shorter crankset mounting on shimano bb

[jmcabellom]

Hi all,

I've decided to mount shorter cranks. Not for fashion, but to avoid aches and pains (currently going to the physiotherapist)

The simplest idea would be to buy a 160mm shimano cranks. The shortest they manufacture. But with very little availability in stores.

So I want to try the following options:

Crankset:
https://www.aliexpress.com/item/1005006221026567.html?UTABTest=aliabtest112699_10029&src=google&src=google&albch=shopping&acnt=439-079-4345&slnk=&plac=&mtctp=&albbt=Google_7_shopping&gclsrc=aw.ds&albagn=888888&ds_e_adid=&ds_e_matchtype=&ds_e_device=c&ds_e_network=x&ds_e_product_group_id=&ds_e_product_id=es1005006221026567&ds_e_product_merchant_id=5380662678&ds_e_product_country=ES&ds_e_product_language=es&ds_e_product_channel=online&ds_e_product_store_id=&ds_url_v=2&albcp=22050034252&albag=&isSmbAutoCall=false&needSmbHouyi=false&gad_source=1&gclid=EAIaIQobChMI-JC38tPPjAMV3XF_AB2PnDHAEAQYAiABEgICnvD_BwE&aff_fcid=77ffe5b8862c44258a9d40a9a1f13d74-1744363368266-03059-UneMJZVf&aff_fsk=UneMJZVf&aff_platform=aaf&sk=UneMJZVf&aff_trace_key=77ffe5b8862c44258a9d40a9a1f13d74-1744363368266-03059-UneMJZVf&terminal_id=3774225075594e3589c063ccec86a7f6&OLP=1103400108_f_group4&o_s_id=1103400108&afSmartRedirect=n&gatewayAdapt=glo2esp#nav-description
(around EUR 37.19)

Chainring:
https://www.aliexpress.com/item/1005006695090273.html?spm=a2g0o.productlist.main.21.90c7CluQCluQRV&algo_pvid=beab67e1-1592-4752-9573-84c4a8d8b695&algo_exp_id=beab67e1-1592-4752-9573-84c4a8d8b695-10&pdp_ext_f=%7B%22order%22%3A%22258%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21EUR%2156.72%2124.39%21%21%21458.53%21197.17%21%4021038df617443635618256622edcbc%2112000038428680127%21sea%21ES%21169166724%21X&curPageLogUid=zEd2Ix6kjBZi&utparam-url=scene%3Asearch%7Cquery_from%3A
(around EUR 21.39)

To give more info: I have a Dura Ace FC7900 crankset, mounted on a BB (I think it's series 105) The bike is mainly used on roller. But if it doesn't mess up the shifting too much, I might use it sometime on the road.

I can easily remove one part and put on another. My doubts are about the complete assembly, and that everything works from the beginning.
Do I need some kind of spacer/washer? Would it be necessary to change the bb? Would you consider another option or brand? What would be all that would be necessary to have no problems during assembly?

Thanks for the information and help!

[jmcabellom]

Hello,

I have seen and know that there is a piece, it seems to be called Easton spider, which is used to put (let's say) normal road chainrings.

The spider is:
https://www.aliexpress.com/item/1005008621959650.html?spm=a2g0o.productlist.main.33.790b1fadl8ztu4&algo_pvid=5e8c70cc-1f6f-4403-824a-74fe4b79e7b3&algo_exp_id=5e8c70cc-1f6f-4403-824a-74fe4b79e7b3-13&pdp_ext_f=%7B%22order%22%3A%2218%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21EUR%2125.30%2111.89%21%21%21204.53%2196.12%21%4021038df617443652534724605edc8e%2112000045991953790%21sea%21ES%21169166724%21X&curPageLogUid=M4SY2ERAdevA&utparam-url=scene%3Asearch%7Cquery_from%3A
Around EUR 11.59

and the chainrings would be:
https://www.aliexpress.com/item/1005006863758679.html?spm=a2g0o.productlist.main.23.24df1790QaheMy&algo_pvid=a6b8334c-06a1-41ac-b0a0-498c0668c009&algo_exp_id=a6b8334c-06a1-41ac-b0a0-498c0668c009-11&pdp_ext_f=%7B%22order%22%3A%22923%22%2C%22eval%22%3A%221%22%2C%22orig_sl_item_id%22%3A%221005006863758679%22%2C%22orig_item_id%22%3A%221005005881248056%22%7D&pdp_npi=4%40dis%21EUR%2148.49%2122.79%21%21%21392.00%21184.24%21%402103835e17443651233048346ea65e%2112000046706609645%21sea%21ES%21169166724%21X&curPageLogUid=dPToLsa5Ubp9&utparam-url=scene%3Asearch%7Cquery_from%3A
Around EUR 23.39

Is a better option? it is more expensive, but i don't know if it is worth it. would this option avoid the spacers?

Thanks for the help!!!

[Super_davo]

You can just switch out a Shimano Hollowtech crankset for one of the 24mm steel spindle cranksets.

I have done so on 3 of my bikes when I switched to 165mm cranks. I have tried two different models - the Goldix CNC road crankset and the Senicx PR3.
Of those, I think the Senicx PR3 is the better choice - its a bit lighter, its got more "shaped" cranks and it was much easier to set up the front mech without it hitting the crank arm. Neither come in 160 though so if that's what you want, then its either the Cruzbike or spend megabucks and get a carbon set with Ti spindle etc.

I just used the standard rings that came with the crankset, and did not need any washers at all. Front shifting is fine, and its lighter & looks better than a spider with the Shimano rings. You might need to tweak the limit screws and tension a little, but it wasn't a hard job to do.

On my best bike I switched the bottom bracket to DUB and fitted a Leese carbon crankset. IMO its not such a good system as 24mm Shimano, as it relies on washers for preload which you can't get anywhere near as precise. It does come in a fair bit lighter though, to the tune of about 250 grams over the Senicx and Goldix.

[ZacItaly15]

IF you have to frequently swap form Shimano OEM crankset to Goldix Senicx or Cruzbike I don't suggest to buy this crankset.
The coupling in Shimano crankset is steel/steel and it's very strong.
The coupling in Goldix Cruzbike Senicx are aluminum/aluminum and the torque is very high (54n/m if i'm not wrong)
Every time you disassembly the aluminum crankset you're damaging the thread

So, If you thing to frequently swap, always choose steel axle and steel/steel contact.

[Blueberry]

I've heard 24mm aluminum axles are a bit questionable, steel or titanium are safer bets but also more expensive.

[frenzen]

I've heard 24mm aluminum axles are a bit questionable, steel or titanium are safer bets but also more expensive.

these cranks that OP suggested has a steel axle but yes in early days there were these 24mm spindles that did crack or break because they were aluminum on ali.