GT RTS and Middleburn cranks...Help please

[Phat_bob]

Hi folks,
Warning - I'm a newbie so prepare to answer some daft questions! Loving this site though..but I digress.

I've just bought a set of Middleburn cranks from ebay. The ring sizes are 48 / 36 / 22 (and comments about these ring sizes welcome - are they as waaay off the scale as they look in the flesh?) The large ring is like a bl00dy tractor wheel but I reckon it's gonna get me flying. Will get smaller rings if it turns out I cannot get it moving without severe thigh-burn!
Anyway - slotted it on my GT RTS last night and the granny ring is rubbing on the suspension (the housing for the bolt which holds the sus to the rocker).

My questions:
Has anyone encountered similar granny-ring issues (particularly on an RTS)? The Middleburn replaced the original Shimano STX Special Edition which has been on the bike since it was new.
What are my options? (smaller granny ring (it only just catches), longer spindled BB (currently 113 (I think)), smaller spacers between the granny ring and spider (clutching at straws here).

Nice one - cheers.

 

[bduc61]

well well
why do you make a question if you know the answer

spindle should be the correct one :idea:

smalller ring might do the trick but its only a half measure
and smaller spacers may worsen the situation ( the chain need a bit of breathing air )

so now you need to learn the chain line concept

 

[Pickle]

Longer BB spindle should sort it.

RTS lover here, so lets see pics of the old girl

 

[JeRkY]

Was the STX setup a 94mm BCD compact drive system...and the middleburns a std 110mm BCD setup?

If so is the RTS designed around the later compact systems?

Personally I would put a shimano crank back on there and save the middleburns for a different bike....Unlike Pickle, I'm not a GT fan :twisted:

 

[Pickle]

Unlike Pickle, I'm not a GT fan :twisted:

Ohh really

 

[Phat_bob]

Excellent advice folks, many thanks (except the bit about sticking the Shimano back on - I don't have another frame to put the Middleburn on - yet!). And I'm with Pickle on the GTs.

 

[lewis1641]

hi mate. do you live anywhere near anston/dinnington and have a big dog ( i say big, all dogs are bidg compared to two jack russels!)

i recognise the bike in the picture. i am certain i drove past you about 6 months ago. i spotted the wheels first then the frame. i was in traffic and in a rush otherwise i would have stopped and offered you 50 quid for it!



if it was you, awesome looking machine

 

[Phat_bob]

Afternoon,

I do indeed live out Dinnington way.
Was that 50 for the wheels, the whole bike or the dog?

 

[lewis1641]

the bike and the dog!