Wobble crank

Downhill dominator

Hi well it says it in the name.Every time i go out it ither

1.becomes loose on the ride or

2. it becomes loose the next day

and i am always tightning it up any suggestions.

Oh forgot to mention it is a crappy make bb there is a stock drive side crank/truitive on the left

nicklouse

replace. worn out.

Downhill dominator

replace what are you sure i took it to a bike shop the said it was the cranks was mangled and deformed from all the hardcaore dh i have been doing

supersonic

Sounds like need replacing then!

nicklouse

Downhill dominator wrote:

replace what are you sure i took it to a bike shop the said it was the cranks was mangled and deformed from all the hardcaore dh i have been doing

more like poor maintanence.

Downhill dominator

ecuse :evil: me but the fact is that no it is not poor mantenence but rather crap quality parts

supersonic

What crank and BB?

nicklouse

Downhill dominator wrote:

ecuse :evil: me but the fact is that no it is not poor mantenence but rather crap quality parts

if when things had started to come lose it is often very posible to "fix" it as the interface between the cranks and the bb is not to damaged. but after 2 or 3 times the interface is worn out and the whole set up generally needs to be replaced. (ok some times the bb is ok).

Downhill dominator

right here it is in one the left hand truitive crank is loose because there is a mangled bit where it joins the bb now i know i asked what,s wrong but now i know. What cranks would you recommend

supersonic

I still dont know your BB or existing crank model, or budget. Are you wanting to replace the Bb too?

Downhill dominator

I said earlier the it is a cheapiy make and yes i want to replce them both bb and cranks for the cheapest but good set possible

supersonic

So you want a cheap as possible set, and already have a cheap set that you dont like. The thing I might recommend the same one! If I knew which set it was, then I can maybe avoid that style, bottom bracket type etc. I'll take a total stab in the dark and say get a Shimano Octlink LX crank and BB for 50 quid. Or is that too much?

Downhill dominator

50 thats fine but what about cranks or should i go to a recycle place and pinch some truitive cranks

supersonic

50 will get you the whole lot from CRC! Really is a bargain.

skyliner

Or you could get the new Deore HTII with BB for £55.00. Not convinced it would stand up to big drops(FR stylee), but should work on DH tracks.

Downhill dominator

cheers skyliner will look into that are they cranks yeah please put bb or cranks avter what ever it is you put because i don,t know all the names yet :oops:

danrj

ok guys, so I'm a total newb on this forum and I have a similar problem.

Basically this is not on my downhill/freeride bike -I have just replaced bb and crankset on that with some saints from CRC... so all good there.

I have a 04 Specialized Rockhopper that I have run as stock since I got it (replaced back wheel, new chain & block etc but BB and cranks still the same). This bike is mainly used for commuting as I don't ride xc anymore - have put skinny continental tires on etc and am running v-brakes to loose the weight.

Anyway, the problem is the cranks.. and BB I suppose. I have specialized strongarm cranks (I know I know, they're supposed to be rubbish - but these have been good for 3 yrs) and I think a shimano es70 bb (i think, I don't know - this is the problem).
The cranks have started to go and they loosen all the time - I tried to get off and stop riding whenever it happened but basically i've kind of given up on them.. unfortunately I think they've worn the fitting on the bb out.. so that needs replacing too.

So basically, can someone tell me if I take my spare pair of isis truaviv hussfelt cranks that came off my canondale chase and fit them to the chainrings from the strongarm cranks.. what size of isis BB do I need to get for my rockhopper? I have no idea and can't find the manual anywhere.

I must stress that this is my a2b London bike and is not an outlet for money (I prefer to spend my money on bikes that I can actually have fun on) and is also a total spare parts convention so I just want to get it up and runnning.
Must also stress that while I love bikes and know a fair amount some of the technicalities are lost on me.

cheers in advance guys.

skyliner

Downhill dominator wrote:

cheers skyliner will look into that are they cranks yeah please put bb or cranks avter what ever it is you put because i don,t know all the names yet :oops:

You get the lot for that (crank, rings, and BB). It'll need to be professionally fitted for best results, because the external bearings will wear too quickly if the BB shell on the frame isn't faced to prepare it correctly.

But it should be a much stiffer, more durable setup than your cheap OEM one fitted to your bike now.

skyliner

ISIS BB's are not cheap to replace. But they wear out quickly IME. £34.99 for the BB.
I'd opt for the Deore HTII as the BB comes with it, and it'll only cost you the price of fitting the ISIS, plus the part. And if you charm the shop staff, you could even get free fitting.
Just make sure they face the BB shell, even if you have to pay extra for it.

supersonic

dan, whether the chainrings will fit depends on the bolt circle pattern and diameter. Bottom bracket size depends on the shell width, and axle length (which is dependant on crank).

danrj

supersonic - how do I find out the shell width? I'm slightly confused about axle width.

Skyliner - I'm flattered that you think I'm good looking enough to charm any bike mechanic!! Although I did manage to convince one to fit my other saints in his lunchbreak - got charged 20 quid for it though so perhaps I'm not smooth enough... Bike shops tend to be more accomodating when you've just paid over the odds to get the part from them rather than getting off CRC and giving it to them to fit!


Do you both reckon that I'm making this too hard for myself and that I shuold just get the hollowtech cranks from CRC and pay a little to get them fitted? I just don't want to piss 70 odd quid away on a bike thats kind of on the way out anyway.

Arg... my bikes seem to be a black hole for my hard earned money at the moment.

danrj

ha - amazing.
The forum automactically changed the other word for urine I used to 'wee wee'... I feel like a ten year old

supersonic

If you feel confident, have a go yourself - though you will need some tools such as a crank extractor and bottom bracket tool to remoave the old one. Shell width is the width of the part the BB screws into - usually 68mm, sometimes 73mm. Some BBs can be adapted for both. Axle width depends on the chainset and how its designed. HT2 cranks come with spacers to be used with practically any frame - though the frame must be faced to ensure the bearings align correctly.