turtlek Posted October 10, 2008 Share i rode crater cruise last year on a compact road crank not an issue with shifting at all and would definitely recommend it perfect ratios for most hills and great for top end speed Sounds promising. Are all MTB BBs English thread? Ie' date=' is it an easy conversion? [/quote'] ? I suspect so Jules, I never seen an Italian fred MTB in my time. I have an MTB BB on my roadbike (albeit with a spacer on each side!) no problem. Long story that ........But I have seen Bianchi mtb's.... guess they have eyetie thread... but my bianchi has british threads BOB it says it was also made in italy Link to comment Share on other sites More sharing options...
NotSoBigBen Posted October 10, 2008 Share i rode crater cruise last year on a compact road crank not an issue with shifting at all and would definitely recommend it perfect ratios for most hills and great for top end speed Sounds promising. Are all MTB BBs English thread? Ie' date=' is it an easy conversion? [/quote'] I suspect so Jules, I never seen an Italian fred MTB in my time. I have an MTB BB on my roadbike (albeit with a spacer on each side!) no problem. Long story that ........But I have seen Bianchi mtb's.... guess they have eyetie thread... Correct sah! Saw an oke wif a Beeyanchee MTB riding wif MarkStockton just last night so it could well be ..... Link to comment Share on other sites More sharing options...
NotSoBigBen Posted October 10, 2008 Share i rode crater cruise last year on a compact road crank not an issue with shifting at all and would definitely recommend it perfect ratios for most hills and great for top end speed Sounds promising. Are all MTB BBs English thread? Ie' date=' is it an easy conversion? [/quote'] I suspect so Jules, I never seen an Italian fred MTB in my time. I have an MTB BB on my roadbike (albeit with a spacer on each side!) no problem. Long story that ........But I have seen Bianchi mtb's.... guess they have eyetie thread... but my bianchi has british threads BOB it says it was also made in italy OK so vat frows my feory out ve windows .... sorry BOB! Link to comment Share on other sites More sharing options...
CaptainDura Posted October 10, 2008 Share So if you take off your granny ring, how do you move your cranks closer to the frame to make up the space where the granny was ? Link to comment Share on other sites More sharing options...
CaptainDura Posted October 10, 2008 Share and are 29 tooth chainrings readily available ? Link to comment Share on other sites More sharing options...
oclv110 Posted October 10, 2008 Share If your BB have a spacer, you take that out. Link to comment Share on other sites More sharing options...
turtlek Posted October 10, 2008 Share Captain Dura you cant move your cranks closer you would have to adjust your limit screws on your front derailer and the 29tooth chainring should be able to be ordered through any LBS i know cool heat has stock because i picked mine up today Link to comment Share on other sites More sharing options...
TNT1 Posted October 10, 2008 Share i rode crater cruise last year on a compact road crank not an issue with shifting at all and would definitely recommend it perfect ratios for most hills and great for top end speed Sounds promising. Are all MTB BBs English thread? Ie' date=' is it an easy conversion? [/quote'] I suspect so Jules, I never seen an Italian fred MTB in my time. I have an MTB BB on my roadbike (albeit with a spacer on each side!) no problem. Long story that ........But I have seen Bianchi mtb's.... guess they have eyetie thread... but my bianchi has british threads BOB it says it was also made in italy OK so vat frows my feory out ve windows .... sorry BOB! Too much vino in the bianchi canteen that day... Link to comment Share on other sites More sharing options...
CaptainDura Posted October 10, 2008 Share Captain Dura you cant move your cranks closer you would have to adjust your limit screws on your front derailer Thats a shame as you really want the two chainrings to sit nicely in the middle. With the current 3 ring setup the middle chainring is in the middle (duh!) of the cluster. so one would want to move the chaninrings so the smallest one (29T) is now just off centre to the inside and the large one is just off centre to the outside. Or even better yet, seeing it is mtbing, and we gonna be using it in the mountains, if the smallest one could shift as much as possible to the left to keep the chain as straight as possible for the bigger sprockets at the back where it is going to be used the most. Link to comment Share on other sites More sharing options...
TNT1 Posted October 10, 2008 Share Captain Dura you cant move your cranks closer you would have to adjust your limit screws on your front derailer Thats a shame as you really want the two chainrings to sit nicely in the middle. With the current 3 ring setup the middle chainring is in the middle (duh!) of the cluster. so one would want to move the chaninrings so the smallest one (29T) is now just off centre to the inside and the large one is just off centre to the outside. Or even better yet' date=' seeing it is mtbing, and we gonna be using it in the mountains, if the smallest one could shift as much as possible to the left to keep the chain as straight as possible for the bigger sprockets at the back where it is going to be used the most. [/quote'] Am I missing something? Just get a shorter BB axle? Link to comment Share on other sites More sharing options...
turtlek Posted October 10, 2008 Share ok Captain dura in order for you to do exactly as you explained on your current setup it would take removing the BB taking the spacers off and getting a shorter BB axle but with you doing that you stand the chance of the frame getting trashed from the little holes where your previous Granny ring would have been sitting Link to comment Share on other sites More sharing options...
TNT1 Posted October 10, 2008 Share ok Captain dura in order for you to do exactly as you explained on your current setup it would take removing the BB taking the spacers off and getting a shorter BB axle but with you doing that you stand the chance of the frame getting trashed from the little holes where your previous Granny ring would have been sitting Naturally you would have to check clearance first, but if it passes, then it works? Link to comment Share on other sites More sharing options...
turtlek Posted October 10, 2008 Share ok Captain dura in order for you to do exactly as you explained on your current setup it would take removing the BB taking the spacers off and getting a shorter BB axle but with you doing that you stand the chance of the frame getting trashed from the little holes where your previous Granny ring would have been sittingNaturally you would have to check clearance first' date=' but if it passes, then it works?[/quote'] yes it would work but ith a whole load more work than just setting your derailers as i previously suggested Link to comment Share on other sites More sharing options...
GoLefty!! Posted October 10, 2008 Share converting a triple into a double is easy. SImply remove the inner chain ring. No modification necessary. It may be possible to move the cranks closer to the frame if the opposite side of the crank (assuming it is a modern two piece) has the end of the axle has about 3mm machined off and the spline lengthen by the corresponding 3mm to allow the non drive side crank to rest closer to the frame, maintaining symmetry. This will reducethe Qfactor.This is a lot of work for a cobbled together system that will have problems. Option 2 is buy a proper double ring MTB chainset. ControlTech are about to release a carbon 29x44 and 29x42 chainsets for MTB. Not sure if you can fit a 29T chinring to a std MTB spider because the BDC is different. You may be able to mod a road Compact because I thin the BCD is the same. No issue going this route if theres no compatibilty issues. Link to comment Share on other sites More sharing options...
stringbean Posted October 10, 2008 Share Been doing this for years,works like a bomb.When mtb goes 10 speed we will only have 2 blades in front.Current setup with campag rd FD saves about 100g. Link to comment Share on other sites More sharing options...
stringbean Posted October 10, 2008 Share If you have a 104/64 4 arm bcd(xt,new xtr etc) you can't go lower than a 34 middle because the chain catches on the spider.Specialities TA make a ring to fit on the granny gear 24,26,28,29,30.Your big ring then gets put where your middle ring used to be.Better chainline,gears work perfect.I'm running a 28/42 up front and it is perfect for mountainbiking. Link to comment Share on other sites More sharing options...
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