake cables are in good condition, and the cut ends haven't unraveled, then you may be able to re-use them (re-fitting them through the outer cable is the usual challenge), but even then the lengths could be off - if the cables take a significantly different route on the new frame then your old cables might be too short. Also, if the new cable routes differ from your current bike then you'll probably need new pieces of outer cable as again the lengths (and number) of these often vary from one frame to another. Inner and outer cables are relatively cheap though.

Re the frame size, you certainly are better going with your own gut feeling on that and you've obviously thought it through. Due to the inconsistency in frame sizing between different manufacturers the 16" in that frame could well be the equivalent of the 18" of my one anyway (my top tube certainly does slope a lot - Kona are one of those that measures frame size from centre of bottom bracket to top of seat post so the slope isn't factored into their measurement at all). In any case, when it comes to mountain bikes in particular, if you were to err at all you are better off erring in favour of a smaller frame - sounds like that won't arise though.

blog_blog_blog

I,d say a 17 is too small, but a 16 not a chance!
It would be a big waste to build up a bike to find out its too small, Its a xc frame not a DH/jump frame so 4 inchs crouch clearance aint needed(did i read that you said it from some old guy ?>) Toptube will be to short for you.

Dont know toptube distance of your 2004 bike , but compared to 2009 bike ,the 18" frame is 50mm shorter than your 19" and the 16" frame is 90mm shorter, Would be kneeing the bars!

Best thing to do it measure your existing frame and compare it to spec,s on that 18/16" frame. I think it is slightly sloping , so add 20-30mm for horizontal toptube lenght

Goodluck
Ps they will fit the headset 4 little ,Going for a FSA. cheap enough, grey XTR colour frame, nice stealth build.